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Prevalence and Prediction of Obstructive Coronary Artery Disease in Patients Undergoing Primary Heart Valve Surgery

Abstract

Background:

The prevalence of coronary artery disease (CAD) in valvular patients is similar to that of the general population, with the usual association with traditional risk factors. Nevertheless, the search for obstructive CAD is more aggressive in the preoperative period of patients with valvular heart disease, resulting in the indication of invasive coronary angiography (ICA) to almost all adult patients, because it is believed that coronary artery bypass surgery should be associated with valve replacement.

Objectives:

To evaluate the prevalence of obstructive CAD and factors associated with it in adult candidates for primary heart valve surgery between 2001 and 2014 at the National Institute of Cardiology (INC) and, thus, derive and validate a predictive obstructive CAD score.

Methods:

Cross-sectional study evaluating 2898 patients with indication for heart surgery of any etiology. Of those, 712 patients, who had valvular heart disease and underwent ICA in the 12 months prior to surgery, were included. The P value < 0.05 was adopted as statistical significance.

Results:

The prevalence of obstructive CAD was 20%. A predictive model of obstructive CAD was created from multivariate logistic regression, using the variables age, chest pain, family history of CAD, systemic arterial hypertension, diabetes mellitus, dyslipidemia, smoking, and male gender. The model showed excellent correlation and calibration (R² = 0.98), as well as excellent accuracy (ROC of 0.848; 95%CI: 0.817-0.879) and validation (ROC of 0.877; 95%CI: 0.830 - 0.923) in different valve populations.

Conclusions:

Obstructive CAD can be estimated from clinical data of adult candidates for valve repair surgery, using a simple, accurate and validated score, easy to apply in clinical practice, which may contribute to changes in the preoperative strategy of acquired heart valve surgery in patients with a lower probability of obstructive disease.

Keywords:
Coronary Artery Disease; Heart Valve Disease; Coronary Angiography; Computed Tomography Angiography

Resumo

Fundamento:

A prevalência de doença arterial coronariana (DAC) nos pacientes valvares é semelhante à da população geral, com associação usual aos fatores de risco tradicionais. Ainda assim, a busca por DAC obstrutiva é mais agressiva nos valvulopatas em pré-operatório, determinando a angiografia coronariana invasiva (ACI) a praticamente todos os pacientes adultos, uma vez que se acredita que a cirurgia de revascularização miocárdica deva ser associada à troca valvar.

Objetivos:

Avaliar a prevalência de DAC obstrutiva e identificar fatores a ela associados em adultos candidatos à cirurgia cardíaca primariamente valvar entre os anos de 2001 a 2014 no Instituto Nacional de Cardiologia (INC) e elaborar um modelo preditivo de DAC obstrutiva através de escore derivado de análise multivariada. A partir da estimativa da probabilidade pré-teste de DAC obstrutiva, espera-se melhor estratégia pré-operatória para cada paciente.

Métodos:

Estudo transversal avaliando 2.898 pacientes com indicação de cirurgia cardíaca por qualquer etiologia. Desses, foram estudados 712 pacientes valvopatas submetidos à ACI nos 12 meses anteriores à cirurgia. Diferenças com valor de p < 0,05 foram consideradas estatisticamente significativas.

Resultados:

A prevalência de DAC obstrutiva foi de 20%. Um modelo preditivo de DAC obstrutiva foi criado a partir de regressão logística multivariada, utilizando as variáveis idade, dor torácica, história familiar de DAC, hipertensão arterial sistêmica, diabetes mellitus, dislipidemia, tabagismo e sexo masculino. O modelo demonstrou excelente correlação e calibração (R2 = 0,98), além de ótima acurácia (ROC de 0,848; IC95% 0,817 - 0,879) e validação em diferente população valvar (ROC de 0,877; IC 95%: 0,830 - 0,923).

Conclusões:

É possível estimar DAC obstrutiva a partir de dados clínicos com elevada acurácia, o que pode vir a permitir estabelecer estratégias pré-operatórias de acordo com a probabilidade pré-teste individual, evitando a indicação indiscriminada de procedimentos desnecessários e invasivos, principalmente nos grupos de menor probabilidade de DAC obstrutiva. (Arq Bras Cardiol. 2017; [online].ahead print, PP.0-0)

Palavras-chave:
Doença Arterial Coronariana; Doenças das Valvas Cardíacas; Angiografia Coronariana Invasiva; Angiografia por Tomografia Computadorizada

Introduction

Coronary artery disease (CAD) in patients with valvular heart disease has the usual association with traditional risk factors. Nevertheless, the search for obstructive CAD is more aggressive in the preoperative period of patients with valvular heart disease, resulting in the indication of invasive coronary angiography (ICA) to almost all patients older than 35 years, because it is believed that coronary artery bypass surgery should be associated with valve replacement in the presence of obstructive CAD.

Angina is the major symptom, even though it can have other causes in valvular heart disease,11 Tarasoutchi F, Montera MW, Grinberg M, Barbosa MR, Piñeiro DJ, Sánchez CRM, et al. Diretriz Brasileira de Valvopatias - SBC 2011/ I Diretriz Interamericana de Valvopatias - SIAC 2011. Arq Bras Cardiol. 2011;97(5):01-67. PMID:22286365 such as left ventricular hypertrophy or overload. Association of obstructive CAD with the impaired heart valve, mainly the aortic valve, is common; however, increasing age has been shown to accompany a higher prevalence of CAD, regardless of the valve.22 Chobadi R, Wurzel M, Teplitsky I, Menkes H, Tamari I. Coronary artery disease in patients 35 years of age or older with valvular aortic stenosis. Am J Cardiol. 1989;64(12):811-2. PMID:2801537,33 Lin SS, Lauer MS, Asher CR, Cosgrove DM, Blackstone E, Thomas JD, et al. Prediction of coronary artery disease in patients undergoing operations for mitral valve degeneration. J Thorac Cardiovasc Surg. 2001;121(5):894-901. DOI: 10.1067/mtc.2001.112463
https://doi.org/10.1067/mtc.2001.112463...
Older patients tend to have degenerative aortic valve disease more often, but CAD does not differ between patients with aortic or mitral valve impairment in the same age group.44 Lappé JM, Grodin JL, Wu Y, Bott-Silverman C, Cho L. Prevalence and Prediction of Obstructive Coronary Artery Disease in Patients Referred for Valvular Heart Surgery. Am J Cardiol. 2015;116(2):280-5. doi: 10.1016/j.amjcard.2015.03.063.
https://doi.org/10.1016/j.amjcard.2015.0...

The epidemiology of valvular heart disease is heterogeneous and has changed over the past decades in different countries. Rheumatic heart disease was the major cause of valvular heart disease until the mid-20th century, after which, with the widespread use of antibiotics and better access to health care, a substantial reduction in the incidence of that inflammatory valvular heart disease occurred in developed countries.55 Soler-Soler J, Galve E. Worldwide perspective of valve disease. Heart Br Card Soc. 2000;83(6):721-5. PMID:10814642. The current prevalence of rheumatic valvular disease is estimated to be 2.5% in the USA and Canada, and 22% in Europe.66 Iung B, Vahanian A. Epidemiology of acquired valvular heart disease. Can J Cardiol. 2014;30(9):962-70. doi: 10.1016/j.cjca.2014.03.022.
https://doi.org/10.1016/j.cjca.2014.03.0...
Concomitantly, with the increase in life expectancy, the prevalence of age-related heart diseases increased, the degenerative etiology being the most common cause of valvular heart disease in developed countries.77 Ribeiro GS, Tartof SY, Oliveira DWS, Guedes ACS, Reis MG, Riley LW, et al. Surgery for Valvular Heart Disease: A Population-Based Study in a Brazilian Urban Center. PLoS ONE [Internet]. 2012 May 29 [cited 2016 Jul 14];7(5). Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3362603/doi: 10.1371/journal.pone.0037855
http://www.ncbi.nlm.nih.gov/pmc/articles...
In addition, the higher mean age and, consequently, the higher number of chronic diseases and associated atherosclerotic risk factors increase the prevalence of CAD, which, in North-American and Anglo-Saxon patients with valvular heart disease ranges from 20% to 40%.88 Enriquez-Sarano M, Klodas E, Garratt KN, Bailey KR, Tajik AJ, Holmes DR. Secular trends in coronary atherosclerosis--analysis in patients with valvular regurgitation. N Engl J Med. 1996;335(5):316-22. doi: 10.1371/journal.pone.0037855.
https://doi.org/10.1371/journal.pone.003...
,99 Fournier JÁ, Sanchez-Gonzalez A, Cortacero JÁ, Martinez A. Estudio angiográfico prospectivo de la enfermedad arterial coronaria en pacientes con patología valvular crónica severa. Rev Esp Cardiol.1998;41:462-6.

In developing countries, rheumatic heart disease is still the major cause of valvular heart disease.1010 Iung B, Vahanian A. Epidemiology of valvular heart disease in the adult. Nat Rev Cardiol. 2011;8(3):162-72. doi: 10.1038/nrcardio.2010.202.
https://doi.org/10.1038/nrcardio.2010.20...
In Brazil, its prevalence reaches 60.3%, with a mean age of 37 years.77 Ribeiro GS, Tartof SY, Oliveira DWS, Guedes ACS, Reis MG, Riley LW, et al. Surgery for Valvular Heart Disease: A Population-Based Study in a Brazilian Urban Center. PLoS ONE [Internet]. 2012 May 29 [cited 2016 Jul 14];7(5). Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3362603/doi: 10.1371/journal.pone.0037855
http://www.ncbi.nlm.nih.gov/pmc/articles...
It usually affects young individuals, who have less risk factors for atherosclerosis, and, thus, lower prevalence of obstructive CAD.1111 Kruczan DD, Silva NA de S e, Pereira B de B, Romão VA, Correa Filho WB, Morales FEC. Coronary artery disease in patients with rheumatic and non-rheumatic valvular heart disease treated at a public hospital in Rio de Janeiro. Arq Bras Cardiol. 2008;90(3):197-203. doi: 10.1038/nrcardio.2010.202
https://doi.org/10.1038/nrcardio.2010.20...
,1212 Sampaio RO, Jonke VM, Falcão JL, Falcão S, Spina GS, Tarasoutchi F, et al. Prevalence of coronary artery disease and preoperative assessment in patients with valvopathy. Arq Bras Cardiol. 2008;91(3):183-6, 200-4. PMID:18853061.

The guidelines suggest that, because of the impact of non-treated CAD, its diagnosis is paramount.11 Tarasoutchi F, Montera MW, Grinberg M, Barbosa MR, Piñeiro DJ, Sánchez CRM, et al. Diretriz Brasileira de Valvopatias - SBC 2011/ I Diretriz Interamericana de Valvopatias - SIAC 2011. Arq Bras Cardiol. 2011;97(5):01-67. PMID:22286365 Preoperative ICA is indicated to almost all patients older than 35 years, and non-invasive functional tests are not recommended because of their limited specificity. In the ACC/AHA guideline, coronary computed tomography angiography (CCTA) is suggested for patients with a low or intermediate pretest probability of CAD (class of recommendation IIa, level of evidence C), because of its high negative predictive value to exclude obstructive CAD.1313 Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP, Guyton RA, et al. 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2014;129(23):e521-643. doi: 10.1161/CIR.0000000000000031
https://doi.org/10.1161/CIR.000000000000...

Stratification of obstructive CAD based on current indications does not seem to be the best strategy in our population. The ICA is a high-cost invasive procedure with widely documented morbidity and mortality. The development of tools to estimate the pretest probability of obstructive CAD, as performed in the general population, is urgent, to better select patients who will benefit from different preoperative strategies, therefore preventing the indiscriminate indication of unnecessary and invasive procedures, mainly in groups with a lower clinical probability of obstructive CAD.

This study was aimed at developing a predictive score for obstructive CAD in adult candidates for primary heart valve surgery, and at validating that score in an independent cohort of patients from another tertiary reference institution.

Methods

Selection of patients

The population studied comprises adults with primary acquired valvular heart disease from a tertiary reference hospital, submitted to heart valve replacement or repair surgery between 2001 and 2014.

Inclusion criteria

This study included patients older than 18 years with primary acquired valvular heart disease, submitted to heart valve surgery between 2001 and 2014, who underwent ICA within 12 months from surgery.

Data collection

Data were obtained retrospectively from medical record review and comprised the following variables: age, sex, chest pain, systemic arterial hypertension, diabetes mellitus, dyslipidemia, family history of CAD, smoking, surgery type, and impaired heart valve.

Obstructive CAD was defined as luminal obstruction greater than 50% in the left main coronary artery (LCA) and obstruction greater than 70% in the other major epicardial vessels, on preoperative ICA, according to the recommendations of the Brazilian Guidelines on Valvular Heart Diseases.11 Tarasoutchi F, Montera MW, Grinberg M, Barbosa MR, Piñeiro DJ, Sánchez CRM, et al. Diretriz Brasileira de Valvopatias - SBC 2011/ I Diretriz Interamericana de Valvopatias - SIAC 2011. Arq Bras Cardiol. 2011;97(5):01-67. PMID:22286365

In our study, we dichotomized the symptoms according to the presence or absence of chest pain. Chest pain was defined as the presence of atypical or typical angina, according to the classification of the Brazilian Guidelines on Chronic Coronary Artery Disease,1414 Cesar LA, Ferreira JF, Armaganijan D, Gowdak LH, Mansur AP, Bodanese LC, et al. Guideline for Stable Coronary Artery Disease. Arq Bras Cardiol. 2014;103(2):01-59. PMID:25410086 with two or three of the following characteristics: retrosternal discomfort or pain; triggered by exercise or emotional stress; relieved by rest or nitroglycerin use. Absence of chest pain was defined when the patient had none (asymptomatic) or only one of the above-cited characteristics (non-cardiac chest pain).

The risk factors were defined by the physicians in charge of filling out the patients' registration forms, according to their clinical judgement and the existing classifications at the time.

Exclusion criteria

Patients with incomplete clinical data were excluded from the study.

Statistical analysis

The categorical variables were described as frequency, being compared by use of chi-square test. The only continuous variable used in this study was age, which had a normal distribution confirmed by use of Kolmogorov-Smirnov test, was presented as mean and standard deviation and compared in the different groups by use of Student t test. Differences with p-value < 0.05 were considered statistically significant.

The variables associated with the outcome 'obstructive CAD' were assessed using univariate and multivariate logistic regression. The risk factors traditionally related to CAD and the variables that, on univariate analysis, showed association with obstructive CAD were included in multivariate analysis. The final model comprised the variables with statistically significant association in the multivariate model and those historically associated with CAD.

To test the calibration of the model in the derivation cohort, linear regression was used, correlating the mean estimated pretest probability (patients were divided into deciles of increasing probability of obstructive CAD) with the observed prevalence.

The predictive accuracy for obstructive CAD of the model, in both the derivation and validation cohorts, was tested by constructing the ROC curve and assessing the area under the curve.

The SPSS software (SPSS Inc., USA), version 22.0, was used for the statistical analysis.

Score validation

The score was validated in an independent sample (validation cohort) with 294 adult patients with primary valvular heart disease, candidates for heart valve surgery from 1999 to 2005, originating from another tertiary reference hospital for heart surgery, and whose preoperative clinical and angiographic data made them eligible for the study.

Results

From 2001 to 2014, a total of 2898 primary heart valve surgeries were recorded in adults, 1074 of whom with ICA performed in the 12 months preceding surgery were included in the study, while 362 of whom were excluded due to incomplete clinical data in the hospital registry.

The prevalence of obstructive CAD in patients with valvular heart disease and ICA in the preoperative period was 20% (145 patients).

Of the 712 patients studied, 330 (46%) were of the male sex and 382 (54%) of the female sex. Their mean age was 58 (± 12.5) years, and 145 (20%) had obstructive CAD. Chest pain was reported by 165 (23%) patients. Aortic repair surgery was performed in 291 (41%) patients, while mitral repair surgery, in 302 (42%). Double aortic-mitral repair surgery was performed in 109 (15%) patients, while combined coronary artery bypass graft surgery and valvular heart repair surgery, in 139 (20%). The prevalences of cardiovascular risk factors, impaired heart valve and obstructive CAD are shown in Table 1.

Table 1
Clinical characteristics of the population and according to the subgroups without and with obstructive CAD

Patients with obstructive CAD were older, had higher prevalence of chest pain and of traditional risk factors as compared to patients without obstructive CAD. The aortic valve, as compared to the mitral valve, was more often impaired in the former. The male sex showed a higher trend to obstructive CAD as compared to the female sex.

On univariate analysis, chest pain showed a strong association with obstructive CAD (odds ratio, 6.9; 95%CI: 4.67-10.4; p < 0.001), in addition to traditional risk factors and age. Mitral valve impairment showed no association with obstructive CAD.

The variables that associated with obstructive CAD on univariate analysis, such as traditional risk factors for atherosclerosis (age, sex, arterial hypertension, diabetes mellitus, dyslipidemia, family history and smoking), were entered into the multivariate analysis, in addition to aortic valve impairment, which had statistical significance. Age (p < 0.001), family history of CAD (p < 0.001) and angina (p < 0.001) were independent predictors of obstructive coronary lesion. Aortic valve impairment had no relevant association after adjusting for the other risk factors. Multivariate analysis is shown in Table 2.

Table 2
Univariate and multivariate analysis of risk factors for obstructive CAD

A predictive logistic model for obstructive CAD was created based on the correlation degree between statistically significant independent predictive variables, in addition to the traditional risk factors, which, even though lacking statistical significance in the last analysis, comprised the model, because of their proven association with CAD. The logistic model is represented by the following equation:

Logit (CAD) = - 6.872 + (0.257 x male sex) + (0.066 x age) + (1.344 x chest pain) + (0.369 x hypertension) + (0.404 x diabetes) + (0.445 x dyslipidemia) + (0.297 x smoking) + (0.885 x family history of CAD)

To make clinical use easier, a score of point addition was developed, a simplification of logistic regression, where points are attributed to patients according to their clinical characteristics. One point should be added to every 5 complete yeas of life (from age zero), 1 point to each traditional risk factor (male sex, arterial hypertension, dyslipidemia, diabetes mellitus and smoking), 2 points to a family history of CAD, and 4 points to chest pain (Table 3).

Table 3
Simplified score to predict obstructive CAD

Patients who scored 10 points or less (estimated pretest probability < 5%) were considered to have low pretest probability, while those who scored more than 17 points (estimated pretest probability > 30%) were considered to have high pretest probability. Those who scored between 11 and 16 points comprised the intermediate group (estimated pretest probability between 5% and 30%).

The model showed an excellent correlation between estimated pretest probability and the obstructive CAD prevalence found in our population (Table 4).

Table 4
Prevalence of obstructive CAD according to the category of estimated pretest probability

To test the calibration of the predictive model, linear regression was applied correlating the estimated pretest probability (divided into deciles with increasing probability of obstructive CAD, and comprised by approximately 72 patients per decile) with the prevalence observed in the derivation cohort. A positive and significant correlation was observed between the estimated probability and the observed prevalence of obstructive CAD (R2 = 0.98), proving the predictive capacity of the model, represented in the 0.9954 slope of the line (close to 1.0), confirming that there is neither underestimation nor overestimation of the model tested (Figure 1).

Figure 1
Calibration of the predictive model

Both the logistic and the simple additive models had excellent accuracy to predict obstructive CAD in the derivation cohort, being represented by the areas under the ROC curve of 0.848 (95%CI: 0.817 - 0.879) and 0.844 (95%CI: 0.812 - 0.875), respectively (Figure 2).

Figure 2
Comparison of the ROC curves of the logistic and simple additive models in the derivation and validation cohorts.

To validate the models developed, we used data from a different population of 294 adult patients from another tertiary reference hospital for heart surgery, with primary valvular heart disease, candidates for heart valve surgery from 1999 to 2005. Their preoperative clinical and angiographic variables were eligible for the study.

In that validation cohort, similarly to our findings, the patients with obstructive CAD were older, mainly of the male sex and had a high prevalence of traditional risk factors. Angina occurred significantly more often in the group of patients with CAD (Table 5).

Table 5
Clinical characteristics of the validation cohort.

Both the logistic and simple additive models had excellent and similar accuracy to predict obstructive CAD in the validation cohort, represented by the areas under the ROC curve of 0.877 (95%CI: 0.830 - 0.923) and 0.882 (95%CI: 0.836 - 0.927), respectively (Figure 2).

Discussion

In our cohort, the observed prevalence of obstructive CAD was 20%, lower than that of the cohorts of developed countries,88 Enriquez-Sarano M, Klodas E, Garratt KN, Bailey KR, Tajik AJ, Holmes DR. Secular trends in coronary atherosclerosis--analysis in patients with valvular regurgitation. N Engl J Med. 1996;335(5):316-22. doi: 10.1371/journal.pone.0037855.
https://doi.org/10.1371/journal.pone.003...
,99 Fournier JÁ, Sanchez-Gonzalez A, Cortacero JÁ, Martinez A. Estudio angiográfico prospectivo de la enfermedad arterial coronaria en pacientes con patología valvular crónica severa. Rev Esp Cardiol.1998;41:462-6. and similar to that of the populations of developing countries.1515 Li S-C, Liao X-W, Li L, Zhang L-M, Xu Z-Y. Prediction of significant coronary artery disease in patients undergoing operations for rheumatic mitral valve disease. Eur J Cardio-Thorac Surg Off J Eur Assoc Cardio-Thorac Surg. 2012;41(1):82-6. doi: 10.1016/j.ejcts.2011.04.018.
https://doi.org/10.1016/j.ejcts.2011.04....

16 Manjunath CN, Agarwal A, Bhat P, Ravindranath KS, Ananthakrishna R, Ravindran R, et al. Coronary artery disease in patients undergoing cardiac surgery for non-coronary lesions in a tertiary care centre. Indian Heart J. 2014;66(1):52-6 doi: 10.1016/j.ihj.2013.12.014.
https://doi.org/10.1016/j.ihj.2013.12.01...

17 Emren ZY, Emren SV, Kılıçaslan B, Solmaz H, Susam İ, Sayın A, et al. Evaluation of the prevalence of coronary artery disease in patients with valvular heart disease. J Cardiothorac Surg. 2014;9:153. doi: 10.1186/s13019-014-0153-1.
https://doi.org/10.1186/s13019-014-0153-...

18 Yan T, Zhang G, Li B, Han L, Zang J, Li L, et al. Prediction of coronary artery disease in patients undergoing operations for rheumatic aortic valve disease. Clin Cardiol. 2012;35(11):707-11. doi: 10.1002/clc.22033.
https://doi.org/10.1002/clc.22033...
-1919 Munoz San José JC, de la Fuente Galán L, Garcimartín Cerrón I, de la Torre Carpenter M, Bermejo García J, et al. Coronariografía preoperatoria en pacientes valvulares. Criterios de indicación en una determinada población. Rev Esp Cardiol. 1997;50(7):467-73.PMID:9304173. The prevalence of obstructive CAD in individuals aged less than 50 years was 3.3%, similar to that of other Brazilian studies. Sampaio et al. have reported a prevalence of 3.42% in a sample of 3736 patients with a mean age of 43.7 years.1212 Sampaio RO, Jonke VM, Falcão JL, Falcão S, Spina GS, Tarasoutchi F, et al. Prevalence of coronary artery disease and preoperative assessment in patients with valvopathy. Arq Bras Cardiol. 2008;91(3):183-6, 200-4. PMID:18853061. Kruczan et al.1111 Kruczan DD, Silva NA de S e, Pereira B de B, Romão VA, Correa Filho WB, Morales FEC. Coronary artery disease in patients with rheumatic and non-rheumatic valvular heart disease treated at a public hospital in Rio de Janeiro. Arq Bras Cardiol. 2008;90(3):197-203. doi: 10.1038/nrcardio.2010.202
https://doi.org/10.1038/nrcardio.2010.20...
have shown a global prevalence of obstructive CAD of 15.9%, 6% in patients aged less than 50 years.

The patients with obstructive CAD were older, mainly of the male sex and had a high prevalence of traditional risk factors and of chest pain.

There was a univariate association between atherosclerotic risk factors, chest pain, family history, and aortic valve impairment. However, on multivariate analysis, there was no independent association between dysfunctional valve and obstructive CAD, confirming reports in the literature.33 Lin SS, Lauer MS, Asher CR, Cosgrove DM, Blackstone E, Thomas JD, et al. Prediction of coronary artery disease in patients undergoing operations for mitral valve degeneration. J Thorac Cardiovasc Surg. 2001;121(5):894-901. DOI: 10.1067/mtc.2001.112463
https://doi.org/10.1067/mtc.2001.112463...
Therefore, it was not entered in the logistic model. Similarly, the etiology of valvular heart disease has no independent association with CAD,1111 Kruczan DD, Silva NA de S e, Pereira B de B, Romão VA, Correa Filho WB, Morales FEC. Coronary artery disease in patients with rheumatic and non-rheumatic valvular heart disease treated at a public hospital in Rio de Janeiro. Arq Bras Cardiol. 2008;90(3):197-203. doi: 10.1038/nrcardio.2010.202
https://doi.org/10.1038/nrcardio.2010.20...
but with other aggregated risk factors.

In the general population, calculators to predict and stratify CAD are widely used, and only patients with high probability and no response to clinical treatment or with tests with high-risk changes are referred for invasive stratification, while most patients with low or intermediate pretest probability being suitable for non-invasive stratification.1414 Cesar LA, Ferreira JF, Armaganijan D, Gowdak LH, Mansur AP, Bodanese LC, et al. Guideline for Stable Coronary Artery Disease. Arq Bras Cardiol. 2014;103(2):01-59. PMID:25410086

The pretest probability of obstructive CAD is more often calculated by use of the score described in the 1970s by Diamond and Forrester,2020 Diamond GA, Forrester JS. Analysis of probability as an aid in the clinical diagnosis of coronary-artery disease. N Engl J Med. 1979;300(24):1350-8. DOI:10.1056/NEJM197906143002402.
https://doi.org/10.1056/NEJM197906143002...
who used estimates of postmortem studies and cross-sectional studies of the North-American population. Although limited and not contemplating other cardiovascular risk factors, that score is still widely used, and continues to be recommended by the guidelines. This currently used model has been shown to overestimate the probability of CAD, and, thus, could be updated.2121 Genders TSS, Steyerberg EW, Alkadhi H, Leschka S, Desbiolles L, Nieman K, et al. A clinical prediction rule for the diagnosis of coronary artery disease: validation, updating, and extension. Eur Heart J. 2011; 32(11):1316-30. doi: 10.1093/eurheartj/ehr014.
https://doi.org/10.1093/eurheartj/ehr014...
,2222 Yang Y, Chen L, Yam Y, Achenbach S, Al-Mallah M, Berman DS, et al. A Clinical Model to Identify Patients With High-Risk Coronary Artery Disease. JACC Cardiovasc Imaging. 2015;8(4):427-34. doi: 10.1016/j.jcmg.2014.11.015.
https://doi.org/10.1016/j.jcmg.2014.11.0...

For patients with valvular heart disease, there is no specific calculator to estimate obstructive CAD and, thus, to guide the preoperative period according to the calculated probability.

The AHA/ACC guideline considers CCTA a way to exclude obstructive CAD without performing ICA for patients with low or intermediate pretest probability calculated according to the criteria by Diamond and Forrester, reserving invasive stratification for patients with higher probability of CAD.1313 Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP, Guyton RA, et al. 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2014;129(23):e521-643. doi: 10.1161/CIR.0000000000000031
https://doi.org/10.1161/CIR.000000000000...

In the past years, with the widespread use of CCTA for CAD stratification in the general population, several studies have tested its performance. A meta-analysis that gathered 1107 patients and 12851 coronary artery segments, has validated CCTA as a safe alternative to ICA in the preoperative period of patients with valvular heart disease.2323 Opolski MP, Staruch AD, Jakubczyk M, Min JK, Gransar H, Staruch M, et al. CT Angiography for the Detection of Coronary Artery Stenoses in Patients Referred for Cardiac Valve SurgerySystematic Review and Meta-Analysis. JACC Cardiovasc Imaging [Internet]. 2016 Jun 22 [cited 2016 Jul 25]; Available from: http://dx.doi.org/10.1016/j.jcmg.2015.09.028
http://dx.doi.org/10.1016/j.jcmg.2015.09...
In another study assessing the preoperative period of valvular heart disease, the stratification strategy with CCTA to patients with low or intermediate pretest probability has predicted a significant cost reduction, because 28% of that study cohort would not require ICA.44 Lappé JM, Grodin JL, Wu Y, Bott-Silverman C, Cho L. Prevalence and Prediction of Obstructive Coronary Artery Disease in Patients Referred for Valvular Heart Surgery. Am J Cardiol. 2015;116(2):280-5. doi: 10.1016/j.amjcard.2015.03.063.
https://doi.org/10.1016/j.amjcard.2015.0...
In addition, in 2012, an European study emphasized the importance of having a preoperative strategy, not only because it is a more comfortable diagnostic alternative for the patient, but also more inexpensive than the conventional strategy.2424 Catalán P, Callejo D, Blasco JA. Cost-effectiveness analysis of 64-slice computed tomography vs. cardiac catheterization to rule out coronary artery disease before non-coronary cardiovascular surgery. Eur Heart J - Cardiovasc Imaging. 2013;14(2):149-57. doi: 10.1093/ehjci/jes121
https://doi.org/10.1093/ehjci/jes121...

Although ICA is gold standard for the diagnosis of obstructive lesions, it an invasive method not free from complications, such as death, vascular events (bleedings, hematomas and arterial occlusions), neurological events (ischemic and hemorrhagic) and cardiac events (arrhythmias, perforations, dissections, revascularizations, infarctions, heat failure and cardiogenic shock).2525 Chandrasekar B, Doucet S, Bilodeau L, Crepeau J, deGuise P, Gregoire J, et al. Complications of cardiac catheterization in the current era: a single-center experience. Catheter Cardiovasc Interv Off J Soc Card Angiogr Interv. 2001;52(3):289-95. Doi: 10.1002/ccd.1067.
https://doi.org/10.1002/ccd.1067...

26 West R, Ellis G, Brooks N. Complications of diagnostic cardiac catheterisation: results from a confidential inquiry into cardiac catheter complications. Heart. 2006;92(6):810-4. DOI: 10.1136/hrt.2005.073890
https://doi.org/10.1136/hrt.2005.073890...
-2727 Rossato G, Quadros AS de, Sarmento-Leite R, Gottschall CAM. Analysis of in-hospital complications related to cardiac catheterization. Rev Bras Cardiol Invasiva. 2007;15(1):44-51.Doi; 10.1590/52179-8397200/000100010.
https://doi.org/10.1590/52179-8397200/00...
A Brazilian study with 1916 patients has reported 190 (10.4%) complications in 175 patients.2727 Rossato G, Quadros AS de, Sarmento-Leite R, Gottschall CAM. Analysis of in-hospital complications related to cardiac catheterization. Rev Bras Cardiol Invasiva. 2007;15(1):44-51.Doi; 10.1590/52179-8397200/000100010.
https://doi.org/10.1590/52179-8397200/00...
In a registry comprising 85% of the catheterization laboratories in the USA and including 1,091,557 patients, 14,736 patients (1.35%) had complications, the in-hospital mortality related to the procedure being 0.72%.2828 Dehmer GJ, Weaver D, Roe MT, Milford-Beland S, Fitzgerald S, Hermann A, et al. A contemporary view of diagnostic cardiac catheterization and percutaneous coronary intervention in the United States: a report from the CathPCI Registry of the National Cardiovascular Data Registry, 2010 through June 2011. J Am Coll Cardiol. 2012;60(20):2017-31. doi: 10.1016/j.jacc.2012.08.966.
https://doi.org/10.1016/j.jacc.2012.08.9...

To translate such data into future clinical tools, we elaborated a proposal for the preoperative assessment of patients referred for primary heart valve surgery, and applied it in the derivation cohort.

We developed a simplified easy-to-use score to stratify patients, and thus better guide the preoperative strategy. Using only clinical data, such as age, sex, chest pain and presence or absence of atherosclerotic risk factors, the pretest probability of obstructive CAD can be calculated at bedside with relative simplicity. The calculator developed in this study is available at https://connect.calcapp.net/?app=5tcj4a, and can be used in multifunctional devices.

To illustrate the use of that tool in the preoperative assessment of patients, we created arbitrarily three categories of estimated pretest probability of obstructive CAD: low, < 5%; intermediate, between 5% and 30%; and high, > 30%.

A patient with a score < 17 (low or intermediate probability) should be stratified conservatively, with CCTA, or even directed to heart valve surgery without additional stratification, if the probability is low, ICA being reserved for those with high pretest probability or positive CCTA for obstructive CAD (Figure 3).

Figure 3
Preoperative strategy based on the use of the simple additive score and estimated pretest probability.

In a simulation, applying the strategy proposed by the AHA/ACC guideline to our cohort, using CCTA to assess CAD in patients with low and intermediate pretest probability, we would reduce by 82% the ICA in those patients, with a total 57%reduction in the entire cohort. That strategy has a sensitivity of 99% and a specificity of 90%, using CCTA accuracy data in patients with valvular heart disease.2323 Opolski MP, Staruch AD, Jakubczyk M, Min JK, Gransar H, Staruch M, et al. CT Angiography for the Detection of Coronary Artery Stenoses in Patients Referred for Cardiac Valve SurgerySystematic Review and Meta-Analysis. JACC Cardiovasc Imaging [Internet]. 2016 Jun 22 [cited 2016 Jul 25]; Available from: http://dx.doi.org/10.1016/j.jcmg.2015.09.028
http://dx.doi.org/10.1016/j.jcmg.2015.09...
Considering the complication rate of ICA among us,2727 Rossato G, Quadros AS de, Sarmento-Leite R, Gottschall CAM. Analysis of in-hospital complications related to cardiac catheterization. Rev Bras Cardiol Invasiva. 2007;15(1):44-51.Doi; 10.1590/52179-8397200/000100010.
https://doi.org/10.1590/52179-8397200/00...
,2828 Dehmer GJ, Weaver D, Roe MT, Milford-Beland S, Fitzgerald S, Hermann A, et al. A contemporary view of diagnostic cardiac catheterization and percutaneous coronary intervention in the United States: a report from the CathPCI Registry of the National Cardiovascular Data Registry, 2010 through June 2011. J Am Coll Cardiol. 2012;60(20):2017-31. doi: 10.1016/j.jacc.2012.08.966.
https://doi.org/10.1016/j.jacc.2012.08.9...
we would prevent 40 procedure-related complications (57% reduction).

Adopting an even more conservative strategy, with patients of low probability directed to surgery with no additional preoperative test and CCTA to assess CAD in patients of intermediate probability, we would have a 60% reduction in ICA, with sensitivity of 98% and specificity of 94%, in addition to a 61% reduction in ICA complications in our population.

That conservative strategy could result in a lack of diagnosis lower than 5% (< 2% in our cohort), which would not necessarily expose the patient to a higher risk, because cardiac catheterization itself is not free from severe complications, and it has not been clearly established that coronary artery bypass graft surgery combined with heart valve repair significantly influences patients' prognosis. In addition, ischemic complications in patients with CAD who undergo no revascularization during valve replacement are infrequent.99 Fournier JÁ, Sanchez-Gonzalez A, Cortacero JÁ, Martinez A. Estudio angiográfico prospectivo de la enfermedad arterial coronaria en pacientes con patología valvular crónica severa. Rev Esp Cardiol.1998;41:462-6.,2929 Bonow RO, Kent KM, Rosing DR, Lipson LC, Borer JS, McIntosh CL, et al. Aortic valve replacement without myocardial revascularization in patients with combined aortic valvular and coronary artery disease. Circulation. 1981;63(2):243-51. PMID:6778624. Among us, the mortality of coronary artery bypass graft surgery alone ranges from 4.8% to 8.3%,3030 Lisboa LAF, Moreira LFP, Mejia OV, Dallan LAO, Pomerantzeff PMA, Costa R, et al. Evolution of cardiovascular surgery at the Instituto do Coração: analysis of 71,305 surgeries. Arq Bras Cardiol. 2010;94(2):174-81. PMID:20428610.,3131 Monteiro GM, Moreira DM. Mortalidade em cirurgias cardíacas em Hospital Terciário do Sul do Brasil. Int J Cardiovasc Sci. 2015;28(3):200-5.Doi: 10.5935/2359-4802.20150029.
https://doi.org/10.5935/2359-4802.201500...
and that rate can even triple when that surgery is combined with heart valve repair.3131 Monteiro GM, Moreira DM. Mortalidade em cirurgias cardíacas em Hospital Terciário do Sul do Brasil. Int J Cardiovasc Sci. 2015;28(3):200-5.Doi: 10.5935/2359-4802.20150029.
https://doi.org/10.5935/2359-4802.201500...

It is worth noting that clinical predictive scores are secondary tools, and should not replace the current and previous clinical history, physical exam and previous complementary tests. Patients with a previous history of CAD, left ventricular dysfunction, evidence of myocardial ischemia on tests, or with atherosclerosis evidenced on any other exam or signs of it in other territories (such as reduced lower limb pulses, arterial stiffness and abdominal aneurysm), that increase the probability of CAD,1414 Cesar LA, Ferreira JF, Armaganijan D, Gowdak LH, Mansur AP, Bodanese LC, et al. Guideline for Stable Coronary Artery Disease. Arq Bras Cardiol. 2014;103(2):01-59. PMID:25410086 should be treated on an individual basis.

This study had limitations. It is a retrospective analysis based on a cohort from a single tertiary center of reference, but validated in another independent cohort from another tertiary center of reference for heart surgery. Neither the previous history of CAD nor left ventricular dysfunction could be assessed, but the patients are already directed to ICA according to the recommendations of the guidelines.11 Tarasoutchi F, Montera MW, Grinberg M, Barbosa MR, Piñeiro DJ, Sánchez CRM, et al. Diretriz Brasileira de Valvopatias - SBC 2011/ I Diretriz Interamericana de Valvopatias - SIAC 2011. Arq Bras Cardiol. 2011;97(5):01-67. PMID:22286365 In addition, neither the type of valvular dysfunction (stenosis versus regurgitation) nor its etiology (degenerative, infectious or inflammatory) could be determined, but none of those factors was an independent predictor of CAD in a review of studies on similar populations.

Conclusions

Obstructive CAD can be estimated based on clinical data of adult candidates for heart valve repair surgery by using a simple, accurate, calibrated, validated and easy-to-use score.

Establishing a preoperative flowchart beginning with the use of the predictive score of obstructive CAD and definition of the pretest probability group can be a more comfortable and safer strategy for the patient, preventing the indiscriminate indication of unnecessary and invasive procedures, mainly in the groups with higher probability of obstructive CAD.

  • Sources of Funding
    There were no external funding sources for this study.
  • Study Association
    This article is part of the thesis of master submitted by José Guilherme Cazelli, from Instituto Nacional de Cardiologia (INC-MS).

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    Monteiro GM, Moreira DM. Mortalidade em cirurgias cardíacas em Hospital Terciário do Sul do Brasil. Int J Cardiovasc Sci. 2015;28(3):200-5.Doi: 10.5935/2359-4802.20150029.
    » https://doi.org/10.5935/2359-4802.20150029

Publication Dates

  • Publication in this collection
    28 Sept 2017
  • Date of issue
    Oct 2017

History

  • Received
    14 Dec 2016
  • Reviewed
    12 June 2017
  • Accepted
    13 June 2017
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