OBJECTIVE: To define the prognostic value and cost-effectiveness of the treadmill stress test (TST) in comparison to the dipyridamole myocardial perfusion scintigraphy (DIP), in individuals >75 years of age. METHODS: Consecutive and prospective assessment of 66 patients (40% male) aged 81 ± 5 years of which 57% were hypertensive, 38% had dyslipidemia and 28% were diabetics. The Bruce protocol was adapted for a tilt treadmill and the TST prognostic value was obtained using the Duke treadmill score. RESULTS: The TST duration, recommended maximum heart rate percentage and double product at peak exercise were respectively: 7 ± 3 minutes, 95 ± 9% and 24,946 ± 4,576 (bpm x mmHg). The TST and DIP presented similar positive results for myocardial ischemia (21% vs 15%, respectively). The correlation between the tests was 88% (Kappa 0.63, p<0.01). During 685 ± 120 days of follow-up, nine major events occurred: 6 deaths, 2 acute coronary syndromes and 1 myocardial revascularization. The variables associated with the major events were: age (83 ± 6 vs 80 ± 4 years; p=0.048), male gender (78% vs 33%; p=0.02), ST segment depression (1 ± 1 mm vs 0.25 ± 0.6 mm; p= 0.01), high or intermediate risk determined by the Duke treadmill score - combined in one group (44% vs 2%; p=0.001) and abnormal DIP (44% vs 10%, p= 0.02). CONCLUSION: For this elderly population, the TST was an efficient and viable option with a similar diagnostic value in comparison to the DIP. However, the TST was more accurate in the prediction of major events and offers a lower cost.
Exercise test; efficacy; costo-benefit analysis; cardiovascular diseases; aged, 80 and over; radionuclide imaging
