In comparison to the myocardial perfusion scintigraphy, a treadmill stress test is a viable, efficient and cost effective option to predict cardiovascular events in elderly patients

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 > or = 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.