[Stress tests in old age. The choice of the stress protocol].

Objective: To evaluate, in an elderly Portuguese population, the diagnostic capacities of the most popular treadmill stress test protocols.
Design: Retrospective study of an elderly Portuguese population submitted to a stress test.
Patients and Methods: A population of 45 patients (35 male), aged 65 or more years, consecutively submitted to a stress test. The average age of the group was 67.8 +/- 2.9 years. The three protocols (Bruce, Bruce Modified and Naughton) were comparatively studied in terms of the patients capacity to execute the protocol, capacity to obtain a maximum and a diagnostic stress test, and the complications of the stress test protocol.
Main Results: The Bruce protocol was used in 19 patients, the Bruce Modified in 13 patients and the Naughton protocol in 13 patients. The three protocols did not lead to any complication. The Bruce protocol led to a larger increment in heart rate (p < 0.001) and to larger maximum rate pressure product (p < 0.05) than the Naughton one. The Bruce protocol obtained a larger number of diagnostic tests (p < 0.01) and a significantly lower number of inconclusive stress tests. The Naughton protocol led to a larger duration of the exercise tests and was not suitable for some of the elderly patients owing to the exhaustion of the protocol. The results obtained with the Bruce Modified protocol were among those of other two protocols.
Conclusions: In the elderly, the stress tests are safe and useful in the diagnosis of exercise induced ischemia and in the stratification of cardiovascular risk. From the protocols studied, the Bruce protocol was the most adequate, globally speaking, for this group of patients. The Bruce protocol presented a better diagnostic capacity with no complications related to the protocol.