Prognostic endpoint yield of high-level versus low-level graded exercise testing
Hamm, L.F.; Stull, G.A.; Serfass, R.C.; Ainsworth, B.
Archives of Physical Medicine and Rehabilitation 69(2): 86-89
1988
ISSN/ISBN: 0003-9993 PMID: 3341899 Document Number: 311740
The prognostic endpoint yield (PEY) of a low-level (less than or equal to 4.6 METS) vs a high-level graded exercise test administered soon after myocardial infarction was evaluated with 184 patients. Test endpoints considered prognostically significant for future cardiac events were (1) ST segment depression greater than or equal to 1mm, (2) angina pectoris, and (3) complex ventricular beats. Test endpoints were assigned to both low-level and high-level tests if they occurred less than or equal to 4.6 METS; test endpoints greater than 4.6 METS were assigned to the high-level test only. Allowing the 145 patients who were asymptomatic during the low-level test to continue into the high-level protocol revealed a 2.5 times greater occurrence of angina pectoris (38 vs 15), a 3.4 times greater occurrence of ST segment depression (27 vs 8), and twice the occurrences of ventricular beats (4 vs 2). This substantial increase in prognostic endpoint yield was demonstrated in the presence of a significantly longer exercise time with the high-level test (9.0 vs 5.1 min), with no significant difference between protocols for peak heart rate or systolic blood pressure. Therefore, a high-level graded exercise test appears to increase the yield of test endpoints with known prognostic importance.