The long-term prognostic value of the ST depression criteria for ischemia recommended in the universal definition of myocardial infarction in 43,661 veterans

BackgroundThe third Universal Definition of Myocardial Infarction (UDMI) includes electrocardiographic criteria for ischemia, specifying horizontal or down-sloping ST depression ≥ 0.05 mV in two contiguous electrocardiogram (ECG) leads. We used the surrogate of cardiovascular (CV) death to evaluate the criteria.MethodsWe collected computerized ST amplitude measurements, in different lead groupings, from the resting ECGs of 43,661 patients collected between 1987 and 1999 at the Palo Alto VA. There were 3929 (9.0%) cardiac deaths over a mean follow-up of 7.6 (SD 3.8) years.ResultsWe found that horizontal or down-sloping ST depressions in contiguous leads, depending upon the lead groupings, had sensitivities ranging from 1% to 5%, specificities exceeding 99%, and relative risks for CV death ranging from 3.1 to 7.0 (p < 0.001 for each individual relative risk) while horizontal or down-sloping ST depressions in a single lead had comparable values. We found that up-sloping ST depressions had greater sensitivities than horizontal or down-sloping ST depressions. Additionally, we found that ST depressions isolated to the inferior or anterior leads, without concomitant lateral depressions, were poor predictors of CV death.ConclusionThese findings reinforce and further characterize the value of ST depressions for predicting CV death. Furthermore, if these findings can be reproduced in the acute setting, they would undermine the requirement for contiguous lead depressions with slope assessment as well as prioritize ST depression in V4, V5, and V6 when assessing for myocardial ischemia.