Unusual prognostic significance of exercise-induced ST elevation in coronary patients

Follow-up surveillance of 1136 coronary patients (918 men and 218 women) observed in Seattle community practice reveals a higher incidence of subsequent myocardial infarction, cardiac arrest or cardiac death in over 4% who manifested ST elevation during maximal exercise testing and recovery. Quantitative measurements of 100-beat signal-averaged ECG responses transmitted by dataphone from 15 testing sites provide objective classification into ST depression (less than O mV) and ST elevation (greater than O mV) during exercise and five minutes of recovery. Whereas the annual incidence of CHD events in 18.3% of men with ST depression only during exercise is 2.0%/year, it is 4.1%/year in 71.6% of men with ST depression persisting into recovery and 8.2%/year with ST elevation during exercise and recovery (P less than 0.05). Even higher event rates occur with exercise of short duration and in a subgroup who had invasive studies which demonstrated at least two vessels with 70% or more stenosis and ejection fractions under 50%.