Prediction of coronary artery disease and cardiac events using electrocardiographic changes during hemodialysis

Hemodialysis (HD) patients have a high rate of cardiac morbidity and mortality. Both symptomatic and silent ischemic heart disease may occur frequently during HD because HD simultaneously reduces coronary artery oxygen delivery while increasing myocardial oxygen demand. The purpose of the present study is to prospectively evaluate the usefulness of a significant ST depression induced by HD for the diagnosis of coronary artery disease (CAD) and as the predictor of subsequent cardiac events in HD patients. Sixty-one patients undergoing chronic HD (50 men, 11 women; mean age, 61 years) admitted for such cardiac symptoms as chest pain (n = 43), arrhythmia (n = 5), or heart failure (n = 13) were studied; 38 patients had CAD by coronary angiography. Electrocardiograms performed during HD showed an additional depression (>/=1.0 mV) of the ST segment in 18 patients (positive-ST group), but not in 43 patients (negative-ST group). The incidence of CAD was significantly greater in the former (100%) than in the latter group (46%). A prospective follow-up was performed for 21 +/- 2 months, and cardiac events occurred in all positive-ST group patients and in 21 negative-ST group patients. Event-free survival was poorer in the positive-ST group (P < 0.0001). A Cox proportional hazards model identified the significant ST depression as an independent risk factor for cardiac morbidity (P < 0.05), but not for all-cause mortality. ST depression during HD is useful to diagnose CAD in symptomatic patients and is considered an important prognosticator of subsequent cardiac events.