Electrocardiographic presentation of blacks with first myocardial infarction does not explain race differences in thrombolysis administration

Abstract

Background Previous studies have suggested that thrombolysis is used less often in blacks than in whites. However, whether the greater prevalence of contraindications or less specific electrocardiographic manifestations of myocardial infarction (MI) account for this difference is unclear. Methods and Results We studied 498 consecutive patients (32% blacks) with first MI. Initial electrocardiograms were analyzed, blinded to race and outcome, for ST-segment deviation and bundle branch block to determine eligibility for thrombolysis. The relation of electrocardiographic eligibility for thrombolysis and actual use of thrombolysis in both races was explored. Among blacks, 45% received thrombolysis compared with 66% of whites (P <.001). A similar proportion of blacks and whites were eligible for thrombolysis (59% and 66% respectively, P =.116), but 62% of electrocardiography-eligible blacks were treated with thrombolysis compared with 75% of whites (P =.016). After accounting for eligibility for electrocardiography and other clinical variables likely to affect the decision to administer thrombolysis by means of conditional logistic regression, blacks were still less likely to receive thrombolysis (relative risk 0.73; 95% confidence interval 0.55 to 0.97). Conclusions We conclude that the differences in thrombolysis administration to blacks and whites are not accounted for by differences in electrocardiographic presentation or other measured variables. Unmeasured differences in clinical presentation of MI may explain racial differences in thrombolysis and merits further study. (Am Heart J 2000;140:200-5.)