The authors tested their hypothesis that electrocardiographic manifestations other than that of myocardial infarction (MI) that are more prevalent in blacks explain the disparity in thrombolysis rates between blacks and whites. Patients for this study were recruited from those examined at a major urban teaching hospital with first acute MI as part of a prospective natural history study of the relation of race and left ventricular hypertrophy to outcome conducted from March 1993 to June 1995.

Blacks were more likely than whites to be younger, female, hypertensive, have diabetes, and have a higher systolic blood pressure. With regard to in-hospital treatment, blacks were less likely than whites to receive a beta-blocker, thrombolysis, and thrombolysis or early PTCA, and were more likely to receive a calcium blocker. There were no racial differences in electrocardiographic localization of MI, although blacks were more likely to have LVH and were less likely to develop Q waves by the time of discharge.

On the basis of electrocardiograms, only 64% of the patients were eligible for thrombolysis. Although a similar proportion of blacks and whites were electrocardiography-eligible, the use of thrombolysis in electrocardiography-eligible blacks was considerably lower than in whites. Of the electrocardiography-ineligible group, whites were twice as likely as blacks to get treated. There were no significant differences in contraindications to thrombolytic therapy. In adjusted analyses, black race (RR=0.74), eligibility for electrocardiography (RR=1.58), time to presentation (RR=0.97), and Q-wave MI at presentation (RR=1.39) were statistically significantly associated with risk for thrombolytic therapy.

The authors conclude that, despite the greater prevalence of LVH, electrocardiographic manifestations of MI in blacks and whites were similar and racial differences in thrombolysis administration remained significant after accounting for electrocardiography and clinical eligibility. After discussing possible race patterns in type/severity of symptoms that were unmeasured in this study, the authors add, "clearly the area of racial differences in symptom perception and recognition by care givers merits further analysis as does the possibility of racial bias."