Effect of delay on racial differences in thrombolysis for acute myocardialinfarction

Objective To analyze the effect of delay times on racial differences in thr ombolysis for acute myocardial infarction. Background Lower rates of thromb olytic therapy in blacks with acute myocardial infarction have recently bee n reported, but the reasons for this disparity are unknown. We hypothesized that lower rates of thrombolysis are caused by delay in presentation after symptom onset. Methods From November 1992 through November 1996, consecutive patients with a first acute myocardial infarction presenting to a large, urban teaching hospital were prospectively enrolled. Delay times were determined retrospec tively from review of medical records. Patients were prospectively followed up for in-hospital cardiac events and death. A multivariable regression mo del was built to relate presentation times and other variables to thromboly sis administration. Results A total of 395 patients were included in the study, of which 33% we re block. Symptom onset to emergency department presentation and door-to-ne edle times were significantly longer in blacks. Thrombolysis was administer ed significantly less often in blacks compared with whites (47% vs 68%, P = .001). Black race and age above 60 years were independently associated wit h delayed presentation and prolonged door-to-needle times. Black race, time to presentation, and non-Q-wave myocardial infarction were independently a ssociated with not receiving thrombolysis. In-hospital mortality rates were similar in both groups. Conclusions Blacks presented later than whites for first acute myocardial i nfarction. late arrival strongly influenced the rate of thrombolysis admini stration, Lower rates of thrombolysis and prolonged door-to-needle times we re apparent in blacks after adjustment for delay times and other clinical f actors, a finding that merits further investigation.