Use of thrombolytic therapy for acute myocardial infarction: Effects of gender and age on treatment rates

Background: Although there have been efforts to increase the utilization of thrombolytic therapy, there are still many patients who might benefit from this treatment who do not receive it. Women and the elderly have been particularly undertreated, despite evidence that their survival can be improved with thrombolysis. This study was undertaken to determine the relative rates of treatment of women vs. men and the elderly vs. younger subjects and to examine factors that might explain differences in treatment frequency. Methods and Results: This is a retrospective study of patients who presented to the Emergency Departments of four local hospitals in 1993 and 1994 with evidence for acute ST-elevation myocardial infarction. Demographic data, past medical history, information on co-morbid illnesses, and times to hospital arrival, first electrocardiogram, physician notification, and thrombolytic therapy were recorded as was survival to hospital discharge. Data for patients who did or did not receive thrombolytic therapy were compared. Men were treated more frequently in both tertiary and community hospitals. Women were older, but within each age bracket, men were treated more often. The time of arrival was similar for men and women, but men who arrived within 6 hours or 6-12 hours after pain onset were treated at a higher rate than women. For patients without contraindications, treatment was not affected by gender or age. However, treatment rates decreased with increased prevalence of exclusionary factors, and since both women and the elderly tended to have more such factors, elderly women were treated at a markedly lower rate. The single clinical factor that increased thrombolytic usage in women compared to men was a history of prior myocardial infarction. Conclusion: Despite convincing evidence that thrombolytic therapy is beneficial in women and the elderly, these groups have been relatively neglected unless attention is called to clinical risk, for example, by history of prior myocardial infarction.