Selection of Patients for Coronary Angiography and Coronary Revascularization Early after Myocardial Infarction: Is There Evidence for a Gender Bias?

Abstract

OBJECTIVE: To determine whether a gender bias exists in the selection of patients for diagnostic and therapeutic cardiovascular procedures early after myocardial infarction. DESIGN: A retrospective cohort study. SETTING: A community-based tertiary care teaching hospital. PATIENTS: A total of 2473 consecutive patients with a principal discharge diagnosis of acute myocardial infarction and a peak creatine kinase MB fraction of at least 4%. MEASUREMENTS: Comparison of men and women regarding the frequency with which they underwent various cardiac procedures. RESULTS: Women had coronary angiography during hospitalization for myocardial infarction much less frequently than men (odds ratio, 0.55; 95% Cl, 0.46 to 0.65), but the age-adjusted rates were similar in women and men (odds ratio, 0.91; Cl, 0.75 to 1.12). An abnormal ejection fraction (less than 50%) was equally frequent in women and men who underwent left ventriculography (odds ratio, 0.85; Cl, 0.56 to 1.30). Among patients who had coronary angiography, women had a significantly lower rate of severe coronary artery disease, defined as either a left main stenosis of more than 50%, three-vessel disease, or two-vessel disease with a proximal left anterior descending stenosis of more than 70% (odds ratio, 0.67; Cl, 0.48 to 0.93). When adjustments were made for age, women had percutaneous transluminal coronary angioplasty as often as men (odds ratio, 1.16; Cl, 0.83 to 1.62) but had coronary artery bypass graft surgery significantly less frequently (odds ratio, 0.58; Cl, 0.37 to 0.91). When adjustments were made for age and the severity of coronary artery disease, the difference in rates was of borderline significance (odds ratio, 0.65; Cl, 0.41 to 1.01). CONCLUSIONS: No evidence of a difference in the rate of coronary angiography early after myocardial infarction between women and men was found after age adjustment. Among patients who have cardiac catheterization early after myocardial infarction, women and men are equally likely to have angioplasty, but women are less likely than men to have coronary artery bypass surgery.