Sex differences in coronary catheterization and revascularization following acute myocardial infarction: Time trends from 1994 to 2003 in British Columbia

BACKGROUND: Studies before the turn of the century reported sex differences in procedure rates. It is unknown whether these differences persist. OBJECTIVES: To examine time trends and sex differences in coronary catheterization and revascularization following acute myocardial infarction (AMI). METHODS: A retrospective analysis was performed of all patients 20 years of age or older who were admitted to hospital in British Columbia with an AMI between April 1, 1994, and March 31, 2003. Segmented regression analysis was used to examine the inflection point of the time trend in 90-day catheterization rates post-AMI. Multivariable Cox regression modelling was used to evaluate sex differences in receiving catheterization and revascularization following AMI. RESULTS: Ninety-day coronary catheterization rates increased significantly over the study period for both men and women (P<0.0001 for trend), with a steeper increase beginning in September 2000. Women were less likely to undergo catheterization than men, even after adjustment for baseline differences; this sex effect was modified by age and care in the intensive care unit or cardiac care unit (ICU/CCU). Specifically, ICU/CCU admission eliminated the sex difference among patients who were younger than 65 years of age. Conditional on receiving cardiac catheterization post-AMI, female sex was not associated with a lower likelihood of receiving revascularization within one year (HR 0.96; 95% CI 0.91 to 1.02). CONCLUSIONS: Despite recent increases in catheterization rates post-AMI, women were less likely to undergo catheterization than men. Interestingly, access to ICU/CCU care removed the sex difference in catheterization access in patients younger than 65 years of age.