SEX-RELATED DIFFERENCES IN THE TREATMENT AND OUTCOMES OF CANADIAN ACUTE CORONARY SYNDROME PATIENTS OVER THE PAST DECADE

The question of whether gender-related disparities still exist in the treatment and outcomes of patients presenting with acute coronary syndromes (ACS) remains controversial. Using data from four registries spanning a decade, we sought to determine whether sex-related differences have persisted over time, and examined the treating physician's rationale for adopting a conservative management strategy in women compared to men. From January 1999 to December 2008, 14,196 patients with non-ST-segment elevation (NSTE)-ACS (without ST-segment elevation ≥0.1 mV in ≥2 contiguous leads or left-bundle branch block) were recruited into the Canadian Acute Coronary Syndrome I (ACSI; 1999-2001), ACSII (2002-2003), Global Registry of Acute Coronary Events (GRACE/GRACE2; 2004-2007), and Canadian Registry of Acute Coronary Events (CANRACE; 2008) prospective multicenter registries. A total of 4874 women and 9322 men were admitted with NSTE-ACS. Women were significantly older than men, and more likely to have a history of heart failure, diabetes, or hypertension, and less likely to have had prior revascularization. Fewer women were treated with ticlopidine/clopidogrel, heparin and glycoprotein IIb/IIIa inhibitors compared to men in the GRACE and CANRACE registries (P ≤ 0.05). Women were also less likely to undergo coronary angiography (Figure) and had higher unadjusted in-hospital mortality rates (2.7% vs. 1.6%, P < 0.001). Over time, significant increases were seen in the use of cardiac catheterization and PCI for both genders (all P for trend <0.001). Multivariable analysis confirmed that female gender was independently associated with lower in-hospital coronary angiography (adjusted odds ratio [aOR] 0.76, 95% confidence interval [CI] 0.69-0.84, P < 0.001) and higher in-hospital mortality (aOR 1.26, 95% CI 1.02-1.56, P = 0.036), irrespective of age (P for interaction = 0.76 for mortality). The lower use of coronary angiography in women was consistently seen over time. In the ACS-II registry, the reason most frequently cited by physicians for adopting a conservative approach was the perception that patients were “not high risk enough” in 52% of women compared with 47% of men (P = 0.24) who did not have coronary angiography. Despite temporal increases in the use of invasive cardiac procedures, women are still more likely to be treated conservatively with associated worse outcomes. Greater awareness of this treatment-risk paradox may assist in bridging the gender gap between current evidence-based guidelines and actual practice.