Abstract 14925: Inverse Association between Family History of Premature Coronary Artery Disease and the Risk of Death in Patients with Coronary Artery Disease

Abstract

Background: Family history (FHx) of premature coronary artery disease (CAD) is an established cardiovascular risk factor. However the impact of FHx on outcomes of patients with CAD is unclear. Methods & Results: The Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH) Program is an inclusive prospective registry of patients undergoing coronary angiography. Between April 2002 and Mar 2013, 99,667 patients were enrolled. 30,030 (30%) patients reported FHx, defined as a first degree relative with premature CAD (males <55, females <65 years). We investigated the association between FHx and all-cause mortality at 1 year, using multivariable logistic regression, adjusting for clinical characteristics, comorbidities, and the extent of CAD. Patients with normal angiography (15.2%) were excluded. Compared to those without FHx, those with FHx were younger (60.1 vs 64.0 years, p<0.0001), more likely female (30.5% vs 29.5%; p=0.0018), and were less likely to have previously diagnosed CAD, congestive heart failure, stroke, or chronic kidney disease (all p<0.0001) Conversely, those with FHx were more likely current smokers (31.8% vs 25.3%) and to have hypertension (68.8% vs 65.5%) and dyslipidemia (75.7% vs 68.1%), all p<0.0001). The indication for angiography was an acute coronary syndrome (ACS) in 55% of both groups (p=0.57), and the extent of CAD was similar. Overall, FHx was associated with reduced 1-year mortality in fully adjusted models (odds ratio [OR] 0.56, 95% CI 0.51 to 0.62). This protective association was present in patients with and without a previous CAD event (OR 0.66 [95% CI 0.60 to 0.78] vs 0.53 [95% CI 0.47 to 0.59], respectively), and in patients with and without an ACS (OR 0.56 [95% CI 0.50 to 0.63] vs 0.56 [95% CI 0.48 to 0.65], respectively). There was slight attenuation of association with age, but FHx remained protective even in those aged 80 or more (OR 0.72, 95% CI 0.57 to 0.90). Conclusion: In patients with angiographic CAD, a family history of premature CAD is associated with lower mortality, independent of clinical characteristics, mode of presentation, and extent of disease. Further investigation of potential patient- and system-level mediators of this seemingly paradoxical relationship is required.