IS A FAMILY HISTORY OF CORONARY HEART DISEASE AN INDEPENDENT CARDIOVASCULAR RISK FACTOR?

Background: Although a family history (FHx) is an accepted risk factor for cardiovascular (CV) disease, few studies have examined the predictive strength of a positive FHx after adjusting for other conventional risk factors and medications Methods: We analyzed 12,922 patients with ACSs, without evidence of prior CV disease enrolled in the ISACS-TC registry between January 2010 to January 2021. Main outcome measures were the adjusted rates of STEMI and 30-day mortality from STEMI using multivariable logistic regression models Results: Overall, 3,147 patients (24,4%) self-reported an FHx of CV disease, defined as first-degree relative with premature CV events (men, age<55 years; women, age<65 years). There were 214 (17.4%) patients with FHx of CV, but without CV risk factors and 2,933 (28.3%) patients with FHx of CV associated with one or more CV risk factors. After adjusting for age, sex, cigarette smoking, obesity, and history of diabetes, hypertension and hypercholesterolemia, FHx of CV disease was associated with a significantly lower incidence of STEMI in patients with CV risk factors, but not in those without (ORs: 0.71; 95% Cl: 0.61 to 0.83 vs 0.87; 95% Cl: 0.52 to 1.48; interaction p=0.02). The magnitude of this protective association was weaker in younger than older patients (OR 0.81; 95% CI 0.66 to 0.98 vs 0.59; 0.45 to 0.76, interaction p=0.02). Prior use of evidence-based medications (aspirin, beta-blockers, ACE inhibitors/ARBs and statins) did not consistently change prior estimates on FHx of CV disease (OR: 0.79; 95% Cl: 0.65 to 0.96). Patients who presented with STEMI had a twofold excess risk of 30-day mortality (OR: 2.03; 95% CI: 1.36 to 3.11; p<0.001) compared with controls Conclusion: There is little evidence to consider a positive self-reported FHx of CV disease as a significant risk factor for development of STEMI and related high rate of CV mortality. Paradoxically, FHx of CV disease is associated with reduced severity CV disease outcomes in patients with the four primary CV risk factors, diabetes, cigarette smoking, hypertension, and hypercholesterolemia. Further investigation on the relation between FHx of CV and behavioral risk factors known to affect cardiovascular health is required