Prognostic significance of positive family history in outcomes after coronary artery bypass grafting: Do we need to update our assumptions?

Background Recent research suggests a protective role for positive family history of premature cardiovascular disease (FHpCVD) in patients undergoing coronary artery bypass grafting. We aimed to further investigate this unlikely association. Methods In this registry-based cohort study, patients who underwent first-time non-emergent coronary bypass surgery at Tehran Heart Center between 2007 and 2016 were included. Patients with and without FHpCVD were compared in terms of all-cause mortality and first non-fatal cardiovascular events (CVEs) comprising non-fatal acute coronary syndrome, non-fatal stroke or transient ischemic attack, and repeat coronary revascularization. Results A total of 13,156 patients were included (mean age 60.83 ± 9.57, 74.5% male), among which 2684 (20.4%) patients had FHpCVD. Median follow-up was 77.7 months. FHpCVD was weakly associated with reduced all-cause mortality using inverse probability weight (IPW) method (hazard ratio [HR] = 0.853; 95% confidence interval [CI] 0.730–0.997; P = 0.046), and not associated with non-fatal CVEs considering death as the competing event (sub-distribution HR [SHR] = 1.124; 95% CI 0.999–1.265; P = 0.053). Within a subgroup of patients without previous myocardial infarction or revascularization (7403 cases; 56.3%), FHpCVD was associated with lower mortality (HR = 0.700; 95% CI 0.548–0.894; P = 0.004) and higher non-fatal CVEs (SHR = 1.197; 95% CI 1.019–1.405; P = 0.028), whereas among patients with previous coronary events, there was no association between FHpCVD and outcomes. Conclusions FHpCVD was associated with lower all-cause mortality but higher non-fatal CVEs, especially in those without prior coronary events. Such discordance calls for caution in assuming a protective role for FHpCVD. The prognostic significance of FHpCVD needs further evaluation among surgical patients.