Background: The value of family history of coronary artery disease (CAD) in diagnosing acute coronary syndrome (ACS) in chest pain patients is uncertain, especially in relation to high-sensitivity assays for cardiac troponin T (hs-cTnT), which have improved ACS diagnostics. Our objective was to investigate the association between verified family history of CAD and ACS in chest pain patients, overall and in different strata of initial hs-cTnT.
Methods: Data on chest pain patients visiting four emergency departments in Sweden during 2013-2016 were cross-referenced with national registers of kinship, diseases and prescriptions. Family history of early CAD was defined as the occurrence of myocardial infarction or coronary revascularization before the age of 55 years in male and 65 years in female first-degree relatives. The outcome was combined including ACS and cardiovascular death within 30 days of presentation.
Results: Of 28,188 patients, 4.7% of patients had ACS. In total, 8.2% and 32.4% had a family history of early and ever-occurring CAD, respectively. Family history of CAD was positively associated with the outcome, independently of age, gender, cardiovascular risk factors and electrocardiogram findings. The strongest association was observed for family history of early CAD (odds ratio 1.62, 95% confidence interval 1.35-1.94). Stronger associations were observed in young patients (e.g. <65 years) and in patients with non-elevated initial hs-cTnT levels (p-value for interaction = 0.004 and 0.001, respectively).
Conclusions: Family history of CAD is associated with ACS in chest pain patients, especially in patients of young age or with non-elevated initial hs-cTnT levels.
Keywords: Chest pain; acute cardiac care; emergency department; myocardial infarction; one-hour algorithm; troponin.