Familial risk of myocardial infarction with non-obstructive and obstructive coronary arteries-A nation-wide cohort study

Abstract

ABSTRACTBackgroundThe familial risk among patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) is unknown. Previous studies of family history in myocardial infarction (MI), have not made a distinction between MINOCA and MI due to coronary artery disease (MI-CAD), based on angiographic findings.ObjectivesTo investigate familial risk of MI without and with obstructive coronary arteries.MethodsA register-based cohort study with a total of 15,462 MINOCA cases, 204,424 MI-CAD cases, 38,220 control subjects without MI and with non-obstructive coronary arteries. First-degree relatives were identified 1995-2020. Cox proportional hazard regression models were used to compare familial risk in MINOCA and MI-CAD with control subjects.ResultsDuring a mean follow-up of 8.1 ± 4.2 years, MINOCA occurred in 1.0% of first-degree relatives with MINOCA whereas MI-CAD occurred in 9.7% of first-degree relatives of MINOCA. The age- and sex-adjusted hazard ratio (HR) for a MINOCA-relative experiencing MINOCA and MI-CAD, compared to control subjects, was 0.99 (95% confidence interval [CI] 0.80-1.23) and 1.10 (95% CI 1.03-1.18), respectively. During a mean follow-up of 8.5 ±4.8 years, MI-CAD occurred in 12.2% of first-degree relatives with MI-CAD with age- and sex-adjusted HR 1.43 (95% CI 1.37-1.49).ConclusionsNo increased familial risk of MINOCA was observed for MINOCA-patients whereas there was an increased familial risk for MI-CAD when compared to control subjects. These results may indicate that genetic factors and shared environmental factors within a family leading to CAD are important also for MINOCA, thus MI-CAD and MINOCA could share underlying mechanisms.Condensed AbstractIn this register-based nation-wide cohort study including 15,462 MINOCA cases, 204,424 MI-CAD cases, and 38,220 control subjects, studied between 1995-2020, we show that there is an increased familial risk for MINOCA having a first-degree relative with MI-CAD, without an increased familial risk of MINOCA having a first-degree relative with MINOCA compared to controls. Age- and sex-adjusted hazard ratio (HR) for MICAD was 1.10 (95% confidence interval 1.03-1.18), and for MINOCA 0.99 (95% confidence interval 0.80-1.23). These results may indicate that genetic factors and shared environmental factors within a family leading to CAD are important also for MINOCA.