Prevalence of Myocardial Infarction With Obstructive and Non-Obstructive Coronary Arteries in a Middle-Aged Population With Chronic Airflow Limitation: A Cross-Sectional Study.

Purpose: Myocardial infarctions (MIs) can occur in underlying obstructive coronary artery disease (MI-CAD) or in non-obstructive coronary arteries (MINOCA). The primary objectives of the study were to investigate the prevalence of MI-CAD and MINOCA in people with CAL, and to explore if CAL is an independent risk factor for MI-CAD and MINOCA. Secondary objectives were to explore these research questions stratified by sex and by smoking history.

Patients and methods: Cross-sectional analysis of the population-based Swedish CArdioPulmonary bioImage Study (SCAPIS) of people aged 50-64 years. CAL was defined as a post-bronchodilator ratio of forced expiratory volume in one second and forced vital capacity below 0.70. MI-CAD was defined as a self-reported MI with coronary computed tomography angiography findings of previous revascularization or at least one significant coronary stenosis (>50%), and MINOCA as self-reported MI with no previous revascularization and no significant coronary stenosis.

Results: In total, 1735 (8.3%) of 20,882 included participants had CAL. MI-CAD was more common than MINOCA both in people with (2.8 vs 0.6%) and without CAL (1.2 vs 0.3%). Compared with those without CAL, people with CAL had an almost doubled independent risk of both MI-CAD ([adjusted OR] 1.72; [95% CI] 1.22-2.42) and MINOCA (1.99; 1.02-3.86). In men, CAL was associated with increased risk of MINOCA (2.63; 1.23-5.64), and in women with increased risk for MI-CAD (3.43; 1.68-1.26).

Conclusion: Middle-aged people with CAL have an almost doubled risk of both MI-CAD and MINOCA, compared with people without CAL. In contrast to people without CAL, the risk of MINOCA is increased in men and the risk of MI-CAD is increased in women. In a clinical context, both MI types should be considered in CAL.