Comparison of Patients With Nonobstructive Coronary Artery Disease With Versus Without Myocardial Infarction (from the VA Clinical Assessment Reporting and Tracking [CART] Program).

Comparisons of the outcomes of patients with myocardial infarction with nonobstructive coronary artery disease (MINOCA) and patients with nonobstructive coronary artery disease (CAD) without myocardial infarction (MI) are limited. Here we compare the outcomes of patients with MINOCA and patients with nonobstructive CAD without MI and assess the influence of medical therapy on outcomes in these patients. Veterans who underwent coronary angiography between 2008 to 2017 with nonobstructive CAD were divided into those with or without pre-procedural troponin elevation. Patients with prior revascularization, heart failure, or who presented with cardiogenic shock, STEMI, or unstable angina were excluded. After propensity matching, outcomes were compared between groups. The primary outcome was major adverse cardiovascular events (MACE: mortality, myocardial infarction, and revascularization) within one year: 3,924 patients with nonobstructive CAD and a troponin obtained prior to angiography were identified (n=1,986 with elevated troponin) and restricted to 1,904 patients after propensity-matching. There was a significantly higher risk of MACE among troponin-positive patients compared with those with a negative troponin (HR 2.37; 95% CI, 1.67 to 3.34). Statin (HR 0.32; 95% CI, 0.22 to 0.49) and ACE inhibitor (HR 0.49; 95% CI, 0.32 to 0.75) therapy after angiography was associated with decreased MACE, while P2Y12 inhibitor, calcium-channel and beta-blocker therapy were not associated with outcomes. In conclusion, Veterans with MINOCA are at increased risk for MACE compared with those with nonobstructive CAD and negative troponin at the time of angiography. Specific medications were associated with a reduction in MACE, suggesting an opportunity to explore novel approaches for secondary prevention in this population.