Introduction:
Myocardial Infarction with non-obstructive coronary artery disease (MINOCA) is found in 5%-6% of patients with acute myocardial infarction (AMI). As such, the diagnosis and management of AMI patients with non-obstructive coronary artery disease (NOCAD) poses a challenge as compared to patients with MI with coronary artery disease (MICAD).
Hypothesis:
To evaluate the characteristics and outcomes of MINOCA in older patients as compared with MICAD patients, with and without revascularization.
Methods:
This was a retrospective observational study of patients ≥80 years old who underwent invasive coronary angiography (ICA) for AMI between 2009-2019 at Kaiser Permanente Los Angeles Medical Center. MINOCA was defied as <50% stenosis of coronary arteries on angiography with a troponin level ≥0.05 ng/ml. Patients with MINOCA vs MICAD were compared. Multivariate logistic regression was used to identify independent predictors of MINOCA and Kaplan-Meier survival analysis was used to analyze all-cause mortality between cohorts.
Results:
A total of 259 patients with MINOCA (mean ± SD age 83.8±2.7 years, 68% female) and 687 patients with MICAD (84.7±3.4 years, 40% female) were analyzed. Younger age (odds ratio [OR]=1.11; 95% confidence interval [CI]=1.05-1.18), female sex (OR=3.14; CI=2.20-4.48), black race (OR=2.53; CI=1.61-3.98), no history of prior stroke (OR=1.56; CI=1.06-2.33), atrial fibrillation or flutter (OR=2.04; CI:1.38-3.02), lower troponin levels (OR=1.08; CI:1.03-1.11), and lower triglyceride levels per 10 mg/dl increments (OR=1.06; CI:1.03-1.11) increased the odds of having MINCOA as compared to MICAD. At median follow-up of 2.4 years, MINOCA was associated with a lower rate of death (44.8% vs 55.2%, p<0.01) compared to un-revascularized MICAD, but no difference (31.3% vs 40.4%, p=0.68) when compared to re-vascularized MICAD.
Conclusions:
Patients age ≥80 years with MINOCA have fewer traditional risk factors compared to their counterparts with MICAD and fewer deaths compared to un-revascularized MICAD, but similar mortality compared to revascularized MICAD