Abstract 13384: Prognosis of Patients With Myocardial Infarction With Non-Obstructive Coronary Arteries as Compared With Obstructive Coronary Disease

Abstract

Introduction: The prognosis of patients with Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA) is poorly understood. We examined the prevalence of adverse events (mortality, re-infarction and readmission) in patients with MINOCA over 1 year versus patients with acute myocardial infarction (AMI) and obstructive coronary artery disease (MICAD). Methods: Between July 2009 and December 2010, both patients with STEMI and NSTEMI, aged >65 years, from the National Cardiovascular Data Registry (NCDR ® ) CathPCI Registry were classified as having either obstructive or non-obstructive CAD (n=570,219) on the basis of their angiographic reports revealing no epicardial vessel with stenosis ≥50% (MINOCA) or at least one stenosis ≥50% (MICAD). Re-hospitalizations, repeat AMI, and mortality were assessed via linkage to Medicare data. We had the following exclusion criteria: (a) patients presenting with cardiac arrest within 24 hours (n=3,510), (b) patients with AMI as a complication during hospitalization (n=1,751), and (c) patients not in the Medicare data, or that could not be matched with Medicare through the patient beneficiary ID and discharge date (n=469,722). Analyses comparing MINOCA and MICAD were performed using the chi-squared test for categorical variables and the T-test for continuous variables. Results: Among 95,236 AMI patients, 4,831 patients (5.1%) had MINOCA. Compared to those with MICAD, patients with MINOCA were younger (75±7 vs 76±7, P<0.001), more likely to be female (78% vs 42%, P<0.001), and were predominately white (89% vs 91%, P<0.001). Outcomes over 1 year are described in the Table. Conclusion: In an elderly AMI population, the occurrence of MINOCA accounts for 5% of AMI presentations. Although MINOCA patients had fewer adverse events over 1 year compared with MICAD patients, they remain at modest to high risk for readmission and mortality. Further studies are needed to define whether or not these events are preventable.