Clinical profile and arrhythmic burden in MINOCA

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Myocardial infarction (MI) with nonobstructive coronary arteries (MINOCA) is considered to be a puzzling clinical phenomenon with unclear prognosis. This study aims to compare the clinical characteristics, impact of arrythmias and prognosis of MINOCA with MI with obstructive coronary artery disease (MICAD). METHODS: Data was obtained from our university hospital database. Patients with MI between 28 August 2018 and 31 December 2020 were included in the study. Subjects were divided in 2 groups: 1 - MINOCA; 2 -MICAD. Follow-up analysis included death from any cause, major adverse cardiac events (MACE: cardiac death, MI, stroke), readmissions due to cardiovascular causes, and in-hospital mortality. Median follow up was 18 months. RESULTS: MINOCA occurred in 49 (11 %) out of 443 pts with MI. There were no differences in age (p=0.732). In MINOCA group there were more females (34.7% vs 22.8%, p<0.001), never smokers (30.6% vs 21.8%, p<0.001), lower rates of hypertension (67.3% vs 73.8%, p=0.036), diabetes (18.3% vs 29.9%, p<0.001), hyperlipidaemia (28,5 % vs 35.7%, p=0.475), stroke in anamnesis (2.0% vs 6.8%, p<0.001), preavious MI (2.0% vs 22.8%, p<0.001). Symptoms at admission didn't differ between the two groups, however MINOCA group had lower mean heart rate (72±15 vs 87±19, p<0.001), lower systolic arterial pressure (139±22 vs 145±28, p<0.001). There were no significant differences between STEMI or NSTEMI: 55.1 % and 44.9 % in the MINOCA group vs 53.8 % and 46.2 % in MICAD (p=0.534). MINOCA patients had lower C-RP levels (19 vs 56 mg/L, p<0.001), high-sensitivity cardiac troponin T levels: (112 vs 376 ng/L, p<0.001) and lower BNP levels (99±26.9 vs 142±64.2, p<0.001). Left ventricular dysfunction (EF < 50 %) was more prevalent in the MICAD group (16.3% vs 27.9%, p<0.001). There was no need in inotropic support in MINOCA patients (0% vs 4.8%, p=0.04). Atrial fibrillation (AF) was more often found in MICAD group (4.1% vs 6.8%, p <0.001). There were no diffrenecs in ventricular arrhythmias during admmision in both groups. Death rates were lower in hospital (0% vs 2.8%, p=0.131) and during the follow up period (8.1% vs 10.9 %, p=0.369). There was no significant difference in MACE outcomes (p=0.612) and readmission of cardiovascular causes (p=0.310) in both groups. Independent predictors for MACE in MINOCA patients were older age (≥60 years), females, reduced LVEF and atrial fibrillation. CONCLUSION: MINOCA patients had lower prevalence of classic cardiovascular risk factors, no clinical differences at admission, lower levels of C-RP and high-sensitivity cardiac troponin T, preserved left ventricle EF, lower in- hospital and during follow up death rate, but no significant difference in MACE outcomes. Older age, females, reduced LVEF and atrial fibrillation are considered to be predictors of MACE in MINOCA. Further research is needed to provide more evidence on the optimal management.