Coronary slow flow is not an adverse prognostic factor in MINOCA patients in the 5-year follow-up

Introduction: The research aimed to compare the characteristics and outcomes of myocardial infarction with non-obstructive coronary arteries (MINOCA) patients with coronary slow flow (CSF) vs. normal coronary flow (no CSF) in a 5-year follow-up. Material and methods: Between 2010–2015 were identified 111 patients as having final MINOCA diagnosis and available calculated corrected TIMI frame count (cTFC). CSF was defined as cTFC greater than 27 frames per second in any of the three coronary arteries. The primary endpoint was the 5-year major adverse cardiovascular events rate, defined as cardiac death, myocardial infarction, or hospitalization due to angina. Results: The mean cTFC was 28.9 ± 6.1 frames per second (median: 28, IQR 24–33; min-max: 19–58). 62 (55.9%) patients had normal coronary flow, and 49 (44.1%) had CSF. Patients did not differ in sex (females no CSF vs. CSF: 58% vs. 61%, p = 0.7) or age (63 ± 15 years vs. 63 ± 13 years, p = 0.8). Patients with CSF characterized higher rates of chronic kidney disease (0 vs. 8.2%, p = 0.035). No statistically significant difference was observed for any of the analysed points. MACE rates for no CSF vs. CSF were 9.6% vs. 14.3% (HR 0.80, 95% CI 0.28–2.96, p = 0.7), respectively. Conclusions: CSF was not associated with a higher risk of adverse events among MINOCA patients at five years.