Background and aim: Acute coronary syndrome with non-critical coronary arteries comprises distinct entities with unique pathophysiological, diagnostic, therapeutic and prognostic characteristics. The aim was to compare the clinical and prognostic features of cohorts presenting NSTEMI and non-critical coronary arteries disease, i.e. MINOCA, type 2 myocardial infarction (MI), Takotsubo syndrome (TTS), with a cohort of classical type 1 MI with critical coronary arteries disease.
Methods: In this single-center observational retrospective study, 18223 patients who underwent invasive coronary angiography between 2005 and 2022 were screened. Overall, 1162 patients were included (301 MINOCA, 237 type 2 MI, 138 TTS, and 486 with type 1 MI). The primary endpoint was a composite of non-fatal acute MI, non-fatal TIA or stroke, hospitalization for HF (hHF), and death. Secondary endpoints were (1) hHF, (2) a composite event of atrial fibrillation (AF), TIA, and/or stroke, and (3) all-cause mortality.
Results: The average age was 68.2 years, with 47% being male. At admission, the TTS group was the most hypotensive and echocardiographic compromised, with lower incidence of obesity and diabetes mellitus (DM). Type 2 MI group was more prone to hypertension and had a similar incidence of DM and diastolic dysfunction compared to type 1 MI. However, compared to type 1 MI, type 2 MI patients received less frequent DAPT, nitrates, beta-blockers, and statins upon discharge. The MINOCA group received therapy similar to type 1 MI.
Over a median follow-up of 62 [30-102] months, 358 patients reached the primary endpoint, 84 had hHF, 76 had AF/TIA/stroke, and 253 died. At Kaplan-Meier analysis, type 2 MI patients were more likely to reach the primary endpoint, following type 1 MI (Fig.1). TTS group had the best outcomes (0.01) for death (0.01) and HFh. (0.01), while type 2 MI had higher probability of developing AF/TIA/stroke (0.01) (Fig.2).
Cox Regression analysis confirmed type 1 MI as a predictor of worse outcomes compared to other groups, after adjustment for male gender, older age, DM, anemia, reduced systolic function, high C-reactive protein, left bundle branch block, and statins on discharge (Fig.3).
Conclusions: Critical coronary disease is confirmed to have the worst prognosis. Although type 2 MI had similar clinical characteristics as type 1 MI, the former was more burdened by arrhythmic and embolic events and diverged in therapy at the time of discharge.
