Prognostic impact of cardiac MRI in acute myocardial injury with non-obstructive coronary arteries: The role of 2D speckle-tracking echocardiography and CMR imaging

Abstract

Acute myocardial injury with non-obstructive coronary arteries (aMINOCA), broader term than MINOCA, including ischemic and non-ischemic causes, represents a diagnostic dilemma, and the prognostic markers have not been clarified. this study sought to assess the prognostic impact of cardiovascular magnetic resonance (CMR) in patients with aMINOCA. Prospective study including patients presenting aMINOCA, admitted from June 2019 to September 2020, undergoing 2D STE Echocardiography and CMR assessment at admission. A 1.5-T CMR was performed using a comprehensive protocol (cines, T2-STIR and late gadolinium enhancement sequences). CMR (performed at an average of 3.22 days from presentation) was able to identify the cause for the troponin rise in 82% (24/29) of the patients (41% myocarditis, 35% MI, and 7% Takotsubo cardiomyopathy), whereas a normal CMR was identified in 17%. 2D LV Global longitudinal systolic myocardial strain (2D GLS) correlated significantly with the amount of LGE (r 2 = 0.230; P = 0.021). Pick troponin level was significantly higher in groups of patients with LGE (18.6 vs. 1.6; P = 0.012) and with myocardial edema (24.4 vs. 4.1; P = 0.026). At follow-up, we found that both LVEF assessed by CMR and amount of myocardial edema were significantly correlated with the absence of recovery of the GLS at 6 months-follow-up echocardiography (r 2 = 0.243; P = 0.032 and r 2 = 0.410; P = 0.003). In contrast, no significant correlation between echography LVEF, 2D GLS and recovery of the GLS at follow-up was founded (r 2 = 0.07; P = 0.71 and r 2 = 0.185; P = 0.06). In a prospective study including 29 patients with non-obstructive coronary myocardial injury, CMR identified a final diagnosis in 82% of patients. 2D speckle-tracking echocardiography was a useful tool in the diagnostic process and follow-up. Presence of myocardial oedema assessed by CMR at admission is a strong predictive factor of absence of LV systolic function recovery.