Left atrial reservoir strain is reduced in patients with Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA)

Abstract

BACKGROUND: Left atrial (LA) deformation imaging is a promising method for evaluation of LA function and has been shown to be a strong prognostic marker for arrhythmias including atrial fibrillation (AF). Myocardial infarction with non-obstructive coronary arteries (MINOCA) represents a management conundrum given the poorly understood pathogenic mechanisms. The aim of our study was to characterise the trends of LA reservoir strain (LASr) in patients with MINOCA. METHODS: Patients admitted with acute myocardial infarctions were assessed and those diagnosed with MINOCA who underwent transthoracic echocardiogram (TTE) within 48-hours of their coronary angiogram were reviewed. Two-dimensional speckle tracking strain analysis of the LA was performed offline using vendor independent software (TomTec Arena) and compared to healthy controls identified from our echocardiography database. We excluded patients with history of AF or heart failure. RESULTS: A total of 80 patients were included; 40 MINOCA patients (70% male, mean age 56.0+/-13.5 years) where compared to 40 controls (74% male, mean age 54.3+/-13.5 years). Overall, patients with MINOCA had a greater number of cardiovascular risk factors including smoking, hypertension, hyperlipidaemia, and diabetes mellitus (p<0.01 for all). LVEF was normal in all patients and not significantly different between groups (p=0.55). Interestingly, though there was no difference in indexed LA volumes, patients with MINOCA had a significantly lower LA reservoir strain (25.47+/-6.44 vs 28.56+/-5.54; p=0.03) CONCLUSIONS: Patients with MINOCA demonstrated lower LASr despite normal LVEF and LAVI. Our findings suggest LA dysfunction may be implicated in the pathogenesis of MINOCA. Further studies are required to evaluate the significance of our findings.