564 Cardiac magnetic resonance myocardial feature tracking for optimized risk assessment after acute myocardial infarction in patients with type 2 diabetes

Abstract

Abstract Objective Type 2 diabetes mellitus (T2DM) associates with worse cardiovascular outcome following acute myocardial infarction (AMI) as compared to non-diabetic patients. Since the mechanisms behind these observations are not fully understood we aimed to quantify the underlying pathophysiology on ventricular and atrial levels and study their prognostic implications using cardiovascular magnetic resonance (CMR) quantitative feature-tracking (FT) and tissue characterization. Research Design and Methods: A total of 1147 consecutive patients with AMI (n = 265 with diabetes; n = 882 without diabetes) undergoing cardiac magnetic resonance (CMR) imaging in median 3 days after AMI were included in this multicenter study. Left ventricular (LV) function and volumetry included LV ejection fraction (LV-EF), global longitudinal (GLS), radial (GRS) and circumferential strain (GCS) as well as left atrial (LA) strain and strain rate parameters of LA reservoir, conduit and booster pump function. LV damage assessment included infarct size (IS), edema and microvascular obstruction (MO). The clinical study endpoint was the rate of major adverse cardiovascular events (MACE) at 12 months. Results T2DM patients had impaired LA reservoir (19.8 vs. 21.2%, p < 0.01) and conduit strains 7.6 vs. 9.0%, p < 0.01) but no differences in ventricular function or myocardial damage. They were at higher risk of MACE than non-diabetic patients (10.2% vs. 5.8%, p < 0.01) with the majority of MACE occurring in patients with LVEF ≥ 35%. Whilst LVEF was an independent predictor of adverse events in non-diabetic patients (p = 0.04 on multivariable analysis), LV GLS as well as LA strain emerged as independent predictors of poor prognosis in patients with diabetes (p < 0.02 on multivariable analysis). Considering patients with diabetes and LVEF ≥35% (n = 237), GLS and LA reservoir strain below median were significantly associated with higher 12-month event rates. Conclusions In patients with diabetes, LA and LV longitudinal strain permit optimized risk assessment early after reperfused AMI with incremental prognostic value over and above LVEF.