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Background Angiotensin converting enzyme-2 (ACE2) is an analogue of the ACE that cleaves Angiotensin II to Angiotensin 1-7, a peptide with vasodilatory properties. Previous studies showed increased ACE2 activity among patients with chronic heart failure. ACE2 activity has been shown to correlate with the NYHA functional class in this setting, suggesting a compensatory role in advanced heart failure. The relationship between ACE2 activity and myocardial function in patients with ST-elevation acute myocardial infarction (STEMI) remains unknown.

Background The presence of microvascular obstruction (MO) on delayed enhanced cardiac magnetic resonance (DECMR) imaging is associated with adverse remodeling and poor prognosis after STEMI. Identifying which patients that may develop MO prior to undergoing acute mechanical reperfusion maybe important in managing patients for more direct interventions. We sought to evaluate clinical predictors of MO as depicted by DECMR. Methods We included 255 patients with their first STEMI reperfused with primary percutaneous intervention. A standard DE-CMR was performed acutely at a mean of 3.9±2.0 days after admission. Clinical risk factors, time to reperfusion as well as angiographic variables were prospectively collected. The angiographic area at risk and the infarct size as a % of the left ventricle (LV) were computed. The number of segments with MO, defined as an area of hypoenhancement surrounded by delayed enhancement on DE-CMR, were summed to calculate MO extent.

Methods A standard Contrast-enhanced Cardiac Magnetic Resonance (ce-CMR) was performed pre-implantation of CRT device in 78 cardiac heart failure patients (64±11 years) with ischemic and non-ischemic dilated cardiomyopathy. Systolic function was assessed by cine imaging. Myocardial scar was characterized by a standard 2D segmented gradient echo inversion-recovery sequence applied in sequential short axis slices. Total scar was expressed as percentage of LV mass and the core and border zone as percentage of total scar). Patients were followed every 6 months to look for appropriate ICD therapy episodes. Results During a mean follow up of 25 months (percentile 25 th 75 th =15-34 months), appropriate therapy of ICD devices occurred in 11.5% of patients. The analysis showed that the percentage of total scar was a strong predictor of VA (ventricular fibrillation or ventricular tachycardia) needing ICD therapy (HR 1.096 [1.053 to 1.143], p