Long-Term Incremental Prognostic Value of Cardiovascular Magnetic Resonance After ST-Segment Elevation Myocardial Infarction: A Study of the Collaborative Registry on CMR in STEMI.

OBJECTIVES: This study sought to investigate whether early post-infarction cardiac magnetic resonance (CMR) parameters provide additional long-term prognostic value beyond traditional outcome predictors in ST-segment elevation myocardial infarction (STEMI) patients. BACKGROUND: Long-term prognostic significance of CMR in STEMI patients has not been assessed yet. METHODS: This was a longitudinal study from a multicenter registry that prospectively included STEMI patients undergoing CMR after infarction. Between May 2003 and August 2015, 810 revascularized STEMI patients were included. CMR was performed at a median of 4 days after STEMI. Infarct size, microvascular obstruction (MVO), and left ventricular (LV) volumes and function were measured. Primary endpoint was a composite of all death and decompensated heart failure (HF). RESULTS: During median follow-up of 5.5 years (range 1.0 to 13.1 years), primary endpoint occurred in 99 patients (39 deaths and 60 HF hospitalization). MVO was a strong predictor of the composite endpoint after correction for important clinical, CMR, and angiographic parameters, including age, LV systolic function, and infarct size. The independent prognostic value of MVO was confirmed in all multivariate models irrespective of whether it was included as a dichotomous (presence of MVO, hazard ratio [HR]: 1.985 to 1.995), continuous (MVO extent as % LV, HR: 1.095 to 1.097), or optimal cutoff value (MVO extent ≥2.6% of LV; HR: 3.185 to 3.199; p < 0.05 for all). MVO extent ≥2.6% of LV was a strong independent predictor of all death (HR: 2.055; 95% confidence interval: 1.076 to 3.925; p = 0.029) and HF hospitalization (HR: 5.999; 95% confidence interval: 3.251 to 11.069; p < 0.001). Finally, MVO extent ≥2.6% of LV provided incremental prognostic value over traditional outcome predictors (net reclassification improvement index: 0.16 to 0.30; p < 0.05 for all models). CONCLUSIONS: Early post-infarction CMR-based MVO is a strong independent prognosticator in revascularized STEMI patients. Remarkably, MVO extent ≥2.6% of LV improved long-term risk stratification over traditional outcome predictors.

[Coronary artery ectasia: etiopathogenesis, diagnosis and treatment]. / Ectasia delle arterie coronarie: eziopatogenesi, diagnosi e trattamento.

Coronary ectasia is a dilation of coronary arteries, angiographically defined if the diameter of the artery is ≥ 1.5 times greater than that of the intact adjacent vascular segment. An association has been found between coronary artery ectasia and a broad spectrum of different diseases, first of all atherosclerotic coronary artery disease. The mechanisms that determine the abnormal dilatation of the vascular lumen and the etiology of coronary artery ectasia are still poorly understood. Various hypotheses have been formulated over the time, the most accredited between these recognizes as main responsible an uncontrolled activity of a particular family of enzymes that degrade the extracellular matrix, the metalloproteinases. This exaggerated activity can be due to an increase in the absolute sense of these enzymes and/or a reduction in the levels of their natural specific inhibitors. Coronary ectasia may have a variable clinical presentation. It is often an occasional finding detected at coronary angiography or following the occurrence of atypical chest pain, stable angina or even acute coronary syndrome. The frequent coexistence of coronary artery ectasia and atherosclerotic coronary artery disease and their common histopathological features have led to hypothesize that coronary ectasia may represent a variant of atherosclerosis. However, some significant differences between these two diseases leave open the hypothesis that coronary artery ectasia may be a pathological entity per se.