Myocardial fibrosis predicts adverse outcome after MitraClip implantation.

BACKGROUND: High-risk patients with mitral regurgitation (MR) may be treated by a percutaneous mitral valve repair with the MitraClip, but identification of patients who may benefit remains difficult. We aimed to determine whether myocardial fibrosis predicts outcome in MR patients undergoing MitraClip implantation and is beneficial in clinical decision making. METHODS: Preprocedural to the MitraClip implantation, myocardial fibrosis was analyzed with cardiovascular magnetic resonance (CMR) through late gadolinium enhancement. The CMR data were core-lab adjudicated measured before the MitraClip implantation. Adverse outcome was defined as New York Heart Association (NYHA) class III or IV after 1 month or death within 1 month after the MitraClip implantation. RESULTS: In total, 23 patients underwent preprocedural CMR, mean age 80 ± 9 years, 45% male, 64% atrial fibrillation and 73% NYHA class III or IV at baseline. Myocardial fibrosis was present in 55% of the patients with degenerative MR and in 64% of the patients with functional MR. An adverse outcome occurred in 69% of the patients with myocardial fibrosis and in 11% of the patients without myocardial fibrosis (P = 0.01). CONCLUSIONS: Our hypothesis-generating study showed that the presence of myocardial fibrosis predicts adverse outcome in patients undergoing MitraClip implantation. After confirmation with larger sample size, identification of myocardial fibrosis might contribute to assess prognosis and to clinical decision making.

The hypertrabeculated (noncompacted) left ventricle is different from the ventricle of embryos and ectothermic vertebrates.

Ventricular hypertrabeculation (noncompaction) is a poorly characterized condition associated with heart failure. The condition is widely assumed to be the retention of the trabeculated ventricular design of the embryo and ectothermic (cold-blooded) vertebrates. This assumption appears simplistic and counterfactual. Here, we measured a set of anatomical parameters in hypertrabeculation in man and in the ventricles of embryos and animals. We compared humans with left ventricular hypertrabeculation (N=21) with humans with structurally normal left ventricles (N=54). We measured ejection fraction and ventricular trabeculation using cardiovascular MRI. Ventricular trabeculation was further measured in series of embryonic human and 9 animal species, and in hearts of 15 adult animal species using MRI, CT, or histology. In human, hypertrabeculated left ventricles were significantly different from structurally normal left ventricles by all structural measures and ejection fraction. They were far less trabeculated than human embryonic hearts (15-40% trabeculated volume versus 55-80%). Early in development all vertebrate embryos acquired a ventricle with approximately 80% trabeculations, but only ectotherms retained the 80% trabeculation throughout development. Endothermic (warm-blooded) animals including human slowly matured in fetal and postnatal stages towards ventricles with little trabeculations, generally less than 30%. Further, the trabeculations of all embryos and adult ectotherms were very thin, less than 50 µm wide, whereas the trabeculations in adult endotherms and in the setting of hypertrabeculation were wider by orders of magnitude. It is concluded in contrast to a prevailing assumption, the hypertrabeculated left ventricle is not like the ventricle of the embryo or of adult ectotherms. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.

CT angiography vs echocardiography for detection of cardiac thrombi in ischemic stroke: a systematic review and meta-analysis.

BACKGROUND AND PURPOSE: Cardiac thrombi are an important cause of embolic stroke. We studied the diagnostic yield and diagnostic accuracy of cardiac CT angiography (CTA) compared to echocardiography for detection of cardiac thrombi in ischemic stroke patients. METHODS: We performed a systematic review and meta-analysis of the literature on cardiac CTA versus echocardiography for detection of cardiac thrombi in ischemic stroke patients. We included studies (N ≥ 20) in which both cardiac CTA (index test) and echocardiography (reference test) were performed and data on cardiac thrombi were reported. Results were stratified for type of echocardiography: transesophageal (TEE) vs transthoracic (TTE). RESULTS: Out of 1530 studies, 14 were included (all single center cohort studies), with data on 1568 patients. Mean age varied between 52 and 69 years per study and 66% were men. Reported time intervals ranged from 0 to 21 days between stroke and first test, and from 0 to 199 days between tests. In ten studies that compared CTA to TEE, CTA detected cardiac thrombi in 87/1385 (6.3%) patients versus 68/1385 (4.9%) on TEE (p < 0.001). In four studies comparing CTA to TTE, CTA detected thrombi in 23/183 (12.5%) patients versus 12/183 (6.6%) on TTE (p = 0.010). Pooled sensitivity and specificity of CTA versus TEE were 86.0% (95% CI 65.6-95.2) and 97.4% (95% CI 95.0-98.7), respectively. CONCLUSIONS: CTA may be a promising alternative to echocardiography for detection of cardiac thrombi in patients with ischemic stroke, especially now that CTA is standard care for patient selection for endovascular treatment. However, studies were too heterogeneous and of insufficient methodological quality to draw firm conclusions. Large, prospective studies on this topic are warranted.