Background-Endomyocardial biopsy (EMB) represents the gold standard for diagnosing myocarditis and nonischemic cardiomyopathies. This study focuses on the risk of complications and the respective diagnostic performance of left ventricular (LV), right ventricular (RV), or biventricular EMB in patients with suspected myocarditis and/or cardiomyopathy of unknown origin. Methods and Results-In this 2-center study, 755 patients with clinically suspected myocarditis (nϭ481) and/or cardiomyopathy of nonischemic origin including those with infiltrative or connective tissue disease (nϭ274) underwent either selective LV-EMB (nϭ265; 35.1%), selective RV-EMB (nϭ133; 17.6%), or biventricular EMB (nϭ357; 47.3%) after coronary angiography and exclusion of significant coronary artery disease. Cardiovascular magnetic resonance, including late gadolinium enhancement, imaging was performed in 540 patients (71.5%). The major complication rate for LV-EMB was 0.64% and for RV-EMB, 0.82%. Considering postprocedural pericardial effusion that occurred after biventricular EMB, the minor complication rate for LV-EMB varied between 0.64% to 2.89% and for RV-EMB, between 2.24% and 5.10%. Diagnostic EMB results were achieved significantly more often in those patients who underwent biventricular EMBs (79.3%) compared to those who underwent either selective LV-EMB or selective RV-EMB (67.3%; PϽ0.001). In patients with biventricular EMB, myocarditis was diagnosed in LV-EMB samples in 18.7% and in RV-EMB samples in 7.9% (Pϭ0.002) , and it was diagnosed in both ventricles in 73.4%. There were no differences in the number of positive LV-EMB, RV-EMB, or LV-and RV-EMB findings when related to the site of cardiovascular magnetic resonance-based late gadolinium enhancement. Conclusions-Both

Cardiovascular magnetic resonance imaging and EMB have good diagnostic performances as single techniques in patients with TnI-positive acute chest pain in the absence of CAD. The combined application of CMR and EMB yields a considerable diagnostic synergy by overcoming some limitations of CMR and EMB as individually applied techniques.

Background-Acute aortic intramural hematoma (IMH) is an important subgroup of aortic dissection, and controversy surrounds appropriate management. Methods and Results-Patients with acute aortic syndromes in the International Registry of Acute Aortic Dissection (1996 -2011) were evaluated to examine differences between patients (based on the initial imaging test) with IMH or classic dissection (AD