Background: An unequivocal diagnosis of myocarditis and cardiac virus persistence is based on histological, immunohistological, and molecular biological analyses of endomyocardial biopsies (EMBs). Biopsy-based diagnosis of myocarditis has become increasingly important because recent studies have demonstrated the beneficial effects of biopsy-based causal treatment strategies (immunosuppressive or antiviral). Because the risks of major complications caused by EMB procedures have not yet been well defined, we evaluated the incidence of major and minor complications of right ventricular EMB procedures in this retrospective and prospective single-center study.
Methods and results: With the use of a modified Cordis bioptome, 1919 patients underwent 2505 EMB procedures retrospectively over a 9-year period (January 1995 to December 2003), and 496 patients underwent 543 EMB procedures prospectively between January 2004 and December 2005. A total of 2415 patients had 3048 EMB procedures via the right femoral vein approach under biplane fluoroscopic control to evaluate unexplained left ventricular dysfunction (retrospective left ventricular ejection fraction, 49.8+/-18.8%; prospective, 48.8+/-19.7%) after exclusion of secondary causes. During each EMB procedure, an average of 8.2+/-0.8 EMBs were obtained retrospectively and 10.1+/-0.6 specimens prospectively for a total of 26 025 specimens. No patient died or required emergency cardiac surgery. Other major complications like cardiac tamponade requiring pericardiocentesis or complete atrioventricular block requiring permanent pacing were very rare: 0.12% in the retrospective study and 0% in the prospective study. Minor complications such as pericardial effusion, conduction abnormalities, or arrhythmias occurred in 0.20% of the EMB procedures in the retrospective study and 5.5% in the prospective study.
Conclusions: The EMB procedure via the femoral vein approach under fluoroscopic guidance has a very low complication rate when performed by experienced operators.