Evaluation of the role of endomyocardial biopsy in 851 patients with unexplained heart failure from 2000-2009.

BACKGROUND Endomyocardial biopsy (EMB) is often considered when the pathogenesis of heart failure cannot be determined by noninvasive testing. Uncertainty remains about the diagnostic and clinical use of EMB in various clinical scenarios. METHODS AND RESULTS We examined the characteristics of a cohort of patients with unexplained heart failure who underwent EMB at a tertiary care medical center. We categorized each patient into a clinical scenario as outlined by the 2007 AHA/ACC/ESC guidelines and determined the number of times EMB provided a diagnosis or altered the clinical course. A total of 851 patients underwent EMB from 2000-2009. Overall, 25.5% of EMBs provided a diagnosis and 22.7% of EMBs changed clinical course. Heart failure associated with unexplained restrictive cardiomyopathy was the most common clinical scenario, comprising 33.6% (286/851) of EMBs, and 84 (29.4%) of these EMBs were diagnostic. EMB for unexplained heart failure of <2 weeks duration had a diagnostic yield at 35% (39/109). There were 4 uncommon scenarios where EMB had a high diagnostic and clinical yield. There were 16 complications for an overall rate of 1.9%. CONCLUSIONS We confirm that EMB is useful in acute onset unexplained cardiomyopathy. We demonstrate a role for EMB in suspected infiltrative disease and in the management of rare clinical scenarios, such as suspected hypersensitivity myocarditis, anthracycline cardiomyopathy, cardiac tumors, and arrhythmogenic right ventricular dysplasia/cardiomyopathy. Our results suggest low use of EMB in chronic heart failure that responds to usual care.