The usefulness of left ventricular endomyocardial biopsy in clinical decision making in patients with unexplained heart failure

Introduction: In recent years, the recommendations for an endomyocardial biopsy (EMB) were significantly extended. However, the proposed criteria are based on the consensus of experts and require further clinical trials. Aim: To present the results of our diagnostic and therapeutic management based on left ventricular EMB (LV-EMB) in patients with unexplained heart failure (HF). Material and methods: LV-EMBs were performed between August 2016 and March 2019. Bioptates analysis included histological, immunohistochemical and viral genome examinations. Patients meeting the inclusion criteria had additional immunosuppressive treatment. Results: LV-EMBs were performed in 30 patients. The mean +/- SD age was 38.9 +/- 7.6 years. About 75% of patients were in NYHA class III or IV, eight were in cardiogenic shock, and four required intra-aortic balloon pump support. Fourteen patients had myocarditis and four had a viral infection. In 9 patients, steroid therapy was implemented. During the mean +/- SD observational period of 10.5 +/- 8.1 months, all patients survived, and 11 had an ejection fraction (EF) of over 35%, of whom 6 (66%) were on additional immunosuppressive therapy and 5 (24%) on standard HF therapy (HR = 2.85; 95% CI: 0.86-9.36; p = 0.08). An increase of > 20 percentage points in the absolute EF was observed in 4 (44%) patients on steroid therapy and 3 (14%) on standard HF therapy (HR = 2.32; 95% CI: 0.51-10.39; p = 0.27). Conclusions: An LV-EMB performed by skilled physicians is a safe procedure, verifies the cardiac magnetic resonance results, and allows the use of additional therapeutic options in patients with unexplained HF.