Outcomes and clinical impact of early endomyocardial biopsy in patients with fulminant myocarditis.

While endomyocardial biopsy (EMB) is recommended in adult patients with fulminant myocarditis (FM), the clinical impact of its timing is still unclear. To assess if early EMB is associated with better prognosis in patients admitted in intensive care units for a FM. Data were collected from 419 adult patients with clinically suspected FM admitted to intensive care units (ICUs) across 36 tertiary centers in 15 countries worldwide. Histology or cardiac magnetic resonance imaging confirmed the diagnosis in 306 (73%) cases. The primary outcome of survival free of heart transplantation (HTx) or left ventricular assist device (LVAD) at one year was specifically compared between patients with early EMB (within two days after ICU admission, n = 103) and delayed EMB (n = 80). A propensity score-weighted analysis was done to control for confounders. Median age on admission was 40 [29–52] years and 322 (77%) patients received temporary mechanical circulatory support. 273 (65%) patients survived without HTx/LVAD. The primary outcome was significantly different between patients with early and delayed EMB (70% vs. 49%, P = 0.004). After propensity score weighting, the early EMB group still significantly differed from the delayed EMB group in terms of survival free of HTx/LVAD (63% vs. 40%, P = 0.021). Moreover, early EMB was independently associated with a lower rate of death or HTx/LVAD at one year (odds ratio of 0.44; 95% confidence of interval: 0.22–0.86; P = 0.016). EMB should be broadly and promptly used in patients admitted to ICU for clinically suspected FM. [ABSTRACT FROM AUTHOR]