Influence of Early Endomyocardial Biopsy on the Treatment and Prognosis in Fulminant Myocarditis
- 1Tokyo Medical University
Abstract
BACKGROUNDBecause of the high mortality rate associated with fulminant myocarditis (FM), there is limited evidence regarding the prognostic efficacy of endomyocardial biopsy (EMB). In this study, we aimed to evaluate the influence of EMB in the early phase after admission on treatment and prognosis in FM using a large-scale nationwide registry in Japan.
METHODSPatients with FM who required catecholamine or mechanical circulatory support between 2012 and 2017 from 235 hospitals across Japan were included. The primary outcome of death or heart transplantation within 90 days according to performance of early EMB were determined using Kaplan-Meier and Cox regression analyses. Factors associated with performance of early EMB, and subsequent medical treatment were analyzed.
RESULTSThe median age of 736 patients with clinical FM was 56 years, and 407 patients (55%) received EMB. Most EMB (89%) were performed during the early phase (within 5 days of admission) and 63% were performed on the first day of admission. The prognosis of FM patients who underwent EMB was more favorable than that of those who did not based on the landmark analysis (log-rank test, P=0.04). Factor analysis demonstrated that FM patients who underwent EMB had a lower left ventricular ejection fraction, higher incidence of cardiogenic shock on admission, and higher rate of early mechanical circulatory support, as well as early initiation of corticosteroids and guideline-directed medical therapy (GDMT) for heart failure. Absence of any GDMT was associated with a less favorable prognosis on multivariate analysis (hazard ratio, 4.34 [95% CI, 3.14-6.01]; P<0.0001).
CONCLUSIONSAlthough performing EMB in the early phase after admission depends on disease severity in FM patients, it is associated with early initiation of advanced medical treatment and may contribute to improving the prognosis.
WHAT IS NEW?O_LIFulminant myocarditis patients who did not undergo endomyocardial biopsy had a higher mortality rate than those who underwent endomyocardial biopsy after considering immoral time bias associated with the performance of early endomyocardial biopsy. C_LIO_LIEarly endomyocardial biopsy was associated with early initiation of mechanical circulatory support, early administration of corticosteroids and immunoglobulins and a higher rate of administration of guideline-directed medical therapy for heart failure during hospitalization. C_LIO_LIIn the prognostic factor analysis, guideline-directed medical therapy for heart failure during hospitalization was strongly associated with a favorable prognosis of patients with fulminant myocarditis. C_LI
WHAT ARE THE CLINICAL IMPLICATIONS?O_LIThere is limited evidence regarding the influence of endomyocardial biopsy in the early phase after admission on the treatment and prognosis in patients with fulminant myocarditis. Our results provide valuable insights indicating that combination of accurate histological diagnosis by endomyocardial biopsy in the early phase and appropriate cardioprotective therapy leads to a favorable prognosis of patients with fulminant myocarditis. C_LI
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BibTeX
@misc{takei2026influence,
title = {{Influence of Early Endomyocardial Biopsy on the Treatment and Prognosis in Fulminant Myocarditis}},
author = {Y. Takei and T. Chikamori and K. Kanaoka and K. Onoue and K. Satomi and Y. Saito},
howpublished = {medRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.24.26363980},
url = {https://www.medrxiv.org/content/10.64898/2026.09.24.26363980v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Influence of Early Endomyocardial Biopsy on the Treatment and Prognosis in Fulminant Myocarditis
AU - Y. Takei
AU - T. Chikamori
AU - K. Kanaoka
AU - K. Onoue
AU - K. Satomi
AU - Y. Saito
PY - 2026
DA - 2026/09/24
PB - medRxiv
DO - 10.64898/2026.09.24.26363980
UR - https://www.medrxiv.org/content/10.64898/2026.09.24.26363980v1
AB - BACKGROUNDBecause of the high mortality rate associated with fulminant myocarditis (FM), there is limited evidence regarding the prognostic efficacy of endomyocardial biopsy (EMB). In this study, we aimed to evaluate the influence of EMB in the early phase after admission on treatment and prognosis in FM using a large-scale nationwide registry in Japan. METHODSPatients with FM who required catecholamine or mechanical circulatory support between 2012 and 2017 from 235 hospitals across Japan were included. The primary outcome of death or heart transplantation within 90 days according to performance of early EMB were determined using Kaplan-Meier and Cox regression analyses. Factors associated with performance of early EMB, and subsequent medical treatment were analyzed. RESULTSThe median age of 736 patients with clinical FM was 56 years, and 407 patients (55%) received EMB. Most EMB (89%) were performed during the early phase (within 5 days of admission) and 63% were performed on the first day of admission. The prognosis of FM patients who underwent EMB was more favorable than that of those who did not based on the landmark analysis (log-rank test, P=0.04). Factor analysis demonstrated that FM patients who underwent EMB had a lower left ventricular ejection fraction, higher incidence of cardiogenic shock on admission, and higher rate of early mechanical circulatory support, as well as early initiation of corticosteroids and guideline-directed medical therapy (GDMT) for heart failure. Absence of any GDMT was associated with a less favorable prognosis on multivariate analysis (hazard ratio, 4.34 [95% CI, 3.14-6.01]; P<0.0001). CONCLUSIONSAlthough performing EMB in the early phase after admission depends on disease severity in FM patients, it is associated with early initiation of advanced medical treatment and may contribute to improving the prognosis. WHAT IS NEW?O_LIFulminant myocarditis patients who did not undergo endomyocardial biopsy had a higher mortality rate than those who underwent endomyocardial biopsy after considering immoral time bias associated with the performance of early endomyocardial biopsy. C_LIO_LIEarly endomyocardial biopsy was associated with early initiation of mechanical circulatory support, early administration of corticosteroids and immunoglobulins and a higher rate of administration of guideline-directed medical therapy for heart failure during hospitalization. C_LIO_LIIn the prognostic factor analysis, guideline-directed medical therapy for heart failure during hospitalization was strongly associated with a favorable prognosis of patients with fulminant myocarditis. C_LI WHAT ARE THE CLINICAL IMPLICATIONS?O_LIThere is limited evidence regarding the influence of endomyocardial biopsy in the early phase after admission on the treatment and prognosis in patients with fulminant myocarditis. Our results provide valuable insights indicating that combination of accurate histological diagnosis by endomyocardial biopsy in the early phase and appropriate cardioprotective therapy leads to a favorable prognosis of patients with fulminant myocarditis. C_LI
ER -