Prognostic Nutritional Index in Risk of Mortality Following Fulminant Myocarditis

Background: Fulminant myocarditis (FM) is an acute fatal inflammation disease, but its chronic phase is unclear. A Japanese nationwide registry evaluated the long-term mortality in FM patients using a prognostic nutritional index (PNI). Methods and Results: The retrospective cohort study included patients with clinically suspected or histologically proven FM available for PNI. PNI was assessed on admission and at discharge. We divided patients into two groups based on PNI at discharge (PNI ≤40 or PNI >40) and analyzed the change in PNI and mortality between the groups. Of 323 patients (the median [first-third quartiles] age of this cohort was 50 [37-64] years, and 143 [44%] were female), PNI ≤40 at discharge was in 99 (31%) patients. The median PNI in all patients increased from 41 (36-46) on admission to 43 (39-48) at discharge (P<0.0001). Patients with PNI ≤40 had a lower event-free rate of death or rehospitalization with cardiovascular causes than those with PNI >40 (log-rank P=0.0001). When the PNI at discharge, age, sex, left ventricular ejection fraction, and Barthel index were evaluated in a multivariable Cox regression analysis, the PNI had an independent association with the death or rehospitalization with cardiovascular causes (hazard ratio, 0.95 [95% confidence interval, 0.91-0.99]; P=0.0289). Conclusions: One-third of FM patients with low PNI at discharge had a higher risk of mortality than those with high PNI in the chronic phase. This study provokes clinical insight into the phenotype of chronic inflammation in FM and optimal follow-up management with low PNI.