Survival and Left Ventricular Function Changes in Fulminant Versus Non-Fulminant Acute Myocarditis
Background—Previous reports have suggested that despite their dramatic presentation, patients with fulminant myocarditis (FM) might have better outcome than those with acute non-fulminant myocarditis (NFM). In this retrospective study, we report outcome and changes in left ventricular ejection fraction (LVEF) in a large cohort of patients with FM compared with NFM.
Methods—The study population consists of 187 consecutive patients admitted between May 2001 and November 2016 with a diagnosis of acute myocarditis (onset of symptoms <1 month) of whom 55 required inotropes and/or mechanical circulatory support (FM) whilst the remaining 132 patients were hemodynamically stable (NFM). We also performed a sub-analysis in 130 adult patients with acute viral myocarditis and viral prodrome within 2 weeks from the onset, which includes 34 FM vs. 96 NFM. Patients with giant-cell, eosinophilic myocarditis or cardiac sarcoidosis and subject <15 years of age were excluded from the latter sub-analysis.
Results—In the whole population (n=187) in-hospital death or heart transplantation (HTx) was 25.5% vs. 0% in FM vs. NFM, respectively (p<0.0001). Long-term HTx free survival at 9 years was lower in FM than NFM (64.5% vs. 100%, Log Rank p<0.0001). Despite greater improvement in LVEF during hospitalization in FM vs. NFM forms (median: 32%, interquartile: 20-40% vs. 3%, 0-10%, respectively, p<0.0001), the proportion of patients with LVEF<55% at last follow up was higher in FM vs. NFM (29% vs. 9%, Relative risk 3.32, 95% confidence interval: 1.45-7.64, p=0.003). Similar results regarding survival and changes in LVEF in FM vs. NFM were observed in the subgroup (n=130) with viral myocarditis. None of the patients with NFM and LVEF≥55% at discharge had a significant decrease in LVEF at follow up.
Conclusions—Patients with FM have an increased mortality and need for HTx, compared to those with NFM. From a functional viewpoint, FM patients have a more severely impaired LVEF at admission that, despite steep improvement during hospitalization, remains lower than that in patients with NFM at long term follow up. These findings hold true also considering only the viral forms and are at odd with previous studies showing better prognosis in FM.
- Received February 28, 2017.
- Revision received April 12, 2017.
- Accepted May 24, 2017.