Abstract 4134777: Predictive Factors for Early Recovery from Mechanical Circulatory Support in Patients with Fulminant Myocarditis

Background: Fulminant myocarditis (FM) requiring veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is fatal and has a complicated clinical course. In such FM cases, predicting which cases are likely to achieve early recovery is crucial for developing acute-phase treatment strategies. We aimed to examine the factors predicting early recovery in fatal cases of FM requiring VA-ECMO using multicenter cohort of patients with myocarditis. Methods: We retrospectively analysed 343 patients with FM requiring VA-ECMO between April 2012 and March 2017. The early recovery group was defined as patients who were successfully weaned off mechanical circulatory support (MCS) within 7 days from MCS deployment and discharged with favorable outcomes. We divided patients into early recovery group and non-early recovery group. Predictors of early recovery were investigated by performing a multivariate analysis, including significant variables ( p <0.05) identified from a univariate analysis of baseline clinical parameters and meaningful variables from previous reports. Results: Among the eligible patients, 71 were assigned to the early recovery group, whereas 272 were assigned to the non-early recovery group. The baseline patient demographics showed the early recovery group was significantly younger (45 [30-63] years vs. 56.5 [40-67] years, p =0.003), had higher WBC counts (11,400 [8,500-16,000] /μL vs. 9,900 [7,162.5-13,297.5] /μL, p =0.009), and had lower CK-MB levels (38.5 [18.0-75.3] U/L vs. 73.0 [42.5-137.0] U/L, p <0.001), than the non-early recovery group. In the histological diagnosis, the proportions of lymphocytic and eosinophilic myocarditis were similar between the two groups, whereas the proportions of giant cell myocarditis tended to be higher in the non-early recovery group. Multivariate analysis showed the independent predictors of early recovery were age ≤40 years (OR: 3.25; 95% CI: 1.42-7.44), WBC ≥ 11,000 /μL (OR: 3.10; 95% CI: 1.39-6.86) and CK-MB ≤ 61 U/L (OR: 2.46; 95% CI: 1.06-5.72), and if all conditions were fulfilled, the early recovery rate increased to 61.5%. Conclusions: Early recovery group had higher inflammatory parameter levels but lower myocardial damage marker levels on admission in addition to age ≤40 years, suggesting that patients having a strong acute-phase inflammatory response with a lower degree of myocardial damage, could recover earlier.