Prognostic Factors Associated With Early Recovery From Veno-Arterial Extracorporeal Membrane Oxygenation Support in Patients With Fulminant Myocarditis

Abstract

Background: Fulminant myocarditis is life-threatening and often requires mechanical circulatory support. Predicting its clinical course is crucial, yet data on early recovery predictors, particularly with veno-arterial extracorporeal membrane oxygenation, remain lacking.

Methods and results: We aimed to identify prognostic factors of early recovery in fulminant myocarditis requiring veno-arterial extracorporeal membrane oxygenation by retrospective analysis of a nationwide registry in Japan. Early recovery was defined as successful weaning from mechanical circulatory support within 7 days and discharge without heart transplantation or long-term mechanical circulatory support. A total of 343 patients were analyzed; 71 were classified as early recovery and 272 as nonearly recovery. The early recovery group was significantly younger, had higher white blood cell counts, and lower creatine kinase-myocardial band level than the nonearly recovery group. To enhance clinical interpretability, we dichotomized continuous variables using optimal cutoff values derived from the Youden index. Multivariable logistic regression analysis showed the independent factors of early recovery were age ≤40 years (odds ratio [OR], 3.25), white blood cell count ≥11 000/μL (OR, 3.10), and creatine kinase-myocardial band ≤61 U/L (OR, 2.46), and if all conditions were fulfilled, the early recovery rate increased to 61.5%. Additionally, although not statistically significant, the number of rehospitalization with cardiovascular causes, death, or heart transplantation at 1-year follow-up was higher in the nonearly recovery group.

Conclusions: Our study suggested younger patients who have a strong inflammatory response but less myocardial damage on admission could recover earlier. Conversely, in cases where mechanical circulatory support duration is prolonged, careful monitoring is required for prolonged left ventricular dysfunction and subsequent prognosis.

Registration: URL: https://www.umin.ac.jp/; Unique identifier: UMIN000039763.

Keywords: fulminant myocarditis; inflammation; veno‐arterial extracorporeal membrane oxygenation.

Figure 1. Patient enrollment and assignment flowchart of the Japanese Registry of Fulminant Myocarditis.

ESC indicates European Society of Cardiology; FM, fulminant myocarditis; ISFC, International Society and Federation of Cardiology; JCS, Japanese Circulation Society; JROAD‐DPC, Japanese Registry of All Cardiac and Vascular Diseases‐Diagnosis Procedure Combination; MCS, mechanical circulatory support; VA‐ECMO, veno‐arterial extracorporeal membrane oxygenation; and WHO, World Health Organization.

Figure 2. Proportion of early recovery based on number of prognostic factors fulfilled.

The relationship between the number of prognostic factors fulfilled and the proportion of early recovery was evaluated. The proportion of early recovery increased as more prognostic factors were fulfilled. Early recovery was defined as patients who were successfully weaned off MCS within 7 days from MCS deployment by the improvement of cardiac function and discharged without heart transplantation or long‐term MCS. MCS indicates mechanical circulatory support.

Figure 3. Comparison of receiver‐operating characteristic curves for individual factors and their combination.

This figure compares receiver‐operating characteristic curves of individual factors (age, WBC, CK‐MB) and their combination. The combined model shows the highest AUC (0.72), indicating improved predictive accuracy when factors are combined. AUC indicates area under the curve; CK‐MB, creatine kinase‐myocardial band; and WBC, white blood cell.

Figure 4. Relationship between MCS duration and odds ratio of LVEF ≥50% at discharge.

Odds ratios for achieving LVEF ≥50% at discharge were calculated for each MCS duration group, showing a decreasing trend as MCS duration prolonged. LVEF indicates left ventricular ejection fraction; and MCS, mechanical circulatory support.