Initial lactic acid as a predictor of mortality in acute fulminant myocarditis patients undergoing heart transplantation
I Kim, J Park, H J Lee, H Kim, J H Yang, J Hyun, H J P, H Y Kim, S R Kim, M N Kim, K H KimAbstract
Background
Fulminant myocarditis (FM) is a catastrophic condition frequently requiring extracorporeal membrane oxygenation (ECMO) and occasionally heart transplantation (HTPL). Data regarding outcomes after HTPL in FM are limited. Lactic acid is a known marker of tissue perfusion and prognostic indicator in cardiovascular diseases. This study evaluated the prognostic value of initial lactic acid in FM patients who underwent HTPL.
Methods
Clinical data were retrospectively collected from 8 centers in Korea (2001–2021). Among FM patients receiving ECMO, those who subsequently underwent HTPL were analyzed for 180-day mortality. Receiver operating characteristic (ROC) analysis identified the optimal cutoff value of initial lactic acid for predicting 180-day mortality, and Kaplan–Meier (KM) analysis compared survival between groups.
Results
Thirty-one patients underwent HTPL for FM (mean age 45 ± 14 years; 61% male). The cumulative 180-day mortality was 22.6%. ROC analysis demonstrated an AUC of 0.78 (p = 0.025), with an optimal cutoff of 3.75 mmol/L. Based on this threshold, 20 patients had lactate < 3.75 mmol/L and 11 had ≥ 3.75 mmol/L (mean 2.3 ± 0.9 vs 7.5 ± 3.5 mmol/L, p = 0.001). Baseline clinical, laboratory, and echocardiographic characteristics showed no significant differences between the two lactate groups. Patients with higher lactate exhibited significantly poorer survival (log-rank p = 0.012); Cox proportional hazards analysis revealed HR 6.31 (95% CI 1.22–32.8, p = 0.028).
Conclusion
Among FM patients requiring HTPL, overall mortality remained substantial. Elevated initial lactic acid (≥ 3.75 mmol/L) was independently associated with worse 180-day survival, underscoring its prognostic importance. Early lactate assessment may aid risk stratification and postoperative management in this critically ill population.For image description, please refer to the figure legend and surrounding text.