Abstract
Outcomes on children with myocarditis listed for heart transplantation (HT) is sparse and conflicting. Our study aims to determine if this population of listed patients have better outcomes pre- and post-HT in the current era given the advent of ventricular assist devices (VADs).
We queried the Pediatric Heart Transplant Society (PHTS) database from 1993-2019 to identify patients with myocarditis and dilated cardiomyopathy (DCM). Patients were divided into two eras: earlier (1993-2008) and current era (2009-2019). Clinical characteristics were compared. Kaplan-Meier method with log-rank test and adjusted using multiphase parametric hazard modeling to examine outcomes.
During the study period, of the 9755 patients listed for HT, 323 (3%) had myocarditis and 3279 (34%) DCM. A higher proportion of myocarditis patients in the current era were status 1A (85% vs 58% earlier era), have lower AST (mean 195 vs. 560 U/L), ALT (mean 109 vs. 277 U/L) and higher eGFR (mean 96 vs. 75 ml/min/1.73m2) (p<0.05 for all) at listing. VAD use was higher in myocarditis patients in the current era at listing (28 vs. 8%; p<0.001) and at time of HT (38 vs. 12%; p<0.001). Waitlist and post-transplant survival has not improved for patients with myocarditis over time (Figure a-b). In the current era, 5 year survival post-HT was higher in patients with DCM vs. myocarditis (88 vs. 79.5%, p=0.058). On multivariate analysis, myocarditis patients have increased post-HT mortality [HR 6.9, 95% CI 3.0-15.6; p<0.0001].
Patients with myocarditis in the current era have better renal and hepatic function at listing and increased VAD use at listing and at HT. Overtime, however, there have been no improvements in waitlist or post-transplant outcomes for patients with myocarditis and post-transplant survival continues to be worse in patients with myocarditis compared to those with DCM.