Registry-based estimation of cardiac event-free survival in congenital heart disease complicated by pulmonary hypertension: A nationwide registry study from Japan.

Background: Pulmonary hypertension (PH) is a major determinant of outcomes in congenital heart disease (CHD), yet tools for individualized prognostic estimation are limited. This study aimed to develop an exploratory, clinically oriented prediction model for estimating cardiac event-free survival in patients with CHD-PH. Methods: Data from the nationwide Japanese Association of CHD-PH Registry were analyzed in a retrospective cohort derived from a prospectively maintained registry. Cardiac event-free survival was evaluated using Cox proportional hazards models incorporating prespecified, routinely available clinical and hemodynamic variables. Cardiac events were defined as death, transplantation, clinical worsening requiring treatment escalation, or PH-related hospitalization. Results: A total of 224 patients were included, and 23 experienced 29 cardiac events during a median follow-up of 1.5 years. These included 7 cardiovascular deaths, 1 lung transplantation, and 1 atrial septostomy, 13 cases of clinical worsening. The cardiac event-free survival rates were 94.0% and 86.2% at 1 and 2 years, respectively. In multivariable analysis, trisomy 21 (hazard ratio [HR] 3.63), elevated pulmonary vascular resistance index (PVRI; HR 13.2), and elevated central venous pressure (CVP; HR 3.27) were associated with worse outcomes. These associations were consistent in sensitivity and subgroup analyses. Model-based estimates demonstrated risk gradients across clinically relevant profiles and were incorporated into a prototype prediction tool. Conclusions: An exploratory pragmatic prediction model for cardiac event-free survival in CHD-PH was developed using nationwide registry data. These findings support the feasibility of a registry-based prognostic framework; however, further validation is required before clinical application.