Mitral Valve Intervention, Pulmonary Hypertension, and Survival in 219 Shone's Syndrome Patients

Relationships between pulmonary hypertension (PHTN), mitral valve intervention (MVI), and death among patients with Shone's syndrome (SS) are unclear. Our recent data suggested temporal progression of MV disease and early survival benefit with MVI at initial operation. In this expanded cohort, we characterized trajectory and impact of PHTN on survival, and its relationship to MVI(s).

Record review of 219 SS patients undergoing operation at our quaternary center between 1956-2022, 111 of whom were pediatric (< age 18 yrs.). Patients were determined to have PHTN using a time-defined hierarchical algorithm consisting of cardiac catheterization data, echocardiographic parameters, pulmonary vasodilator therapy, and record-verified PHTN diagnosis. Analysis includes risk-adjusted predicted survival and freedom from PHTN curves stratified by MVI timing.

Among 219 patients, 92 (43%) had mitral valve stenosis on presentation, with mean gradients of 3.5 (IQR 4.7). Sixty patients had at least one MVI (15 (6%) and 8 (3%) had 3 or more). Median follow-up was 19 years (IQR 29) with 18 (8%) deaths. Ninety-three (42%) patients developed PHTN, with 50% and 25% freedom from PHTN at 37 and 51 years from presentation. PHTN was strongly associated with death (p <0.001). In unadjusted analyses, MVI, even if successive, delayed the onset of PHTN at 10 years and improved survival (p<0.001). However, this protective effect was lost after risk-adjustment.

PHTN development in SS is progressive and mirrors the survival curve, suggesting it is a major mortality risk-factor. Salutary effects of early and/or successive MVI are reduced after risk-adjustment.