Abstract 1936: Benefits of Percutaneous Pulmonary Valve Implantation are Sustained after 1 year
Background- Percutaneous pulmonary valve implantation (PPVI) is increasingly considered for the treatment of right ventricular outflow tract (RVOT) dysfunction in order to prolong conduit lifespan, thereby delaying and possibly avoiding the need for further surgery. We have previously demonstrated early clinical benefit following this procedure and now investigate whether further improvement occurs within the first year.
Methods and Results- We reviewed the outcome of 61 patients, from a total of 102 implanted with the current PPVI device, who had reached one-year follow-up. We compared clinical outcome, objective exercise capacity, echocardiographic and magnetic resonance (MR) parameters at 1 year with those recorded early after the procedure. There was no mortality. 7/61 patients were explanted within the first year [stent fracture(1), residual obstruction(2), valve instability(2), coronary artery compression (1), hemolysis(1)] whilst 4 underwent 2nd PPVI [stent fracture(3), residual obstruction(1)]. In the remainder, the reduction in RVOT gradient seen on echo immediately following PPVI was sustained at one year (pre 3.7 ± 0.8 m/s, post 3.0 ± 0.7 m/s, one year 3.0 ± 0.8 m/s, ANOVA, t-test p = 0.75) and MR showed a sustained reduction in pulmonary regurgitant fraction (pre 20 ± 19 %, post 3 ± 6 %, one year 5 ± 8 %, ANOVA, t-test p = 0.38). On MR, RV end-diastolic volume (pre 96 ± 28 mL/m2, post 84 ± 29 mL/m2, one year 86 ± 22mL/m2, ANOVA, t-test p = 0.57) and RV ejection fraction (pre 53 ± 12%, %, post 56 ± 12%, one year 57 ± 10%, P = 0.51) showed no further change, whilst the early improvement in cardiopulmonary exercise capacity previously demonstrated, though sustained at one year, did not improve further (VO2max pre 23.5 ± 7.7mL/kg/min, post 25.2 ± 7.3 mL/kg/min, one year 25.8 ± 8.3mL/kg/min, ANOVA, t-test p = 0.47).
Conclusions- The hemodynamic benefits of PPVI are sustained at one year, however, further functional improvement could not be demonstrated; this suggests limited potential for myocardial remodelling following initial relief of adverse loading conditions. These findings support an increasing inclination for early intervention in this population before RV dysfunction becomes irreversible.