Progressive intermediate-term improvement in ventricular and atrioventricular interaction after transcatheter pulmonary valve replacement in patients with right ventricular outflow tract obstruction.

BACKGROUND: Relief of postoperative right ventricular outflow tract (RVOT) obstruction with transcatheter pulmonary valve replacement (TPVR) results in functional improvement in the short term which we investigated at baseline (BL), early follow-up (FU), and midterm FU after TPVR.

METHODS: Echocardiography and cardiopulmonary exercise testing were performed at BL and at early (median 6 months) and midterm FU (median 2.5years) after TPVR.

RESULTS: Patients with RVOT obstruction (n=22, median age 17years) were studied. The max RVOT Doppler gradient fell from BL to early FU (60±24 to 26±8mm Hg, P<.001). Left ventricular (LV) end-diastolic and stroke volume increased at early FU (both P<.001) without further change, whereas LV ejection fraction improved throughout FU (P<.001). LV end-systolic and diastolic eccentricity (leftward septal displacement) improved early (both P≤.003), and end-diastolic eccentricity improved further at midterm FU (P=.02). Furthermore, whereas mitral inflow A wave velocity increased (P=.003), the LV A' velocity declined early (P=.007) without further change at midterm. RV systolic and early diastolic function was impaired at BL. Whereas RV strain improved partially at early and midterm FU (P≤.02), RV E' velocity did not improve throughout FU. Mildly impaired LV strain at BL fully recovered by midterm FU (P≤.002). Peak oxygen uptake improved at early and midterm FU (all P≤.003).

CONCLUSIONS: Patients with RVOT obstruction had biventricular systolic and diastolic dysfunction at BL. Relieving RVOT obstruction with TPVR reduced adverse ventricular and compensatory atrioventricular interaction, resulting in progressive biventricular functional improvement and remodeling at early and midterm FU.