Serial Changes in Right Ventricular Outflow Tract Gradient and Endocarditis Risk After Transcatheter Pulmonary Valve Replacement.

Background: Infective endocarditis (IE) after transcatheter pulmonary valve replacement (TPVR) remains a significant concern. Although there are overall good short-term and long-term hemodynamic outcomes, limited data exist comparing postimplantation echocardiographic findings leading to IE.

Objectives: To compare the progressive echocardiographic performance of percutaneous implanted pulmonary valves before the development of IE.

Methods: This is a single-center retrospective cohort study of all patients who underwent successful TPVR using either Medtronic Melody or Edwards Sapien valves from 2009 to 2021. Patient demographics, procedural details, and yearly echocardiographic findings were collected and compared as appropriate. The risk of IE was compared between groups defined by baseline characteristics using time-to-event methods. Joint modeling was used to evaluate the association between peak-to-peak gradient trajectories over time and the risk of IE. The predictive performance of using peak-to-peak gradient thresholds to predict IE was evaluated using receiver operating characteristic (ROC) analyses.

Result: A total of 226 patients underwent successful TPVR of which 26 patients developed IE. The annualized incidence of IE was 2.96 per 100 patient years. Patients with and without IE had similar ages, weights, and diagnoses. All IE cases were with the Melody valves. Patients who had higher postimplantation echo-derived peak instantaneous gradients (PGs) were significantly more likely to develop IE. Patients with immediate postimplant invasive peak to peak gradient ≥ 15 mmHg were more likely to develop IE. Higher PGs over time were significantly associated with a higher risk of IE (HR 1.04 per mmHg; 95% CI: 1.00-1.07, p = 0.03). ROC analyses indicate that PGs over time have poor predictive performance of IE.

Conclusion: Echocardiographic performance following TPVR was generally acceptable and similar to other studies. Patients who ultimately developed IE trended to have higher PPG post-TPVR and higher gradients over time before the development of IE. The rate of change of echo-derived gradients in patients with lower initial invasive gradients was more pronounced. These findings suggest that longitudinal monitoring of echocardiographic gradient could provide targeted surveillance in those identified at higher risk for IE.