Core-Laboratory Evaluation of Implantation Depth and Clinical Outcomes in TAVR: Optimize PRO Study

Standardized implant protocols have shown promise in improving outcomes in transcatheter aortic valve replacement (TAVR). However, the impact of implantation depth on clinical outcomes remains unclear.

The aim of this study was to evaluate clinical and hemodynamic outcomes across varying TAVR implantation depths using data from the Optimize PRO study.

This prospective, multicenter Optimize PRO study included patients with symptomatic severe aortic stenosis undergoing TAVR with Evolut PRO and Evolut PRO+ systems. Patients were stratified by core laboratory-adjudicated noncoronary cusp implantation depth. The echocardiographic outcome composite included no or trace paravalvular regurgitation, aortic mean gradient ≤ 10 mm Hg, and no prosthesis-patient mismatch at discharge.

Patients (N = 603) were stratified by implantation depth: <1 mm (n = 88), 1 to ≤3 mm (n = 196), >3 to ≤5 mm (n = 170), and >5 mm (n = 149). Baseline characteristics were similar across implantation depth groups, except for a higher proportion of women for higher implantation depths. Higher implantation depths were associated with less resheathing and recapture (27.3% [24 of 88], 33.7% [66 of 196], 48.8% [83 of 170], and 51.7% [77 of 149]; P < 0.001) and shorter median hospital stay (1 day [Q1-Q3: 1-1 day], 1 day [Q1-Q3: 1-2 days], 2 days [Q1-Q3: 1-3 days], and 2 days [Q1-Q3: 1-4 days]; P < 0.001). Rates of valve migration (0%, 0.5% [95% CI: 0.1%-3.6%], 0.6% [95% CI: 0.1%-4.1%], and 1.3% [95% CI: 0.3%-5.3%]; P = 0.63) were low across implantation depth groups. The 1-year all-cause mortality or all-stroke rate was comparable across implantation depth groups (8.1% [95% CI: 3.9%-16.2%], 7.2% [95% CI: 4.3%-11.8%], 10.7% [95% CI: 6.9%-16.5%], and 12.5% [95% CI: 8.1%-19.2%]; P = 0.40). After 1 year, higher implantation depths were associated with lower rates of permanent pacemaker implantation (2.3% [95% CI: 0.6%-8.8%], 9.2% [95% CI: 5.9%-14.3%], 15.9% [95% CI: 11.2%-22.4%], and 20.3% [95% CI: 14.6%-%27.7]; P < 0.001). Rates of NYHA functional class I were numerically different across implantation depth groups but did not reach statistical significance (77.8% [56 of 72], 71.8% [130 of 181], 65.2% [101 of 155], and 67.7% [84 of 124]; P = 0.09 across all classes). In men, echocardiographic outcome composite rates were not statistically different across depth groups (58.6% [17 of 29], 50.6% [39 of 77], 43.8% [35 of 80], and 36.1% [26 of 72]; P = 0.14), although the exploratory trend test reached statistical significance (P = 0.02).

Higher TAVR device implantation was associated with improved clinical outcomes with similar safety events, including valve migration, across depths. The long-term effect of this approach, including the ability to perform redo TAVR safely, will be further studied in the future. (Optimize PRO; NCT04091048).