Transcatheter aortic valve implantation with the novel-generation Navitor device: Procedural and early outcomes

Early clinical outcomes of transcatheter aortic valve implantation using the NAVITOR system

Transcatheter aortic valve implantation (TAVI) using the NAVITOR system has been relatively underreported due to its recent introduction in Japan. This study aimed to assess the short-term outcomes of TAVI with the NAVITOR in real-world clinical practice. Patients with severe aortic stenosis who underwent TAVI using the NAVITOR system at our institution between December 2022 and December 2023 were prospectively enrolled. We evaluated the 30-day post-TAVI outcomes using the Valve Academic Research Consortium 3 (VARC-3). Among 32 consecutive patients (mean age, 84 years; 19% female), technical success was achieved in 31 (96.8%). One patient developed a subclavian artery vascular dissection, requiring balloon angioplasty during the TAVI procedure, and another received a permanent pacemaker due to persistent advanced atrioventricular block. At the 30-day follow-up, device success was achieved in 31 (96.8%) patients, with early safety observed in 27 (84.3%). One patient experienced sudden unexplained death after discharge. None of the patients experienced myocardial infarction, valve embolisation, life-threatening bleeding, or acute kidney injury within 30 days after the procedure. Echocardiographic follow-up showed a median effective orifice area index of 1.26 ± 0.27. Contrast-enhanced computed tomography was performed in 19 patients 30 days after the procedure, revealing hypo-attenuated leaflet thickening (HALT) in 10 (52.6%). Although the 30-day outcomes of TAVI using the NAVITOR system appeared promising, a relatively high incidence of HALT was observed.

Re-sheathing failure with Navitor during transcatheter aortic valve implantation: a case report

Background

Self-expanding valves used in transcatheter aortic valve implantation (TAVI) are designed to allow recapture and repositioning, facilitating optimal placement and mitigating conduction disturbances and paravalvular leakage. Here, we present a rare case in which the Navitor (Abbott Structural Heart, Santa Clara, CA, USA) could not be recaptured.

Case summary

An 81-year-old Japanese woman with very severe aortic stenosis and a massively calcified nodule at the non-coronary cusp (NCC) underwent TAVI with a 25 mm Navitor valve. During the initial deployment attempt, non-uniform expansion (NUE) was observed on the NCC side when the valve was 80% deployed. An attempt was made to recapture and reposition the valve, but the delivery system capsule failed to fully re-sheath the prosthesis, leaving approximately one-third of the valve outside the capsule and preventing complete recapture. The Navitor was promptly redeployed while still within the basal ring. Following redeployment, the NUE resolved, and the valve was successfully positioned 3 mm below the basal ring on the NCC side and 4 mm below the left coronary cusp. We hypothesized that interference between the capsule tip and the calcified nodule on the NCC leaflet inhibited the re-sheathing process.

Conclusion

This report documents a rare complication involving the failure to recapture the Navitor valve. In cases with large calcified nodules on the leaflet, caution is essential during the re-sheathing process. We strongly recommend re-deploying the prosthesis rather than attempting to remove it from the basal ring to minimize procedural risks and ensure proper valve placement.

Transcatheter Aortic Valve Replacement With the Navitor System: Real-World United Kingdom Experience

The Navitor transcatheter heart valve (THV) is the latest iteration of the Portico self-expanding valve system. Early prospective studies have shown promising outcomes, however, there is a lack of complementary 'real-world' data. This study aimed to assess early safety and efficacy outcomes of the Navitor THV using registry data from 6 high-volume United Kingdom transcatheter aortic valve replacement (TAVR) centers. Demographic, procedural, and in-hospital outcome data were retrieved from 6 United Kingdom centers. The primary safety end point was 30-day mortality. Primary efficacy end points were procedural success, mean aortic gradient, and ≥moderate paravalvular leak. Secondary end points included rates of new permanent pacemaker implantation, stroke, and vascular injury. A total of 574 patients (mean age 83.4 years; 54.5% female) underwent Navitor TAVR between January 2020 and May 2023. The 30-day mortality in this patient cohort was 1.6%. Procedural success was 98.1%, mean echo-derived gradient post-TAVR was 7.7 ± 4.8 mm Hg (95% confidence interval [CI] 7.2 to 8.3, p <0.001) and 5.1% of patients had ≥moderate paravalvular leak (sample proportion estimate [p̂] = 0.051, 95% CI [0.035, 0.073], p <0.001). New permanent pacemaker implantation to discharge was required in 11% (p̂ = 0.119, 95% CI 0.088 to 0.158, p <0.001), stroke occurred in 1.2% of patients (p̂ = 0.017, 95% CI 0.006 to 0.036, p <0.001) and significant vascular injury in 1.6% (p̂ = 0.014, 95% CI 0.005 to 0.032, p <0.001). In conclusion, early procedural outcomes with Navitor TAVR compare favorably to new-generation THVs. Procedural success was high with a low incidence of complications.

Third-Generation Transcatheter Aortic Heart Valve with Reverse Parachute Sealing Cuff in Patients with Aortic Valve Disease

BACKGROUND

The Navitor (Abbott Inc, IL, USA) transcatheter heart valve is a novel third-generation self-expanding bioprosthesis with specific features to mitigate paravalvular regurgitation (PVR). Owing to its novelty, there is a paucity of data on its application in clinical practice.

METHODS

Consecutive cohort analysis of the use of the Navitor system in an as-treated clinical setting at a quaternary heart hospital.

RESULTS

Sixty consecutive non-clinical trial patients treated with Navitor were identified. All patients underwent a successful procedure. The mean age was 79.3 years (±SD 7.82), 56.67% (n=34) were female, and the mean STS score was 4.87 (±SD 5.70). At 30 days post-procedure, all patients were alive with no readmissions for heart failure. One patient had a major vascular complication (1.7%). Four patients (7.14% of patients without a pre-existing pacemaker) received a new permanent pacemaker. Two patients (3.4%) had a non-disabling stroke. PVR at 30 days was trivial or none in 75% of patients, and no patient had worse than mild PVR.

CONCLUSIONS

The Navitor system in this as-treated cohort was associated with favourable clinical, haemodynamic, and safety outcomes.

Early Safety and Performance of the Premounted Dry-Pericardium Vienna Self-Expandable Transcatheter Aortic Valve System: 30-Day Outcomes of the First-in-Human VIVA Feasibility Study

The purpose of this first-in-human (FIH) study was to determine the safety and feasibility of the transfemoral premounted dry-pericardium Vienna Self-Expandable Supra-Annular Aortic Valve System. This novel system is repositionable and retrievable and comes already premounted on the delivery system, eliminating the need for assembly and crimping of the device before valve implantation. This is a prospective, nonrandomized, single-arm, single-center, first-stage FIH feasibility study, which will be followed by a second-stage pivotal, multicenter, multinational study in symptomatic patients with severe aortic stenosis. The first-stage FIH study evaluated the safety and feasibility of the device in 10 patients with severe aortic stenosis based on recommendations by the Valve Academic Research Consortium-2 for transcatheter aortic valve implantations. The mean patient age was 79 ± 5 years, 60% were male, and all patients were in New York Heart Association functional class II to III. The primary safety end point was successful when all patients were alive at 30-day follow-up. Device and technical success were observed in all patients. Two patients had a stroke, 1 of which occurred 5 days after the procedure. New permanent pacemakers were implanted in 2 patients (22.2%), of which only 1 was because of complete heart block. Only 1 patient (10%) had moderate paravalvular leak at 30 days. After the procedure, the mean aortic valve gradient decreased from 48.7 ± 10.8 mm Hg to 8.8 ± 4.3 mm Hg. In conclusion, this FIH feasibility study demonstrates successful procedural feasibility, with no 30-day mortality and favorable valve hemodynamic performance, leading to an improvement in quality of life. ClinicalTrials.gov identifier NCT04861805.

Outcomes of Transcatheter Aortic Valve Replacement in Patients With Severely Reduced Left Ventricular Systolic Function in the Low Systolic Function and Transcatheter Aortic Valve Implantation (LOSTAVI) International Registry

Transcatheter aortic valve replacement (TAVR) is an established therapy for severe, symptomatic aortic valve stenosis even in patients with impaired left ventricular systolic function. However, there is uncertainty on the clinical effectiveness of the currently available TAVR devices in patients with reduced left ventricular ejection fraction (LVEF). The LOSTAVI (Low Systolic function and Transcatheter Aortic Valve Implantation) registry is a retrospective observational study using baseline, procedural, discharge, and long-term follow-up details. A total of 3 groups of interest were distinguished: extremely reduced LVEF (<25%), severely reduced LVEF (25% to 30%), and reduced LVEF (31% to 35%). Unadjusted and adjusted analyses were carried out for in-hospital and follow-up outcomes. A total of 923 patients were included from 12 centers, with 146 patients (16%) with LVEF <25%, 425 (46%) with LVEF 25% to 30%, and 352 (38%) with LVEF 31% to 35%. Several baseline and procedural features were different across groups, including age, risk, functional class, and prevalence of bicuspid disease (all p <0.05). In-hospital mortality was similar in the 3 groups (7 [4.8%], 18 [4.2%], and 7 [2.0%], respectively, p = 0.661), but major adverse events were more common in those with extremely reduced and severely reduced LVEF (19 [13%], 53 [13%], and 25 [7.1%], respectively, p = 0.024). The 12-month follow-up confirmed the significant detrimental impact of reduced LVEF on both death (21 [14%], 49 [12%], and 25 [7.1%], respectively, p = 0.024) and major adverse events (37 [25%], 89 [21%], and 53 [15%], respectively, p = 0.016). The adjusted analysis confirmed the significant prognostic role of LVEF on both outcomes, whereas TAVR device type was not associated with death or major adverse events (all p >0.05). In conclusion, TAVR yields favorable early and 1-year results in patients with reduced LVEF, including those with extremely depressed systolic dysfunction. However, reduced LVEF still represents a major adverse prognostic factor for both short- and mid-term outcomes.

Prosthesis Tailoring for Patients Undergoing Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation (TAVI) has risen over the past 20 years as a safe and effective alternative to surgical aortic valve replacement for treatment of severe aortic stenosis, and is now a well-established and recommended treatment option in suitable patients irrespective of predicted risk of mortality after surgery. Studies of numerous devices, either newly developed or reiterations of previous prostheses, have been accruing. We hereby review TAVI devices, with a focus on commercially available options, and aim to present a guide for prosthesis tailoring according to patient-related anatomical and clinical factors that may favor particular designs.