Influence of Tissue Technology on Pannus Formation on Bioprosthetic Heart Valves

Seven-year outcomes following aortic valve replacement with a novel tissue bioprosthesis

OBJECTIVE

As bioprosthetic aortic valve replacement (AVR) extends to younger cohorts, tissue durability is of paramount importance. We report 7-year outcomes from an AVR bioprosthesis utilizing novel tissue.

METHODS

This was an international investigational device exemption trial for novel AVR with annual follow-up and a subset re-consented at 5 years for extended 10-year follow-up. Safety end points and echocardiographic measurements were adjudicated by an independent clinical events committee and by a dedicated core laboratory, respectively.

RESULTS

Between January 2013 and March 2016, 689 patients underwent AVR with the study valve. Mean age was 66.9 ± 11.6 years, Society of Thoracic Surgeons risk score was 2.0% ± 1.8%, and 74.3% of patients were New York Heart Association functional class II and III. Five-year follow-up was completed by 512 patients, and 225 re-consented for extended follow-up. Follow-up duration was 5.3 ± 2.2 years (3665.6 patient-years), and 194 and 195 patients completed 6- and 7-year follow-ups, respectively. One-, 5-, and 7-year freedom from all-cause mortality was 97.7%, 89.4%, and 85.4%, respectively. Freedom from structural valve deterioration at 7 years was 99.3%. At 7 years, effective orifice area and mean gradients were 1.82 ± 0.57 cm2 (n = 153), and 9.4 ± 4.5 mm Hg (n = 157), respectively. At 7 years, predominantly none (96.8% [152 out of 157]) or trivial/trace (2.5% [4 out of 157]) paravalvular regurgitation and none (84.7% [133 out of 157]) or trivial/trace (11.5% [18 out of 157]) transvalvular regurgitation were observed.

CONCLUSIONS

We report the longest surgical AVR follow-up with novel tissue in an investigational device exemption trial utilizing an independent clinical events committee and an echocardiography core laboratory. This tissue demonstrates excellent outcomes through 7 years and is the benchmark for future surgical and transcatheter prostheses.

Five-Year Outcomes After Bicuspid Aortic Valve Replacement With a Novel Tissue Bioprosthesis

BACKGROUND

This study investigated the safety and effectiveness of surgical aortic valve replacement with RESILIA tissue (Edwards Lifesciences) through 5 years in patients with native bicuspid aortic valves. Outcomes were compared with those for patients with tricuspid aortic valves.

METHODS

Of 689 patients from the COMMENCE (ProspeCtive, nOn-randoMized, MulticENter) trial who received the study valve, 645 had documented native valve morphology and core laboratory-evaluable echocardiograms from any postoperative visit, which were used to model hemodynamic outcomes over 5 years. Linear mixed-effects models were used to estimate longitudinal changes in mean gradient and effective orifice area.

RESULTS

Patients with native bicuspid aortic valves (n = 214) were more than a decade younger than those with tricuspid aortic valves (n = 458; 59.8 ± 12.4 years vs 70.2 ± 9.5 years; P < .001). The bicuspid aortic valve cohort exhibited no structural valve deterioration over 5 years, and rates of paravalvular leak and transvalvular regurgitation were low (0.7% and 2.9%, respectively [all mild] at 5 years). These outcomes mirrored those in patients with native tricuspid aortic valves. The model-estimated postoperative mean gradient and effective orifice area, as well as the rate of change of these outcomes, adjusted for age, body surface area, and bioprosthesis size, did not differ between the 2 cohorts.

CONCLUSIONS

Among patients with bicuspid aortic valves, RESILIA tissue valves demonstrated excellent outcomes to 5 years, including no structural valve deterioration and very low rates of paravalvular and transvalvular regurgitation. These results are encouraging for RESILIA tissue durability in young patients.

Identification of CT-derived Internal Area in Failed Surgical Stented Bioprostheses for Valve-in-Valve Implantation

In participants who underwent valve-in-valve transcatheter aortic valve replacement, hypoattenuating intra-annular material within the failed surgical bioprostheses reduced the CT-derived internal area and interfered with expansion of intra-annular-positioned implanted valves, leading to postprocedural patient-prosthesis mismatch.

Long-run savings associated with surgical aortic valve replacement using a RESILIA tissue bioprosthetic valve versus a mechanical valve

BACKGROUND

Prior economic analyses demonstrate that legacy tissue valves are associated with substantial financial savings over the long run after a surgical aortic valve replacement (SAVR). Bioprostheses with RESILIA tissue reduce calcification, the primary cause of structural valve deterioration (SVD), and have demonstrated promising pre-clinical and 5-year clinical results. This economic evaluation quantifies the expected long-run savings of bioprosthetic valves with RESILIA tissue relative to mechanical valves given 5-year clinical results and expected performance through year 15.

METHODS

Simulation models estimated disease progression across two hypothetical SAVR cohorts (tissue vs. mechanical) of 10,000 patients in the US over 15 years. One comparison evaluated RESILIA tissue valves relative to mechanical valves. The other compared legacy SAVR tissue and mechanical valves. Health outcome probabilities and costs were based on literature and expert opinion. Incidence rates of health outcomes associated with mechanical valve were calculated using relative risks of expected outcomes in tissue valve versus mechanical valve patients. The comparisons also accounted for anti-coagulation monitoring in both cohorts. Savings estimates are based on US healthcare costs and do not yet account for the premium associated use of RESILIA relative to a standard tissue valve.

RESULTS

Relative to mechanical SAVR, the median net discounted savings for a patient receiving SAVR with a RESILIA tissue valve is $20,744 ($US, 2020; 95% CI = $15,835-$26,655) over a 15-year horizon. While 30-day and 1-year savings were not significant, expected savings after 5 years are $9,110 (95% CI = $6,634-$11,969). Net savings for RESILIA SAVR valves were approximately 30-50% larger than savings anticipated using legacy tissue SAVR valves.

CONCLUSION

RESILIA tissue valves are associated with lower health expenditures relative to mechanical valves.

Reimbursement Savings Associated With Tissue Versus Mechanical Surgical Aortic Valve Replacement in Thailand

OBJECTIVES

Surgical aortic valve replacement (SAVR) is an indicated treatment for severe aortic stenosis. Although mechanical valves are typically more durable, tissue SAVR valves do not require lifetime anticoagulation monitoring and may have lower rates of expensive sequelae. This economic evaluation estimates payer costs to the 3 largest Thai health insurance mechanisms for tissue versus mechanical SAVR.

METHODS

A deterministic and Monte Carlo simulation model based on literature and expert opinion estimated total payer costs for tissue and mechanical valves over a 25-year duration for 3 separate age cohorts (45, 55, and 65 years). Reimbursements levels for hospitalization services were from the Thai Diagnosis Related Groups. Separate models are generated for the 3 main Thai health insurance mechanisms.

RESULTS

The discounted expected 25-year reduction in payer savings associated with tissue SAVR are $2540, $2529, and $2311 per surgery for patients aged 45, 55, and 65 years, respectively, for the largest Thai insurer. Expected cost reductions associated with tissue SAVR are larger for each of the other schemes and generally decrease with patient age. Most savings accrue within 10 years of surgery. Reoperation costs are larger with tissue valves, but reductions in complications and anticoagulation monitoring more than offset these expenditures. Results are robust to multiple sensitivity and scenario analyses.

CONCLUSIONS

Coverage and reimbursement of tissue valves can financially benefit Thai insurers and reduce expenditures in the Thai health system compared with mechanical valves. As tissue valve technology evolves and reoperation rates decline, the financial benefit associated with tissue valves will increase.