Medtronic CoreValve System shows low mortality and improved quality of life in new patient populations

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Medtronic have presented new clinical data that shows positive clinical outcomes at one year for the CoreValve System in new populations including patients with a degenerated surgical bioprosthesis, end-stage renal disease and patients with low gradient aortic stenosis. Results from the three populations evaluated within the CoreValve US Expanded Use Study were presented at the Transcatheter Cardiovascular Therapeutics (TCT) symposium.

In March, the CoreValue System became the first transcatheter aortic valve replacement (TAVR) to be approved in the US for valve-in-valve procedures in both high and extreme risk patients with failed surgical valves. However, TAVR is not approved for the other two patient populations.

“It’s encouraging to see patients benefitting from the CoreValve System, many of whom have been unable to receive treatment due to these severe comorbidities,” says Michael Reardon, professor of cardiothoracic surgery at Houston Methodist DeBakey Heart & Vascular Center, and chairman of the patient screening committee of the CoreValve US Pivotal Trial. “When treated with the CoreValve system, not only do these patients live longer, they are able to achieve and maintain a good quality of life, which is really important for these individuals and their loved ones.”

Contributing to CoreValve’s FDA for valve-in-valve procedures, new data on 109 patients with failed surgical valves in the Expanded Use Study showed a low rate of all-cause mortality (13.4%) and major stroke (3.1 %) at one year. These rates included patients with small surgical valve sizes (17mm inner diameter) who had not been previously studied. Importantly, all patients demonstrated a statistically significant improvement in quality of life as measured by the Kansas City Cardiomyopathy Questionnaire (KCCQ), with an average improvement of 31.8 at one year (P < 0.001) on the 100-point scale.  Additionally, 93.6% of the initial 109 patients were in NYHA class III and IV at baseline, and in the surviving patients at one year, 73.2% were in NYHA Class I.

Patients in the Valve-in-Valve study also experienced a low rate of moderate aortic regurgitation (6.4%) with no cases of severe regurgitation and benefitted from strong hemodynamic performance with a mean gradient of 16.5mmHg at one year despite placement within small surgical valves.

“In valve-in-valve procedures, the CoreValve system’s unique supra-annular design helps maximize blood flow through the aortic valve, which is particularly important when implanting within a surgical valve where the original orifice area is often compromised. TAVR provides physicians with an alternative treatment option for patients facing another open heart surgery,” continues Dr. Reardon.

The end-stage renal disease subset of patients within the Expanded Use Study also showed a low rate of mortality and stroke. Despite the clinical challenges of treating this patient population, CoreValve exceeded the objective performance goal for all-cause mortality or major stroke set out in the original CoreValve Extreme Risk Study (30.3 % in this population vs. the objective performance goal of 43% in the US Pivotal ER). 

Additionally, the rate of all-cause mortality among the end-stage renal patients in the Expanded Use Study was lower than that of patients undergoing dialysis in the Transcatheter Valve Therapy (TVT) Registry (30.3% vs. 41%). End-stage renal patients also showed a significant improvement in quality of life at one year with an average increase in the KCCQ overall summary score of 27.5 points compared to baseline.

Findings from the low gradient aortic stenosis (LG-AS) patient population within the Expanded Use Study were also comparable to the CoreValve Extreme Risk Study. Patients with LG-AS treated with the self-expanding valve had a low rate of all-cause mortality or major stroke whether or not they had LG-AS with normal ejection fraction  (26.0% for LG-NEF, N=113) or LG-AS with low ejection fraction  (26.3% for LG-LEF, N=46).  The KCCQ score confirmed the patients’ improvement in quality of life at one year with average improvements of 25.8 (LG-NEF) and 30.5 (LG-LEF), respectively.