Update: Added data from study of new patient populations
Medtronic (NYSE:MDT) said today it released the 1st real-world registry study of its CoreValve transcatheter aortic valve implant, reporting outcomes in-line with its clinical trials of the device.
The medtech giant also released new data from 3 studies focusing on new patient populations with significant comorbidities today. Data from all of the CoreValve studies was presented at the annual Transcatheter Cardiovascular Therapeutics conference in San Franscisco.
The 6,160-patient Society of Thoracic Surgeons and American College of Cardiology TVT registry study reported a 5.2% rate of all-cause mortality and 2.6% rate of stroke at 30 days. Those rates are consistent with the 6.9% and 5% rates, respectively, from the pivotal trial, Fridley, Minn.-based Medtronic said.
“It is reassuring to see that the profound clinical results in the U.S. CoreValve pivotal studies were replicated among patients at high or extreme surgical risk in a ‘real-world’ clinical setting. The favorable results from the CoreValve analyses are likely attributable to operator experience, thoughtful patient selection, and effective education and training based on the ‘best practices’ learned in the U.S. pivotal studies, including the use of CT-based sizing. We believe that these results indicate that the CoreValve self-expanding bioprosthesis is safe and effective in patients with severe aortic stenosis unsuitable for surgery across a wide spectrum of U.S. medical centers,” co-principal investigator Dr. Jeffrey Popma of Boston’s Beth Israel Deaconess Medical Center said in prepared remarks.
The registry study reported that implantation was sucessful in 98% of cases, with only 0.7% requiring conversion to surgery. The pivotal trial reported a 96.8% successful implantation rate and 0.2% rate of cases which required conversion to surgery.
Of patients in the registry, 89.3% were able to be treated via transfemoral access, compared to 77.3% in the pivotal trial, and only 1.5% required valve related readmissions, compared to 5.9% in the pivotal trial.
The CoreValve demonstrated a mean gradient of 7.7 ± 4.2 mm Hg at 30 days and 8.1 ± 3.9 at 1 year, Medtronic reported. Patients reported improved quality of life on the Kansas City cardiomyopathy questionnaire, improving from 40.9% to 68.7%, and a reduction in NYHA Class III/IV symptoms from 83.8% to 13.4%.
Patients in the registry trial were similar to those in the pivotal trial in terms of age, average STS risk model score and similar comorbidity profiles and NYHA classes, Medtronic said.
Medtronic also released data from 3 studies focused on patients with comorbidities including degenerated surgical bioprosthesis, end-stage renal disease and low gradient aortic stenosis.
While TAVR is not approved for end-stage renal disease or gradient aortic stenosis, Medtronic said its CoreValve is the 1st transcatheter heart valve approved in the U.S. for valve-in-valve procedures in high and extreme risk patients.
“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. 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,” Dr. Michael Reardon of the Houston Methodist DeBakey Heart & Vascular Center said in a press release.
In a 109-patient study of a population with failed surgical valves in Medtronic’s expanded use study, the company found a 13.4% rate of all-cause-mortality and 3.1% rate of major stroke at 1 year. Rates included patients with small surgical valve sizes with 17mm inner diameters who had not been previously studied.
Patients demonstrated improved quality of life scores on the KCCQ scale, with an average improvement of 31.8 on a 100-point scale over 1 year. Of the 93.6% of patients in NYHA class III and IV at baseline, 73.2% were NYHA class 1 after a year. Only 6.4% demonstrated moderate aortic regurgitation, and no patients had reported cases of severe regurgitation.
“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,” Dr. Reardon said.
In patients with end-stage renal disease, Medtronic said patients with the Corevalve exceeeded the 30.3% all-cause mortality goals set out in its original CoreValve extreme risk study. Patients with end-stage renal failure also showed improved KCCQ scores of 27.5 points compared to baseline.
Findings from a study of patients with low gradient aortic stenosis reported being comparable with the CoreValve extreme risk study as well, Medtronic reported. Rates of all-cause mortality and major stroke were comparable between those who had low ejection fractions and normal ejection fractions, at 26.3% and 26% respectively. Patients also reported increased quality of life KCCQ scores, averaging 25-30% improvements.
The CoreValve system is approved by the FDA for patients at extreme risk for surgery, and won CE Mark approval in the European Union in 2007.