Medtronic's CoreValve Shows Superior Survival to Surgery in High-Risk Patients With Low STS Scores

April 2, 2016—Medtronic plc announced new clinical data on the self-expanding CoreValve system from the high-risk study of the CoreValve United States pivotal trial, showing superior outcomes in survival for transcatheter aortic valve replacement (TAVR) compared to surgery at 2 years for the subgroup of patients with a Society of Thoracic Surgeons (STS) predicted-risk-of-mortality score estimate ≤ 7%. The data were presented at the ACC.16, the American College of Cardiology 65th annual scientific session, held April 2–4 in Chicago, Illinois. 

In Medtronic’s press release, Michael Reardon, MD, Chairman of the Patient Screening Committee of the CoreValve US pivotal trial, commented, “It was encouraging to see that CoreValve patients with lower STS mortality risk scores within the high-risk study achieved a superior survival benefit relative to surgery, as did all patients in the study at 2 years. The survival advantage compared to surgery appeared to widen between year 1 and year 2, reinforcing the notion that the CoreValve system is a viable treatment solution for patients with severe aortic stenosis at high risk." Dr. Reardon is Professor of Cardiothoracic Surgery and Allison Family Distinguished Chair of Cardiovascular Research at Houston Methodist DeBakey Heart & Vascular Center in Houston, Texas.

According to Medtronic, this analysis of the subcohort compared 202 patients treated with the CoreValve system against 181 patients who received surgical aortic valve replacement. The CoreValve TAVR patients demonstrated superior outcomes in all-cause mortality at 2 years compared to surgical patients (15% vs 26.3%; P = .01). In addition, rates of combined all-cause mortality or major stroke were superior for TAVR with the CoreValve system (17.1% vs 31.9%; P = .0018).

Additionally, patients in the CoreValve treatment arm of the analysis experienced significantly better valve hemodynamics than patients treated with surgery, as both gradients and the rates of severe patient prosthesis mismatch were statistically lower at each time point in the follow-up (P < .0001). Rates of life-threatening or disabling bleeding were also statistically lower in the CoreValve group (20.2% vs 34.9%; P = .001). The pacemaker rate for the CoreValve group was 27.7% at 2 years, which is in line with CoreValve patients in the broader high-risk study.

These patients also demonstrated notable improvements in their quality of life (QoL). The QoL scores for the CoreValve-treated patients showed strong medical benefit, defined as a Kansas City Cardiomyopathy Questionnaire summary score of ≥ 60 and with a < 10-point decrease from baseline.

In January 2014, the US Food and Drug Administration approved the CoreValve system for extreme-risk patients. In June 2014, the CoreValve was approved for patients at high risk for surgery.  In March 2015, the device was approved in the United States for valve-in-valve procedures in both high- and extreme-risk patients with failed surgical valves. CoreValve received European CE Mark approval in 2007.