Patients who received Medtronic’s (NYSE:MDT) CoreValve implant in an early study saw a lot of benefits with the transcatheter aortic valve implantation system, but incidence of valve leakage and cardiovascular death marred 3-year outcomes.
In a study published this week in the American Journal of Cardiology researchers praised the CoreValve results as "amazingly good" while still acknowledging that early rates of paravalvular regurgitation were a significant concern among high-risk patients.
The study included 150 high-risk patients treated at a single clinic from March 2008 to September 2010. Valve leakage was a problem right away, with more than half of those patients identified with leaks, mostly mild, immediately after surgery. Leakage, or aortic regurgitation was deemed a significant risk factor for all-cause mortality and cardiovascular morality, researchers said.
Of the 150 original patients, 75% survived the 1st year after surgery and 59% made it out to 3 years. TAVI patients are generally a very sick population, unable to undergo open surgery to treat a failing aortic valve. Prior to the procedure, 95% of patients included in the study were diagnosed with NYHA functional class III or IV heart failure. That dropped to 33% of the patients at 1 year, but that benefit diminished over time, with 38% of patients at III or IV at 3 years.
These early results may have been muddled by inexperience among clinicians, poor patient selection and poor sizing of the implants, that researchers noted. Given the limitations of the study and complicating factors, the outcomes were "amazingly good for the time period," Beth Israel Deaconess Hospital’s Dr. Jeffrey Popma told TCTMD.
The mortality rates are comparable with other studies, but regurgitation rates are high compared to what doctors are used to in "contemporary practice," he added.