Medtronic announced new data showing that transcatheter aortic valve replacement (TAVR) with the CoreValve System continued to provide safe and effective treatment, while maintaining exceptional rates of survival out to two years for patients who were considered too ill or frail to have their aortic valves replaced through traditional open-heart surgery.

Without treatment, these patients had a 50% chance of death at one year.

Two year results from 305 patients treated with the CoreValve System in the Extreme Risk Study of the CoreValve U.S. Pivotal Trial were presented during a late-breaking first report session at the Transcatheter Cardiovascular Therapeutics (TCT) 2014 Conference.

Consistent with the positive one-year clinical results, all-cause mortality (36.5 percent) and major stroke (5.1 percent) at two years were low for this extreme risk cohort.

The CoreValve device continued to demonstrate sustained favorable hemodynamic (blood flow) performance at two years as evidenced by low, single-digit mean gradients (blood flow resistance) of 8.7 mmHg; this is consistent with one month and one year rates (8.7 mmHg and 8.9 mmHg, respectively). Low rates of paravalvular leak (PVL) seen at one year were maintained, with just 4.4 percent of all treated patients experiencing moderate to severe PVL at two years.

The study also found that the marked improvement patients experienced in heart failure symptoms at one year (as measured by NYHA Class) was maintained at two years: 92 percent of heart failure patients improved at least one class by two years, and 58 percent of patients improved at least two classes by two years.

"The fact that nearly two out of three patients are alive at two years with low rates of stroke and re-hospitalization, and with substantial improvements in heart failure symptoms, is remarkable given patients’ complex medical conditions, extreme frailty and inability to have a surgical procedure," said Steven Yakubov, M.D., who was an investigator in the CoreValve U.S. Pivotal Trial and is medical director at OhioHealth Research Foundation and system chief of Advanced Structural Heart Disease at OhioHealth.

The CoreValve System is approved by the U.S. Food and Drug Administration (FDA) for patients at extreme risk and high risk for surgery. Since receiving CE (Conformité Européenne) Mark in 2007, the CoreValve System has been implanted in more than 65,000 patients in more than 60 countries.