A modern technique for replacing heart valves without major surgery is safe even for very elderly patients, researchers say.

The procedure can yield "excellent short- and mid-term outcomes in a patient population with a lethal disease that without this technology would undoubtedly die,” said Dr. Vinod H. Thourani from Emory University, Atlanta, Georgia.

The results of the study, involving patients in their nineties, were "surprising and quite honestly rewarding," Thourani added.

Known as transcatheter aortic valve replacement (TAVR), the new technique has been revolutionizing the care of patients with a narrowed aortic valve (so-called aortic stenosis) who are too frail to undergo the traditional "open" surgery.

Instead of cutting through the chest to reach the heart, doctors insert the new valve through a catheter that's been threaded into the heart through a small incision in the arm or the groin.

For the current study, Thourani and colleagues looked specifically at outcomes in some of the oldest patients to participate in a large randomized trial called PARTNER-I, which was the first multicenter randomized trial to show the superiority of TAVR over medical therapy.

In the 531 nonagenarians who underwent TAVR, procedural success rates were 74 to 78 percent, the researchers reported in Annals of Thoracic Surgery.

Within the first 30 days after TAVR, roughly a third of the patients had some kind of major complication - such as a stroke, renal failure, or need for a pacemaker - and 38 patients (7 percent) died.

But once patients recovered from the surgery, their risk of death was equivalent to that of the general population, according to the researchers.

By six months after TAVR, patients were reporting significantly better quality of life than they had at baseline, the researchers found.

These extremely elderly patients would face very high risks from open surgical valve replacement, but "with the advent of this TAVR procedure, cardiac surgeons and cardiologists are able to offer these well-deserving patients a treatment option that otherwise would have been prohibitive,” Thourani said.