Patients who received moderate anesthesia while undergoing percutaneous transcatheter aortic valve replacement (TAVR) had a shorter length of stay in the hospital and lower 30-day mortality compared with patients who received general anesthesia, according to an observational registry analysis.

Lead researcher Jay Giri, MD, MPH, of the University of Pennsylvania, presented the results of the study during a late-breaking clinical trial session at the Society for Cardiovascular Angiography and Interventions scientific sessions on May 6 in Orlando.

The researchers evaluated 10,997 patients who underwent TAVR from a transfemoral approach between April 2014 and June 2015 and were part of the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy registry.

Of the patients, 15.8 percent received moderate anesthesia. The rates of moderate anesthesia increased over time.

The procedural success rates were 98.4 percent with moderate anesthesia and 98.6 percent with general anesthesia. The 30-day mortality or stroke rates were 4.8 percent and 6.4 percent, respectively, while the mean length of stay in the hospital was 6.0 days and 6.7 days, respectively. Both of the differences were statistically significant.

Propensity-matched analyses that took 51 variables into account found that the 30-day mortality rates were 2.96 percent in the moderate anesthesia group and 4.01 percent in the general anesthesia group. The 30-day mortality/stroke rates were 4.80 percent and 6.36 percent, respectively. The differences were statistically significant.

During the TAVR procedures, 5.9 percent of patients were converted from moderate to general anesthesia.

Study author Howard Herrmann, MD, of the University of Pennsylvania, said the researchers could not make conclusions as to why patients receiving moderate anesthesia had a lower mortality rate.

“We can’t answer that from this data analysis,” he said at a news conference. “There are limitations to propensity weighted analyses. We tried to find the variables that were available to us either in the registry or others that we thought would be relevant and compare for those. But that doesn’t mean there aren’t other variables that are different between the two groups that we didn’t account for. That’s always a problem with a retrospective propensity analysis.”

Herrmann said the researchers would need to enroll approximately 5,000 patients in a randomized trial to compare moderate anesthesia with general anesthesia in a prospective analysis.

“There are certainly advantages to not having general anesthesia from the standpoint of hemodynamic perturbations, recovery, length of stay, how soon patients can get up out of bed,” he said. “All of those play into that. I can’t that we know [the lower mortality] is all related to the lack of general anesthesia and the use of sedation.”