Fewer Complications, Lower Risk of Death With Conscious Sedation for TAVR

The use of local anesthesia or conscious sedation during transcatheter aortic valve replacement is associated with a lower risk of complications, including a reduced need for a prolonged intensive care unit (ICU) stay as well as a lower risk of death at 30 days, when compared with use of general anesthesia, according to a review of registry data.

Additionally, there was no difference in the rate of paravalvular leakage between those treated with local anesthesia/conscious sedation in the series and those treated with a general anesthetic, report investigators.

Given these benefits, “a less invasive strategy, which is also less time-consuming and less complicated, is much more attractive,” lead investigator Oliver Husser, MD, PhD (St. Johannes Hospital, Dortmund, Germany), told TCTMD.

In recent years, the drive to simplify TAVR procedures, particularly as operators and the heart team gain clinical experience, has led some higher-volume centers to perform the bulk of their cases with conscious sedation only. From a patient’s perspective, it’s usually the preferred approach since they feel better faster, have less downtime, and mobilize more quickly compared with general anesthesia.

“When you start with your first cases you might prefer the controlled situation of general anesthesia—maybe you don’t want the patient to move—with the opportunity to use transesophageal echocardiography,” or TEE, said Husser. “As you become familiar with the procedure and get used to doing more and more cases, the more you start looking for ways to optimize and simplify the procedure and the setting. Switching to conscious sedation is one aspect of that.”

Chandan Devireddy, MD (Emory University School of Medicine, Atlanta, GA), who was not involved in the study, told TCTMD that conscious sedation is the default strategy at his center as part of their “minimalist” approach to transfemoral TAVR procedures. That said, they review each case individually to make sure the patient can be appropriately treated with conscious sedation.

“For us, the patients with general anesthesia are typically done [that way] because there is something about their case that is more complex,” said Devireddy.

For example, in morbidly obese patients, vascular access might be more of a challenge, or a patient might have psychological issues about being able to lie flat, he said. Additionally, patients with reduced LV function or anatomic issues predisposing them to an increased risk of coronary obstruction might be treated with general anesthesia in case they need to undergo emergent cardiopulmonary bypass and surgery.

Devireddy pointed out that one of the criticisms of conscious sedation is that it might be associated with a higher rate of paravalvular leak given that TEE is not used. However, he said their center has not had problems using TEE during conscious sedation, although much of this is based on operator experience and the heart team’s comfort with TTE.

In an editorial accompanying the study, Didier Tchétché, MD, and Chiara De Biase, MD (Clinique Pasteur, Toulouse, France), called local anesthesia/conscious sedation the “contemporary gold standard for TAVR,” with positive signals provided by this study to support its use as the first-line option. They also questioned whether TEE is routinely needed, particularly given the technological improvements in valve deployment, reduced aortic regurgitation rates, and rare cases of tamponade or annular rupture.  

Less Than Half Treated With Conscious Sedation

The study, which was published March 19, 2018, in JACC: Cardiovascular Interventions, is an analysis of 16,543 patients included in the German Aortic Valve Registry (GARY) between 2011 and 2014. During this time, 49% of patients underwent TAVR with local anesthesia or conscious sedation.

Patients treated with local anesthesia/conscious sedation were not as sick as those treated with general anesthesia. Overall, they were younger, had a lower STS score, and a lower American Society of Anesthesiologists class than those treated with general anesthesia.

In the entire cohort, as well as in a propensity-matched analysis of 2,624 patients with similar baseline characteristics, use of conscious sedation was associated with shorter procedure and fluoroscopy times, fewer conversions to sternotomy, and a lower rate of vascular complications. Additionally, conscious sedation was associated with less cardiopulmonary resuscitation, respiratory failure, low-output syndrome, and psychological syndromes, as well as fewer days spent in the ICU.

The 30-day mortality rate among those treated with conscious sedation was 3.5% compared with 4.9% for those treated with general anesthesia. In a multivariate-adjusted risk model, conscious sedation was associated with an 18% lower risk of death at 30 days (P < 0.001). In the propensity-matched population, the 30-day mortality rate in the conscious sedation and general anesthesia arms was 2.8% and 4.6%, respectively (P < 0.001).

At 1 year, these are no significant difference in mortality between the two anesthesia strategies, just trends in the entire and propensity-matched populations.

“With time, we see that the initial benefit disappears,” said Husser. “One possible explanation is that in the long run, the patient’s comorbidities catch up. You get them safely through the procedure, but you don’t change the overall prognosis, at least not by the anesthesia strategy. In the long run, the mortality benefit disappears as the comorbid conditions catch up.”

Conscious Sedation for Low-Risk Patients?

Despite their attempts to rule out residual bias, Husser and Devireddy both said it’s truly impossible to eliminate the influence of confounding variables on outcomes favorable to conscious sedation. Still, Devireddy noted that data from TVT Registry has also shown that local anesthesia/conscious sedation is associated with lower in-hospital and 30-day mortality compared with general anesthesia.

“So now we have a European and US dataset, which suggests that in addition to the reasons for improved patient quality of life and reduced cost, there’s reasons for teams to learn and absorb the conscious sedation strategy, which includes possibly reducing morbidity and mortality,” he said.

Where things are likely to be more heatedly contested is in low-risk patients if TAVR is approved in this patient population, he said. While a low-risk surgical patient would be expected to bounce back even faster from TAVR with conscious sedation than a higher-risk patient, the specter of complications is the issue.

Should low-risk patients be done exclusively in the OR, or should they be done in the cath lab? You can’t afford to have a hiccup with a low-risk patient because of a lack of preparedness. Chandan Devireddy

“If a patient is low risk and has a rare complication, you have to be prepared to emergently address that issue, especially if it requires a surgical therapy,” said Devireddy. “How conscious sedation affects that, especially if that’s done in a cardiac cath lab, is an area that is currently being debated. Should low-risk patients be done exclusively in the OR, or should they be done in the cath lab? You can’t afford to have a hiccup with a low-risk patient because of a lack of preparedness.”

Studies have shown that conscious sedation can dramatically cut costs, but Devireddy pointed out that the average length of hospital stay in the GARY analysis was 9 days, which is unheard of in US hospitals. Although the extended length of stay is tied with German reimbursement issues, Devireddy said the German hospitals and the healthcare system as a whole still aren’t seeing the full benefits of conscious sedation, not the least of which are increased mobilization, earlier discharge, and lowered costs.