Conscious Sedation During TAVR Best for
Most Patients

Marlene Busko

March 19, 2020

Outcomes after transcatheter aortic valve replacement (TAVR) in US hospitals during a recent 3-year period were better among patients who had the procedure done under conscious sedation than under general anesthesia, a new study shows.

These registry-study findings are being presented as part of the virtual American College of Cardiology (ACC) 2020 Annual Scientific Session and simultaneously published online March 16 in JACC: Cardiovascular Interventions.

Among more than 120,000 patients who had TAVR at more than 500 US sites between January 2016 and March 2019, the use of conscious sedation increased from 33% to 64% of procedures, with wide variation among sites.

A total of 1.1% of patients who had conscious sedation vs 1.3% of patients who had general anesthesia died while hospitalized — a 15% relative difference.

"Part of the reason we did this study is we don't think there is a big difference between doing general anesthesia and doing conscious sedation," senior author David J. Cohen, MD, MSc, from the University of Missouri-Kansas City, told | Medscape Cardiology.

However, the research showed that "the differences are small, but they're there. A 15% difference in mortality – that's important."

Based on these findings, "We think that conscious sedation is fundamentally a better and safer technique," he said. "Maybe not for every single patient, but for the vast majority of patients the outcomes are better and certainly no worse."

Moreover, the outcomes are those that patients care about — mortality, being discharged to home, and length of hospital stay.

The study also estimates that the healthcare system could save around $25 million per year if all hospitals used conscious sedation during TAVR as often as the hospitals in the highest quartile.   

"So there's no downside, only upside, and it applies to the vast majority of patients," Cohen summarized.

"In our center, we probably are at this level of 60% to 70%," he added. "We want to do conscious sedation, but if there's any concern on the part of the anesthesiologist, we'll just do general anesthesia."

Importantly, certain patients undergoing TAVR — such as those with severe obesity, obstructive sleep apnea, or severe lung disease — may require general anesthesia.

"We're not saying if you do general anesthesia for selected patients it's a bad thing," Cohen cautioned, "but you could do better if you do more conscious sedation. "

Invited to comment, Gilbert H. Tang, MD, surgical director of the structural heart program at the Mount Sinai Health System in New York City, echoed these words.

The study showed that "TAVR with conscious sedation is superior to general anesthesia," Tang said, "However, the approach should depend on the heart team and anesthesiology team discussion, in the best interest of the patient for optimal outcomes. "

"I think everyone will agree," he said, that "you want to do what's best for the patient and what's comfortable for the heart team irrespective of the [sedation/anesthesia] strategy."

More Robust Analysis

The early pivotal TAVR trials were done using general anesthesia, but more recently, the use of TAVR with conscious sedation rather than general anesthesia with endotracheal intubation has been increasing, although the exact numbers are unknown, the authors write.

And several large propensity, score-based observational studies published between 2017 and 2019 have reported that conscious sedation is associated with lower in-hospital mortality and shorter hospital stays, but those studies likely had treatment selection bias and residual confounding, they suggest.

In this analysis then, Neel M. Butala, MD, MBA, Beth Israel Deaconess Medical Center, Boston, Massachusetts, and colleagues aimed to 1) examine the variation in the use of conscious sedation for TAVR over time, and 2) evaluate the safety and effectiveness of conscious sedation vs general anesthesia using instrumental variable analysis, a method to make an observational study more like a randomized trial by controlling for unmeasured confounders.

From the Society for Thoracic Surgeons (STS)/ACC Transcatheter Valve Therapy (TVT) Registry, the group identified 120,080 patients who had TAVR at 559 US sites, from January 2016 to March 2019.

During this time, the percentage of procedures that were done using conscious sedation almost doubled, plateauing in the final 6 months.  

And the proportion of sites using any conscious sedation during TAVR increased from 50% to 76%.

The use of this procedure varied widely among the sites: 26% performed >80% of TAVR with conscious sedation, and 13% did not perform any TAVR cases with conscious sedation.

In hospitals in the lowest and highest quartiles of use of conscious sedation during TAVR, this type of sedation was used in a median of 0% of TAVR cases and 91% of cases, respectively.

The researchers used instrumental variable analysis to compare outcomes in patients whose type of anesthesia would differ if they went to a hospital with high or low use of conscious sedation.

Using this method, the use of conscious sedation was associated with a 0.2% absolute risk difference in in-hospital death, the primary study endpoint (P = .010).

And compared with general anesthesia, conscious sedation during TAVR was also associated with a lower rate of 30-day death (2.0% vs 2.5%, respectively), fewer days in the hospital (3.5 vs 4.3 days), and a higher rate of being discharged to home (88.9% vs 86.1%, all P < .001).

"Our results would not apply to those patients who always receive general anesthesia, even at high conscious sedation use centers (eg, patients with severe lung disease on oxygen or significant right ventricular dysfunction)," the authors caution.

Study Limitations, Next Steps

A study limitation is that the registry data did not specify the type of conscious sedation that was used, Cohen acknowledged.

This could vary. For example, a patient could be given a very powerful sedative such as propofol (Diprivan), and his or her respiration and oxygen saturation would be monitored, and an anesthesiologist would be always present. Or the patient could receive sedation like that for angioplasty —diazepam (Valium) or midazolam (Versed) and a narcotic — without an anesthesiologist.

It would be useful to look at the TAVR volumes and compare outcomes within different TAVR volume quartiles, Tang suggested.

In low-volume centers, the anesthesiologist may be uncomfortable with complex cases, whereas larger academic centers would perform more complex procedures and may paradoxically have a slightly higher rate of complications, he speculated.

Future research should investigate what drives the differences in the use of conscious sedation, the authors suggest.

Cohen reports institutional grant support and consulting fees from Edwards Lifesciences, Medtronic, Boston Scientific, and Abbott. Butala is funded by the John S. LaDue Memorial Fellowship at Harvard Medical School and reports consulting fees and ownership interest in HiLabs, outside the submitted work. The disclosures of the other authors are listed with the original article.

American College of Cardiology (ACC) 2020 Annual Scientific Session  

JACC Cardiovasc Interv. Published online March 16, 2020. Abstract

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