Introduction
Transcatheter aortic valve replacement (TAVR) initially emerged as an alternative to surgical aortic valve replacement (SAVR) for patients not previously considered surgical candidates due to comorbidities.1 The technology was then applied to patients considered high-risk for complications after SAVR, with studies demonstrating non-inferiority.2 Subsequently, TAVR was studied in the intermediate-risk patients, and more recently low risk patients.3-5 TAVR volumes have increased every year from 2011 to 2019, and now exceed surgical aortic valve replacement (SAVR).5, 6 The high cost of TAVR devices and increased costs compared to SAVR have prompted concerns of cost efficacy.7-13 The use of monitored anesthesia care (MAC) has evolved as one potential strategy for cost savings. MAC has increasingly been employed as a safe and effective alternative to general anesthesia (GA), with the proportion of TAVR performed under MAC nearly doubling from 33% in 2016 to 64% in 2019.14, 15
However, there have been concerns of adverse events during the use of MAC in TAVR.16 Early series noted conversion rates from MAC to GA as high as 17%, at a time when surgical access of the femoral artery was frequently required.17-19 More recent studies examining the conversion rate from MAC to GA found fewer than one percent of cases planned for MAC required conversion to GA, with reasons for conversion including patient discomfort and procedural complications, such as post-deployment aortic dissection with rupture and pericardial effusion causing tamponade.20 On the other hand, the advantages of MAC are well-documented. Studies using propensity-matching to compare outcomes between anesthesia modalities in TAVR found MAC was associated with reductions in fluoroscopy, procedure, and LOS times, as well as an increase in the proportion of patients discharged home.21, 22 A recent instrumental variable analysis of the Transcatheter Valve Therapy Registry revealed decreased in-hospital and 30-day mortality, shorter hospital length of stay (LOS), and higher proportion of discharges to home when TAVR was performed with MAC compared to GA.14 Prospective randomized trials have also demonstrated the safety of MAC for TAVR.23
Despite the promising clinical outcomes for TAVR with MAC, the cost effectiveness of the approach in lower-risk patients has not been well documented. Several early single-center studies compared costs between modalities in TAVR and demonstrated cost-savings with MAC.14, 24-26 None of these included patients deemed low surgical risk, for which TAVR gained FDA-approval in August 2019.27 Comorbidities have been associated with adverse outcomes in TAVR.28 Given temporal differences in surgical risk and anesthesia modality as trends in TAVR use change, it is difficult to separate the effect of anesthesia modality from the effect of comorbidities.
Patient outcomes after TAVR at Veteran Affair (VA) TAVR centers have been shown to compare favorably with benchmark data outside the VA.29 The relative uniformity of the VA patient population and prospectively-collected databases at our institution offered a unique study opportunity. We sought to compare clinical outcomes and cost data between both anesthesia modalities for patients undergoing transfemoral TAVR. This included more recent cases, in which TAVR was used in lower-risk patients with fewer comorbidities.