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.