- More than five years after transcatheter aortic valve replacements were cleared in the U.S., a "significant inverse association" between hospitals' procedure volumes and patient outcomes appears to have persisted, according to registry data analyzed by cardiologists published in the New England Journal of Medicine Wednesday.
- That relationship held up even once researchers eliminated data from a hospital's first year of procedures to account for an initial learning curve. Still, there was "substantial variability" in mortality and complications among low-volume hospitals, and researchers noted these hospitals were more likely than their high-volume counterparts to serve rural areas and treat black and Hispanic patients.
- The findings play into an ongoing debate over whether CMS should loosen requirements set in 2012 that hospitals perform at least 20 TAVR procedures per year, or 40 over two years, to receive coverage for TAVR cases. The issue has been in the spotlight again as CMS revisited the national coverage determination in a draft policy issued last week.
Scrutiny of CMS' coverage policy comes as TAVR supporters have mounting data that the procedure could be put to use for an even broader population.
When CMS set its TAVR coverage policy in 2012, a year after the procedure was approved in the U.S., there was not extensive data available on the relationship between hospitals' procedure volume and patients' outcomes, the authors of the NEJM analysis noted.
Since then, the American College of Cardiology and the Society for Thoracic Surgeons have set up the Transcatheter Valve Therapy Registry, which requires hospitals to report patient outcomes in hospital and at 30 days and one year after.
While other data reviews have been published in recent years, cardiologists believed an up-to-date analysis was warranted, given expansion to intermediate-risk patients and introduction of newer technologies. The NEJM authors reviewed 113,662 TAVR procedures completed at 555 hospitals between Jan. 1, 2015, and Dec. 31, 2017, about 85% of which involved a transfemoral approach.
When the first 12 months of procedure data were excluded to account for a learning curve, researchers found hospitals in the lowest volume quartile (which performed an average of 27 TAVR procedures per year) saw a 30-day mortality rate of 3.10%, compared to 2.61% in the highest volume sector, in which hospitals averaged 143 procedures annually.
The volume-outcomes consideration has dogged industry and CMS alike, which convened a July 2018 advisory panel that ultimately failed to reach consensus on whether patients benefit from the volume-based requirements.
Last week's updated National Coverage Determination draft policy kept some volume requirements, but proposed changes to how a hospital qualifies for coverage and subsequently retains it. To initiate coverage, a site would have to perform 50 open heart procedures of any type in the preceding year and 20 aortic valve related procedures over the preceding two years. To maintain coverage, a site would have to perform 50 TAVR procedures each year.
"On balance, the proposed memo looks positive for TAVR adoption. By lessening the requirements for hospitals and clinicians to begin programs, there could be a faster increase in the number of sites offering TAVR in the U.S.," Jefferies analysts wrote to investors in response.
The study authors also said that in terms of monitoring TAVR site quality, while programs currently receive quarterly reports with national benchmarks, there is no system for external review and assessment in the event corrective actions are needed.
"A transition from procedural volume to direct quality metrics is being proposed, but without an external certification or accreditation system an updated NCD may not have the intended effect," the authors wrote. "In addition, we think an updated NCD should include an effective mechanism to require hospitals to submit complete and accurate data for quality metrics to be valid."
The cardiologists also recommended further study into access to TAVR, noting that their study does not address the population of patients who may consider the procedure but lack access to care.
TAVR, originally reserved for use in patients at high risk for complications in open heart surgery, got a surge of momentum weeks ago at the American College of Cardiology annual conference when both Edwards Lifesciences and Medtronic released data backing expanded use of the procedure in patients at low risk for complications from open heart surgery. Medtronic's Evolut Low-Risk trial showed non-inferiority compared to traditional surgery, while Edwards' Partner 3 trial proved superiority.