Better Access to Transcatheter Aortic Valve Replacement Associated With Improved Outcomes

Greater access to transcatheter aortic valve replacement (TAVR) may be associated with improved outcomes in patients with severe aortic stenosis, data suggest.

In an observational, retrospective cohort study that included almost 22,000 patients who received TAVR, the 30-day mortality rate was 3.1% in Ontario, where access was lower, and 2.5% in New York State, where access was greater.

"We compared the outcomes in two jurisdictions to better understand if outcome differences exist and if they are related to access to technology," senior study author Art Sedrakyan, MD, PhD, professor of population health sciences at Weill Cornell Medical College in New York City and director of the Institute for Health Technologies and Interventions, told Medscape Medical News.

"There are outcome differences that favor patients getting care in New York, but we believe it might be related to early access to the technology in New York and accumulating more experience," said Sedrakyan.

The study was published online February 1 in the Canadian Journal of Cardiology.

Comparing Two Jurisdictions

The investigators examined population-based administrative data to identify adults in Ontario and New York who received TAVR between January 2012 and December 2018. They included 5007 patients at 11 hospitals in Ontario and 16,814 patients at 36 hospitals in New York in their analysis. The primary outcome was 30-day in-hospital mortality after TAVR.

The Ontario hospitals had a higher median TAVR volume (528 vs 268), but New York hospitals had a broader range of volumes: 1-2559 TAVRs compared with 13-839 in Ontario. From 2012 to 2018, access to TAVR increased from 18.2 per million to 87.4 per million in Ontario and from 31.9 per million to 220.4 per million in New York, representing an almost threefold higher use of TAVR in the latter.

The rate of 30-day in-hospital mortality was higher in Ontario. The rate of readmissions, which was a secondary outcome, did not differ significantly between Ontario and New York (14.6% vs 14.1%, respectively).

Access site, urgency status, and year of procedure were the most important influences on mortality. Patients who had transfemoral TAVR had a 58% lower mortality rate than did those who did not. Mortality risk was more than twice as high for patients who had urgent TAVR (odds ratio, 2.31). Finally, mortality rates were higher in the early years of the study period.

The investigators also calculated what the mortality rate for New York patients would have been if they had been treated in Ontario. The expected mortality for the New York patients was 3.6% compared with the 2.5% observed in the study, resulting in an observed-expected (O-E) ratio of 0.7. The O-E ratio for readmission was not significantly different between the two jurisdictions.

A sensitivity analysis restricted to patients undergoing elective, transfemoral-access-only TAVR found no significant differences in mortality or readmission between the two cohorts.

The investigators noted that Ontario patients were likely sicker than were those in New York because the province had restricted TAVR access to inoperable and high-risk patients during the study period, whereas New York did not. The reduction of the gap in short-term outcomes between the two locations when urgent cases were excluded from the analysis suggests that New York has a lower bar for performing urgent procedures in wait-listed patients. The investigators did not compare wait times, however, because New York State did not collect that data.

Potential data-recording differences between the primary databases were a limitation of the study, according to the investigators. "Comorbidity coding might be different in the countries, and risk stratification can be improved," said Sedrakyan. "But this is an important study that helps policy makers understand that there are public health implications related to decisions to approve, adopt, and conduct TAVR operation."

Further study would help determine whether more recent outcomes have improved, he said. "Unfortunately, we don't have funding to do more of these cross-border analyses," said Sedrakyan. "We think more international outcome studies are warranted with direct comparison."

Ensuring Equal Access

Commenting on the study for Medscape Medical News, David Messika-Zeitoun, MD, PhD, a cardiologist at the University of Ottawa Heart Institute, pointed out two notable limitations. First, the predictive model did not have any individual comparisons. Second, valve-on-valve procedures represented 0.2% of the New York cohort but 11% of the Ontario group. Messika-Zeitoun was not involved in the study.

"If you look at the patients who had proximal (transfemoral) transaortic valve intervention (TAVI) and elective interventions, there is no difference," he said.

However, the use of province- and state-wide data and the relatively long period of observation are strengths of the study, Messika-Zeitoun added.

The results provide four key lessons, he continued. They underscore the importance of monitoring access, waiting time, and results. They also remind clinicians "to assess whether aortic stenosis patients are treated according to their need, meaning, for example, that all patients over 75 years suitable for a TAVI get a TAVI in Canada," said Messika-Zeitoun. The results also reveal the need to ensure equity of access and treatment opportunities across Canada. Finally, they "emphasize the importance of early detection, follow-up by a cardiologist with expertise in valvular heart disease, and timely intervention, which is the mandate of the Canadian Cardiology Society Working Group," he concluded.

The study received support from ICES, which is funded by the Ontario Ministry of Health and the Ministry of Long-Term Care. Sedrakyan reported no relevant financial relationships. Messika-Zeitoun has received research grants from Edwards Life Sciences.

Can J Cardiol. Published February 1, 2023. Full text

Richard Mark Kirkner is a medical journalist based in the Philadelphia area.

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Credits:
Lead image: National Institutes of Health
Image 1: Weill Cornell Medicine
Image 2: University of Ottowa

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Cite this: Better Access to Transcatheter Aortic Valve Replacement Associated With Improved Outcomes - Medscape - May 04, 2023.