JACC Study Shows Long-Term Survival Benefit of TEVAR Compared to Open Repair
February 12, 2019—Peter Chiu, MD, et al conducted a retrospective study to evaluate the effectiveness of thoracic endovascular aortic repair (TEVAR) compared to open surgical repair for aneurysms in the descending anatomy. Their findings were published in Journal of the American College of Cardiology (JACC), ultimately concluding that TEVAR should be considered the first-line therapy for this pathology in the studied population of United States Medicare beneficiaries.
The investigators sought to collect data to address concerns that despite the steady rise in TEVAR application since FDA approval in 2005, some analyses have shown that outcomes after open surgical procedures may be superior after 2 years.
In response to this debate, Chiu et al studied a cohort of Medicare patients with intact descending thoracic aortic aneurysms who underwent TEVAR or open surgical repair between 1999 and 2010, with follow-up through 2014.
"The studies that led to TEVAR device approvals were robust, well-conducted, and reported in great detail, giving us a fair amount of certainty as to the applicability of TEVAR," said corresponding author Michael D. Dake, MD, in comments to Endovascular Today. Dr. Dake is Senior Vice President for Health Sciences at the University of Arizona in Tucson. "However, as with all investigational device exemption trials, the patient populations were carefully screened and the operator pools highly selected. In order to further evaluate the real-world performance of TEVAR compared to open repair outside of the trial setting, we undertook this study of the Medicare database."
The study’s primary endpoint was all-cause mortality, and the secondary endpoint was open or endovascular reintervention in the descending thoracic aorta. At 180 days, mortality was higher in the surgical repair group (23.8%; 95% confidence interval [CI], 21.4%–26.1%) compared with TEVAR (10.2%; 95% CI, 9.0%–11.4%).
Despite a reduced late hazard of death and a lower risk of reintervention in the surgical repair group, it was found that the restricted mean survival time difference favored TEVAR, with a difference of -209.2 days (95% CI, -298.7 to -119.7 days; P < .001), revealing a substantial survival disadvantage with surgical repair at 9 years.
Interestingly, it was also determined that hospital volume affected perioperative outcomes, which, when combined with the declining use of open repair overall, raises the question of whether regionalization and concentration of care should be further explored.
The authors acknowledged the limitations of the analysis but also the extensive, nuanced means undertaken to account for them to the degree possible as well as to mitigate the introduction of biasing factors. Limitations included the retrospective use of database information rather than prospective randomization and the noncontemporary time periods of data collection between the two arms.
In an accompanying letter, Bavaria and McCarthy highlighted that most open cases were performed prior to 2005 and most TEVAR cases were performed after. To balance this, propensity score matching was used to match one open surgical repair patient (n = 1,235) with two TEVAR patients (n = 2,470) to create comparable groups. Patients were excluded if they underwent concomitant cardiac surgical procedures or branch vessel revascularization other than carotid-to-subclavian bypass, or if they had aortic dissection, trauma, or aortoenteric fistula.
"We know that the perfect head-to-head real-world analysis is impossible to create, but acknowledging this, we are confident in the methods and analyses employed and, ultimately, the finding that in this population, TEVAR should remain the preferred option in most patients," said Dr. Dake.
As summarized in JACC, the study concluded that TEVAR should be considered the first-line repair option for descending thoracic aortic aneurysms in Medicare beneficiaries and that open surgical repair should be restricted to high-volume centers and those with a low risk of perioperative mortality.