NEW YORK - Endovascular repair (EVAR) of abdominal aortic aneurysms (AAAs) is associated with an initial survival advantage over open repair, according to a study of "real-world" data from California.
However, the difference disappears in the long term, researchers report in JAMA Surgery, online September 2.
Dr. David C. Chang of Harvard Medical School in Boston said by email that the study "highlights the importance of looking at real-world data in evaluating surgical options. Clinically, our study found that the survival advantage for EVAR repairs is maintained until 3 years, after which mortality was higher for patients who had EVAR repairs."
The team studied more than 23,000 patients who underwent AAA repair between 2001 and 2009. Just over half had EVAR while the remaining patients underwent open repair. Median follow-up was for three years.
EVAR was associated with improved 30-day all-cause mortality (1.54% vs. 4.74%) and significantly improved survival until three years postoperatively. After that mortality rose, and the researchers found no difference in long-term mortality for the entire cohort after adjusting for confounders (hazard ratio, 0.99; p=0.64).
EVAR was linked with a significantly higher rate of reinterventions and AAA late ruptures. At five years, for instance, the reintervention rate was 6.59% in the EVAR group vs. 1.48% in the open group.
"This is different from data from clinical trials," Dr. Chang pointed out. "The short-term survival advantage of EVAR from clinical trials data likely eroded as patient risk factors exact their toll over time. These are real-world issues and concerns that are often not captured in idealized clinical trials."
Senior author Dr. Samuel E. Wilson, of the University of California-Irvine Medical Center, added by email that EVAR is safer than the open procedure, which it has replaced. The mortality advantage last for three years, "then other morbidity, especially effects of smoking, even out survival."
Dr. Chang went on to note that "our use of data from the State of California also has an important policy implication: That many states actually have better and more complete population data than the federal government when it comes to healthcare quality. While research and policies related to healthcare quality are driven mostly by the federal government
currently (through Medicare), the federal government has limited data on patient care outside of Medicare."
"Therefore," Dr. Chang concluded, "an argument can be made that the federal government should delegate healthcare research and quality improvement responsibilities to individual states, and support state-level efforts to examine and improve healthcare quality. Healthcare, like politics, is all local."
In an accompanying editorial, Drs. Jamie E. Anderson and James W. Holcroft, of the University of California Davis Medical Center, Sacramento, observe that the study "offers a glimpse into the future of population-based health services research methods."
In a joint email, they said, "Harnessing information already captured for patient care or billing purposes to advance medical research makes sense."