Carotid Revascularizations Declining as Outcomes Improve, Medicare Data Show

Rates of carotid artery stenting (CAS) and carotid artery endarterectomy (CEA) have decreased in recent years, and for patients who do undergo either procedure, stroke rates are declining, according to a contemporary study of patients in the United States.

“My take-home would be that this is good news in a way,” lead investigator Judith H. Lichtman, PhD, MPH (Yale University School of Public Health, New Haven, CT), told TCTMD. “It’s unexpected that the trends for these procedures would be going down, but I think it probably signals that we are doing a better job of prevention for heart disease and stroke in terms of being able to reduce some of the risk factors that put people at risk for needing the procedures.”

Lichtman and colleagues say recent data suggest that awareness and treatment of hypertension and dyslipidemia have increased, and that health behaviors have improved, with increases in exercise frequency and decreases in smoking being reported among US adults. Advances in medical therapy, they say, may be factoring into physician decisions to recommend revascularization for patients with asymptomatic carotid disease less frequently than in the past.

“The other good news is that even though we found that the volume of procedures for any given hospital seemed to be going down, the outcomes are better,” Lichtman said.

Revascularization Down More Than 50%

For the study, which appears in the September 19, 2017, issue of JAMA, Lichtman and colleagues looked at data on Medicare beneficiaries treated with either CEA (n = 937,111) or CAS (n = 231,077) between 1999 and 2014.

Overall, the number of CEA procedures dropped 57% (from 298 to 128 per 100,000 beneficiary-years) from the beginning to the end of the study period. Annual rates of CAS, meanwhile, increased at the start of the study, but were on the decline by 2007 and continued on a downward trend, ending where they began at the start of the study (from 40 to 38 per 100,000 beneficiary-years).

Wide regional variation in rates was seen for both procedures throughout the 16-year study period.

The composite outcome of ischemic stroke or death at 30 days after CEA decreased from 4.4% to 3.1% (absolute decrease 1.4%) from the beginning to the end of the study, and all-cause mortality likewise decreased from 1.6% to 1.1% (absolute decrease 0.5%). In adjusted analyses, annual reductions were 2.9% (95% CI 2.6%-3.2%) for 30-day ischemic stroke or death, and 3.0% (95%CI 2.6%-3.4%) for 30-day all-cause mortality.

Other outcomes after CEA also decreased, including in-hospital mortality (adjusted annual reduction 5.2%), 30-day ischemic stroke, MI, or death (adjusted annual reduction 2.7%), and ischemic stroke at 1 year (adjusted annual reduction 2.2%).

While outcome patterns for CAS were more complex to interpret, the rate of ischemic stroke at 1 year decreased an absolute 1.6% from the beginning to the end of the study (from 8.1% to 6.3%). Changes in 30-day ischemic stroke or death, in-hospital mortality, 30-day all-cause mortality, and 30-day ischemic stroke, MI, or death were not significant. In adjusted analyses, however, annual reductions in these outcomes were significant and remained so across most demographic subgroups. Exceptions included black patients and those ages 85 years and older, who did not see statistically significant reductions in 30-day outcomes that included ischemic stroke. Older patients also did not see any statistically significant change in ischemic stroke at 1 year.

“This is a good example of some of the real-world procedure rates, subgroups, and outcomes,” Lichtman observed. “When we looked at regional variation we were able to see that there was a consistent decrease in the procedure rate, but it does seem like there are certain areas of the country where there continue to be distinctive geographic patterns [of] high or low rates.”

To TCTMD, Lichtman said that given the limited national surveillance of carotid revascularization among patients not enrolled in clinical trials, studies such as this “give us an idea of whether or not we’re getting better and trying to reach [national] targets.” One such target is the American Heart Association’s 2020 Impact Goal, which is striving to improve the cardiovascular health of all Americans by 20% while reducing deaths from cardiovascular diseases and stroke by 20% in the next 3 years.