Use of pulmonary artery catheters (PACs) decreased by nearly 70 percent from 1999 to 2013 despite improving clinical outcomes, according to a cohort study of Medicare beneficiaries.

Kevin Ikuta, of the department of medicine at Yale University, led a team of researchers who calculated the rate of PAC placement per 1,000 hospital admissions in Medicare patients age 65 and older. They published their findings online in JAMA Cardiology.

Among more than 68 million beneficiaries in the study, 457,193 (55 percent men, mean age of 76.3 years) received a PAC.

Researchers found a 67.8 percent relative decrease in PAC use over the duration of the study—from 6.28 per 1,000 admissions in 1999 to 2.02 per 1,000 admissions in 2013. There were significant year-on-year decreases from 1999 to 2011, the research indicated, followed by stable use through 2013.

Notably, PACs in heart failure (HF) patients increased from 2009 to 2013, from 4 per 1,000 admissions to 5.8 per 1,000 admissions. PAC use in acute MI and respiratory patients showed a sustained decrease throughout the study.

“These findings are consistent with several potential explanations, including that the clinical profile of patients being admitted with HF has changed during the study period, that clinicians question the results and applicability of previous clinical trials, or that there are other clinical factors driving the use of PACs (e.g., the need for invasive hemodynamic evaluation prior to consideration for advanced HF therapies, including mechanical circulatory support or transplantation),” Ikuta and colleagues wrote. “These results do not offer any insight into the appropriateness of PAC use, which remains a point of considerable controversy.”

In-hospital mortality among patients with PACs decreased from 30.1 percent in 1999 to 8.6 percent in 2013. The 30-day mortality of those patients decreased from 33.8 percent to 13.4 percent over the same timeframe.

The authors cautioned only Medicare beneficiaries were studied, and said their findings may not be generalizable to younger patients or those without insurance.