PCI mortality rates poor indicators of hospital quality

Annual hospital percutaneous coronary intervention (PCI)-related mortality rates might be unreliable measures of a center’s performance, according to work published in JAMA Cardiology Sept. 18, proving unhelpful for identifying high-quality care in a study of 67 New York hospitals.

First author Alexander T. Sandhu, MD, MS, and colleagues at the Stanford University School of Medicine in Stanford, Calif., said in JAMA the decision to start publicly reporting PCI outcomes nearly three decades ago was a pivotal one for cardiology. The practice first began in New York in 1991 as part of an effort to empower patients to make informed decisions about their medical care and slowly expanded to other states, reaching Pennsylvania in 2001 and Massachusetts in 2005.

“In cardiovascular surgery, earlier studies found that public reporting was associated with quality improvement activities among hospitals with a reduction in mortality,” Sandhu and co-authors wrote. “However, studies on PCI public reporting found unintended adverse consequences that have muted enthusiasm for this practice.”

Those consequences included a reduction in coronary angiography and PCI rates in Massachusetts after 2005, the authors said. It seemed that publicly reporting PCI data was deferring PCI in high-risk patients who might benefit from the intervention.

Sandhu et al. studied 1998-2016 data from the New York Percutaneous Intervention Reporting System to determine whether hospitals’ annual PCI mortality rates are indicative of their future performance. The analysis included 67 New York hospitals and spanned 960 hospital years.

The authors found that hospitals with low PCI-related mortality (those with an observed-to-expected (O/E) ratio of less than 1) and high PCI-related mortality (an O/E ratio of greater than 1) saw inverse associations between their O/E mortality ratio in the index year and the subsequent change in the ratio. Little of the variation in risk-adjusted mortality could be explained by hospitals’ prior performance.

An increase in the O/E mortality ratio from 1 to 2 in the index year was linked to a higher O/E mortality ratio of just 0.15 the following year, the team reported, suggesting annual PCI-related mortality stats may be poor indicators of hospital quality.

It’s not all bad news, though, according to an editorial penned by Gregory J. Dehmer, MD, of Virginia Tech. Dehmer said that while Sandhu and his team concluded PCI mortality is a poor metric for public reporting, “that does not mean it should be abandoned as an outcome tracked internally by hospitals.” The data shows that, for instance, a center with high mortality rates one year need not panic, because their results the following year are likely to be better.

“In some instances, an operator’s annual mortality rate is determined not by their judgment or skill but more on how many times they were on call when the patient dying of a myocardial infarction with cardiogenic shock presented,” Dehmer wrote. “All PCI-related mortalities should be subject to an unbiased internal review, which may be difficult in smaller hospitals with competing physicians.”

Patients, too, he said, should take Sandhu et al.’s results with a grain of salt. Mortality due to PCI is important and should be central to the informed consent process, but reported mortality rates should also be acknowledged as subject to randomness.

“Perhaps when seeing an increased PCI-related mortality rate at a facility based on data several years in the past, more important questions for a patient to ask are, ‘Are you aware of this, has anything been done to address this, and what is your current mortality rate?’” Dehmer wrote. “Those questions reflect the purpose of quality improvement, and the answer would be a marker of a quality program.”