Patients may have slightly higher in-hospital mortality after PCI in safety net hospitals

The mortality difference between safety net and non-safety net hospitals appeared to attenuate as hospitals' percutaneous coronary intervention (PCI) volume increased.

Patients who receive percutaneous coronary intervention (PCI) at safety net hospitals may have a marginally higher risk of in-hospital mortality than those receiving PCI at non-safety net hospitals, a recent study found.

Researchers used the National Cardiovascular Data Registry from 2009 to 2015 to compare risk-adjusted PCI outcomes between safety net hospitals (defined as hospitals where 10% or more of PCI patients were uninsured) and non-safety net hospitals. They assessed more than 3.7 million patients who underwent PCI at 282 safety net hospitals and 1,134 non-safety net hospitals. Results were published on Aug. 7 by JACC: Cardiovascular Interventions.

Compared to non-safety net hospitals, safety net hospitals were more likely to be rural institutions, to be located in the southern U.S., and to have lower PCI volume. Patients who received PCI at safety net hospitals had significantly higher risk-adjusted in-hospital mortality (odds ratio, 1.23; 95% CI, 1.17 to 1.32; P<0.001). Overall, they had a 0.4% higher absolute risk of in-hospital mortality than those treated at non-safety net hospitals (number needed to harm, 250).

The mortality difference between safety net and non-safety net hospitals appeared to attenuate as hospital PCI volume increased, albeit with wide confidence intervals, the authors noted. Risk-adjusted rates of periprocedural bleeding and acute kidney injury were not significantly different between the two types of hospitals.

Limitations of the study included its observational nature and the possibility of reporting inaccuracies in the registry. The study authors also noted the registry's omission of potentially important data on the degree of risk factor control at baseline, socioeconomic status, and access to health care.

An accompanying editorial called the slight absolute difference in mortality between safety net and non-safety net hospitals “encouraging” but pointed out that there is great heterogeneity among safety net hospitals and that gaps in the data preclude adequate risk adjustment when making comparisons.

“It may well be that, not only are PCI outcomes noninferior at [safety net hospitals] compared with non-[safety net hospitals], the sicker, more complicated patient with more comorbidities might perhaps be better served at a [safety net hospital],” the editorialist wrote.