Iso-osmolar versus low-osmolar contrast media and outcomes after percutaneous coronary intervention: Insights from the VA CART Program

Objectives: To assess whether contrast media type is associated with outcomes in veterans undergoing percutaneous coronary intervention (PCI). Background: There is uncertainty about the impact of iso-osmolar contrast medium (IOCM) versus low-osmolar contrast medium (LOCM) on acute kidney injury (AKI) and other major adverse renal or cardiovascular events (MARCE) after PCI. We assessed the association between contrast media type and MARCE in patients who underwent PCI within the Veterans Administration Healthcare System. Methods: We reviewed PCIs performed between 2009 and 2019 using data from the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program. The primary endpoint was MARCE, a composite of myocardial infarction, stroke, all-cause death, AKI, and dialysis onset at 30 days. Results: The analysis cohort consisted of 50,389 patients of whom 25,555 received LOCM and 24,834 received IOCM. There was significant variation in contrast type across sites. After adjustment for comorbidities, no significant association between contrast media type and MARCE was observed in both site—unadjusted (odds ratio [OR] for IOCM: 0.99; 95% confidence interval [CI]: 0.92–1.08; p = 0.97) and site-adjusted (OR: 1.06; 95% CI: 0.95–1.18; p = 0.30) analyses. Similar results were obtained when contrast volume was imputed or the data was subset to individuals with available contrast volume. Conclusion: In a large cohort of veterans undergoing PCI, we found considerable site variation in the type of contrast media used but no significant association between contrast media type and the incidence of MARCE, both before and after adjustment for the site.