Utilization and Outcomes of Clinically Indicated Invasive Cardiac Care in Veterans with Acute Coronary Syndrome and Chronic Kidney Disease

Significance statement: Of studies reporting an association of CKD with lower use of invasive cardiac care to treat acute coronary syndrome (ACS), just one accounted for the appropriateness of such care. However, its findings in patients hospitalized nearly 30 years ago may not apply to current practice. In a more recent cohort of 64,695 veterans hospitalized with ACS, CKD was associated with a 32% lower likelihood of receiving invasive care determined to be clinically indicated. Among patients with CKD, not receiving such care was associated with a 1.39-fold higher risk of 6-month mortality. Efforts to elucidate the reasons for this disparity in invasive care in patients with ACS and CKD and implement tailored interventions to enhance its use in this population may offer the potential to improve clinical outcomes.

Background: Previous studies have shown that patients with CKD are less likely than those without CKD to receive invasive care to treat acute coronary syndrome (ACS). However, few studies have accounted for whether such care was clinically indicated or assessed whether nonuse of such care was associated with adverse health outcomes.

Methods: We conducted a retrospective cohort study of US veterans who were hospitalized at Veterans Affairs Medical Centers from January 2013 through December 2017 and received a discharge diagnosis of ACS. We used multivariable logistic regression to investigate the association of CKD with use of invasive care (coronary angiography, with or without revascularization; coronary artery bypass graft surgery; or both) deemed clinically indicated based on Global Registry of Acute Coronary Events 2.0 risk scores that denoted a 6-month predicted all-cause mortality ≥5%. Using propensity scoring and inverse probability weighting, we examined the association of nonuse of clinically indicated invasive care with 6-month all-cause mortality.

Results: Among 34,430 patients with a clinical indication for invasive care, the 18,780 patients with CKD were less likely than the 15,650 without CKD to receive such care (adjusted odds ratio, 0.68; 95% confidence interval, 0.65 to 0.72). Among patients with CKD, nonuse of invasive care was associated with higher risk of 6-month all-cause mortality (absolute risk, 21.5% versus 15.5%; absolute risk difference 6.0%; adjusted risk ratio, 1.39; 95% confidence interval, 1.29 to 1.49). Findings were consistent across multiple sensitivity analyses.

Conclusions: In contemporary practice, veterans with CKD who experience ACS are less likely than those without CKD to receive clinically indicated invasive cardiac care. Nonuse of such care is associated with increased mortality.