ISCHEMIA-Chronic Kidney Disease Trial

BACKGROUND: Among patients with advanced CKD, cardiovascular disease is the leading cause of death,15-30 times higher than the age-adjusted cardiovascular mortality rate in the general population. The projected 4-year mortality is \>50% in patients with advanced CKD and is worse than that for patients in the general population who have cancers, heart failure, stroke or MI. Participants with advanced CKD are 5-10 times more likely to die than to reach end stage renal disease (ESRD). Despite this, \~80% of contemporary coronary artery disease (CAD) trials exclude participants with advanced CKD. Most of the treatments aimed at reducing cardiovascular events in advanced CKD are therefore extrapolated from cohorts without advanced CKD. Participants with advanced CKD and cardiovascular disease are undertreated with less frequent use of statins and revascularization therapies, and the optimal management approach to these patients is unknown. Participants with advanced CKD are notably underrepresented in contemporary trials comparing revascularization with medical therapy in SIHD patients, such as the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial or the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial,making any assessment about the efficacy of revascularization plus medical therapy vs. initial medical therapy alone in this cohort problematic. Participants with advanced CKD are at increased risk for complications of the assigned invasive procedure, specifically contrast-induced acute kidney injury (AKI), dialysis, major bleeding and short-term risk of death. However, there is controversy in the medical literature regarding the incidence (\<1% to \>30%), effective treatment (saline hydration, N-acetyl cysteine, or sodium bicarbonate), and prognosis of contrast induced AKI (\<0.5% to \>5% requiring dialysis). In addition, although contrast induced AKI have been associated with increase in short-term mortality, residual confounding in these studies makes interpretation difficulty. Moreover, it is unknown if these short-term increased risks are offset by long-term benefits. Limited observational studies in the CKD cohort suggest a long-term survival benefit of revascularization when compared with medical therapy alone, despite an increase in short-term risks. However, the medical therapy in these trials was not optimized, drug eluting stents were rarely used and there is undoubtedly inherent selection and ascertainment bias with observational studies. The above has resulted in clinical equipoise in the management of these patients, with the rates of revascularization only around 10-45%. The results of ISCHEMIA-CKD will have profound implications for guidelines, health policy, and clinical practice.