Cost-Effectiveness of Coronary Artery Bypass Grafting and Percutaneous Coronary Intervention in Patients With Chronic Kidney Disease and Acute Coronary Syndromes in the US Medicare Program.

Background Coronary revascularization provides important long-term clinical benefits to patients with high-risk presentations of coronary artery disease, including those with chronic kidney disease. The cost-effectiveness of coronary interventions in this setting is not known. Methods and Results We developed a Markov cohort simulation model to assess the cost-effectiveness of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) in patients with chronic kidney disease who were hospitalized with acute myocardial infarction or unstable angina. Model inputs were primarily drawn from a sample of 14 300 patients identified using the Medicare 20% sample. Survival, quality-adjusted life-years, costs, and cost-effectiveness were projected over a 20-year time horizon. Multivariable models indicated higher 30-day mortality and end-stage renal disease with both PCI and CABG, and higher stroke with CABG, relative to medical therapy. However, the model projected long-term gains of 0.72 quality-adjusted life-years (0.97 life-years) for PCI compared with medical therapy, and 0.93 quality-adjusted life-years (1.32 life-years) for CABG compared with PCI. Incorporation of long-term costs resulted in incremental cost-effectiveness ratios of $65 326 per quality-adjusted life-year gained for PCI versus medical therapy, and $101 565 for CABG versus PCI. Results were robust to changes in input parameters but strongly influenced by the background costs of the population, and the time horizon. Conclusions For patients with chronic kidney disease and high-risk coronary artery disease presentations, PCI and CABG were both associated with markedly increased costs as well as gains in quality-adjusted life expectancy, with incremental cost-effectiveness ratios indicating intermediate value in health economic terms.

Comparative Effectiveness of Medical Therapy, Percutaneous Revascularization, and Surgical Coronary Revascularization in Cardiovascular Risk Subgroups of Patients With CKD: A Retrospective Cohort Study of Medicare Beneficiaries.

RATIONALE & OBJECTIVE: Prior studies suggesting that medical therapy is inferior to percutaneous (percutaneous coronary intervention [PCI]) or surgical (coronary artery bypass grafting [CABG]) coronary revascularization in chronic kidney disease (CKD) have not adequately considered medication optimization or baseline cardiovascular risk and have infrequently evaluated progression to kidney failure. We compared, separately, the risks for kidney failure and death after treatment with PCI, CABG, or optimized medical therapy for coronary disease among patients with CKD stratified by cardiovascular disease risk. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: 34,385 individuals with CKD identified from a national 20% Medicare sample who underwent angiography or diagnostic stress testing without (low risk) or with (medium risk) prior cardiovascular disease or who presented with acute coronary syndrome (high risk). EXPOSURES: PCI, CABG, or optimized medical therapy (defined by the addition of cardiovascular medications in the absence of coronary revascularization). OUTCOMES: Death, kidney failure, composite outcome of death or kidney failure. ANALYTICAL APPROACH: Adjusted relative rates of death, kidney failure, and the composite of death or kidney failure estimated from Cox proportional hazards models. RESULTS: Among low-risk patients, 960 underwent PCI, 391 underwent CABG, and 6,426 received medical therapy alone; among medium-risk patients, 1,812 underwent PCI, 512 underwent CABG, and 9,984 received medical therapy alone; and among high-risk patients, 4,608 underwent PCI, 1,330 underwent CABG, and 8,362 received medical therapy alone. Among low- and medium-risk patients, neither CABG (HRs of 1.22 [95% CI, 0.96-1.53] and 1.08 [95% CI, 0.91-1.29] for low- and medium-risk patients, respectively) nor PCI (HRs of 1.14 [95% CI, 0.98-1.33] and 1.02 [95% CI, 0.93-1.12], respectively) were associated with reduced mortality compared with medical therapy, but in low-risk patients, CABG was associated with a higher rate of the composite, death or kidney failure (HR, 1.25; 95% CI, 1.02-1.53). In high-risk patients, CABG and PCI were associated with lower mortality (HRs of 0.57 [95% CI, 0.51-0.63] and 0.70 [95% CI, 0.66-0.74], respectively). Also, in high-risk patients, CABG was associated with a higher rate of kidney failure (HR, 1.40; 95% CI, 1.16-1.69). LIMITATIONS: Possible residual confounding; lack of data for coronary angiography or left ventricular ejection fraction; possible differences in decreased kidney function severity between therapy groups. CONCLUSIONS: Outcomes associated with cardiovascular therapies among patients with CKD differed by baseline cardiovascular risk. Coronary revascularization was not associated with improved survival in low-risk patients, but was associated with improved survival in high-risk patients despite a greater observed rate of kidney failure. These findings may inform clinical decision making in the care of patients with both CKD and cardiovascular disease.

Comparative Utilization and Temporal Trends in Cardiac Stress Testing in U.S. Medicare Beneficiaries With and Without Chronic Kidney Disease.

OBJECTIVES: The authors aimed to analyze temporal trends in cardiac stress testing in U.S. Medicare beneficiaries from 2008 to 2012, types of stress testing, and comparative utilization related to the presence and severity of chronic kidney disease (CKD). BACKGROUND: A long-held perception depicts patients with CKD as being treated less intensively for cardiovascular disease than nonrenal patients. We wondered whether use of diagnostic testing for ischemic heart disease is affected by the presence of CKD. METHODS: Using the 20% Medicare sample, we assembled yearly cohorts of Medicare beneficiaries (∼4,500,000 per year) from 2008 to 2012. Beneficiaries 66 years or older undergoing a first cardiac stress test, with no previous history of coronary revascularization and no acute coronary syndrome within 60 days, were identified, as was the type of stress test. We analyzed temporal trends and compared testing rates related to CKD stage versus no CKD. A Poisson regression model estimated the likelihood of stress testing in 2012 by CKD stage, adjusted for demographic characteristics and comorbid conditions. RESULTS: Approximately 480,000 older patients (∼29,000 with CKD) underwent stress tests in 2008, progressively declining to ∼400,000 in 2012 (∼38,000 with CKD). In 2008 to 2012, 78% to 80% of all stress testing in non-CKD patients used nuclear imaging, as did 87% to 88% in CKD patients. Rates of stress testing declined progressively for non-CKD and CKD patients in 2008 to 2012: 11.5 to 9.4 per 100 patient-years and 16.8 to 13.4 per 100 patient-years, respectively. The adjusted Poisson model, with non-CKD as the reference, showed an increasing likelihood of stress testing with worsening CKD: incidence rate ratio 1.01 for stages 1 to 2 (p = NS), 1.05 for stage 3 (p < 0.0001), 1.01 for stage 4 (p = NS), 1.04 for stage 5 nondialysis (p = NS), and 1.15 for stage 5 dialysis (p < 0.0001). CONCLUSIONS: Overall rates of cardiac stress testing (over three-fourths using nuclear imaging) declined in 2008 to 2012 among Medicare beneficiaries 66 years or older but were consistently higher for CKD than for non-CKD patients. The effect of screening algorithms for transplant candidates was unknown. Our data refute underutilization of cardiac stress testing in CKD patients.

Percutaneous Coronary Intervention Versus Optimal Medical Therapy for Stable Angina in Advanced CKD: A Decision Analysis.

BACKGROUND: Percutaneous coronary intervention (PCI) use is low in the setting of stable symptomatic angina in individuals with advanced chronic kidney disease (CKD) despite high cardiovascular risk in this population, and PCI is frequently deferred out of concern for precipitating dialysis therapy. Whether this is appropriate is uncertain, and patient-centered data comparing the relative risks and benefits of continued medical therapy versus PCI in patients with advanced CKD and stable angina are scarce. STUDY DESIGN: Decision analysis. SETTING & POPULATION: Hypothetical cohort of individuals with advanced CKD (stages 4-5 with estimated glomerular filtration rates ≤ 20mL/min/1.73m2) and stable angina. MODEL, PERSPECTIVE, & TIMELINE: A Markov model with a Monte Carlo simulation through 12 cycles, that is, 3 years of 3-month intervals, with 10,000 microsimulations predicted mean quality-adjusted life-years. INTERVENTION: PCI first, medical management, or dialysis (hemodialysis [HD]) followed by PCI. OUTCOMES: Outcomes modeled were progression to HD therapy (for those not assigned to the preemptive HD strategy), catheter infection, and death. RESULTS: Our analysis showed mean quality-adjusted life-years of 1.103 ± 0.69 for PCI first, 1.088±0.70 for medical management, and 0.670±0.58 for HD followed by PCI. Probabilistic sensitivity analysis found PCI as the preferred strategy > 60% of the time. LIMITATIONS: Values for probabilities and utilities were estimated and/or derived from multiple sources that were not uniform in their populations in terms of age, comorbid condition burden, and degree of kidney failure, and several simplifying assumptions were made. CONCLUSIONS: Our analysis demonstrates that quality-adjusted life expectancy is similar for the PCI first and medical management strategies in patients with advanced CKD with stable angina and that the decision depends on patient preferences other than those incorporated in our model. Both strategies are superior to preemptive dialysis.

Risks of death and end-stage renal disease after surgical compared with percutaneous coronary revascularization in elderly patients with chronic kidney disease.

BACKGROUND AND PURPOSE: Revascularization by coronary artery bypass graft (CABG) surgery or percutaneous coronary intervention (PCI) is frequently deferred in patients with chronic kidney disease (CKD) to avoid precipitating end-stage renal disease (ESRD), but reliable estimates of absolute and relative risks of death and ESRD after CABG and PCI are unavailable. METHODS AND RESULTS: CKD patients undergoing CABG (n=4547) or PCI (n=8620) were identified and tracked using the 5% Medicare sample. The cumulative incidence of ESRD and death were reported for observed events. A Cox model with the Fine-Gray method was used to account for competing risks in assessing relative hazards of death and ESRD. Three-year cumulative incidence of ESRD was lower (CABG, 6.8%; PCI, 5.4%) than death (CABG, 28.3%; PCI, 32.8%). The adjusted hazard ratio of death was higher during the first 3 months after CABG than after PCI (1.25; 95% confidence interval, 1.12-1.40; P<0.001), but lower from 6 months onward (0.61; 95% confidence interval, 0.55-0.69). Conversely, risk of ESRD after CABG was higher during the first 3 months (1.59; 95% confidence interval, 1.27-2.01; P<0.001), but was not statistically significant from 3 months onward. The adjusted hazard ratio of combined death or ESRD was similar to death. CONCLUSIONS: Among CKD patients undergoing coronary revascularization, death is more frequent than ESRD. The incidence of ESRD was lower throughout follow-up after PCI, but long-term risks of death or combined death and ESRD were lower after CABG. Our data suggest better overall clinical outcomes with CABG than with PCI in CKD patients.