Renal function and coronary bypass surgery in patients with ischemic heart failure

OBJECTIVE: Chronic kidney disease is a known risk factor in cardiovascular disease, but its influence on treatment effect of bypass surgery remains unclear. We assessed the influence of chronic kidney disease on 10-year mortality and cardiovascular outcomes in patients with ischemic heart failure treated with medical therapy (medical treatment) with or without coronary artery bypass grafting. METHODS: We calculated the baseline estimated glomerular filtration rate (Chronic Kidney Disease Epidemiology Collaboration formula, chronic kidney disease stages 1-5) from 1209 patients randomized to medical treatment or coronary artery bypass grafting in the Surgical Treatment for IsChemic Heart failure trial and assessed its effect on outcome. RESULTS: In the overall Surgical Treatment for IsChemic Heart failure cohort, patients with chronic kidney disease stages 3 to 5 were older than those with stages 1 and 2 (66-71 years vs 54-59 years) and had more comorbidities. Multivariable modeling revealed an inverse association between estimated glomerular filtration rate and risk of death, cardiovascular death, or cardiovascular rehospitalization (all P< .001, but not for stroke, P » .697). Baseline characteristics of the 2 treatment arms were equal for each chronic kidney disease stage. There were significant improvements in death or cardiovascular rehospitalization with coronary artery bypass grafting (stage 1: hazard ratio, 0.71; confidence interval, 0.53-0.96, P » .02; stage 2: hazard ratio, 0.71; confidence interval, 0.59-0.84, P<. 0001; stage 3: hazard ratio, 0.76; confidence interval, 0.53-0.96, P » .03). These data were inconclusive in stages 4 and 5 for insufficient patient numbers (N » 28). There was no significant interaction of estimated glomerular filtration rate with the treatment effect of coronary artery bypass grafting (P » .25 for death and P » .54 for death or cardiovascular rehospitalization). CONCLUSIONS: Chronic kidney disease is an independent risk factor for mortality in patients with ischemic heart failure with or without coronary artery bypass grafting. However, mild to moderate chronic kidney disease does not appear to influence long-term treatment effects of coronary artery bypass grafting. (J Thorac Cardiovasc Surg 2020; 1-9)

Optimal medical therapy with or without surgical revascularization and long-term outcomes in ischemic cardiomyopathy

Objectives: Optimal medical therapy in patients with heart failure and coronary artery disease is associated with improved outcomes. However, whether this association is influenced by the performance of coronary artery bypass grafting is less well established. Thus, the aim of this study was to determine the possible relationship between coronary artery bypass grafting and optimal medical therapy and its effect on the outcomes of patients with ischemic cardiomyopathy. Methods: The Surgical Treatment for Ischemic Heart Failure trial randomized 1212 patients with coronary artery disease and left ventricular ejection fraction 35% or less to coronary artery bypass grafting with medical therapy or medical therapy alone with a median follow-up over 9.8 years. For the purpose of this study, optimal medical therapy was collected at baseline and 4 months, and defined as the combination of 4 drugs: angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, beta-blocker, statin, and 1 antiplatelet drug. Results: At baseline and 4 months, 58.7% and 73.3% of patients were receiving optimal medical therapy, respectively. These patients had no differences in important parameters such as left ventricular ejection fraction and left ventricular volumes. In a multivariable Cox model, optimal medical therapy at baseline was associated with a lower all-cause mortality (hazard ratio, 0.78; 95% confidence interval, 0.66-0.91; P » .001). When landmarked at 4 months, optimal medical therapy was also associated with a lower all-cause mortality (hazard ratio, 0.82; 95% confidence interval, 0.62-0.99; P » .04). There was no interaction between the benefit of optimal medical therapy and treatment allocation. Conclusions: Optimal medical therapy was associated with improved long-term survival and lower cardiovascular mortality in patients with ischemic cardiomyopathy and should be strongly recommended.

Myocardial viability and long-term outcomes in ischemic cardiomyopathy

BACKGROUND: The role of assessment of myocardial viability in identifying patients with ischemic cardiomyopathy who might benefit from surgical revascularization remains controversial. Furthermore, although improvement in left ventricular function is one of the goals of revascularization, its relationship to subsequent outcomes is unclear. METHODS: Among 601 patients who had coronary artery disease that was amenable to coronaryartery bypass grafting (CABG) and who had a left ventricular ejection fraction of 35% or lower, we prospectively assessed myocardial viability using single-photonemission computed tomography, dobutamine echocardiography, or both. Patients were randomly assigned to undergo CABG and receive medical therapy or to receive medical therapy alone. Left ventricular ejection fraction was measured at baseline and after 4 months of follow-up in 318 patients. The primary end point was death from any cause. The median duration of follow-up was 10.4 years. RESULTS: CABG plus medical therapy was associated with a lower incidence of death from any cause than medical therapy alone (182 deaths among 298 patients in the CABG group vs. 209 deaths among 303 patients in the medical-therapy group; adjusted hazard ratio, 0.73; 95% confidence interval, 0.60 to 0.90). However, no significant interaction was observed between the presence or absence of myocardial viability and the beneficial effect of CABG plus medical therapy over medical therapy alone (P=0.34 for interaction). An increase in left ventricular ejection fraction was observed only among patients with myocardial viability, irrespective of treatment assignment. There was no association between changes in left ventricular ejection fraction and subsequent death. CONCLUSIONS: The findings of this study do not support the concept that myocardial viability is associated with a long-term benefit of CABG in patients with ischemic cardiomyopathy. The presence of viable myocardium was associated with improvement in left ventricular systolic function, irrespective of treatment, but such improvement was not related to long-term survival. (Funded by the National Institutes of Health; STICH ClinicalTrials.gov number, NCT00023595.). (AU)