Sympathetic overactivity and sudden cardiac death among hemodialysis patients with left ventricular hypertrophy.

BACKGROUND: We prospectively investigated whether cardiac autonomic imbalance is associated with sudden cardiac death (SCD) among a group of hemodialysis patients with left ventricular hypertrophy (LVH). METHODS: In a prospective cohort study, we enrolled 196 asymptomatic patients on chronic hemodialysis who had LVH as determined by echocardiography and had undergone twenty-four-hour ambulatory Holter electrocardiography between dialysis sessions (males/females, 114/82; mean age, 65+/-12 years) to analyze heart rate variability. We calculated the percentage difference between adjacent NN intervals more than 50 ms (pNN50) and high-frequency component (HF, 0.15-0.40 Hz) as parameters of cardiac parasympathetic activity, and the low-frequency component (LF, 0.04-0.15 Hz)/HF component ratio as a parameter of sympathetic activity. RESULTS: During 4.5+/-1.9-year follow-up, 21 patients who had undergone coronary revascularization within 60 days of enrollment were excluded from the analysis. Among the remaining 175 patients (male/female, 105/70; 66+/-12 years), SCD was recognized in 23 patients. On stepwise Cox hazard analysis, SCD was positively associated with age and LF/HF ratio, and tended to be inversely associated with pNN50. On Kaplan-Meier analysis, SCD-free survival rates at 5 years were 29.4% and 98.1% in patients with LF/HF ratios of 1.9 or more and below 1.9, respectively. CONCLUSIONS: The presence of cardiac sympathetic overactivity may predict the occurrence of SCD in the asymptomatic hemodialysis patients with LVH.

Oral nicorandil to reduce cardiac death after coronary revascularization in hemodialysis patients: a randomized trial.

BACKGROUND: Survival after invasive coronary revascularization is worse in patients with chronic kidney disease than in patients without chronic kidney disease. We examined whether oral administration of nicorandil, a hybrid nitrate and adenosine triphosphate-sensitive potassium channel opener, could improve outcome after coronary revascularization in hemodialysis patients. STUDY DESIGN: Open-labeled prospective randomized trial. SETTING & PARTICIPANTS: Maintenance hemodialysis patients who underwent percutaneous coronary artery intervention and had complete coronary revascularization (absence of both restenosis and de novo coronary lesion) at coronary arteriography 6 months later. Enrollment occurred between January 1, 2002, and December 31, 2004. INTERVENTIONS: Treatment with or without oral administration of nicorandil, 15 mg/d. OUTCOMES & MEASUREMENTS: The primary end point was cardiac death (sudden cardiac death or death from acute myocardial infarction or congestive heart failure). The secondary end point was all-cause death. End-point adjudication was performed masked to the intervention. RESULTS: 129 patients (91 men, 38 women) with a mean age of 66 +/- 9 (SD) years. During a 2.7 +/- 1.5-year follow-up, 26 died of cardiac events (acute myocardial infarction, 6; congestive heart failure, 5; sudden cardiac death, 15), and 12 died of noncardiac causes. Cardiac death-free survival rates were greater in the nicorandil group than in the control group (P = 0.009; at 3 years, 86.6% in the nicorandil group and 70.7% in the control group). All-cause death-free survival rates were also greater in the nicorandil group than in the control group (P = 0.01; at 3 years, 79.2% in the nicorandil group versus 60.5% in the control group). Additional percutaneous coronary artery intervention was performed in 6 participants in the nicorandil group and 2 participants in the control group. No serious side effects of nicorandil were reported during the course of the study. LIMITATIONS: Small sample size and open-label design. CONCLUSIONS: Oral administration of nicorandil may reduce cardiac death and improve the survival of hemodialysis patients after coronary revascularization.

Myocardial fatty acid imaging identifies a group of hemodialysis patients at high risk for cardiac death after coronary revascularization.

We prospectively evaluated if impaired myocardial fatty acid metabolism is involved in cardiac death after revascularization by percutaneous coronary artery intervention in dialysis patients. A cohort of hemodialysis patients was assessed by dual single-photon emission computed tomography using the radioiodinated fatty acid analogue BMIPP and radiolabeled thallium chloride. Tomography was done within one month before the first coronary intervention and at the last follow-up angiography at which neither restenosis nor de novo lesions were detected. Radiolabel uptake on tomography images was graded in segments and calculated as summed BMIPP or thallium scores. Among the 90 hemodialysis patients in the study, 19 died of cardiac events. Multivariate Cox hazard analysis found a significant association of cardiac death with the BMIPP summed scores at the last follow-up angiography. Kaplan-Meier analysis showed the cardiac death-free survival rates at 3 years of follow-up were significantly higher in patients with lower BMIPP summed scores. These results suggest that myocardial fatty acid imaging may be a useful test to identify high risk groups of cardiac death in hemodialysis patients.

Association of insulin resistance with de novo coronary stenosis after percutaneous coronary artery intervention in hemodialysis patients.

BACKGROUND/AIMS: De novo coronary atherosclerosis may be involved in the poor prognosis after percutaneous coronary artery intervention (PCI) in hemodialysis patients. We aimed to clarify the factors associated with de novocoronary lesion in this population. METHODS: We enrolled 106 patients on hemodialysis (72 men, 34 women; mean age, 65.4 +/- 8.9 years), who had firstly received PCI with bare-metal stents for single coronary lesions and undergone follow-up coronary angiography (CAG) 6 months thereafter. Coronary lesion with stenosis of >50% diameter that was newly recognized at follow-up CAG was defined as de novo coronary stenosis. The values of biochemical parameters were determined as the means of several measurements between PCI and follow-up CAG. RESULTS: Follow-up CAG revealed de novo coronary stenosis in 40 (37.7%) of the 106 hemodialysis patients who had received PCI. Stepwise multiple logistic regression analysis showed that de novo coronary lesions were strongly associated with homeostasis model assessment insulin resistance index (HOMA-IR; 1 mM x [microU/ml]: odds ratio, 7.312; p =0.001). This significant association of HOMA-IR with de novo coronary stenosis was recognized in the diabetic and nondiabetic subgroups. CONCLUSIONS: Insulin resistance may be involved in the progression of nonculprit coronary atherosclerosis after PCI in hemodialysis patients.