Serum malondialdehyde and coronary artery disease in hemodialysis patients

BACKGROUND/AIMS: It has been suggested that enhanced oxidative stress participates in the acceleration of coronary artery disease (CAD) in patients with end-stage renal disease (ESRD). The aim of this study was to investigate the relationship between the level of malondialdehyde (MDA), which is a marker of lipid peroxidation, and the severity of CAD in ESRD patients. METHODS: We conducted a study of 39 hemodialysis patients (median age 58 years; 27 males and 12 females; diabetics 44%). In these patients, the predialysis serum concentrations of MDA and C-reactive protein (CRP) were measured. We performed multirow spiral computed tomography to derive coronary artery calcification (CAC) scores, as a marker of CAD severity. RESULTS: Eleven of the 39 patients had minimal CAC (28%, CAC score <10), 10 patients had mild to moderate CAC (26%, 10-400), and 18 patients had severe CAC (46%, >400). The MDA levels increased (p < 0.05) with increasing CAC category and were correlated (r = 0.35, p < 0.05) with the CAC scores. The levels of MDA also correlated with the serum concentrations of CRP and albumin (r = 0.34, p < 0.05 and r = -0.32, p < 0.05, respectively). Patients in the highest tertile of MDA compared with the other patients were over four times as likely to have severe CAC, and the highest tertile of MDA was an independent predictor of severe CAC, along with a previous cardiovascular event. CONCLUSION: An increased level of MDA, which was associated with inflammatory markers, was a predictive factor for severe CAC in ESRD patients.     

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.     

Myocardial consequences of remifentanil in patients with coronary artery disease

Remifentanil may be an alternative to conventional opioids forminimally invasive direct coronary artery bypass surgery becauseof its extremely short duration of action. The aim of this studywas to investigate the effects of remifentanil on myocardialblood flow, metabolism and systemic haemodynamic variables inpatients with coronary artery disease. After approval by thelocal ethics committee, 12 male patients were investigated beforeelective coronary artery bypass grafting. Systemic haemodynamicvariables, myocardial blood flow and metabolism were measuredwhen patients were awake and when they were anaesthetized withhigh-dose remifentanil (2.0 µg kg^–1 min^–1),or with remifentanil 0.5 µg kg^–1 min^–1 combinedwith propofol (target-controlled infusion aiming at a plasmaconcentration of 2.0 µg ml^–1). Myocardial bloodflow was measured using a modified Kety–Schmidt technique.High-dose remifentanil anaesthesia significantly reduced cardiacindex (CI) (–25%) as a consequence of a decrease in strokevolume index (SVI) (-14%) and heart rate (-13%). Mean arterialpressure (MAP) was 30% lower than that in the awake patient.Myocardial blood flow and myocardial oxygen uptake (MV     

Myocardial temperature mapping in patients with left main coronary artery disease

Two consecutive groups of high risk patients with left main coronary disease (greater than 50% stenosis) undergoing aortocoronary bypass grafting using different cardioplegia delivery methods were compared retrospectively for perioperative myocardial infarction (MI) and mortality. Group I (July 1979 to June 30, 1982, n = 53) received an initial 1000 ml aortic root cardioplegia infusion from a pressure regulated (85-100 mmHg) delivery system. Regional mid-myocardial wall temperatures determined the distal anastomoses sequence (with the warmest region bypassed first) followed by additional 400 ml cardioplegia infusions. Group II patients (March 1976 to June 30, 1979, n = 47) had their cardioplegia administered by a hand-held syringe without regional temperature mapping. The volume injected varied and was based on cessation of electrical activity or a septal temperature less than 20 degrees C. Background data were similar except that Group I was significantly older than Group II (63.4 +/- 1.4 years vs 57.1 +/- 1.5 years, p less than 0.01). Despite this, there was only 1 (2%) perioperative MI in Group I vs 6 (13%) in Group II (p less than 0.05). There was also a marked reduction in cardiac mortality with 1 (2%) cardiac death in Group I vs 5 (11%) in Group II (p = 0.09). These data suggest that the delivery of adequate volumes of cardioplegia, in conjunction with myocardial temperature directed bypass grafting, can improve myocardial preservation in high risk patients.     

Detecting asymptomatic coronary artery disease using routine exercise testing and exercise thallium scintigraphy in patients with atherosclerotic vascular disease

ECG-monitored exercise testing has been proposed as a relatively inexpensive and effective means of screening for asymptomatic coronary artery disease in patients presenting for peripheral vascular surgery. Despite the fact that exercise thallium scintigraphy is also dependent on the patient's ability to exercise, using this test in conjunction with ECG-monitored exercise testing may enhance sensitivity and specificity of non-invasive evaluation. Thirty-two patients were subjected to ECG-monitored exercise testing, exercise thallium scintigraphy and coronary angiography. The sensitivity of ECG-monitored exercise testing for detecting coronary artery disease was calculated at 81.8% and the specificity at 87.5%, while the figures for exercise thallium scintigraphy were 73.1% and 33.3% respectively. Using these two methods in combination yielded a predictive accuracy of 90.6%. The only advantage of exercise thallium scintigraphy over exercise ECG appears to be in patients in whom the latter test could not be interpreted or was non-diagnostic.     

The value of computed tomography-derived coronary artery calcification score in coronary artery disease detection in asymptomatic hemodialysis patients

BACKGROUND: We evaluated the value of coronary artery calcification (CAC) score in coronary artery disease (CAD) detection in asymptomatic hemodialysis (HD) patients by evaluating the association among CAC score, exercise electrocardiography (EECG), and Thallium-201 dipyridamole scintigraphy. Correlation between aortic pulse wave velocity (PWV) and CAC score was also evaluated. METHODS: CAC score was assessed with conventional computed tomography in 40 patients. Thirty patients completed EECG and 25; those with a positive CAC score and/or a positive EECG performed Thallium dipyridamole scintigraphy. Carotid-femoral PWV was assessed in all patients. RESULTS: There was no association among CAC score and EECG or Thallium dipyridamole scintigraphy. In contrast, CAC score was correlated with aortic PWV. CONCLUSION: The previous results question the role of CAC score in the detection of CAD in asymptomatic HD patients. The correlation between CAC score and aortic PWV raises the possibility that CAC score represents more an indicator of coronary artery medial wall calcification than a marker of CAD.     

Risk stratification for cardiac death in hemodialysis patients without obstructive coronary artery disease

The incidence of cardiac death is higher among patients receiving dialysis compared with the general population. Although obstructive coronary artery disease is involved in cardiac deaths in the general population, deaths in hemodialysis patients occur in the apparent absence of obstructive coronary artery disease. To study this further, we prospectively enrolled 155 patients receiving hemodialysis after angiography had confirmed the absence of obstructive coronary lesions. All patients were examined by single-photon emission computed tomography using the iodinated fatty acid analog, BMIPP, the uptake of which was graded in 17 standard myocardial segments and assessed as summed scores. Insulin resistance was determined using the homeostasis model assessment index of insulin resistance (HOMA-IR). During a mean follow-up of 5.1 years, 42 patients died of cardiac events. Stepwise Cox hazard analysis associated cardiac death with reduced BMIPP uptake and increased insulin resistance. Patients were assigned to subgroups based on BMIPP summed scores and HOMA-IR cutoff values for cardiac death of 12 and 5.1, respectively, determined by receiver operating characteristic analysis. Cardiac death-free survival rates at 5 years were the lowest (32.2%) in the subgroup with both a summed score and assessment equal to or above the cutoff values compared with any other combination (52.9-98.7%) above, equal to, or below the thresholds. Thus, impaired myocardial fatty acid metabolism and insulin resistance may be associated with cardiac death among hemodialysis patients without obstructive coronary artery disease.     

Off-pump coronary artery bypass grafting in patients with end-stage renal disease on hemodialysis

BACKGROUND: Coronary artery bypass grafting (CABG) for hemodialysis patients is high risk compared with other patient groups. The aim of this study was to analyze the potential benefits of off-pump CABG for hemodialysis patients. METHODS: From April 1994 through December 2000, 26 hemodialysis patients underwent CABG. The off-pump group consisted of 15 patients operated on without a pump and the on-pump group consisted of 11 patients operated on with a pump. RESULTS: There was no difference between the two groups with regard to mean age, mean number of diseased vessels and mean number of anastomoses per patient. No patient died in either group during hospitalization. The postoperative complication rate was low in both groups. The postoperative ventilation time was shorter in the off-pump group (8.5 vs 26.1 hours, p < 0.001, respectively [off-pump group vs on-pump group]). The length of ICU stay was shorter in the off-pump group (1.7 vs 3.5 days, p = 0.01, respectively [off-pump group vs on-pump group]). The medial cost was lower in the off-pump group (26,200.80 dollars versus 44,024.10 dollars p = 0.0001 respectively [off-pump group vs on-pump group]). CONCLUSIONS: Off-pump CABG provided excellent less-invasive cardiac surgical results for dialysis patients.     

Comparison of percutaneous coronary intervention with medication in the treatment of coronary artery disease in hemodialysis patients

It has been reported that percutaneous coronary intervention (PCI) is beneficial for coronary artery disease (CAD) among the general population. However, its effects in patients who are on hemodialysis (HD) remain unclear. A prospective cohort study was performed to clarify whether PCI has a therapeutic advantage over medical therapy among HD patients with CAD. A follow-up study to 5 yr was conducted among 259 HD patients with ischemic heart disease. Mean follow-up was 39 mo. Patients were divided into three groups: 122 patients without significant stenosis, 88 patients who had significant stenosis and were treated with PCI, and 49 patients who had significant stenosis and were treated with medication only. The primary end point was cardiac death, and the secondary end point was all-cause death. The results showed that the 5-yr cardiac survival rate was 41.6% in the medication group, 77.1% in the PCI group (P = 0.0006), and 84.5% in the nonstenosis group (P < 0.0001). The 5-yr all-cause survival rate was 19.3% in the medication group, 48.4% in the PCI group (P = 0.004), and 64.3% in the nonstenosis group (P < 0.0001). Even after adjustment for other risk factors, effects of PCI on the risk for cardiac and all-cause death remained significant and independent (odds ratio 0.14; 95% confidence interval 0.08 to 0.25, P = 0.0006; and odds ratio 0.37; 95% confidence interval 0.26 to 0.54, P = 0.0062, respectively). Results were consistent when the therapeutic effect of PCI or medication was analyzed using propensity-matched patients. These data suggested that PCI could improve the prognosis of HD patients with CAD. PCI would be recommended for HD patients with CAD.     

Prognostic value of nonlinear heart rate dynamics in hemodialysis patients with coronary artery disease

BACKGROUND: Although altered nonlinear heart rate dynamics predicts death in patients with coronary artery disease (CAD), its prognostic value in chronic hemodialysis patients with CAD is unknown. METHODS: We analyzed 24-hour electrocardiogram for nonlinear heart rate dynamics and heart rate variability in a retrospective cohort of 81 chronic hemodialysis patients with CAD. RESULTS: During a follow-up period of 31 +/- 20 months, 19 cardiac and 8 noncardiac deaths were observed. Cox hazards model, including diabetes, left ventricular ejection fraction, and the number of diseased coronary arteries, revealed that abnormal alpha2 (defined as both increase and decrease in alpha2 because of its J curve relationship with cardiac mortality), decreased approximate entropy and decreased heart rate variability (triangular index and ultra-low frequency power) were significant and independent predictors of cardiac death. No significant and independent predictive power for noncardiac death was observed in either the heart rate dynamics or the heart rate variability measures. The predictive power of alpha2 and approximate entropy was independent of that of triangular index and ultra-low frequency power. Combinations of two categories of measures improved the predictive accuracy; overall accuracy of approximate entropy + ultra-low frequency power for cardiac death was 87%. CONCLUSION: Altered nonlinear heart rate dynamics are independent predictors of cardiac death in chronic hemodialysis patients with CAD and their combinations with decreased heart rate variability provide clinically useful markers for risk stratification.     

血液透析患者冠状动脉钙化的危险因素

目的 研究血液透析患者冠状动脉钙化情况,并分析其相关危险因素.方法 选择行血液透析治疗的患者201例,横断面调查所有患者血红蛋白、透析前后血清钙、血清磷、血清钾、尿素氮、肌酐、全段甲状旁腺激素、总蛋白、白蛋白、总胆固醇、甘油三酯、C反应蛋白、血清铁、铁蛋白、总铁结合力和冠状动脉钙化情况,分析冠状动脉钙化相关危险因素.结果 201例血液透析患者中发生冠状动脉钙化137例,总钙化发生率为68.2％.冠状动脉钙化组与无钙化组比较,年龄、性别、高血压、糖尿病、收缩压、脉压差、血钾、血磷、Kt/V及腰臀比差异均有统计学意义(P＜0.05).年龄、透析龄、性别、收缩压、脉压差、血钾、血磷为冠状动脉钙化的独立危险因素(P＜0.05);Kt/V为冠状动脉钙化的独立保护因素(P＜0.05).结论 血液透析患者冠状动脉钙化的发生率偏高;年龄、透析龄、性别、收缩压、脉压差、血钾、血磷为冠状动脉钙化的独立危险因素;Kt/V为冠状动脉钙化的独立保护因素.     

Myocardial perfusion scintigraphy as a screening method for significant coronary artery stenosis in cardiac transplant recipients.

BACKGROUND: Several studies have explored the feasibility of using myocardial perfusion imaging to detect allograft vasculopathy after heart transplantation. We undertook the present prospective consecutive study to comparatively evaluate the role of serial myocardial perfusion single-photon emission computed tomography (SPECT) scanning and coronary arteriography (CAG) in detecting coronary artery stenosis suitable for coronary angioplasty in heart transplant recipients. METHODS: Within a 2-week interval during a follow-up period of 5.6 (95% confidence limits 2.1 to 12) years, 255 serial CAGs and myocardial perfusion scintigraphies were performed in 67 patients. Arteriography and scintigraphy were performed once yearly after heart transplantation. We retrospectively analyzed the data. RESULTS: Myocardial scintigraphy showed pathologic reversible defects in 9 out of 67 patients. Four of these patients had significant (>50% and also >70%) focal segmental stenosis in the middle and proximal parts of the coronary arteries (Type A lesions), 1 had diffuse and circumferential narrowing in the distal parts (Type B lesions), whereas CAG showed no lesions in the remaining 4 patients. The patients with significant Type A lesions were revascularized with percutaneous coronary angioplasty. Coronary arteriography showed that 1 patient had extensive Type A and Type B lesions, whereas myocardial perfusion scans detected no. The predictive value of a negative (normal) SPECT was 98% (95% confidence limits 94% to 100%) for the detection of lesions suited for revascularization. CONCLUSIONS: Annual myocardial SPECT seems well suited to screen for significant coronary artery stenosis. A SPECT study without reversible defects virtually excludes lesions suitable for coronary artery revascularization.     

Clinical significance of natriuretic peptides and cyclic GMP in hemodialysis patients with coronary artery disease

BACKGROUND: Plasma concentrations of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and cyclic guanosine monophosphate (cGMP) are suitable markers of 'dry body weight' (DW) in hemodialysis (HD) patients. However, it is still unknown whether these markers can be applied to patients with renal failure and coronary artery disease (CAD). We examined the reliability of these peptides as volume markers in HD patients with CAD. We also assessed the relationship between natriuretic peptides and indices of left ventricular (LV) function. METHODS: Plasma concentrations of ANP, BNP and cGMP were determined before and after HD in patients with CAD (group 1, n = 19, mean age 63 +/- 12 years) and were compared with those of patients without cardiac disease (group 2, n = 20, age 61 +/- 15 years). Using data obtained by cardiac catheterization, we examined the relationship between natriuretic peptides and indices of LV function in HD patients with CAD. RESULTS: Baseline ANP (244 +/- 205 pg/ml), BNP (713 +/- 928 pg/ml) and cGMP (29.6 +/- 21.6 pmol/ml) were significantly higher in group 1 than in 11 healthy volunteers (18.6 +/- 9.9 pg/ml, 7.7 +/- 7.6 pg/ml, cGMP 8.9 +/- 4.9 pmol/ml, respectively). HD significantly reduced plasma ANP (87 +/- 75 pg/ml) and BNP (477 +/- 702 pg/ml) although they were still above normal control. HD reduced plasma cGMP (7.2 +/- 4.5 pmol/ml) to normal values, suggesting the elimination of cGMP across the dialyzers. Baseline levels of ANP, BNP and cGMP in group 2 were less than those of group 1 but higher than the control. HD reduced natriuretic peptides in group 2 to levels lower than those in post-HD group 1. After HD, there was no significant correlation between reductions in body weight and changes in ANP or BNP. Baseline ANP and BNP levels closely correlated with pulmonary artery pressure, pulmonary artery wedge pressure, left ventricular end-diastolic pressure and left ventricular ejection fraction. A significant correlation was observed between BNP levels and the severity of CAD. CONCLUSION: ANP, BNP and cGMP seem to be a useful markers for fluid overload but not for DW in HD patients with CAD. Plasma ANP and BNP might be useful markers for left ventricular function.     

Prognosis after off-pump coronary artery bypass in patients receiving hemodialysis

PURPOSE: This study was performed to evaluate the perioperative and long-term results of off-pump coronary artery bypass grafting (OPCAB) in hemodialysis (HD)-dependent patients. METHODS: We retrospectively analyzed the results of isolated OPCAB performed at Tokyo Women's University Medical Center East from February 27, 2000, to May 12, 2006. Perioperative data for patients receiving HD (group HD, n=39) were compared with data from patients not receiving HD (group noHD, n=60). The long-term results of group HD also were examined. RESULTS: Group HD consisted of 34 males and 5 females with a mean age of 63.2+/-10.2 years. The percentage of patients in group HD with complete all-arterial revascularization was significantly lower than in group noHD. However, the mortality rate, number of distal anastomoses, operative time, intensive care unit (ICU) stay, hospital stay, bleeding during surgery, blood transfusions, intubation time, intra-aortic balloon pumping use, and emergency ratio were similar in the two groups. During a mean follow-up of 27.0+/-13.7 months, the actuarial 1-and 5-year survival rates of group HD were 80% and 70%, respectively. CONCLUSION: In patients receiving HD, OPCAB is safe and improves survival.     

The efficacy of hemodialysis in interventional therapy in coronary artery disease patients with chronic renal insufficiency

The aim of this study was to explore the efficacy and safety of hemodialysis in interventional therapy for patients with coronary artery disease combined with chronic renal insufficiency. With the aging and social development, the number of coronary artery disease patients with chronic renal insufficiency gradually increased. Total 58 coronary heart disease patients with chronic renal dysfunction were selected. These patients were characterized with typical angina symptoms and typical electrocardiogram (ECG) changes of onset angina. Continuous oral administration of sodium bicarbonate tablets 1?g 3/day?×?3 days and slow intravenous input sodium chloride 1000 ～1500 mL 3–12?h before operation were given. By this way, all patients were treated by hydration and alkalization. After percutaneous coronary intervention (PCI) treatment, patients were immediately transferred to undergo 4?h of dialysis treatment without removing indwelling of femoral artery puncture sheath tube to protect renal function. Changes in renal function including serum creatinine, glomerular filtration rate, and urine were observed and recorded. All patients were successfully underwent PCI treatment. Within one month after PCI, there were no obvious complication and no stent thrombosis occurred. Among of 58 patients, 56 cases showed no significant increase in serum creatinine levels compared with those before operation. However, serum creatinine level of one patient increased to 251?umol/L and one patient still required permanent dialysis. Using hemodialysis in interventional therapy in coronary artery disease patients with chronic renal insufficiency could significantly improve the prognosis of the patients.     

Diagnosis of coronary artery disease by stress echocardiography and perfusion scintigraphy

This meta-analysis was performed to compare the diagnostic efficacy of stress echocardiography (SE) and Stress perfusion studies (SPS) in detecting coronary artery disease (CAD). A meta-analysis of peer reviewed articles, published in English language, reporting head-to-head comparison of vasodilator stress echocardiography (VSE) and SPS for the diagnosis of CAD, was performed. Data of 13 studies comprising of 860 patients from 13 different institutions were analyzed. Algorithms were developed to generate raw data from published papers to calculate statistical parameters with confidence intervals and then compare them at specified significance levels. The overall diagnostic accuracy of the two tests was almost similar, 0.77 for VSE vs 0.8 for SPS (p=ns). SPS gave higher sensitivity, 0.88 vs 0.70 in cumulative data (p<0.0001) while VSE gave higher specificity, 0.90 vs 0.67 (p<0.0001). Accuracy of VSE with state-of-the-art protocols became even better than SPS (p<0.05). In hypertensive patients specificity of SPS was markedly deteriorated. Contrary to this, VSE gave higher specificity (0.90 vs 0.40) in this subgroup of patients as well. VSE might become an effective alternative of SPS where scintigraphy techniques are not available or affordable.     

Off-pump coronary artery grafting in patients with left main coronary artery disease

BACKGROUND: Left main coronary artery disease (LMCD) is considered a relative contraindication to off-pump coronary artery bypass (OPCAB) grafting. This study evaluates the safety and feasibility of OPCAB in these patients compared to an on-pump group (cardiopulmonary bypass, CPB) with LMCD. METHODS: Between January 2000 and July 2002, 95 patients with left main coronary artery stenosis >50% underwent coronary revascularization. Seventy-three unselected patients underwent OPCAB and 22 underwent revascularization using CPB. The techniques used for OPCAB included the use of deep traction sutures in the posterior pericardium and stabilizers to expose the distal coronary targets. Intraluminal coronary shunts were routinely used during construction of the anastomoses. Variables were analyzed using a Student's paired t-test with statistical significance defined as p < 0.05. RESULTS: The mean age in the OPCAB group was 59.9 years and the CPB group 61.8 years (p = 0.54). There were 56 males (77%) in the OPCAB and 18 (82%) in the CPB groups. Mean preoperative left ventricular ejection fraction (LVEF) was 40.3% in OPCAB and 47.3% in CPB (p = 0.015). Average number of grafts was 3.1 in OPCAB and 4.1 in CPB (p = 0.0038). There were no conversions to CPB in those patients initially chosen to undergo OPCAB. There were no early deaths in OPCAB. There was one death in CPB. Mean hospital length of stay was 6.9 days for OPCAB and 9.1 for CPB (p = 0.0159). CONCLUSIONS: Patients with LMCD can undergo OPCAB grafting safely and effectively despite reduced LVEF. LMCD should no longer be seen as a contraindication to perform OPCAB grafting.