Current status of prevention, diagnosis, and management of coronary artery disease in patients with kidney failure

Serum lipids and cardiac function correlate with nitrotyrosine and MMP activity in coronary artery disease patients

AIMS

Peroxynitrite-matrix metalloproteinase (MMP) signalling has been shown to contribute to myocardial ischaemia/reperfusion injury and heart failure and to be influenced by hyperlipidaemia in preclinical models. Therefore, here we investigated the correlation between the markers of peroxynitrite-MMP signalling and hyperlipidaemia in patients with significant coronary stenosis.

METHODS

Five minutes before percutaneous coronary intervention (PCI), arterial blood samples were collected from 36 consecutive patients with coronary artery disease (CAD) selected for elective PCI.

RESULTS

Serum nitrotyrosine positively correlated with MMP-9 activity (r = 0·54, P = 0·01), but not with MMP-2 activity. Nitrotyrosine positively correlated with total (r = 0·58; P < 0·01) and LDL cholesterol (r = 0·55; P < 0·01), serum triglyceride (r = 0·47; P < 0·05), and creatinine (r = 0·42; P < 0·05) and negatively correlated with HDL cholesterol (r = -0·46; P < 0·05) and with left ventricular ejection fraction (LVEF; r = -0·55; P < 0·05), respectively. MMP-2 activity correlated positively with total (r = 0·55; P < 0·05) and LDL cholesterol (r = 0·45; P < 0·05). In statin-treated patients, a significantly reduced serum nitrotyrosine was found as compared to statin naives; however, MMP activities and serum cholesterol levels were not different. MMP-9 activity correlated with urea nitrogen (r = 0·42; P < 0·05) and LVEF (r = -0·73; P < 0·01). Serum creatinine correlated negatively with LVEF (r = -0·50, P < 0·01).

CONCLUSIONS

This is the first demonstration that (i) serum nitrotyrosine correlates with MMP-9 activity, (ii) lipid parameters correlate with nitrotyrosine and MMP-2 activity, (iii) myocardial function correlates with creatinine, nitrotyrosine and MMP-9 activity, and (iv) creatinine correlates with nitrotyrosine and urea nitrogen with MMP-9 activity in patients with CAD. Studying the biomarkers of peroxynitrite-MMP pathway in large prospective trials may reveal their diagnostic avails.

Management of ischemic heart disease in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) and ischemic heart disease (IHD) have strikingly high mortality rates. In the general population, there has been a reduction in the mortality and morbidity rates for IHD through the implementation of effective risk-factor-reduction programs and better interventions for patients with established IHD. No such trend has been observed in patients with end-stage kidney disease. This review article addresses the following topics: (i) epidemiology, pathogenesis, clinical CKD patients with IHD; (ii) diagnostic modalities for IHD and their limitation in CKD patients; (iii) medical treatment options and revascularization strategies for these high-risk patients; and (iv) optimal cardiovascular risk management. Generally, in CKD patients with IHD an aggressive approach to IHD is warranted, a low threshold for diagnostic testing should be employed, and awaiting a clinical trial targeting these patients they should be considered for all proven strategies to improve outcomes.

Outcomes of Off-Pump versus On-Pump Coronary Artery Bypass Surgery in End-Stage Renal Disease Patients with a History of Myocardial Infarction

BACKGROUND

Patients with end-stage renal disease (ESRD) and myocardial infarction (MI) have poor survival. Coronary artery bypass grafting (CABG) in select patients is an effective treatment strategy; however, whether operative technique influences hospital outcome is not defined.

METHODS

Between 1995 and 2000, 342 patients had ESRD (creatinine >2.0 mg/dL or dialysis) and a history of MI at the time of CABG. There were 67 patients that had off-pump coronary artery bypass (OPCAB) (OFF) and 275 that had CABG (ON). The OFF group was compared to the ON group for clinical, operative, outcome data, and influence of acuity of MI.

RESULTS

The OFF group was older (P = .09), but hypertension was more common in the ON group (82% versus 69%, P = .02). The frequency of diabetes, congestive heart failure, peripheral vascular disease, and dyslipidemia were common, but not different between groups. For the OFF versus ON group, creatinine serum level was 3.6 +/- 2.6 versus 3.5 +/- 3.1 (P = 0.17), and history of an acute MI was 39% versus 33% (P = 0.78). The OFF versus ON group had fewer total grafts (2.5 +/- 1 versus 3.8 +/- 1, P < .001). The OFF group had fewer strokes (P = .08), shorter intensive care unit stay (2.4 versus 3.8 days), and shorter hospitalization (8.4 versus 11.7 days), yet mortality was similar (7% versus 9%, P = .79). After acute MI, OFF patients had significantly more postoperative supraventricular tachycardia than ON (69% versus 19%, P < .001).

CONCLUSIONS

Patients with ESRD and an MI have acceptable hospital outcomes regardless of operative strategy. OPCAB or CABG may provide an advantage in certain patients, yet it is the presence of an acute MI that is a predictor of postoperative events.

Acute coronary syndromes in patients with renal disease: what are the issues?

Patients with chronic kidney disease and acute coronary syndromes are at high risk for both bleeding and ischemic events. This risk increases with the severity of renal insufficiency. Management for acute coronary syndromes in the setting of kidney disease is a paradox; as the benefit of current treatment is high, so is the risk for complications. Patients with chronic renal disease are frequently excluded from randomized clinical trials, and therefore, the optimal treatment strategies are often speculative in this high-risk patient population. Additional research is needed to further refine the optimal management of patients with chronic kidney disease in the setting of acute coronary syndromes.

Prediction of coronary artery disease by transesophageal echocardiographic detection of thoracic aortic plaque in patients with chronic kidney disease

BACKGROUND/AIMS

Our aim was to examine the significance of thoracic aortic plaque detected by transesophageal echocardiography (TEE) in the prediction of coronary artery disease (CAD) in patients with chronic kidney disease (CKD).

METHODS

We examined 118 patients (mean age 52 +/- 12 years) with CKD and followed them for a mean of 3.4 +/- 0.8 years. The study group included 52 predialysis patients with moderate to severe CKD (plasma creatinine > or = 200 micromol/l), 32 patients on dialysis treatment, and 34 renal transplant recipients. At baseline, TEE was performed to evaluate thoracic aortic atherosclerosis. CAD was defined by a history of a documented myocardial infarction, a coronary angiogram or a post-mortem autopsy finding showing significant occlusive CAD by the end of the follow-up period.

RESULTS

CAD was documented in 31 (26%) of the 118 study patients. The presence of thoracic aortic plaque had a sensitivity of 100% and a specificity of 37% for CAD and the positive and negative predictive values were 36 and 100%, respectively. In the subset of 36 patients with morphological findings of coronary arteries by angiogram or autopsy, the presence of large thoracic aortic plaques (> or = 3 mm in diameter) had a 73% sensitivity and 90% specificity for significant coronary artery stenosis. The positive and negative predictive values were 95 and 56%, respectively.

CONCLUSION

TEE may be used for detecting high-risk patients with CKD; the absence of thoracic aortic plaque predicted the absence of CAD, and the presence of large aortic plaques predicted significant coronary artery stenosis.

The prognostic value of serum creatinine on admission in fibrinolytic-eligible patients with acute myocardial infarction

BACKGROUND

Previous studies have demonstrated that impaired renal function is associated with unfavourable outcomes in patients with acute coronary syndromes and following percutaneous coronary intervention.

METHODS

We hypothesized that serum creatinine (Cr) on admission is a useful predictor of mortality in fibrinolytic-eligible patients with ST-elevation myocardial infarction (MI). Data were collected from 352 patients with ST-elevation MI, 89% of patients underwent early invasive management.

RESULTS

30-day and 6-month mortality were increased among patients with mild to moderate (Cr > 1.2-2.8 mg/dl) renal dysfunction compared to patients with normal (Cr <or= 1.2 mg/dl) renal function (3.4% vs. 16.1%, p < 0.001 and 4.5% vs. 19.5%, p < 0.001). After adjustment for previously identified correlates of mortality in a multiple logistic regression model, higher Cr on admission remained independently associated with increased mortality (30-day, OR 4.78, 95%CI 1.55-14.73, p = 0.006; 6-month, 3.82 (1.45-10.11), p = 0.007). The incidence of mortality was reduced among those patients with renal dysfunction that also underwent acute percutaneous coronary intervention [30-day, OR 0.13, 95%CI 0.02-1.06, p < 0.03; 6-month, 0.23 (0.05-1.07), p < 0.05].

CONCLUSION

Cr on admission is a strong and independent predictor of mortality in patients with ST-elevation MI. This association does not appear to be mediated by reduced fibrinolytic efficacy, or by higher reinfarction rates among patients with renal dysfunction. Cr on admission is a rapid and widely available marker to identify high-risk patients with ST-elevation MI that have additional improvements in survival when treated with percutaneous coronary intervention.

Tirofiban and eptifibatide treatment of patients presenting with acute coronary syndrome with non-ST segment elevation

OBJECTIVE

This retrospective study was conducted to determine the usage patterns and tolerability of tirofiban and eptifibatide during the first year of their use.

METHODS

We have assessed the appropriate use of these drugs according to the criteria implemented by the Clinical Institute of Cardiovascular Disease as part of a protocol for treating acute coronary syndrome with non-ST segment elevation.

RESULTS

37 patients received tirofiban and 19 patients received eptifibatide. These patients were at high risk of poor outcomes such as myocardial infarction or death. Tirofiban and eptifibatide were used according to the indication criteria: only one case fell outside them. Dosing, time for drug initiation (from last chest pain) and time of infusion were considered appropriate. Tirofiban was involved in two cases of minor bleeding complications and eptifibatide in one case of thrombocytopenia (80,000 platelets per millimeter). These mild adverse drug reactions were reversible with the early withdrawal of the drugs.

CONCLUSIONS

This study shows that tirofiban and eptifibatide have been used optimally, with a close adherence to the pre-established protocol. Both drugs have shown a good level of tolerability.

Contrast nephropathy

Contrast nephropathy will increase mortality up to 30% following angiographic procedures. Before performing such procedures a careful reassessment of the risk/benefit ratio should be performed. Mannitol and diuretics play no role in prevention. Hydration and correction of abnormal electrolyte levels should be done in all patients. Pre-treatment with acetylcysteine and theophylline is a well-accepted strategy and should always be utilized. If creatinine levels are above 2.5 to 3 mg/dl, fenoldopam may provide additional protection, particularly in diabetic patients. However, the role of fenoldopam is controversial. Prophylactic hemodialysis may prove to be an additional tool in the fight against this disease in selected patients.

Analysis of long-term survival after revascularization in patients with chronic kidney disease presenting with acute coronary syndromes

Ischemic heart disease is the most common cause of death in patients with chronic kidney disease (CKD). Patients with CKD who develop an acute coronary syndrome (ACS) have a poor prognosis, with >70% mortality at 2 years. Despite this heavy burden of disease, the optimal management of ACS in this patient population is unknown. Our goal was to compare the effect of coronary revascularization or medical therapy alone on the long-term survival of patients with CKD presenting with ACS. From 1990 to 1998, data were prospectively collected on 4,758 patients admitted to a coronary care unit with the diagnosis of ACS. Of these, 3,104 had preserved renal function, and 1,654 had significant renal dysfunction, as defined by the National Kidney Foundation in the Kidney Disease Outcomes Quality Initiative classification of kidney function as an estimated glomerular filtration rate of <60 ml/min/1.73 m(2). Long-term survival was assessed and outcomes were compared according to whether patients were treated with medical therapy alone or if they underwent a percutaneous or surgical revascularization procedure. Follow-up information was available in 99% of the patients up to 8 years after the index hospitalization. Of the 1,654 patients with significant renal dysfunction, 64 underwent coronary artery bypass surgery, 232 underwent percutaneous coronary revascularization, 280 underwent a diagnostic cardiac catheterization and were subsequently treated medically, whereas 1,078 were treated with medical therapy alone. Percutaneous coronary revascularization was associated with superior long-term survival. In conclusion, patients with severe CKD and ACS had improved long-term survival when treated with percutaneous coronary revascularization.

Risk factors for aortic atherosclerosis determined by transesophageal echocardiography in patients with CRF

BACKGROUND

The significance of various risk factors for cardiovascular disease (CVD) in the pathogenesis of atherosclerosis in patients with chronic renal failure (CRF) is, to a great deal, unresolved. The high risk for CVD in patients with CRF may be caused by the high prevalence of recognized risk factors for CVD or by factors characteristic of CRF in these patients. In this prospective cross-sectional study, we examined risk factors for thoracic aortic atherosclerosis in a population of patients with CRF consisting of predialysis and dialysis patients, as well as renal transplant recipients.

METHODS

Of 118 patients, 52 patients had moderate to severe predialysis CRF, 32 patients were on dialysis treatment, and 34 patients were renal transplant recipients. Mean age was 52 +/- 12 years, and 35 patients (30%) had diabetes. Multiplane transesophageal echocardiography (TEE) was performed using local anesthesia.

RESULTS

Large aortic plaques (LAPs; > or = 3.0 mm in diameter) were found in 39 patients (33%). In univariate analysis, age, duration of hypertension, pulse pressure, low diastolic blood pressure, elevated fibrinogen level, C-reactive protein level, total cholesterol level, low-density lipoprotein cholesterol level, and duration of dialysis or a functioning renal transplant were significantly associated (P < 0.05) with LAP. In multivariate analysis, age, duration of hypertension, and total cholesterol level were associated with LAP.

CONCLUSION

Results of the present TEE study suggest that in addition to duration of hypertension and renal disease, hypercholesterolemia has a role in the pathogenesis of atherosclerosis in patients with CRF.

Are HMG-CoA reductase inhibitors underutilized in dialysis patients?

Patients with end-stage renal disease (ESRD) treated with dialysis have a dramatically elevated rate of cardiovascular disease (CVD) compared to the general population. Lipid-lowering therapy with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors ("statins") has been shown to markedly reduce cardiovascular risk in patients without renal failure, but their effect has not been fully studied in the dialysis population. In this article we will first discuss the known benefits of statin therapy in the general population and summarize the current guidelines for such therapy. We will then examine the evidence linking dyslipidemia and cardiac disease in the dialysis population and discuss possible pathophysiologic mechanisms by which statins could prevent cardiac disease in these patients. We will also review prior clinical studies of the effects of statins in patients on dialysis, with particular attention to the safety and efficacy of these drugs in this population. Finally, we will review how statins are currently being used in the care of dialysis patients and suggest whether an expanded utilization of these drugs could help reduce the enormously high rates of cardiac disease in this patient population.

Impact of cardiac catheterization-percutaneous coronary intervention timing on inhospital mortality

BACKGROUND

It is more convenient and less costly to perform percutaneous coronary interventions (PCIs) in the catheterization laboratory after catheterization, but there is some doubt as to whether it is harmful to patients. Other studies on this topic have been hampered by small sample sizes and an inability to separate patients who underwent PCI after catheterization in the same admission from patients who underwent PCI in a subsequent admission.

METHODS

Data from New York's PCI registry were used to develop a statistical model that predicted inhospital mortality based on preprocedural patient characteristics and the timing of the PCI (at same time as catheterization [combined procedure] or in the same admission as catheterization, but not at the same time [staged procedure]). The difference in mortality for the timing options was compared after adjusting for patient risk factors.

RESULTS

Patients undergoing combined catheterization and PCI were more likely to have undergone a previous PCI and less likely to have had chronic obstructive pulmonary disease, renal failure, a history of congestive heart failure, carotid disease, or diabetes than patients who underwent a staged procedure. After adjustment for patient risk, there were no significant differences in mortality for the 2 timing options (OR 1.14, P =.38 for combined vs staged procedures). However, patients who underwent combined procedures who had congestive heart failure in the same admission or who had Canadian Cardiovascular Society class IV had odds ratios significantly higher than congestive heart failure patients who underwent staged procedures (OR = 1.59, P =.04 and OR = 1.64, P =.04, respectively).

CONCLUSIONS

Combined procedures appear to have mortality as low as staged procedures on average, but are less effective for some groups of high-risk patients.

Benefits and safety of tirofiban among acute coronary syndrome patients with mild to moderate renal insufficiency: results from the Platelet Receptor Inhibition in Ischemic Syndrome Management in Patients Limited by Unstable Signs and Symptoms (PRISM-PLUS) trial

BACKGROUND

The role of glycoprotein IIb/IIIa receptor antagonists for the treatment of patients with acute coronary syndrome and renal insufficiency remains undefined.

METHODS AND RESULTS

Patients from the Platelet Receptor Inhibition in Ischemic Syndrome Management in Patients Limited by Unstable Signs and Symptoms (PRISM-PLUS) trial were stratified by creatinine clearance (CrCl) and assessed with respect to treatment assignment to tirofiban/heparin versus heparin alone for the risk of adverse outcomes and bleeding. Patients with severe renal insufficiency (defined as a serum creatinine > or = 2.5 mg/dL) were excluded from PRISM-PLUS as a whole. Patients with the lowest CrCl (< 30 mL/min) were more likely to present with high-risk clinical features. Decreasing renal function was strongly associated with adverse outcome, increasing the risk for ischemic complications at all time points examined (all P < 0.002). Irrespective of CrCl, therapy with tirofiban reduced the odds of the composite end point of death, myocardial infarction, or refractory ischemia at 48 hours (odds ratio [OR], 0.68; 95% confidence interval [CI], 0.46 to 1.0; P=0.05), 7 days (OR, 0.68; 95% CI, 0.52 to 0.88; P= 0.003), 30 days (OR, 0.78; 95% CI, 0.63 to 0.98; P=0.03), and 6 months (OR, 0.81; 95% CI, 0.68 to 0.98; P=0.03). The risk of myocardial infarction/death was also significantly decreased to a similar magnitude at all time points examined. There was no evidence of treatment-by-CrCl interaction. The presence of declining renal function independently increased the risk for bleeding (OR, 1.57; P < 0.001 for trend across categories), as did therapy with tirofiban, but no unexpected incremental risk of bleeding due to tirofiban was observed among lowest CrCl categories.

CONCLUSIONS

Among patients with mild-to-moderate renal insufficiency in PRISM-PLUS, tirofiban was well tolerated and effective in reducing ischemic acute coronary syndrome complications.