A comparison of coronary artery bypass grafting and percutaneous transluminal coronary angioplasty in patients on hemodialysis

Coronary revascularisation in patients with chronic kidney disease and end-stage renal disease: A meta-analysis

OBJECTIVES

To compare coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) for revascularising coronary arteries in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). CKD is described as a continuous decrease in the glomerular filtration rate or abnormalities in kidney structure or function.

METHODS

PubMed, Cochrane Library and Embase databases were searched for studies on the revascularisation of coronary arteries in patients with CKD and ESRD.

RESULTS

Since no randomised controlled trials (RCTs) have addressed this issue so far, 31 observational studies involving 74 805 patients were included in this meta-analysis. Compared with PCI, patients undergoing CABG have significantly higher early mortality (CKD: RR = 1.62, 95% CI: 1.17-2.25, pheterogeneity = 0.476, I²  = 0; ESRD: RR = 1.99, 95% CI: 1.46-2.71, pheterogeneity = 0.001, I²  = 66.9%). Patients with ESRD undergoing CABG have significantly lower all-cause mortality (RR = 0.95, 95% CI: 0.93-0.96, pheterogeneity < 0.001, I²  = 82.9%) and cardiac mortality (RR = 0.73, 95% CI: 0.58-0.92, pheterogeneity = 0.908, I²  = 0). The long-term risk of repeat revascularisation (CKD: RR = 0.24, 95% CI: 0.19-0.30, pheterogeneity = 0.489, I²  = 0; ESRD: RR = 0.23, 95% CI: 0.15-0.34, pheterogeneity = 0.012, I²  = 54.4%) and myocardial infarction (CKD: RR = .57, 95% CI: 0.38-0.85, pheterogeneity = 0.025, I²  = 49.9%; ESRD: RR = 0.42, 95% CI: 0.40-0.44, pheterogeneity = 0.49, I²  = 0) remained significantly higher in the PCI group.

CONCLUSIONS

Patients with ESRD, but not CKD, who underwent CABG had significantly lower all-cause mortality and cardiac mortality. However, CABG was associated with an increased risk of early mortality in patients with CKD or ESRD. Adequately powered, contemporary, prospective RCTs are needed to define the optimal revascularisation strategy for patients with CKD and ESRD.

Optimal treatment strategies for coronary artery disease in patients with advanced kidney disease: a meta-analysis

Background:

Coronary artery disease (CAD) is the leading cause of death in advanced kidney disease. However, its best treatment has not been determined.

Methods:

We searched PubMed and Cochrane databases and scanned references to related articles. Studies comparing the different treatments for patients with CAD and advanced CKD (estimated glomerular filtration rate <30 ml/min/1.73 m² or dialysis) were selected. The primary result was all-cause death, classified according to the follow-up time: short-term (<1 month), medium-term (1 month-1 year), and long-term (>1 year).

Results:

A total of 32 studies were selected to enroll 84,498 patients with advanced kidney disease. Compared with medical therapy (MT) alone, percutaneous coronary intervention (PCI) was associated with low risk of short-, medium-term and long-term all-cause death (more than 3 years). For AMI patients, compared with MT, PCI was not associated with low risk of short- and medium-term all-cause death. For non-AMI patients, compared with MT, PCI was associated with low risk of long-term mortality (more than 3 years). Compared with MT, coronary artery bypass surgery (CABG) had no significant advantages in each follow-up period of all-cause death. Compared with PCI, CABG was associated with a high risk of short-term death, but low risk of long-term death: 1–3 years; more than 3 years. CABG could also reduce the risk of long-term risk of cardiac death, major adverse cardiovascular events (MACEs), myocardial infarction (MI), and repeat revascularization.

Conclusions:

In patients with advanced kidney disease and CAD, PCI reduced the risk of short-, medium- and long- term (more than 3 years) all-cause death compared with MT. Compared with PCI, CABG was associated with a high risk of short-term death and a low risk of long-term death and adverse events.

Effectiveness of Percutaneous Coronary Intervention Versus Coronary Artery Bypass Grafting in Patients With End-Stage Renal Disease

The optimal coronary revascularization strategy (coronary artery bypass grafting [CABG] or percutaneous coronary intervention [PCI]) in patients with end-stage renal disease (ESRD) remains uncertain. We performed an updated systematic review and meta-analysis of observational studies comparing CABG and PCI in patients with ESRD using a random-effects model for the primary outcome of long-term all-cause mortality. Our review registered through PROSPERO included observational studies published after 2011 to ensure overlap with previous studies and identified 7 new studies for a total of 23. We found that the median sample size in the selected studies was 125 patients (25 to 15,784) with a large variation in the covariate risk adjustment and only 3 studies reporting the indications for the revascularization strategy. CABG was associated with a small reduction in mortality (relative risk 0.92, 95% CI 0.89 to 0.96) with significant heterogeneity demonstrated (p = 0.005, I(2) = 48.6%). Subgroup analysis by categorized "year of study initiation" (<1990, 1991 to 2003, >2004) further confirmed the summary estimate trending toward survival benefit of CABG along with a substantial decrease in heterogeneity after 2004 (p = 0.64, I(2) = 0%). In conclusion, our updated systematic review and meta-analysis demonstrated that in patients with ESRD referred for coronary revascularization, CABG was associated with a small decrease in the relative risk of long-term mortality compared with PCI. The generalizability of the finding to all patients with ESRD referred for coronary revascularization is limited because of a lack of known indications for coronary revascularization, substantial variation in covariate risk adjustment, and lack of randomized clinical trial data.

Mode of Coronary Revascularization and Short term Clinical Outcomes in Patients with Chronic Kidney Disease

Background and Objective: Percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) surgery are two alternative methods for coronary revascularization, but it remains controversial as which one is associated with lower risks of worse clinical outcomes for chronic kidney disease (CKD) patients. We determined the mode of coronary revascularization (PCI vs. CABG) which is associated with lower risk of mortality and morbidity in CKD patients.

Methods: In this cross sectional study, 159 patients with CKD were enrolled from single center of coronary revascularization at Aga Khan University Hospital Karachi between January 2012 and August 2013. All patients with CKD underwent PCI or CABG. The primary outcome was in-hospital composite of death, myocardial infarction (MI), or stroke. We evaluated which mode of coronary revascularization was associated with reduced risks of clinical outcomes.

Results: Out of 159 patients with CKD, 85 (53.5%) received PCI and 74 (46.5%) received CABG. The primary finding of this study is that more patients with moderate to severe CKD underwent PCI and more patients with mild to moderate CKD underwent CABG. In both these categories, no difference was observed in clinical outcomes. There are few factors like age, ST- elevation myocardial infarction (STEMI), non-ST elevation myocardial infarction (NSTEMI) and number of coronary artery disease predicted PCI as treatment strategy in patients with moderate to severe CKD.

Conclusion: Patients with moderate to severe CKD have similar rates of short term clinical outcomes whether they underwent PCI or CABG. Therefore, PCI can be acceptable and less invasive treatment option alternative to CABG, particularly in patients with moderate to severe CKD.

Optimal strategy of coronary revascularization in chronic kidney disease patients: a meta-analysis

BACKGROUND

Patients with chronic kidney disease (CKD) have high risks of coronary artery disease (CAD). Coronary revascularization is beneficial for long-term survival, but the optimal strategy remains still controversial.

METHODS

We searched studies that have compared percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) for revascularization of the coronary arteries in CKD patients. Short-term (30 days or in-hospital) mortality, long-term (at least 12 months) all-cause mortality, cardiac mortality and the incidence of late myocardial infarction and recurrence of revascularization were estimated.

RESULTS

28 studies with 38,740 patients were included. All were retrospective studies from 1977 to 2012. Meta-analysis showed that PCI group had lower short-term mortality (OR 0.55, 95% CI 0.41 to 0.73, P<0.01), but had higher long-term all-cause mortality (OR 1.29, 95% CI 1.23 to 1.35, P<0.01). Higher cardiac mortality (OR 1.08, 95% CI 1.01 to 1.15, P<0.05), higher incidence of late myocardial infarction (OR 1.78, 95% CI 1.65 to 1.91, P<0.01) and recurring revascularization rate (OR 2.94, 95%CI 2.15 to 4.01, P<0.01) is found amongst PCI treated patients compared to CABG group.

CONCLUSIONS

CKD patients with CAD received CABG had higher risk of short-term mortality but lower risks of long-term all-cause mortality, cardiac mortality and late myocardial infarction compared to PCI. This could be due to less probable repeated revascularization.

Impact of preoperative renal dysfunction in patients undergoing off-pump versus on-pump coronary artery bypass

BACKGROUND

The impact of the degree of renal dysfunction (RD) in patients undergoing coronary artery bypass grafting (CABG) ranging from normal to dialysis-dependence is not well defined.

METHODS

A retrospective review of 14,199 patients undergoing isolated, primary CABG from January 1996 to May 2009 at Emory Healthcare was performed. The estimated glomerular filtration rate (eGFR) was estimated by the Modification of Diet in Renal Disease formula: mild RD (eGFR 60 to 90 mL/min/1.73 m2), moderate RD (eGFR 30 to 59), severe RD (eGFR<30). A propensity scoring was used to balance the groups with 46 preoperative covariates. Multivariable logistic and Cox regression methods were used to determine the independent association of eGFR with mortality. Adjusted odds ratios were calculated for outcomes using the normal eGFR group as the reference. Kaplan-Meier curves were created to estimate long-term survival.

RESULTS

A total of 8,086 patients (57.0%) underwent off-pump coronary artery bypass (OPCAB) while 6,113 (43.0%) underwent on-pump CAB. Preoperative RD was common: Normal eGFR (n=3,503/14,199 [24.7%]); mild RD (7,236/14199 [51.0%]); moderate RD (2,860/14,199 [20.1%]); severe RD (283/14,199 [2.0%]); and preoperative dialysis (317/14,199 [2.2%]). Moderate to severe RD or preoperative dialysis was associated with worse adjusted in-hospital mortality: mild RD (odds ratio [OR] 1.42; 95% confidence interval [CI] 0.93 to 2.16; p=not significant); moderate RD (OR 3.55; 95% CI 2.32 to 5.43; p<0.05]; severe RD (OR 8.84; 95% CI 4.92 to 15.9; p<0.05); and dialysis-dependent (OR 9.64; 95% CI 5.45 to 17.0; p<0.05). Adjusted long-term survival was worse across levels of RD. The OPCAB patients with moderate to severe RD had worse long-term survival than on-pump CAB patients; however, the surgery types were similar among normal, mild, and dialysis patients.

CONCLUSIONS

Preoperative RD is common in the CABG population and is associated with diminished long-term survival. Improved early outcomes in patients with RD undergoing OPCAB diminished with worsening RD.

Optimal method of coronary revascularization in patients receiving dialysis: systematic review

BACKGROUND AND OBJECTIVES

Patients receiving dialysis have a high burden of cardiovascular disease. Some receive coronary artery revascularization but the optimal method is controversial.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The authors reviewed any randomized controlled trial or cohort study of 10 or more patients receiving maintenance dialysis which compared coronary artery bypass graft (CABG) to percutaneous intervention (PCI) for revascularization of the coronary arteries. The primary outcomes were short-term (30 d or in-hospital) and long-term (at least 1 year) mortality.

RESULTS

Seventeen studies were found. There were no randomized trials: all were retrospective cohort studies from years 1977 to 2002. There were some baseline differences between the groups receiving CABG compared with those receiving PCI, and most studies did not consider results adjusted for such characteristics. Given the variability among studies and their methodological limitations, few definitive conclusions about the optimal method of revascularization could be drawn. In an exploratory meta-analysis, short-term mortality was higher after CABG compared to PCI. A substantial number of patients died over a subsequent 1 to 5 yr, with no difference in mortality after CABG compared to PCI.

CONCLUSIONS

Although decisions about the optimal method of coronary artery revascularization in dialysis patients are undertaken routinely, it was surprising to see how few data has been published in this regard. Additional research will help inform physician and patient decisions about coronary artery revascularization.

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.

On-pump versus off-pump coronary surgery outcomes in patients requiring dialysis: perspectives from a single center and the United States experience

OBJECTIVE

Coronary artery bypass graft surgery carries increased risk for patients requiring dialysis compared with other groups. Little data exist comparing outcomes of on-pump and off-pump techniques in dialysis patients. This study compares outcomes of bypass grafting in dialysis patients with these two techniques at a single institution and in the United States Renal Data System (USRDS) database.

METHODS

From March 1997 to April 2004, 37 patients requiring dialysis underwent bypass graft surgery at our institution. On-pump surgery was performed for 16 patients and off-pump surgery for 21. From January 1, 2001, to December 31, 2002, a total of 3922 patients in the USRDS underwent bypass graft surgery. On-pump surgery was performed for 3382 and off-pump surgery for 540. Comparisons were made between patients undergoing on-pump and off-pump bypass surgery with respect to demographics, risk factors, and outcomes. Univariate analysis, the Kaplan-Meier method, and a multivariate Cox model were used.

RESULTS

Institutional analysis revealed similar patient demographics, risk factors, use of thoracic artery grafts, and number of distal anastomoses. Outcome analysis was significant for less postoperative atrial fibrillation with the off-pump technique: 37.5% on-pump and 4.8% off-pump (P = .028). USRDS data revealed all-cause survivals at 1 and 18 months of 87.5% and 59.5% for on-pump versus 88.3% and 61.9% for off-pump procedures (P = .226). In a comorbidity-adjusted Cox model, off-pump bypass grafting was associated with a 16% reduction in all-cause mortality (P = .032).

CONCLUSION

Off-pump bypass grafting is uncommon in patients in the United States who require dialysis. Off- pump bypass grafting provides a morbidity benefit and is associated with a lower risk of death.

Coronary surgery in patients requiring chronic hemodialysis

BACKGROUND

In uremic patients coronary surgery and the entire perioperative management is demanding.

METHODS

We analyzed retrospectively data from all patients requiring chronic hemodialysis who under went coronary artery bypass grafting (CABG) between January 1 2001 and December 31 2004 at the Deutsches Herzzentrum Berlin and compared them to those of a randomized nonuremic control group (n = 68), which consisted of patients who underwent CABG during the same period.

RESULTS

During the study period 6315 patients underwent coronary artery bypass grafting at the Deutsches Herzzentrum Berlin. Among these patients, we identified 71 chronic dialysis patients (1.12%). Among dialysis patients, we recorded a perioperative mortality of 5.6%. One-year survival rate was 87.7% among uremic patients and 91.0% in the control group; the corresponding 4-year survival rates were 56.7 and 88.0%, respectively. The incidence of peripheral artery disease was significantly higher in the dialysis group. Uremic patients showed significantly lower hemoglobin serum levels at the time of admission compared to the control group (11.4 +/- 1.62 vs. 13.3 +/- 1.81 mg/dl). These patients received significantly higher numbers of blood transfusions (6.7 +/- 5.6 vs. 2.75 +/- 3.8), and platelet transfusions.

CONCLUSION

Our preliminary study indicates that coronary surgery can be performed with acceptable mid-term results when the specific requirements of this patient group are taken into account.

Coronary artery disease and peripheral vascular disease in chronic kidney disease: an epidemiological perspective

The enormous burden of CAD and PVD inpatients who have CKD contributes substantially to increased morbidity and mortality. The increased risk of vascular disease observed in CKD patients is likely to be multifactorial, with contributions from traditional and nontraditional cardiovascular factors. Given the overwhelming evidence on the known benefits of cardioprotective medications, their underuse remains puzzling in a population at enormous risk. During the past 5 years, the research community and national interest groups have made significant progress in organizing a concerted approach to improve the management of patients who have CKD and vascular disease. Much work remains to be done. The development of national guidelines in the management of these patients at high risk for future cardiovascular events will be a welcome step. The evaluation of multitargeted interventions for reduction of cardiovascular risk through randomized clinical trials is desperately needed. Finally, the low use of known cardioprotective strategies in this high-risk group is a serious issue and warrants immediate attention at local and national levels.

Impact of renal insufficiency on outcome after contemporary percutaneous coronary intervention

BACKGROUND

End-stage renal failure is associated with poor outcomes, including increased mortality, after percutaneous coronary intervention (PCI). The effect of milder degrees of renal insufficiency (RI) is less clear, especially with routine stenting and glycoprotein IIb/IIIa inhibitor therapy, which may be of particular benefit in patients with RI.

METHODS

Clinical, angiographic, procedural, and outcome variables of 7769 consecutive patients who underwent PCI between April 2000 and July 2004 were entered into a prospective database. Inhospital mortality and morbidity were calculated according to baseline creatinine clearance. Simple and multiple logistic regression analyses were performed to determine independent predictors of mortality.

RESULTS

Baseline creatinine clearance was available in 6840 patients. It was normal (> 80 mL/min) in 3474; 1670 had mild RI (61-80 mL/min), 1111 moderate RI (41-60 mL/min), and 585 severe RI (< or = 40 mL/min). Major adverse cardiac events (MACE) (death/myocardial infarction/revascularization) increased substantially with worsening renal function (2.4% vs 3.0% vs 4.8% vs 9.7%, P < .0001), as did mortality (0.3% vs 0.7% vs 1.5% vs 6.0%, P < .0001). Multiple logistic regression analysis identified moderate RI and severe RI as independent predictors of mortality (odds ratio [OR] 3.9, P < .001; OR 12.7, P < .0001, respectively) and morbidity (MACE) (OR 1.5, P < .05; OR 2.5, P < .0001, respectively). Mild RI trended to increase the risk of mortality but did not reach statistical significance as an independent predictor of inhospital death on multiple regression analysis (OR 2.1, P = .1) and did not increase the risk of MACE (OR 1.1, P = .6).

CONCLUSIONS

Despite routine stenting and glycoprotein IIb/IIIa inhibitor therapy, RI remains an independent predictor of increased morbidity, and particularly mortality, after PCI. However, the adverse effect of truly mild RI on outcome is limited.

The Outcome of Cardiac Surgery in Dialysis-Dependent Patients

BACKGROUND

Patients on dialysis for end-stage renal failure (ESRF) are undergoing cardiac surgery with increasing frequency. Furthermore, ESRF is known to be an important risk factor for complications of cardiac operations performed with cardiopulmonary bypass.

AIMS

To evaluate the outcome of dialysis-dependent patients undergoing cardiac surgery at one institution.

METHODS

A retrospective analysis was performed on consecutive patients with ESRF dependent upon maintenance haemodialysis or peritoneal dialysis who underwent cardiac surgery from January 1998 to August 2002.

RESULTS

Thirty-eight patients on dialysis underwent cardiac surgery during this time period (1.5% of total cases). The most common cause for ESRF was diabetic nephropathy (n = 12). Operations performed included isolated coronary artery bypass grafting (CABG, n = 22), CABG and valve surgery (n = 8), and valve surgery alone (n = 6). When allowing for age, sex, surgeon and operative category, the odds ratio for mortality risk of dialysis patients, compared with all others, was 4.9 (95% confidence interval (CI): 1.7-13.9, p = 0.003), and for morbidity risk, was 2.8 (95% CI: 1.4-5.4, p = 0.003).

CONCLUSIONS

Patients on dialysis have an increased morbidity and mortality following cardiac surgery, however we believe ESRF should not be regarded as an absolute contraindication to cardiac surgery or cardiopulmonary bypass.

Association of chronic kidney disease with clinical outcomes after coronary revascularization: the Arterial Revascularization Therapies Study (ARTS)

BACKGROUND

Chronic kidney disease (CKD) is associated with adverse outcomes after coronary artery bypass graft surgery (CABG) and percutaneous coronary interventions (PCI), but it is unclear which of these revascularization strategies is associated with lower risk for morbidity and mortality in this population. In the Arterial Revascularization Therapies Study (ARTS), we compared long-term clinical outcomes after CABG or PCI with multivessel stenting in patients with CKD.

METHODS

The ARTS randomly assigned 1205 participants with and without CKD to CABG or PCI with multivessel stenting. We defined CKD as creatinine clearance < or =60 mL/min, estimated by the Cockroft-Gault equation. The primary outcome was the composite of death, myocardial infarction (MI), or stroke; and, a secondary outcome was repeat revascularization. Participants were followed for a mean of 3 years after their intervention. We evaluated whether randomization to CABG or PCI was associated with different outcomes among participants with CKD.

RESULTS

Two hundred ninety participants (25%) had CKD at entry into ARTS. One hundred fifty-one received PCI, and 139 received CABG. No difference was observed in the primary endpoint with CABG or PCI among CKD participants (adjusted Hazard Ratio [HR] CABG vs PCI = 0.93; 95% CI 0.54-1.60; P = .97). However, CABG was associated with a reduced risk for repeat revascularization (HR = 0.28; 95% CI 0.14-0.54; P < .01). Compared with participants with normal renal function, CKD was associated with a nearly 2-fold risk for the primary outcome (unadjusted HR = 1.9; 95% CI 1.4-2.7; P < .01). After multivariate adjustment, this association remained significant (HR 1.6; 95% CI 1.1-2.4).

CONCLUSIONS

In patients with multivessel CAD and CKD, treatment with CABG or PCI with multivessel stenting led to similar outcomes of death, MI, or stroke, but CABG was associated with decreased repeat revascularizations. When compared with ARTS participants with normal renal function, those with CKD had substantially elevated risk of adverse clinical outcomes after coronary revascularization.

Coronary bypass before simultaneous pancreas-kidney transplants for type 1 diabetics in renal failure

Our study examined the results of coronary artery bypass (CAB) before simultaneous pancreas-kidney (SPK) transplant in type 1 diabetics in renal failure. Of 588 pancreas transplant patients from 1992 to 2002, 77 (24 females, 53 males) were candidates for SPK transplant. All 77 had coronary evaluation and were referred for pretransplant CAB. Among the 77 CAB patients, the mean age was 42 years (range: 30- 63 years), and the duration of diabetes was 28.52 years (range: 9-51 years). All had neuropathy, retinopathy, and nephropathy; 12.9% (n = 10) had angina; and 76% (n = 59) were on dialysis at the time of CAB. The creatinine level of the 18 nondialysis patients was 3.7 mg%; 42.8% (n = 33) had suffered myocardial infarction. The left ventricular ejection fraction (LVEF) was 49% (30-65%). At CAB surgery, 88% (n = 68) triple, 9% (n = 7) double, and 2.5% (n = 2) single arterial grafts were implanted. All 77 CAB patients had severe coronary artery disease (CAD); some vessels could not be bypassed in 9.8%. At surgery, 3.4 grafts/patient were implanted (range: 1-6 grafts). All 59 dialysis patients continued dialysis after CAB; 6 nondialysis patients required dialysis after CAB. The intensive care stay averaged 1.86 days (range: 1-10 days); the hospital stay averaged 10.5 days (range 6-28 days). There was no operative mortality. Eventually, 68 patients underwent SPK transplant; 9 await organs. The waiting period for 68 CAB patients who had SPK was 2 years, 5 months (range: 2 months to 10 years). The SPK operative mortality was 3.9% (n = 3). Significant CAD exists in patients > 30 years of age with type 1 diabetes and renal failure. Pretransplant CAB can be done safely and may reduce posttransplant mortality associated with cardiac events.

The renal patient with coronary artery disease

The patient with chronic kidney disease and coronary artery disease (CAD) presents special challenges. This report reviews the scope of the challenge, the hostile internal milieu predisposing to CAD and cardiac events, management issues, unresolved dilemmas, and the need for randomized trials to allow for evidence-based treatment.

Initial body mass indexes have contrary effects on change in body weight and mortality of patients on maintenance hemodialysis treatment

Malnutrition is a relevant risk factor for mortality for patients on maintenance hemodialysis treatment. In a retrospective study including 377 patients who began hemodialysis treatment between 1986 and 2001, we assessed the prevalence of different statuses of nutrition and the impact of the initial status of nutrition on the change in body weight and patient survival. We found an inverse relationship between body mass index (BMI, kg/m2) and the gain in body weight and BMI within 12 months of hemodialysis treatment. Underweight and normal weight patients had a substantial increase in these parameters, greatest in underweight subjects, whereas overweight and obese patients showed only a moderate increase or none (P =.0019, P =.00036). Adjusted mortality rates showed an inverse correlation with the initial BMI (P <.0001). There was a statistically significant difference in the mortality between patients with normal weight and overweight or obesity, respectively, showing a more favorable prognosis in overweight and obese patients (P =.0007; P =.022; log-rank, normal versus overweight, P =.012). Weight loss was the greatest independent risk factor for mortality in general. Adjusted hazard ratio of death was highest in underweight patients (3.999; CI, 2.708 to 5.905; P <.0001) and decreased to 2.251 (CI, 1.795 to 2.822; P <.0001) in normal weight, 1.927 (CI, 1.390 to 2.670; P <.0001) in overweight, and 1.651 (CI, 0.841 to 3.236; P =.1439) in obese subjects when patients with weight loss were compared with patients who preserved their initial weight or gained weight. Overall, the initial BMI has an influence on the change in body weight as well as on patient survival in general and in the case of weight loss in particular.

Management of heart failure and coronary artery disease in patients with chronic kidney disease

Cardiovascular disease (CVD) is a major contributor to the mortality and morbidity of patients who suffer from chronic kidney disease (CKD). Heart failure and ischemic heart disease (IHD) are both highly prevalent in this population. The diagnosis of myocardial dysfunction is usually based on echocardiography. As in the general population, systolic dysfunction is treated with a combination of diuretics, renin-angiotensin system blockade, and beta-receptor antagonists. Diastolic dysfunction is best managed by eliminating the cause. Non-invasive tests for coronary artery disease (CAD) may be less reliable in patients with renal disease compared with nonuremic patients. Medical therapy of IHD in this population is generally similar to that for other patient groups, but surgical revascularization appears to carry a higher risk of complications with poorer clinical outcomes. The choice of revascularization procedure (coronary artery bypass grafting versus percutaneous transluminal angioplasty) should be based on the specific coronary anatomy of a given patient as well as a consideration of other comorbid factors.

Comparative survival of dialysis patients in the United States after coronary angioplasty, coronary artery stenting, and coronary artery bypass surgery and impact of diabetes

BACKGROUND

The optimal method of coronary revascularization in dialysis patients is controversial. The purpose of this study was to compare the long-term survival of dialysis patients in the United States after PTCA, coronary stenting, or CABG.

METHODS AND RESULTS

Dialysis patients hospitalized from 1995 to 1998 for first coronary revascularization procedures after renal replacement therapy initiation were identified from the US Renal Data System database. All-cause and cardiac survival was estimated by the life-table method and compared by the log-rank test. The impact of independent predictors on survival was examined in a Cox regression model. The in-hospital mortality was 8.6% for 6668 CABG patients, 6.4% for 4836 PTCA patients, and 4.1% for 4280 stent patients. The 2-year all-cause survival (mean+/-SEM) was 56.4+/-1.4% for CABG patients, 48.2+/-1.5% for PTCA patients, and 48.4+/-2.0% for stent patients (P<0.0001). After comorbidity adjustment, the relative risk (RR) for CABG (versus PTCA) patients was 0.80 (95% CI 0.76 to 0.84, P<0.0001) for all-cause death and 0.72 (95% CI 0.67 to 0.77, P<0.0001) for cardiac death. For stent (versus PTCA) patients, the RR was 0.94 (95% CI 0.88 to 0.99, P=0.03) for all-cause death and 0.92 (95% CI 0.85 to 0.99, P=0.04) for cardiac death. In diabetic (versus PTCA) patients, the RR for CABG surgery was 0.81 (95% CI 0.75 to 0.88, P<0.0001) for all-cause death and 0.71 (95% CI 0.64 to 0.78, P<0.0001) for cardiac death, and the RR for the stent procedure was 0.99 (95% CI 0.91 to 1.08, P=NS) for all-cause death and 0.99 (95% CI 0.89 to 1.11, P=NS) for cardiac death.

CONCLUSIONS

In this retrospective study, dialysis patients in the United States had better long-term survival after CABG surgery than after percutaneous coronary intervention. Stent outcomes were relatively worse in diabetic patients. Our data support the need for large clinical registries and prospective trials of surgical and percutaneous coronary revascularization procedures in dialysis patients.

Outcome of cardiac surgery patients with complicated intensive care unit stay

Risk stratification has become an essential element in the practice of cardiac surgery. Several studies have identified preoperative risk factors for adverse outcome. However, outcome is mostly defined by 30-day mortality and morbidity. These data reflect poorly the benefit for the patient. Long-term survival, quality of life, and functional status should be included in a more global analysis of the outcome, particularly in patients with complicated ICU stay. By reviewing the recent data reported in the literature, we can identify a number of preoperative predictive factors for complicated ICU stay, including advanced age, chronic obstructive pulmonary disease, preoperative low ejection fraction, previous myocardial infarction, reoperation, renal failure, combined surgery (coronary artery bypass grafting plus valve surgery), low hematocrit, and neurologic impairment. Short- and long-term outcomes are dependent on the type of postoperative complication. Unfortunately, data regarding the long-term outcome in these situations are very scarce.

Prognostic implications of abnormalities in renal function in patients with acute coronary syndromes

BACKGROUND

Outcomes in patients with mild to moderate renal function (RF) abnormalities presenting with acute coronary syndromes (ACS) are not well defined.

METHODS AND RESULTS

A convenience sample of 4 ACS trial databases including all enrolled patients was assessed to determine 30- and 180-day outcomes. The 4 trials were Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO) IIb, GUSTO-III, Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT), and Platelet IIb/IIIa Antagonism for the Reduction of Acute coronary syndrome events in a Global Organization Network (PARAGON-A). Patients were stratified into ST-segment elevation (STE) and non-ST-segment elevation (NSE) groups and by the presence or absence of abnormal RF (creatinine clearance <70 mL/min). In the STE group, 7670 of 18 621 patients (41%) had abnormal RF. In the NSE group, 8152 of 19 304 (42%) had abnormal RF. Patients with abnormal RF were older, more often female, and more likely to have adverse baseline characteristics. They had higher mortality and higher mortality/nonfatal myocardial infarction (MI) at both 30 and 180 days, regardless of ST-segment status. Creatinine clearance was independently associated with risk of mortality (hazard ratio 0.79 in the STE group and 0.81 in the NSE group) and with risk of mortality/MI (hazard ratio 0.93) in the NSE group at 180 days.

CONCLUSIONS

Patients presenting with ACS frequently have abnormal RF. Abnormal RF is a marker of adverse baseline clinical characteristics and is independently associated with increased risk of death and death/MI.

Long-term survival of dialysis patients after coronary bypass grafting

BACKGROUND

Dialysis patients are undergoing coronary artery bypass grafting (CABG) with increasing frequency. The long-term effect of preoperative dialysis-dependent renal failure on mortality after CABG has not been well studied.

METHODS

We conducted a prospective regional cohort study of 15,574 consecutive patients undergoing isolated CABG in northern New England from 1992 to 1997. Patient records were linked to the National Death Index to assess mortality. Five-year survival and adjusted hazard ratios were calculated.

RESULTS

During 32,589 person-years of follow-up 1298 deaths were recorded. Renal failure was present in 283 patients (1.8%), and 67.8% of patients with renal failure also had diabetes or peripheral vascular disease (PVD). The annual death rate was 3.8% for nonrenal failure patients, 16.9% for all renal failure patients, 7.7% for renal failure patients without diabetes or PVD, and 23.0% for renal failure patients with diabetes or PVD. Five-year survival was 83.5% for nonrenal failure patients, 55.8% for all renal failure patients, 78.5% for renal failure patients without diabetes or PVD, and 42.2% for renal failure patients with diabetes or PVD. After adjustment for differences in base line patient and disease characteristics, renal failure patients without diabetes or PVD had a statistically nonsignificant 57% increase rate of death compared with those without renal failure; renal failure patients with diabetes or PVD had more than a fourfold increased risk of death.

CONCLUSIONS

After adjustment for other risk factors, renal failure remains a highly significant predictor of decreased long-term survival in CABG patients. Patients with renal failure plus diabetes or PVD are at especially high risk of death.

Coronary revascularization improves long-term prognosis in diabetic and nondiabetic end-stage renal disease

To test the hypothesis that coronary revascularization improves long-term prognosis in patients with hemodialysis, 80 of 121 patients (66%) on maintenance hemodialysis who had undergone initial coronary angiography had bypass surgery, catheter angioplasty, or both between 1983 and 1999. Multivessel disease was more frequent (p=0.01) and the duration of hemodialysis therapy was shorter (p=0.01) in patients with diabetes (n=61), than in nondiabetic patients (n=60). Of the patients who underwent revascularization, complete revascularization was achieved in 75% of those with diabetic nephropathy (30/40) and 83% in a similar number of nondiabetic patients (33/40). The 5-year survival rate from initiation of hemodialysis was 79% in diabetic and 96% in non-diabetic patients (p<0.01), exceeding published Japanese (53% vs 70%) and US (26% vs 60%) survival rates. When survival was studied from the date of revascularization, predictors of outcome were age and achievement of complete revascularization. Surprisingly, diabetes was not a predictor of survival outcome. Complete revascularization improves long-term survival in both diabetic and nondiabetic patients.

Outcomes of patients with chronic renal insufficiency in the bypass angioplasty revascularization investigation

BACKGROUND

Although severe chronic kidney disease (CKD) is an independent predictor of mortality among patients with coronary artery disease, the impact of mild CKD on morbidity and mortality has not been fully defined.

METHODS AND RESULTS

Morbidity and mortality for the 3608 patients with multivessel coronary artery disease enrolled in the Bypass Angioplasty Revascularization Investigation randomized trial and registry were compared on the basis of the presence and absence of CKD, defined as a preprocedure serum creatinine level of >1.5 mg/dL. Seventy-six patients had CKD. Patients with renal insufficiency were older and more likely to have a history of diabetes, hypertension, and other comorbidities. Among patients undergoing PTCA, patients with CKD had a greater frequency of in-hospital death and cardiogenic shock (P<0.05 and 0.01, respectively). There was a trend toward a larger proportion of patients with CKD experiencing angina at 5 years (P=0.079). Patients with CKD had more cardiac admissions (P=0.003 and <0.0001 for patients undergoing PTCA and CABG, respectively) and a shorter time to subsequent CABG after initial revascularization than patients without CKD (P=0.01). CKD was associated with a higher risk of death at 7 years, both of all causes (relative risk 2.2, P<0.001) and of cardiac causes (relative risk 2.8, P<0.001).

CONCLUSIONS

CKD is associated with an increased risk of recurrent hospitalization, subsequent CABG, and mortality. This increased risk of death is independent of and additive to the risk associated with diabetes.

The impact of renal insufficiency on clinical outcomes in patients undergoing percutaneous coronary interventions

OBJECTIVES

We sought to determine the effect of varying degrees of renal insufficiency on death and cardiac events during and after a percutaneous coronary intervention (PCI).

BACKGROUND

Patients with end-stage renal disease have a high mortality from coronary artery disease. Little is known about the impact of mild and moderate renal insufficiency on clinical outcomes after PCI.

METHODS

Cardiac mortality and all-cause mortality were determined for 5,327 patients undergoing PCI from January 1, 1994, to August 31, 1999, at the Mayo Clinic, based on the estimated creatinine clearance or whether the patient was on dialysis.

RESULTS

In-hospital mortality was significantly associated with renal insufficiency (p = 0.001). Even after successful PCI, one-year mortality was 1.5% when the creatinine clearance was > or =70 ml/min (n = 2,558), 3.6% when it was 50 to 69 ml/min (n = 1,458), 7.8% when it was 30 to 49 ml/min (n = 828) and 18.3% when it was < 30 ml/min (n = 141). The 18.3% mortality rate for the group with < 30 ml/min creatinine clearance was similar to the 19.9% mortality rate in patients on dialysis (n = 46). The mortality risk was largely independent of all other factors.

CONCLUSIONS

Renal insufficiency is a strong predictor of death and subsequent cardiac events in a dose-dependent fashion during and after PCI. Patients with renal insufficiency have more baseline cardiovascular risk factors, but renal insufficiency is associated with an increased risk of death and other adverse cardiovascular events, independent of all other measured variables.

Differential survival after coronary revascularization procedures among patients with renal insufficiency

BACKGROUND

Acute myocardial infarction, cardiac arrest, and other cardiac events are the major cause of mortality among patients with renal insufficiency. Previous studies of interventions for coronary artery disease among patients with renal insufficiency have not controlled for potentially confounding factors such as coronary artery disease severity and left ventricular function. This study investigates the comparative survival for patients with renal insufficiency and coronary artery disease following coronary artery bypass graft (CABG) surgery as compared with percutaneous coronary artery intervention (PCI), while controlling for confounding factors.

METHODS

This retrospective cohort study of patients undergoing CABG surgery or PCI discharged between 1993 and 1995 uses the New York Department of Health databases and Cox proportional hazards analyses to estimate the mortality risk associated with CABG as compared with PCI for patients with renal insufficiency. Renal function was categorized as creatinine <2.5 mg/dL (N = 58,329), creatinine > or =2.5 mg/dL (N = 840), and end-stage renal disease (ESRD) requiring dialysis (N = 407).

RESULTS

Patients with either ESRD or serum creatinine > or =2.5 mg/dL had more severe coronary artery disease and a greater frequency of comorbid conditions as compared with patients with creatinine <2.5 mg/dL. Creatinine > or =2.5 mg/dL and ESRD were both associated with an increased mortality risk among all distributions of coronary artery disease anatomy. Among patients with ESRD, the risk ratio (RR) of mortality for patients undergoing CABG compared with PCI was 0.39 (95% CI, 0.22 to 0.67, P = 0.0006). Among patients with creatinine > or =2.5 mg/dL, CABG surgery did not convey a survival benefit over PCI (RR, 0.86, 95% CI, 0.56 to 1.33, P = 0.50).

CONCLUSIONS

This study demonstrates a survival benefit among patients with ESRD undergoing CABG surgery as compared with PCI, while controlling for severity of coronary artery disease, left ventricular dysfunction, and other comorbid conditions. These results suggest that management decisions among patients with coronary artery disease should be made in the context of not only location and severity of coronary artery lesions, but also on the presence and severity of renal dysfunction.

Coronary artery bypass grafting in patients with mild renal insufficiency

It is well known that dialysis-dependent renal failure increases the likelihood of a poor outcome following cardiac surgery. However, it is not known whether non-dialysis-dependent mild renal insufficiency also influences clinical outcome. Fifty-five patients with non-dialysis-dependent renal insufficiency undergoing coronary artery bypass grafting (CABG) (Renal group: serum creatinine level >1.5 mg/dl) were enrolled. These patients were then matched on prognostic variables to 148 patients with normal renal function (

CONTROL GROUP

serum creatinine level <1.5 mg/dl). The early postoperative clinical results showed that patients in the Renal group were more likely to develop postoperative renal failure (18% vs 1%: p=0.0002) and hemorrhage requiring re-exploration (11% vs 2%; p=0.01). Total morbidity was significantly higher in the Renal group (40% vs 22%; p=0.01). Multivariate analysis revealed that the Renal group was the second most important predictor of morbidity (odds ratio (OR) =2.2) behind left ventricular dysfunction (OR=2.9). The Renal group was also the second most important predictor of postoperative renal failure (OR=12.5). Therefore, non-dialysis-dependent mild renal insufficiency also increases the risk of morbidity following CABG.

Risks of morbidity and mortality in dialysis patients undergoing coronary artery bypass surgery. Northern New England Cardiovascular Disease Study Group

BACKGROUND

Although dialysis patients are undergoing CABG with increasing frequency, large studies specifically comparing patient characteristics and procedure-related risks in this population have not been performed.

METHODS AND RESULTS

We conducted a regional prospective cohort study of 15,500 consecutive patients undergoing CABG in northern New England from 1992 to 1997. We used multiple logistic regression analysis to examine associations between preoperative dialysis-dependent renal failure and postoperative events and to adjust for potentially confounding variables. The 279 dialysis-dependent renal failure patients (1.8%) were 4.4 times more likely to experience in-hospital mortality than were other CABG patients (12.2% versus 3.0%, respectively; P:<0.001). Dialysis-dependent renal failure patients were older and had more comorbidities and more severe cardiac disease than did other CABG patients. After adjusting for these factors in multivariate analysis, however, dialysis-dependent renal failure patients remained 3.1 times more likely to die after CABG (adjusted odds ratio [OR] 3.1, 95% CI 2.1 to 4.7; P:<0.001). Dialysis-dependent renal failure patients compared with other CABG patients also had a substantially increased risk of postoperative mediastinitis (3.6% versus 1.2%, respectively; adjusted OR 2.4, 95% CI 1.2 to 4.7; P:=0.011) and postoperative stroke (4.3% versus 1.7%, respectively; adjusted OR 2. 1, 95% CI 1.1 to 3.9; P:=0.016), even after controlling for potentially confounding variables. Risks of reexploration for bleeding were similar for patients with and without dialysis-dependent renal failure.

CONCLUSIONS

Preoperative dialysis-dependent renal failure is a strong independent risk factor for in-hospital mortality and mediastinitis after CABG.

Outcome of coronary revascularization in patients on renal dialysis

Previous retrospective studies showed high periprocedure mortality rate and poor outcome after percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG) among renal dialysis patients. The purpose of this study was to compare mortality and clinical event rates in renal dialysis patients after PTCA or CABG. We identified 252 patients from the Emory Cardiovascular Database who were on dialysis and who received PTCA (122 patients) or CABG (130 patients) at Emory University Hospital and Crawford W. Long Hospital between March 1987 and December 1997. Baseline and angiographic characteristics, in-hospital, and 1-year outcome were compared between the 2 groups. Left main disease and 3-vessel coronary artery disease were significantly more common in the CABG group. There was a higher periprocedure and in-hospital mortality in the CABG group (6.9% vs 1.6%, p = 0.04). Patients in the PTCA group underwent repeat revascularization 11 times more frequently within 1 year (22% vs 2%). At 1 year, mortality was 23% in the PTCA group and 27% in the CABG group, with no statistical difference between the 2 groups. This nonrandomized comparison reveals that PTCA and CABG can be performed in selected renal dialysis patients with an acceptable in-hospital major complication rate; however, 1-year mortality remains high in dialysis patients after coronary revascularization. Therefore, attempts at improving outcome in dialysis patients should focus on the prevention and treatment of coronary artery disease before they require coronary revascularization.

Cardiac complications of end-stage renal disease

Cardiovascular disease is the leading cause of death in patients receiving dialysis. This is attributed in part to the shared risk factors of cardiovascular disease and end-stage renal disease. The risk factors for coronary artery disease include the classic cardiac risk factors of diabetes mellitus, hypertension, dyslipidemia, and smoking. Also in this population, hyperparathyroidism, hypoalbuminemia, hyperhomocysteinemia, elevated levels of apolipoprotein (a), and the type of dialysis membrane may play a role. Management begins with risk factor modification and medical therapy including aspirin, beta blockers, angiotensin converting enzyme (ACE) inhibitors, and lipid-lowering agents. Revascularization is often important, and coronary artery bypass grafting appears to be preferable to percutaneous transluminal coronary angioplasty. This is especially true for those with multivessel disease, impaired left ventricular function, severe symptoms, or ischemia. Congestive heart failure is another common problem in dialysis patients. The management includes correction of underlying abnormalities, optimal dialysis, and medical therapy. Data obtained from the general population indicate obvious benefits from ACE inhibitors and beta blockers, and these agents would be considered the therapies of choice. Erythropoetin is also an essential component of therapy, but the ideal hemoglobin concentration has yet to be determined. Peritoneal dialysis may be helpful in severe cases of heart failure. Pericarditis is seen in less than 10% of dialysis patients and is best diagnosed by clinical examination and echocardiography. Intensive dialysis is often the best initial therapy. Pericardiocentesis is reserved for the setting of pericardial tamponade, but a pericardial window is more definitive.

Survival after acute myocardial infarction in patients with end-stage renal disease: results from the cooperative cardiovascular project

Cardiovascular disease (CVD) is the most common cause of death in patients with end-stage renal disease (ESRD). The optimal management strategy in this population is unknown. We studied 640 patients with ESRD and acute myocardial infarction during 1994 to 1995 as part of the Health Care Financing Administration's Cooperative Cardiovascular Project. The majority of patients were treated with medical therapy alone, 46 patients (7%) were treated with percutaneous transluminal coronary angioplasty (PTCA), and 29 patients (5%) underwent coronary artery bypass grafting (CABG). Patient characteristics and comorbid conditions were similar among the three groups. The overall 1-year mortality rate was 53%. Advanced age, low or high body mass index, history of peripheral vascular disease or stroke, the inability to walk independently, and several indicators of cardiac dysfunction were associated with an increased relative risk (RR) for death. Survival curves differed significantly by treatment modality, with 1-year survival rates of 45%, 54%, and 69% in the medical therapy alone, PTCA, and CABG groups, respectively (P = 0.03). After adjustment for confounding variables, the RR for death was less (but not significantly so) in the CABG group (RR, 0.6; 95% confidence interval, 0.3 to 1.1). There are no randomized clinical trial data to guide therapy of CVD in patients with ESRD. On the basis of these and other available data, CABG may be the optimal therapy for CVD in ESRD. In light of the exceptionally poor outcomes observed for patients treated with medical therapy alone, it may be premature to dismiss PTCA as a therapeutic option in this population.