Early and long term results of coronary artery bypass grafts in patients with dialysis dependent renal failure

Comparative analysis of revascularization with percutaneous coronary intervention versus coronary artery bypass surgery for patients with end-stage renal disease: a nationwide inpatient sample database

BACKGROUND

The role of percutaneous coronary intervention (PCI) vs coronary artery bypass grafting (CABG) in patients with coronary artery disease (CAD) and concomitant end-stage renal disease (ESRD) remains unknown.

RESEARCH DESIGN & METHODS

The National Inpatient Sample (NIS) (2002-2017) was queried to identify all cases of CAD and ESRD. The relative merits of PCI vs CABG were determined using a propensity-matched multivariate logistic regression model. Adjusted odds ratios (aOR) for mortality and other in-hospital complications were calculated.

RESULTS

A total of 350,623 [CABG = 112,099 (32%) and PCI = 238,524 (68%)] hospitalizations were included in the analysis. The overall adjusted odds for major bleeding (aOR 1.28, 95% CI 1.25-1.31, P < 0.0001), post-procedure bleeding (aOR 5.19, 95% CI 4.93-5.47, P < 0.0001), sepsis (aOR 1.29, 95% CI 1.26-1.33, P < 0.0001), cardiogenic shock (aOR 1.23, 95% CI 1.20-1.26, P < 0.0001), and in-hospital mortality (aOR 1.65, 95% CI 1.61-1.69, P < 0.0001) were significantly higher for patients undergoing CABG compared with PCI. The need for intra-aortic balloon pump (IABP) placement (aOR 2.52, 95% CI 2.45-2.59, P < 0.001) was higher in the CABG group, while the adjusted odds of vascular complications were similar between the two groups (aOR 0.99, 95% CI 0.94-1.06, P = 0.82). As expected, patients undergoing CABG had a higher mean length of stay and mean cost of hospitalization.

CONCLUSION

CABG in ESRD may be associated with higher in-hospital complications, increased length of stay, and higher resource utilization.

Outcomes in Dialysis-Dependent Indigenous and Non-Indigenous Patients Undergoing Cardiac Surgery at Townsville University Hospital

PURPOSE

Dialysis-dependent patients have a high risk of cardiovascular death but also a high risk for perioperative mortality in cardiac surgery. Our study examined surgical complications and mortality in Indigenous and non-Indigenous dialysis-dependent patients undergoing cardiac surgery at a single centre.

METHODOLOGY

The retrospective study reviewed 72 consecutive dialysis-dependent patients who underwent cardiac surgery between 2008 and 2018. Data was prospectively collected, and follow-up was obtained from physicians and general practitioners. Multivariable analysis was performed to determine predictors of mortality.

RESULTS

The median age of Indigenous Australian patients was 60 years, compared with 65 years for non-Indigenous patients. Indigenous Australian patients had a significantly higher rate of return to theatre (43% versus 17%). The predominant reason for return to theatre for the whole cohort was postoperative bleeding (n=16, 22%). The overall early mortality rate was 10%. There were 35 late deaths (49%) and overall survival at 5 years was 40.92±6.8% (95% CI: 28-54%). History of arrhythmia (p=0.019) was a significant risk factor for mortality, whilst patients who underwent isolated coronary artery bypass grafting (p=0.004), and those who received internal mammary artery grafts (p=0.021) had a reduced hazard ratio for mortality. The median follow-up time was 29 months (IQR 10-52 mo).

CONCLUSION

Dialysis-dependent Indigenous Australian patients present younger for cardiac surgery, with a higher prevalence of co-morbid diabetes and more extensive coronary artery disease. There was no statistically significant difference in early or late mortality between Indigenous and non-Indigenous patients. However, there was a higher rate of return to theatre amongst the Indigenous Australian cohort.

Off-pump versus on-pump complete coronary artery bypass grafting: Comparison of the effects on the renal damage in patients with renal dysfunction

BACKGROUND

We aimed to compare off-pump technique with on-pump technique on renal function in patients with nondialysis-dependent renal dysfunction who underwent coronary artery bypass grafting.

METHODS

The 94 patients with renal dysfunction undergoing isolated coronary artery bypass grafting were retrospectively analyzed. No patient was receiving dialysis. Patients were randomly assigned to conventional revascularization with cardiopulmonary bypass and beating heart. Both groups were compared in terms of renal dysfunction parameters and dialysis requirement. The logistic regression models were constructed to identify risk factors associated with dialysis requirement.

RESULTS

Renal dysfunction requiring dialysis developed in 9 patients in the on-pump group. The measures analysis of variance was performed on the data that showed worsening of renal function in the on-pump group compared with the off-pump group. Cardiopulmonary bypass is significant as independent predictor for the development of postoperative dialysis.

CONCLUSION

These results suggest that off-pump coronary revascularization offers a superior renal protection and has a significantly lower risk for renal complications in patients with nondialysis-dependent renal dysfunction when compared with conventional coronary revascularization with cardiopulmonary bypass.

Coronary Angiography and Revascularization Following Coronary Artery Bypass Grafting in British Columbia: Incidence, Predictors and Longer-term Outcomes

BACKGROUND

Coronary artery bypass grafting (CABG) is established treatment for subsets of coronary artery disease (CAD). Observational data have characterised significant progression of native coronary as well as graft vessel disease during longer-term follow-up, potentially reducing the benefit of CABG. We sought to assess longer-term outcomes following CABG by determining rates of repeat coronary angiography, revascularization procedures, and survival.

METHODS

Data for all patients undergoing isolated CABG in British Columbia between 2001 and 2009 inclusive, and with follow-up until the end of 2013, were retrieved from the British Columbia Cardiac Registry. Cox proportional hazard regression and competing risk regression were performed for survival and subsequent cardiac procedures (coronary angiography, percutaneous coronary intervention [PCI] or repeat CABG).

RESULTS

Data were available from 17,316 patients with a mean age at index CABG of 65.7 ± 9.8 years. At a median follow-up of 8.5 (range 4.0 to 12.9) years, 3185 patients (18.4%) had died, 3135 (18.1%) underwent repeat coronary angiography with or without PCI or repeat CABG, and 11,557 (66.7%) had survived without additional procedures. Of those who underwent angiography, 1459 patients (46.5%) underwent further revascularization. In multivariate analysis, the strongest predictors of long-term mortality were dialysis dependency and age >75, whereas left internal mammary artery utilization and aspirin therapy were protective. Repeat revascularization predicted survival (adjusted hazard ratio 0.76; 95% confidence interval, 0.63-0.92; P = 0.004), whereas angiography alone did not.

CONCLUSIONS

Following CABG, patients frequently undergo repeat coronary angiography. Although only a minority of patients receive further revascularization, this appears to be associated with longer-term survival.

Effect of Prophylactic Dialysis on Morbidity and Mortality in Non-Dialysis-Dependent Patients after Coronary Artery Bypass Grafting: A Pilot Study

BACKGROUND/AIMS

Coronary artery bypass grafting (CABG) is associated with an increased risk of morbidity and mortality in patients with pre-existing renal dysfunction. Numerous measures have been implemented to overcome this problem; however, no improvement in outcomes has been achieved. This study was aimed at investigating the effects of prophylactic dialysis on mortality and morbidity in these patients.

METHODS

This randomized-controlled clinical trial enrolled 88 non-dialysis-dependent patients with chronic kidney disease awaiting CABG surgery. Thirty-nine randomly selected patients received dialysis 3 times prior to surgery, and 49 patients formed the control group. Kaplan-Meier analysis and Cox proportional-hazards models were used to identify factors associated with survival.

RESULTS

There was no significant difference in the development of morbidities between the groups (p = 0.413). A significant difference was evident in the average survival time (p = 0.037). Cox proportional-hazards models determined that the hazard ratio of death after surgery was 10.854-fold greater in non-dialysis patients than in patients who received dialysis (hazard ratio = 2).

CONCLUSION

Prophylactic dialysis prior to CABG decreases mortality, but does not affect morbidity, in patients with renal insufficiency.

Risk Evaluation and Midterm Outcome of Cardiac Surgery in Patients on Dialysis

The medical charts of 54 patients on maintenance dialysis who underwent cardiovascular surgery (37 elective and 17 urgent/emergency) from 1994 to 2004 were retrospectively analyzed. Thirty patients had coronary artery bypass grafting (17 elective and 13 urgent/emergency), 18 had valve replacement (16 elective and 2 urgent/emergency), and 6 underwent aortic surgery (4 elective and 2 urgent/emergency). The overall early mortality rate was 11.1%, comprising 2 patients (5.4%) who had elective operations and 4 (23.5%) who had urgent or emergency operations ( p = 0.049). The overall 5-year survival rate was 48.4%. The 5-year survival rate was 67.2% for elective surgery and 10.5% for urgent/emergency surgery ( p = 0.0001). The midterm clinical results after elective cardiovascular surgery were acceptable, whereas the results after urgent/emergency surgery were poor. For elective surgery, sufficient and detailed preoperative examinations might have contributed to the better operative outcome. Early diagnosis and consultation to avoid urgent/emergency operations in dialysis patients is recommended.

Screening and risk stratification of coronary artery disease in end-stage renal disease

End-stage renal disease (ESRD) is a growing global health problem with major health and economic implications. Cardiovascular complication is the major cause of morbidity and mortality in this population. Clustering of traditional atherosclerotic risk factors, such as diabetes, systemic inflammation, and altered mineral metabolism, contributes to enhanced systemic atherosclerosis in patients with ESRD. Prevalence of obstructive coronary artery disease (CAD) on coronary angiography exceeds 50% in this population. Despite having extensive CAD and vascular disease, patients with ESRD often do not present with classic symptoms because of impaired exercise capacity and diabetes. Furthermore, clinical trial data are exceedingly lacking in this population, resulting in considerable clinical equipoise regarding the optimal approach to the identification and subsequent management of CAD in these patients. Traditional clinical screening tools, including conventional risk prediction models, are significantly limited in their predictive accuracy for cardiovascular events in patients with ESRD. Noninvasive cardiac stress imaging modalities, such as nuclear perfusion and echocardiography, have been shown to improve the traditional clinical model in identifying the presence of CAD. Furthermore, they add incremental prognostic information to angiographic data. Novel imaging techniques and biomarker assays hold significant promise in further improving the ability to identify and risk-stratify for CAD. This review focuses on the current understanding of the clinical risk profile of asymptomatic patients with ESRD with an emphasis on the strengths and limitations of various noninvasive cardiovascular imaging modalities, including the role of novel methods in refining risk prediction. In addition, issues and challenges pertaining to the optimal timing of initial risk assessment ("screening") and possible repeat screening ("surveillance") are addressed. We also summarize the current data on the approach to the patient with ESRD being evaluated for transplantation in the context of recent guidelines and position statements by various professional societies.

Does mild renal failure affect coronary flow reserve after coronary artery bypass graft surgery?

INTRODUCTION

There are only a limited number of studies on the link between mild renal failure and coronary artery disease. The purpose of this study is to investigate the effects of mild renal failure on the distal vascular bed by measuring the coronary flow reserve (CFR) in transthoracic echocardiography after coronary artery bypass grafting (CABG).

METHODS

The study included 52 consecutive patients (12 women and 40 men) who had undergone uncomplicated CABG. The patients were divided into 2 groups. Group 1 included patients with a preoperative glomerular filtration rate (GFR) of 60-90 (mild renal failure), and group 2 included those with a GFR >90. The CFR measurements were carried out through a second harmonic transthoracic Doppler echocardiography.

RESULTS

The mean age was 60.08 ± 1.56 years in group 1 and 60.33 ± 1.19 in group 2. The mean preoperative CFR was 1.79 ± 0.06 in group 1 and 2.05 ± 0.09 in group 2. The mean postoperative CFR was 2.09 ± 0.08 in group 1 and 2.37 ± 0.06 in group 2. There was a statistically significant difference between the 2 groups as to preoperative creatinine clearance, preoperative estimated GFR, postoperative day 7 creatinine clearance, postoperative month 6 creatinine clearance, postoperative day 7 estimated GFR, postoperative month 6 estimated GFR, preoperative CFR, and postoperative CFR (P < .05). CFR was found to be unaffected by the choice of on-pump or off-pump technique (P = .907). After bypass surgery, there was a significant increase in the mean postoperative CFR, when compared with the mean preoperative CFR (P = .001).

CONCLUSION

In our study, we detected a decrease in CFR in patients with mild renal failure. We believe that in patients undergoing CABG for coronary artery disease, mild renal failure can produce adverse effects due to deterioration of the microvascular bed.

Pancreatic resections in renal failure patients: is it worth the risk?

Background. Chronic kidney disease affects 20 million US patients, with nearly 600,000 on dialysis. Long-term survival is limited and the risk of complex pancreatic surgery in this group is questionable. Previous studies are limited to case reports and small case series and a large database may help determine the true risk of pancreatic surgery in this population. Methods. The American College of Surgeons National Surgical Quality Improvement Program database was queried (2005–2011) for patients who underwent pancreatic resection. Renal failure was defined as the clinical condition associated with rapid, steadily increasing azotemia (rise in BUN) and increasing creatinine above 3 mg/dL. Operative trends and short-term outcomes were reviewed for those with and without renal failure (RF). Results. In 18,533 patients, 28 had RF. There was no difference in wound infections, neurologic or cardiovascular complications. Compared to non-RF patients, those with RF had more unplanned intubation (OR 4.89, 95% CI 1.85–12.89), bleeding requiring transfusion (OR 3.12, 95% CI 1.37–14.21), septic shock (OR 8.86, 95% CI 3.75–20.91), higher 30-day mortality (21.4% versus 2.3%, P < 0.001) and longer hospital stay (23 versus 12 days, P < 0.001). Conclusions. RF patients have much higher morbidity and mortality after pancreatic resections and surgeons should consider this before proceeding.

Preoperative estimated glomerular filtration rate as a significant predictor of long-term outcomes after coronary artery bypass grafting in Japanese patients

PURPOSES

The aim of this retrospective study was to investigate the effect of chronic kidney disease (CKD) on outcomes after coronary artery bypass grafting (CABG), and to determine whether preoperative estimated glomerular filtration rate (eGFR) can be a predictor of long-term outcomes after CABG.

METHODS

486 Japanese patients who underwent isolated CABG between December 2000 and August 2010 were evaluated. Preoperative eGFR was estimated by the Japanese equation according to guidelines from the Japanese Society of Nephrology. We defined CKD as a preoperative eGFR of less than 60 ml/min/1.73 m(2). 203 patients had CKD (CK group) and 283 patients did not (N group).

RESULTS

During a mean observation time of 53 months, the overall survival rate was significantly lower in the CK group than in the N group (p = 0.0044). Similarly, the CK group had significantly more unfavorable results with regard to freedom from cardiac death, major adverse cardiovascular and cerebrovascular events (MACCE), and hemodialysis. Using multivariate analyses, preoperative eGFR was an independent predictor of all-cause mortality (HR 0.983; p = 0.026), cardiac mortality (HR 0.963; p = 0.006), and incidence of MACCE (HR 0.983; p = 0.002).

CONCLUSIONS

The CK group had significantly more unfavorable outcomes than the N group. Preoperative eGFR was an independent predictor of long-term outcomes after CABG in Japanese patients.

Treatment outcomes for ischemic heart disease in dialysis-dependent patients

Objective: To compare outcomes following intervention in dialysis-dependent patients with ischemic heart disease.

Background: Ischemic heart disease is a major cause of mortality in dialysis-dependent patients. Coronary revascularization and medical modification to relieve symptoms is common, however, there is no clear consensus regarding optimal treatment.

Method: Ninety dialysis-dependent patients with ischemic heart disease were prospectively assessed between 1999 and 2009, with a median follow-up of 24 months; 35 received best medical management, 31 had percutaneous coronary angioplasty and stenting, and 24 had coronary artery bypass grafting.

Results: By multivariate analysis, higher body mass index and lower logistic EuroSCORE were associated with having either procedure compared to medical management. Using the time-to-event Kaplan-Meier method, both stenting and coronary bypass grafting had lower risks of an adverse outcome than best medical management. Mortality was 40/90 (44.4%). Multivariate predictors of mortality were smoking and a logistic EuroSCORE of 7–14. Overall mortality was not different among groups, however, the stent group had a survival advantage at 30-days and 1-year compared to the coronary bypass group. Composite median survival was 52.3 months. SF-36 questionnaires showed quality of life after bypass grafting was significantly better than medical management or stenting. Physical function was better after bypass grafting compared to medical management or stenting.

Conclusion: Dialysis-dependent patients with ischemic heart disease have poor survival despite intervention. Coronary artery bypass achieves fewer composite adverse events and better quality of life than stenting. Symptoms and coronary anatomy should dictate treatment decisions in dialysis-dependent patients.

Impact of preoperative renal dysfunction on outcomes of off-pump coronary artery bypass grafting

BACKGROUND

This study assessed whether preoperative renal insufficiency predisposes patients undergoing off-pump coronary artery revascularization to postoperative dialysis.

METHODS

From August 2004 through June 2009, 2,275 patients undergoing off-pump coronary artery bypass were categorized into five groups (stages) by glomerular filtration rate (GFR). Of these, 1,855 patients had renal insufficiency: stage 2: 1,406; stage 3: 428; stage 4: 21, and 414 had normal renal function, stage 1. Excluded were 6 patients with end-stage renal disease (stage 5). Preoperative variables and postoperative outcomes were compared among groups.

RESULTS

Preoperative patient characteristics were similar; however, patients with normal renal function were younger (p = 0.001). Serum creatinine rose significantly above baseline on the first postoperative day in the renal insufficiency groups (p = 0.001). The GFR groups had similar inotrope use, reexploration rate, duration of postoperative mechanical ventilation, postoperative stroke, wound infection, and mortality rate. Stage 4 patients had a higher incidence of postoperative myocardial infarction (p = 0.002). Stage 3 and 4 patients had an increased need for postoperative dialysis vs stage 1 patients (p = 0.002).

CONCLUSIONS

Nonparametric contingency analysis showed patients with low preoperative GFR (stage 3 and 4, p < 0.0001) and a history of smoking (p = 0.04) were at increased risk for postoperative dialysis. Patients who required postoperative inotropic support tended toward requiring postoperative dialysis (p = 0.06). Low preoperative ejection fraction (p = 0.83), class III or IV angina (p = 0.069), and postoperative blood transfusions were not associated with the need for postoperative dialysis in patients undergoing off-pump 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.

Perioperative outcomes among patients with end-stage renal disease following coronary artery bypass surgery in the USA

BACKGROUND

Patients with end-stage renal disease (ESRD) requiring chronic haemodialysis who undergo coronary artery bypass graft surgery (CABG) are at significant risk for perioperative mortality. However, the impact of changes in ESRD patient volume and characteristics over time on operative outcomes is unclear.

METHODS

Using the Nationwide Inpatient Sample database (1988-03), we evaluated rates of CABG surgery with and without concurrent valve surgery among ESRD patients and outcomes including in-hospital mortality, and length of hospital stay. Multivariate regression models were used to account for patient characteristics and potential cofounders.

RESULTS

From 1988 to 2003, annual rates of CABG among ESRD patients doubled from 2.5 to 5 per 1000 patient-years. Concomitantly, patient case-mix changed to include patients with greater co-morbidities such as diabetes, hypertension and obesity (all P < 0.001). Nonetheless, among ESRD patients, in-hospital mortality rates declined nearly 6-fold from over 31% to 5.4% (versus 4.7% to 1.8% among non-ESRD), and the median length of in-hospital stay dropped in half from 25 to 13 days (versus 14 to 10 days among non-ESRD).

CONCLUSIONS

Since 1988, an increasing number of patients with ESRD have been receiving CABG in the USA. Despite increasing co-morbidities, operative mortality rates and length of in-hospital stay have declined substantially. Nonetheless, mortality rates remain almost 3-fold higher compared to non-ESRD patients indicating a need for ongoing improvement.

Preoperative renal function as a predictor of survival after coronary artery bypass grafting: comparison with a matched general population

OBJECTIVE

Preoperative renal dysfunction is an established risk factor for early and late mortality after revascularization. We studied how renal function affects long-term survival of patients after coronary artery bypass grafting.

METHODS

Early and late mortality were determined retrospectively among consecutive patients having isolated coronary bypass at a single Dutch institution between January 1998 and December 2007. Patients were stratified into 4 groups according to preoperative renal function. Expected survival was gauged using a general Dutch population group that was obtained from the database of the Dutch Central Bureau for Statistics; for each of our renal function groups, a general population group was assembled by matching for age, gender, and year of operation.

RESULTS

After excluding 122 patients lost to follow-up, 10,626 patients were studied; in 10,359, preoperative creatinine clearance could be calculated. Multivariate logistic regression and Cox regression analysis identified renal dysfunction as a predictor for early and late mortality. When long-term survival of patient groups was compared with expected survival, only patients with a creatinine clearance less than 30 mL x min(-1) showed a worse outcome. Patients with a creatinine clearance between 60 and 90 mL x min(-1) had a long-term survival exceeding the expected survival.

CONCLUSIONS

Severity of renal dysfunction was related to poor survival. When compared with expected survival, however, patients having coronary bypass had a worse outcome only when severe preoperative renal dysfunction was present.

The scope of coronary heart disease in patients with chronic kidney disease

Chronic kidney disease (CKD) affects approximately 13% of the U.S. population and is associated with increased risk of cardiovascular complications. Once renal replacement therapy became available, it became apparent that the mode of death of patients with advanced CKD was more likely than not related to cardiovascular compromise. Further observation revealed that such compromise was related to myocardial disease (related to hypertension, stiff vessels, coronary heart disease, or uremic toxins). Early on, the excess of cardiovascular events was attributed to accelerated atherosclerosis, inadequate control of blood pressure, lipids, or inflammatory cytokines, or perhaps poor glycemia control. In more recent times, outcome research has given us further information that relates even lesser degrees of renal compromise to an excess of cardiovascular events in the general population and in those with already present atherosclerotic disease. As renal function deteriorates, certain physiologic changes occur (perhaps due to hemodynamic, inflammatory, or metabolic changes) that decrease oxygen-carrying capacity of the blood by virtue of anemia, make blood vessels stiffer by altering collagen or through medial calcinosis, raise the blood pressure, increase shearing stresses, or alter the constituents of atherosclerotic plaque or the balance of thrombogenesis and thrombolysis. At further levels of renal dysfunction, tangible metabolic perturbations are recognized as requiring specific therapy to reduce complications (such as for anemia and hyperparathyroidism), although outcome research to support some of our current guidelines is sorely lacking. Understanding the process by which renal dysfunction alters the prognosis of cardiac disease might lead to further methods of treatment. This review will outline the relationship of CKD to coronary heart disease with respect to the current understanding of the traditional and nontraditional risk factors, the role of various imaging modalities, and the impact of coronary revascularization on outcome.

Open heart surgery in patients with end-stage renal failure: fifteen-year experience

OBJECTIVE

Risk factors and results of cardiac surgery with cardiopulmonary bypass (CPB) in hemodialysis-dependent renal failure patients at our center were evaluated.

METHODS

Out of 16,425 patients undergoing open heart surgery with CPB at our center between January 1991 and April 2006, 91 (0.6%) experienced hemodialysis-dependent end-stage renal failure. Preoperative, operative, and postoperative findings of two groups of patients were evaluated: those with normal renal function (control group) and those with chronic renal failure undergoing regular hemodialysis (HDRF group). Survival analyses of the hemodialysis group of patients were performed.

RESULTS

In the hemodialysis group, 54 (59.3%) patients underwent coronary artery surgery, 31 (34.1%) patients had valve surgery, four (4.4%) patients had aortic surgery, and two others (2.2%) experienced concomitant coronary and peripheral artery surgery. CPB and aortic cross-clamping (ACC) times were longer in the HDRF group (p=0.000 and 0.002, respectively). There was no significant difference between the two groups with regard to either reoperations, infections, pulmonary and gastrointestinal system complications, or cerebrovascular event parameters (p=0.167, 0.341, 1.000, 1.000, and 1.000, respectively). There was no difference between groups in the postoperative development of low cardiac output (p=0.398). The early mortality rate was 7.7% (seven patients) in the HDRF group and 4.8% (780 patients) in the controls (p=0.211). The actuarial survival rates in HDRF survivors at one, two, three, four, five, and ten years were overall 86%, 80%, 68.1%, 45.4%, 20%, and 6.8%, respectively.

CONCLUSIONS

Open heart surgery in hemodialysis patients is associated with a higher incidence of risks, but can be performed with acceptable operative complications and mortality with an effective hemodialysis program.

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.

Impact of concomitant cardiac procedure on coronary artery surgery in hemodialysis-dependent patients

OBJECTIVE

Coronary artery bypass grafting (CABG) in hemodialysis-dependent patients is associated with high mortality and morbidity rates. This retrospective study was undertaken to identify the risk factors for in-hospital mortality for hemodialysis-dependent patients.

METHODS

Subjects included 87 consecutive hemodialysis-dependent patients (81 men and 6 women), aged 47-82 years (mean age, 65 years), who underwent CABG. Operative procedures included CABG alone (n=77) and CABG with valve replacement, repair, or the Dor procedure (n=10). Thirty-one perioperative risk factors were subjected to univariate and multivariate analyses to identify the risk factors for hospital death.

RESULTS

The overall in-hospital mortality rate, including operative death, was 14.9% (13/87). Univariate analysis showed the following 7 risk factors to be statistically significant predictors of hospital death: age > or = 70 years, a concomitant cardiac procedure, left ventricular ejection fraction <30%, left ventricular end-systolic volume index >70 ml/m2, a left main lesion, emergency/urgent surgery, and anemia (hemoglobin <10 mg/dl) (p<0.05 for each predictor). Multivariate logistic regression analysis confirmed that a concomitant cardiac procedure (chi-squared = 17.080, p=0.013) and age > or = 70 years (chi-squared = 9.112, p=0.019) are statistically significant independent risk factors for hospital death.

CONCLUSION

A concomitant cardiac procedure and age > or = 70 years were identified as significant independent risk factors for hospital mortality after CABG for hemodialysis-dependent patients. These preoperative risk factors may help in predicting operative risks and improving clinical outcomes in hemodialysis-dependent patients undergoing CABG.

Renal Function and Outcome From Coronary Artery Bypass Grafting

Background— Severe renal dysfunction is associated with a worse outcome after coronary artery bypass graft surgery (CABG). Less is known about the effects of milder degrees of renal impairment, and previous studies have relied on levels of serum creatinine, an insensitive indicator of renal function. Recent studies have suggested that estimated glomerular filtration rate (eGFR) is a more discriminatory measure. However, data on the utility of eGFR in predicting outcome from CABG are limited.

Methods and Results— We studied 2067 consecutive patients undergoing CABG. Demographic and clinical data were collected preoperatively, and patients were followed up a median of 2.3 years after surgery. Estimated GFR was calculated from the Modification of Diet in Renal Disease equation. The primary outcome was all-cause mortality. Mean±SD eGFR was 57.9±17.6 mL/min per 1.73 m 2 in the 158 patients who died during follow-up compared with 64.7±13.8 mL/min per 1.73 m 2 in survivors (hazard ratio [HR], 0.71 per 10 mL/min per 1.73 m 2 ; 95% CI, 0.64 to 0.80; P <0.001). Estimated GFR was an independent predictor of mortality in both models with other individual univariable predictors (HR, 0.80 per 10 mL/min per 1.73 m 2 ; 95% CI, 0.72 to 0.89; P <0.001) and the European system for cardiac operative risk evaluation (HR, 0.88 per 10 mL/min per 1.73 m 2 ; 95% CI, 0.78 to 0.98; P =0.02).

Conclusions— Estimated GFR is a powerful and independent predictor of mortality after CABG.

Does Coronary Artery Bypass Graft Surgery Improve Survival Among Patients With End-Stage Renal Disease?

BACKGROUND

Cardiovascular disease remains the most frequent cause of death for patients with end-stage renal disease. To determine the long-term benefit of surgical revascularization in this high-risk population, we studied our patients with ESRD having coronary artery bypass graft surgery (CABG), comparing the results of off-pump to on-pump revascularization. As a baseline reference group, we used dialysis patients with a diagnosis of coronary artery disease who did not have surgical revascularization or percutaneous coronary interventions. The control group data set was obtained from the United States Renal Data System.

METHODS

From January 1995 through July 2003, 158 patients with end-stage renal disease who were on hemodialysis (excluding those in cardiogenic shock, needing resuscitation, and with emergent or salvage status) underwent CABG. Fifty-nine patients (37.3%) had off-pump revascularization, and 99 patients (62.7%) had bypass grafting utilizing extracorporeal circulation. Preoperative risk factors and operative results were analyzed, and longitudinal survival data obtained.

RESULTS

The mean follow-up time was 39.1 months (median, 33.1) for the on-pump patients and 18.3 months (median, 14.7) for off-pump. The total number of anastomoses per off-pump patient was 2.4 +/- 1.0, and with cardiopulmonary bypass (CPB), it was 3.3 +/- 0.9 (p < 0.001). Patients revascularized off-pump had an operative mortality rate of 1.7%, whereas patients grafted using CPB had an operative mortality of 17.2% (p = 0.003). The predicted risk of mortality for the off-pump group (9.3% +/- 7.4%) was not statistically different from the on-pump cohort (9.1% +/- 7.7%, p = not significant). Logistic regression analysis indicates that CPB use was an independent risk factor for early death (p = 0.01, odds ratio = 13.6, 95% confidence interval: 1.7 to 110). Long-term follow-up demonstrated that the patients revascularized using CPB had improved survival compared with the off-pump patients and the control population.

CONCLUSIONS

Off-pump CABG improves early mortality rate when compared with conventional revascularization. Despite a greater operative mortality, however, long-term survival is improved in the patients revascularized with CPB as compared with the off-pump cohort, suggesting possible advantages from a more complete revascularization in this population.

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.

Off-pump coronary artery bypass grafting in patients with renal dysfunction

BACKGROUND

Renal dysfunction is a predictor of increased morbidity and mortality after coronary artery bypass grafting, whether it is dialysis-dependent or not. Several studies have shown the efficacy of off-pump technique in reducing morbidity and mortality in patients with renal dysfunction. However, the actual effect of renal dysfunction in off-pump coronary artery bypass grafting has not been well understood.

METHODS

We conducted a retrospective review of 402 consecutive patients undergoing off-pump coronary artery bypass grafting from April 2001 to June 2003. Sixty-eight patients had chronic renal dysfunction (group A); 19 patients were dialysis-dependent; 334 patients had normal renal function (group B). Operative variables, morbidity, and mortality were compared between the two groups. Furthermore, multivariable analysis was performed to identify predictors for short-term survival.

RESULTS

Preoperative characteristics were similar in the two groups. Blood transfusion rate was higher in group A than group B (57.4% and 25.7%, respectively; p < 0.001). In-hospital mortality was similar (1.5% and 1.2% in group A and B, respectively; p = 0.853). Multivariable analysis revealed that unstable angina, low ejection fraction, peripheral vascular disease and redo surgery are significant risk factors for poor early result of off-pump coronary artery bypass grafting.

CONCLUSIONS

Early outcomes of off-pump coronary artery bypass grafting in patients with renal dysfunction were comparable to those in patients with normal renal function. Renal dysfunction is not a predictor of poor early outcomes after off-pump coronary artery bypass grafting.

Multiple Risk Assessment of Cardiovascular Surgery in Chronic Renal Failure Patients

BACKGROUND

Chronic renal failure is a major risk factor in cardiovascular surgery. We evaluated results of cardiovascular surgery in chronic renal failure patients (s-creatinine > 200 micromol/L or established dialysis) at our center from 1990 to 2000.

METHODS

One hundred and six chronic renal failure patients underwent cardiovascular surgery (56 coronary artery bypass operations, 25 valve replacements with or without coronary bypass, and 25 other major cardiovascular operations [8 thoracic aorta, 10 abdominal aorta, 7 other]). Matched controls were selected (n = 106) based on age, sex, year, and type of operation and occurrence of diabetes.

RESULTS

There were 88 men and 18 women and mean age was 64 +/- 10 years (standard deviation). Demographics did not differ between chronic renal failure and control patients, except for hypertension (more prevalent in chronic renal failure group, p < 0.05). Intraoperative hemorrhage, perfusion and ischemia time, and reoperation did not differ between groups. Chronic renal failure patients received more transfusions of red blood cells, plasma, and platelets (p < 0.02). Ventilation support (27.6 +/- 59.3 hours), intensive care unit stay (7.7 +/- 8.3 days), and hospital stay (12.3 +/- 10.5 days) were longer (p < 0.02). Early mortality was 16% versus 6.6% (p = 0.04) and 5-year mortality was 79% versus 39% (p < 0.05) for chronic renal failure and control patients, respectively. Independent preoperative risk factors of mortality for chronic renal patients were age greater than 70 years (relative risk = 2.32, p = 0.001), chronic obstructive pulmonary disease (relative risk = 2.59, p = 0.001), diabetes (relative risk = 1.80, p = 0.037), and dialysis (relative risk = 2.03, p = 0.005).

CONCLUSIONS

Chronic renal failure patients suffered more postoperative complications and had substantially increased short-term and long-term mortality rates. Independent preoperative mortality risk factors for chronic renal failure patients were age, chronic obstructive pulmonary disease, diabetes, and chronic dialysis.

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.

Coronary artery bypass grafting in patients on chronic hemodialysis: diabetic nephropathy versus nondiabetic nephropathy

Patients with both end-stage renal disease and diabetes mellitus carry an increased risk of coronary atherosclerosis. This study was performed to evaluate the perioperative and remote outcome of diabetic nephropathy patients on hemodialysis undergoing coronary artery bypass grafting (CABG). We retrospectively analyzed the results of CABG performed between September 1, 1993 and August 31, 2001. Preoperative, perioperative, and follow-up data of patients with hemodialysis primarily due to diabetic nephropathy (Group D, n = 31, 22 males and 9 females with a mean age of 60.1 +/- 6.6) were collected and compared to patients with hemodialysis primarily due to nondiabetic nephropathy (group N, n = 21, 17 males and 4 females with a mean age of 60.9 +/- 11.2). Preoperative risk factors between the 2 groups were not significantly different. The mean number of distal anastomoses was 2.5 +/- 1.2 in Group D and 2.5 +/- 1.0 in Group N (p = not significant [NS]). All patients received at least 1 internal mammary artery graft. There was 1 in-hospital death in each group. Postoperative recovery, mortality, and morbidity were not significantly different between the two groups. At the mean follow-up of 2.7 years, the actuarial 3 year survival rate was 72.8% in Group D and 78.7% in Group N (p = NS). The actuarial 3 year cardiac event-free rate was 79.7% in Group D and 74.7% in Group N (p = NS). CABG for hemodialysis patients can be performed with acceptable risks. Diabetic nephropathy has no impact on early or remote patient outcomes among patients on hemodialysis.

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.

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.

Efficacy of off-pump coronary artery bypass grafting for the patients on chronic hemodialysis

OBJECTIVE

Coronary artery bypass grafting (CABG) under a beating heart is reported to be less invasive and promise earlier recovery. This study was performed to evaluate the efficacy of off-pump CABG in patients with end-stage renal failure.

METHODS

Isolated CABG was performed on 40 hemodialysis patients at Shin-Tokyo Hospital Group between September 1, 1993, and December 31, 2000. Among them, off-pump CABG was performed in 16 and on-pump CABG in 24. Their preoperative, perioperative, and follow-up data were retrospectively collected.

RESULTS

Patient's demographics and coronary risk factors were similar in off-pump and on-pump groups. The mean number of bypass grafts was 1.9 +/- 1.1 in the off-pump group and 2.8 +/- 1.1 in the on-pump group (P < 0.05). Blood transfusion was significantly less frequent in the off-pump group than in on-pump group. Postoperative complications were more frequently observed in the on-pump group (7.1% off-pump vs 25.0% on-pump). There were two hospital deaths in the on-pump group and none in the off-pump group. Postoperative intubation time, ICU stay, and hospital stay were significantly shorter in the off-pump group than in the on-pump group. Although follow-up period was short (1.1 +/- 0.7 years), no cardiac events occurred in the off-pump group.

CONCLUSIONS

Off-pump CABG for hemodialysis patients is safe and useful and it enables early recovery. Postoperative cardiac events were controlled effectively during the short period of follow-up.

Coronary artery bypass grafting for patients with non-dialysis-dependent renal dysfunction (serum creatinine > or =2.0 mg/dl)

INTRODUCTION

Patients with renal dysfunction carry a risk of coronary atherosclerosis. The purpose of this study was to evaluate the outcome after coronary artery bypass grafting (CABG) in patients with decreased renal function (serum creatinine > or =2.0 mg/dl).

METHODS

We retrospectively analyzed consecutive patients who had undergone isolated CABG at Shin-Tokyo Hospital between May 1, 1991 and April 31, 2000. Preoperative, perioperative, and follow-up data of the non-dialysis-dependent patients with preoperative serum creatinine equal to or more than 2.0mg/dl (group R, n=59) were collected, and compared with those of the control patients (serum creatinine < 2.0, group C, n=1666). Group R was further divided into the off-pump and on-pump CABG group and their perioperative results were compared.

RESULTS

Group R included 51 males and eight females with a mean age of 66.4. The mean number of anastomoses was not significantly different between groups; however, clump time and pump time were longer in group R. Postoperative recovery was longer in group R than in group C, which is associated with a more frequent occurrence of major complications (28.8% in group R and 10.7% in group C, P<0.0001) and mortalities (6.8% in group R and 0.5% in group C, P<0.0005). The patients who underwent off-pump CABG experienced relatively faster recovery than those who underwent on-pump CABG, despite decreased renal function. At the mean follow-up of 2.4 years, the actuarial 3-year survival rate of groups R and C were 75.3 and 96.9%, respectively (P<0.0001), excluding hospital mortality. The actuarial 3-year cardiac event-free rate was 76.7% in group R and 87.3% in group C (P<0.05).

CONCLUSIONS

Patients with decreased renal function carry significant operative risks and require prolonged hospital care. Even after adequate surgical revascularization was completed, the long-term cardiac event-free and survival rates in the patients with renal dysfunction were inferior to the patients with normal renal function.

Open heart surgery in patients with dialysis-dependent renal insufficiency

OBJECTIVE

Chronic renal failure (CRF) is commonly considered a significant factor for increased morbidity and mortality after cardiac surgery.

METHODS

To assess the risk in our population we retrospectively analyzed 28 patients (16 men and 12 women, mean age 58.1+/-10.8 years) with end-stage renal disease (ESRD) undergoing cardiac surgery between 1989 and 2001. Sixteen (57.2%) patients had isolated coronary artery bypass grafting (CABG), nine (32.1%) had isolated valve replacement, and three (10.7%) underwent combined CABG and valve replacement. Preoperatively, 20 (71.4%) patients were on hemodialysis and eight (28.6%) on peritoneal dialysis. Mean preoperative duration of dialysis was 38.7+/-24.9 months (range, 3 to 93 months).

RESULTS

There were two perioperative deaths (30-day mortality, 7.1%). Actuarial survival at 1, 2, 5, and 12 years was 0.85+/-0.7, 0.73+/-0.10, 0.65+/-0.12, and 0.54+/-0.14, respectively. Among 22 survivors, mean NYHA class was 1.7+/-0.8 (p < 0.001 vs. preoperatively) and mean CCS class was 1.6+/-0.6 (p < 0.001 vs. preoperatively). CCS/NYHA functional class IV (p = 0.01), urgent/emergency operation (p < 0.001), LVEF < 35% (p < 0.001) were strongly related to early and late mortality.

CONCLUSIONS

Open-heart operations can be performed with acceptable short- and long-term results in patients with CRF on dialysis. Adequate preoperative management with identification of high-risk patients and a more aggressive approach before the onset of symptoms of cardiac failure are advisable.

Outcome of dialysis patients submitted to coronary revascularization

Cardiovascular disease accounts for almost half of the total mortality in patients with end stage renal disease (ESRD). It has recently been debated whether coronary revascularization has the same rate of risks and successes in this cohort of patients compared to patients without renal disease. Since 1991, 17 dialysis patients were submitted to coronary revascularization in our center. Seven patients were following peritoneal, 10 hemodialytic treatment. Four patients were submitted to percutaneous transluminal coronary angioplasty (PTCA) and 13 to surgical revascularization (CABG). In 2 patients the coronary lesion was unique, in the others stenosis of multiple vessels were found. Six patients were diabetic. The mean age at the onset of the coronary artery disease (CAD) was 57.17 +/- 11.6 years. The mean time elapsed from the onset of the CAD and the performance of the PTCA or CABG was 30.1 +/- 35.4 months. The mean time from beginning of dialysis treatment to revascularization was 48.2 +/- 39.6 months. Mean hemoglobin values were 9.7 +/- 1 g/dL, mean phosphorus values were 5.2 +/- 8.7 mg/dL, mean cholesterol values were 211 +/- 49.5 mg/dL. The procedure was technically successful in all patients. Mean survival was 25.09 +/- 28.12 months. Twelve patients died, 5 of whom within one month. Survival at one month was 70.5%, at 6 months 58.8%, at one year 52.9%, at 2 years 47%. There was neither significant difference patients submitted to PTCA and those submitted to CABG, nor between diabetic and non-diabetic patients. In conclusion, coronary revascularization in our experience is a high risk procedure in dialysis patients. The reasons for this could be the severe general conditions of these patients affected with diffuse vasculopathy and the long time elapsed since the onset of the ischemic cardiopathy. Thus, our results could suggest the opportunity of performing earlier screening of coronary situation and revascularization treatment in CAD dialysis patients.

Coronary artery bypass grafting in patients on chronic hemodialysis: surgical outcome in diabetic nephropathy versus nondiabetic nephropathy patients

BACKGROUND

The presence of diabetes mellitus adversely affects the late survival of patients undergoing coronary artery bypass grafting (CABG). The purpose of this study is to clarify the role of diabetic nephropathy on outcomes of a group of patients on chronic hemodialysis undergoing CABG.

METHODS

Between April 1984 and July 1999, 45 patients on chronic hemodialysis underwent CABG. Forty-three had conventional CABG and 2 had off-pump CABG. There were 37 males and 8 females, and the mean age was 57 years (43 to 76 years). Twenty-one patients had diabetic nephropathy (group D) and 24 had nondiabetic nephropathy (group ND). Early and late results were determined in both groups.

RESULTS

Early outcome was not significantly different between the groups. There was no hospital mortality, stroke, or requirement for prolonged mechanical ventilation (>24 hours) in either group. No patients in group D, and only 1 (4.2%) in group ND had low cardiac output syndrome. The difference in the incidence of arrhythmias (23.8% in group D and 25% in group ND), wound infections (9.5% in group D and 8.3% in group ND), and delayed tamponade (5% in group D and 12.5% in group ND) was not statistically significant. However, late results differed significantly between the two groups. Actuarial survival (Kaplan-Meier) at 5 and 9 years was 22.9% and 11.5% in group D and 89.1% and 45.7% in group ND (p = 0.01), respectively. Similarly, the cardiac event-free rate at the same intervals was 50.4% and 0% for group D and 100% and 65.8% for group ND (p = 0.001), respectively.

CONCLUSIONS

Using present technology, CABG can be done in patients on chronic hemodialysis with acceptable early mortality and morbidity. Late results in patients with diabetic nephropathy on hemodialysis are not as favorable as their nondiabetic cohort.

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.

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.