Risks of coronary artery bypass surgery in dialysis-dependent patients--analysis of the 2001 National Inpatient Sample

Short-term and long-term outcomes of on-pump beating-heart coronary artery bypass surgery in dialysis and non-dialysis patients: a retrospective study in a single center

BACKGROUND

This study aimed to evaluate the short-term and long-term outcomes of dialysis and non-dialysis patients after On-pump beating-heart coronary artery bypass grafting (OPBH-CABG).

METHODS

We retrospectively reviewed medical records of 659 patients underwent OPBH-CABG at our hospital from 2009 to 2019, including 549 non-dialysis patients and 110 dialysis patients. Outcomes were in-hospital mortality, length of stay, surgical complications, post-CABG reintervention, and late mortality. The median follow-up was 3.88 years in non-dialysis patients and 2.24 years in dialysis patients. Propensity matching analysis was performed.

RESULTS

After 1:1 matching, dialysis patients had significantly longer length of stay (14 (11-18) vs. 12 (10-15), p = 0.016), higher rates of myocardial infarction (16.85% vs. 6.74%, p = 0.037) and late mortality (25.93% vs. 9.4%, p = 0.005) after CABG compared to non-dialysis patients. No significant differences were observed in in-hospital mortality, complications, or post-CABG reintervention rate between dialysis and non-dialysis groups.

CONCLUSIONS

OPBH-CABG could achieve comparable surgical mortality, surgical complication rates, and long-term revascularization in dialysis patients as those in non-dialysis patients. The results show that OPBH-CABG is a safe and effective surgical option for dialysis patients.

Surgical outcomes of acute type A aortic dissection in dialysis patients: lessons learned from a single-center’s experience

There is a paucity of data describing the safety and efficacy of acute type A aortic dissection (ATAAD) repair surgeries in dialysis patients. Our study aimed to investigated the influence of dialysis on early and late outcomes in end-stage renal disease (ESRD) patients who received repair surgery for ATAAD. A total of 882 ATAAD patients who received emergency aortic dissection repair at our center from January 2015 to December 2019 were retrospectively screened in this study and divided into the dialysis group (n = 16) and the non-dialysis group (n = 866), depending on whether they required dialysis for preoperative ESRD. No significant difference of age, preoperative hemodynamics, organ ischemia conditions, operative variables as well as the 30-Day mortality and in-hospital complications was discovered between two groups. However, the survival rates and the proportion of late aortic event (sudden death and reoperation) free population at 1 and 3 years after surgery were significantly decreased in dialysis patients compared to non-dialysis patients. Our study indicated that the short-term surgical outcomes of ATAAD in dialysis patients were comparable to non-dialysis patient. However, the dialysis patients were associated with a worse long-term prognosis.

Morbidity after elective surgery in patients on chronic dialysis: a systematic review and meta-analysis

BACKGROUND

Patients on chronic dialysis are at increased risk of postoperative mortality following elective surgery compared to patients with normal kidney function, but morbidity outcomes are less often reported. This study ascertains the excess odds of postoperative cardiovascular and infection related morbidity outcomes for patients on chronic dialysis.

METHODS

Systematic searches were performed using MEDLINE, Embase and the Cochrane Library to identify relevant studies published from inception to January 2020. Eligible studies reported postoperative morbidity outcomes in chronic dialysis and non-dialysis patients undergoing major non-transplant surgery. Risk of bias was assessed using the Newcastle-Ottawa Scale and the certainty of evidence was summarised using GRADE. Random effects meta-analyses were performed to derive summary odds estimates. Meta-regression and sensitivity analyses were performed to explore heterogeneity.

RESULTS

Forty-nine studies involving 10,513,934 patients with normal kidney function and 43,092 patients receiving chronic dialysis were included. Patients on chronic dialysis had increased unadjusted odds of postoperative cardiovascular and infectious complications within each surgical discipline. However, the excess odds of cardiovascular complications was attenuated when odds ratios were adjusted for age and comorbidities; myocardial infarction (general surgery, OR 1.83 95% 1.29-2.36) and stroke (general surgery, OR 0.95, 95%CI 0.84-1.06). The excess odds of infectious complications remained substantially higher for patients on chronic dialysis, particularly sepsis (general surgery, OR 2.42, 95%CI 2.12-2.72).

CONCLUSION

Patients on chronic dialysis are at increased odds of both cardiovascular and infectious complications following elective surgery, with the excess odds of cardiovascular complications attributable to being on dialysis being highest among younger patients without comorbidities. However, further research is needed to better inform perioperative risk assessment.

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.

Hospital costs and prognosis in end-stage renal disease patients receiving coronary artery bypass grafting

Background

Coronary artery disease is common in patients with end-stage renal disease (ESRD). Patients with ESRD are a high-risk group for cardiac surgery and have increased morbidity and mortality. Most studies comparing ESRD patients receiving coronary artery bypass grafting (CABG) or percutaneous coronary intervention have found that the long-term survival is good in ESRD patients after CABG. The aim of our study was to compare ESRD patients who underwent CABG with the general population who underwent CABG, in terms of prognosis and hospital costs.

Methods

This study analyzed data from the National Health Insurance Research Database in Taiwan for patients who were diagnosed with ESRD and received CABG (ICD-9-CM codes 585 or 586) between January 1, 2004, and December 31, 2009. The ESRD patients included in this study all received catastrophic illness cards with the major illness listed as ESRD from the Ministry of Health and Welfare in Taiwan.

The control subjects were randomly selected patients without ESRD after propensity score matching with ESRD patients according to age, gender, and comorbidities at a 2:1 ratio from the same dataset.

Results

A total of 48 ESRD patients received CABG, and their mean age was 62.04 ± 10.04 years. Of these patients, 29.2% were aged ≥70 years, and 66.7% were male. ESRD patients had marginally higher intensive care unit (ICU) stays (11.06 vs 7.24 days) and significantly higher ICU costs (28,750 vs 17,990 New Taiwan Dollars (NTD)) than non-ESRD patients. Similarly, ESRD patients had significantly higher surgical costs (565,200 vs. 421,890 NTD), a higher perioperative mortality proportion (10.4% vs 2.1%) and a higher postoperative mortality proportion (33.3% vs 11.5%) than non-ESRD patients.

Conclusions

After CABG, ESRD patients had a higher risk of mortality than non-ESRD patients, and ICU and surgery costs were also higher among the ESRD patients than among patients without ESRD.

Postoperative mortality in patients on chronic dialysis following elective surgery: A systematic review and meta-analysis

RATIONALE & OBJECTIVE

The prognostic significance of dialysis-dependent end-stage kidney disease on postoperative mortality is unclear. This study aims to estimate the odds of postoperative mortality in patients receiving chronic dialysis undergoing elective surgery compared to patients with normal kidney function, and to examine the influence of comorbidities on the excess mortality risk.

METHODS

A systematic search of studies published up to January 2020 was conducted using MEDLINE, EMBASE and CENTRAL databases. Eligible studies reported postoperative 30-day or in-hospital mortality in chronic dialysis patients compared to patients with normal kidney function undergoing elective surgery. Two investigators independently reviewed all abstracts and performed risk of bias assessments using the Newcastle-Ottawa Scale. Quality of evidence was summarised in accordance with GRADE methodology (grading of recommendations, assessment, development and evaluation). Relative mortality risk estimates were obtained using random effects meta-analysis. Heterogeneity was explored using meta-regression. (PROSPERO CRD42017076565).

RESULTS

Forty-nine studies involving 41, 822 chronic dialysis and 10, 476, 321 non-dialysis patients undergoing elective surgery were included. Patients on chronic dialysis had a greatly increased postoperative mortality odds compared to patients with normal kidney function. The excess risk ranged from OR 10.8 (95%CI 7.3-15.9) following orthopaedic surgery to OR 4.0 (95%CI 3.2-4.9) after vascular surgery. Adjustment for age and comorbidity attenuated the excess odds but remained higher for patients on chronic dialysis, irrespective of surgical discipline. Meta-regression analysis demonstrated an inverse linear relationship between excess mortality risk and study-level mean age (slope -0.06; P = 0.001) and diabetes prevalence (slope -0.02; p = 0.001).

CONCLUSIONS

Patients on chronic dialysis have an increased odds for postoperative mortality following elective surgery across all surgical disciplines. This relationship is consistent among all studies, with the excess postoperative mortality attributable to end-stage kidney disease and chronic dialysis treatment may be lower among older patients with diabetes.

Hyperlactatemia of dialysis-dependent patients after cardiac surgery impacts on in-hospital mortality: a two-center retrospective study

Background

Lactate is a well-known marker to estimate prognosis after cardiac surgery and critically ill patients. The liver and kidney have a major role in lactate metabolism; however, there was less characterized about the change of lactate and threshold to predict in-hospital mortality in dialysis-dependent patients undertaking cardiac surgery. We conducted this retrospective observational study to characterize when and how lactate values after cardiac surgery affected in-hospital mortality.

Methods

This two-center retrospective study included dialysis-dependent patients who underwent cardiac surgery with a cardiopulmonary bypass from January 2014 to December 2018. Lactate values were collected at three points: at ICU admission (T1), the maximum level of lactate within 24 h postoperatively (T2), and 24 h after ICU admission (T3). We determined hyperlactatemia as more than 2 mmol/L following previous studies.

Results

We enrolled 122 dialysis-dependent patients. The mean age was 73 ± 8 years and hyperlactatemia was observed in 100 patients (81.9%). In-hospital mortality was 11.4%. Univariate analysis and area under curve in ROC suggested that T2 lactate was the most significantly associated with in-hospital mortality (AUC = 0.845). Multivariate logistic analysis showed a significant association between in-hospital mortality when patients showed early peak lactate levels of > 4.5 mmol/L after ICU admission (adjusted OR 8.35; 95% CI: 1.44–57.13).

Conclusions

In dialysis-dependent patients after cardiac surgery, the early-onset of a maximum arterial lactate concentration of > 4.5 mmol/L was significantly associated with in-hospital mortality.

Perioperative outcomes and risk assessment in dialysis patients: current knowledge and future directions

Perioperative medicine is rapidly emerging as a key discipline to address the specific needs of high-risk surgical groups, such as those on chronic dialysis. Crude hospital separation rates for chronic dialysis patients are considerably higher than patients with normal renal function, with up to 15% of admission being related to surgical intervention. Dialysis dependency carries substantial mortality and morbidity risk compared to patients with normal renal function. This group of patients has a high comorbid burden and complex medical need, making accurate perioperative planning essential. Existing perioperative risk assessment tools are unvalidated in chronic dialysis patients. Furthermore, they fail to incorporate important dialysis treatment-related characteristics that could potentially influence perioperative outcomes. There is a dearth of information on perioperative outcomes of Australasian dialysis patients. Current perioperative outcome estimates stem predominantly from North American literature; however, the generalisability of these findings is limited, as the survival of North American dialysis patients is significantly inferior to their Australasian counterparts and potentially confounds reported perioperative outcomes; let alone regional variation in surgical indication and technique. We propose that data linkage between high-quality national registries will provide more complete data with more detailed patient and procedural information to allow for more informative analyses to develop and validate dialysis-specific risk assessment tools.

Effect of glycemic control on mortality and infections in patients undergoing coronary artery bypass grafting: a Genesee County experience

Background: We report post-coronary artery bypass outcomes and factors affecting the outcomes from the Genesee County, MI, where the population is distinctly characterized by a higher prevalence of renal failure (RF), diabetes, obesity and smoking than the national average. Methods: We performed a retrospective cohort study on 1133 patients undergoing isolated CABG at our hospital from June 2012 to July 2017. Primary outcome was the association between preoperative hemoglobin A1c (HbA1c) and all-cause postoperative mortality after CABG, secondary outcomes included the association between HbA1c and a composite of postoperative infections including sternal-wound infections, leg harvest-site infections, pneumonia or sepsis. Logistic Regression analyses were also performed. Results: There was no difference in the mortality rate (OR 1.0, 95% CI 0.4-2.3) and composite of all infections (OR 1.0, 95% CI 0.7-1.6) between the controlled (HbA1c ≤7%) and uncontrolled (HbA1c >7%) groups. However, RF (OR 5.9, 95% CI 1.5-22.9), smoking (OR 3.7, 95% CI 1.3-11.2) and ejection fraction <35% (OR 3.4, 95% CI 1.4-8.3) were independently associated with increased mortality after CABG. Additionally, low EF (OR 2.4, 95% CI 1.4-4.1) and smoking (OR 2.3, 95% CI 1.2-4.1) were associated with an increased rate of composite of all infections after CABG. Conclusion: Although not different in controlled and uncontrolled diabetic groups, mortality, in our population was associated with comorbidities like RF, smoking and congestive heart failure that are highly prevalent, emphasizing the need for interventions at primary care level to improve the postoperative outcomes after CABG.

Cardiovascular complications in chronic dialysis patients

PURPOSE OF REVIEW

This review article focuses on the most significant cardiovascular complications in dialysis patients [sudden cardiac death (SCD), acute coronary syndromes, heart failure, and atrial fibrillation].

RECENT FINDINGS

Current and ongoing research aims to quantify the rate and pattern of significant arrhythmia in dialysis patients and to determine the predominant mechanism of SCD. Preliminary findings from these studies suggest a high rate of atrial fibrillation and that bradycardia and asystole may be more frequent than ventricular arrhythmia as a cause of sudden death. A recently published matched cohort study in dialysis patients who received a defibrillator for primary prevention showed that there was no significant difference in mortality rates between defibrillator-treated patients and propensity-matched controls. Two randomized controlled trials are currently recruiting participants and will hopefully answer the question of whether implantable or wearable cardioverter defibrillators can prevent SCD. An observational study using United States Renal Data System data demonstrated how difficult it is to keep hemodialysis patients on warfarin, as more than two-thirds discontinued the drug during the first year. The ISCHEMIA-CKD trial may provide answers about the optimal strategy for the treatment of atherosclerotic coronary disease in patients with advanced chronic kidney disease.

SUMMARY

The article reviews the diagnosis of acute coronary syndromes in dialysis patients, current literature on myocardial revascularization, and data on fatal and nonfatal cardiac arrhythmia. The new classification of heart failure in end-stage renal disease is reviewed. Finally, available cohort studies on warfarin for stroke prevention in dialysis patients with atrial fibrillation are reviewed.

Acute Kidney Injury and In-Hospital Mortality after Coronary Artery Bypass Graft versus Percutaneous Coronary Intervention: A Nationwide Study

BACKGROUND

Post-procedural acute kidney injury (AKI) is associated with significantly increased short- and long-term mortalities, and renal loss. Few studies have compared the incidence of post-procedural AKI and in-hospital mortality between 2 major modalities of revascularization - coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) - and results have been inconsistent.

METHODS

We generated a propensity score-matched cohort that includes a total of 286,670 hospitalizations with multi-vessel coronary disease undergoing CABG or PCI (2004-2012) from the National Inpatient Sample database. We compared incidence of AKI, AKI requiring renal replacement therapy (RRT), in-hospital mortality, hospital stay, and charges between CABG and PCI groups.

RESULTS

The incidence of AKI after CABG was higher than PCI (8.9 vs. 4.5%, OR 2.05, 95% CI 1.99-2.12, p < 0.001). The incidence of AKI requiring RRT was also higher after CABG (1.1 vs. 0.5%, OR 2.14, 95% CI 1.96-2.34, p < 0.001). Likewise, in-hospital mortality was higher after CABG than PCI (2.0 vs. 1.4%, OR 1.44, 95% CI 1.35-1.52, p < 0.001). Among patients with pre-existing chronic kidney disease (stages I-IV), those undergoing CABG was associated with 2.0-2.3-fold higher odds of developing AKI than those undergoing PCI. The patients treated with CABG had a significantly longer hospital stay and higher hospital charges.

CONCLUSIONS

Patients undergoing CABG are associated with (1) increased risk of developing post-procedural AKI, (2) higher likelihood of receiving RRT, and (3) worse short-term survival. Long-term renal outcome remains to be studied.

Tissue valves are preferable for patients with end-stage renal disease: an aggregate meta-analysis

BACKGROUND

Valve selection in patients with end-stage renal disease (ESRD) is uncertain. We performed a systematic review and meta-analysis to compare clinical outcome in ESRD patients undergoing valve replacement.

METHODS

We systematically searched multiple databases (2000-October 2015) to identify original studies comparing adverse events between mechanical and biological valve replacement in ESRD patients. End-points studied were: postoperative mortality, bleeding events, need for re-operation, and late survival. A random-effect inverse-variance weighted analysis was performed; event rates are compared as odds ratio (OR and 95% confidence interval) and hazard ratios (HR) for time-to-event data. Mechanical valve and tissue valve replacement were considered as study and control cohorts, respectively.

RESULTS

Fifteen retrospective studies (5523 mechanical and 1600 tissue valve) were included in our meta-analysis. Early mortality was comparable (OR 1.15 [0.77; 1.72]; p = 0.49). The mean follow-up among studies ranged from 1.6-15 years. Bleeding was significantly higher after mechanical valve replacement (OR 2.55 [1.53; 4.26]; p = 0.0003). Structural valve degeneration was present in only 0.6% patients after a tissue valve replacement. Overall survival after valve replacement was poor (median 2.61 years); valve choice did not influence this outcome (pooled HR 0.87 [0.73; 1.04]; p = 0.14).

CONCLUSION

Operative mortality in ESRD patients is comparable between mechanical and tissue valve replacement. Major bleeding episodes are significantly higher after mechanical valve replacement but structural degeneration in tissue valves during the follow-up period is low. Based on the findings from this meta-analysis, we would recommend using tissue valves in patients with ESRD.

Dialysis Patients with Implanted Drug-Eluting Stents Have Lower Major Cardiac Events and Mortality than Those with Implanted Bare-Metal Stents: A Taiwanese Nationwide Cohort Study

OBJECTIVE

To investigate the efficacy and long-term clinical benefits of DES for dialysis patients.

BACKGROUND

It is unclear whether percutaneous coronary intervention (PCI) with drug-eluting stent (DES) implantation is associated with lower rates of major adverse cardiovascular events (MACE) or mortality compared to bare-metal stents (BMS).

METHODS

From a nationwide cohort selected from Taiwan's National Health Insurance Research Database, we enrolled 2,835 dialysis patients who were hospitalized for PCI treatment with stent implantation from Dec 1, 2006. Follow-up was from the date of index hospitalization for PCI until the first MACE, date of death, or December 31, 2011, whichever came first.

RESULTS

A total of 738 patients (26.0%) had DES implanted, and 2,097 (74%) had BMS implanted. The medium time to the first MACE was 0.53 years (interquartile range: 0.89 years; range: 0-4.62 years). At 1-year follow-up, patients treated with BMS had significantly, non-fatal myocardial infarction (MI), all-cause mortality, and composite MACE compared to those treated with DES. The overall repeat revascularization with coronary artery bypass graft (CABG), non-fatal MI, all-cause mortality, and composite MACE were significantly lower in patients treated with DES than those treated with BMS. Multivariate cox regression analysis showed that older age, history of diabetes, history of heart failure, history of stroke, and DES vs. BMS were independent significant predictors of MACE.

CONCLUSIONS

DES implantation conferred survival benefits in dialysis patients compared with BMS implantation.

Clinical outcomes of treatment by percutaneous coronary intervention versus coronary artery bypass graft surgery in patients with chronic kidney disease undergoing index revascularization in Ontario

BACKGROUND

There is a paucity of data on the comparative effectiveness of percutaneous coronary intervention using contemporary drug-eluting stent (DES) compared with coronary artery bypass graft (CABG) surgery in patients with chronic kidney disease.

METHODS AND RESULTS

A population-based study was performed using the Cardiac Care Network, a provincial registry of all patients undergoing cardiac catheterization in Ontario, to evaluate patients treated with either percutaneous coronary intervention using DES or CABG between October 1, 2008, and September 30, 2011. Chronic kidney disease was defined as creatinine clearance <60 mL/min. A total of 1786 propensity-matched patients from 4006 patients with chronic kidney disease undergoing index revascularization for multivessel disease with either DES or isolated CABG (n=893 each group) were analyzed. Baseline and procedural characteristics between percutaneous coronary intervention and CABG groups were well-balanced, including urgent revascularization priority, diabetes mellitus, left ventricular function, and 3-vessel disease. The 1-, 2-, and 3-year Kaplan-Meier survival analyses in propensity-matched patients favored CABG (93.2% versus 89.3%; 86.6% versus 80.3%; 80.8% versus 71.5%, respectively; P<0.001). The CABG cohort had greater 1-, 2-, and 3-year freedom from major adverse cardiac and cerebrovascular events (89.4% versus 71.2%; 81.9% versus 60.5%; 75.2% versus 51.8%, respectively; P<0.001). Cox regression analysis identified DES use to be associated with greater hazard for late mortality (hazard ratio, 1.58; 95% confidence interval, 1.32-1.90) and major adverse cardiac and cerebrovascular events (2.62; 2.28-3.01; all P<0.001).

CONCLUSIONS

In this large provincial registry, CABG was associated with improved early and late clinical outcomes when compared with percutaneous coronary intervention using DES in patients with chronic kidney disease undergoing index revascularization.

How do We Manage Coronary Artery Disease in Patients with CKD and ESRD?

Chronic kidney disease (CKD) has been shown to be an independent risk factor for cardiovascular events. In addition, patients with pre-dialysis CKD appear to be more likely to die of heart disease than of kidney disease. CKD accelerates coronary artery atherosclerosis by several mechanisms, notably hypertension and dyslipidemia, both of which are known risk factors for coronary artery disease. In addition, CKD alters calcium and phosphorus homeostasis, resulting in hypercalcemia and vascular calcification, including the coronary arteries. Mortality of patients on long-term dialysis therapy is high, with age-adjusted mortality rates of about 25% annually. Because the majority of deaths are caused by cardiovascular disease, routine cardiac catheterization of new dialysis patients was proposed as a means of improving the identification and treatment of high-risk patients. However, clinicians may be uncomfortable exposing asymptomatic patients to such invasive procedures like cardiac catheterization, thus noninvasive cardiac risk stratification was investigated widely as a more palatable alternative to routine diagnostic catheterization. The effective management of coronary artery disease is of paramount importance in uremic patients. The applicability of diagnostic, preventive, and treatment modalities developed in nonuremic populations to patients with kidney failure cannot necessarily be extrapolated from clinical studies in non-kidney failure populations. Noninvasive diagnostic testing in uremic patients is less accurate than in nonuremic populations. Initial data suggest that dobutamine echocardiography may be the preferred diagnostic method. PCI with stenting is a less favorable alternative to CABG, however, it has a faster recovery time, reduced invasiveness, and no overall mortality difference in nondiabetic and non-CKD patients compared with CABG. CABG is associated with reduced repeat revascularizations, greater relief of angina, and increased long term survival. However, CABG is associated with a higher incidence of post-operative risks. The treatment chosen for each patient should be an individualized decision based upon numerous risk factors. CKD is associated with higher rates of CAD, with 44% of all-cause mortality attributable to cardiac disease and about 20% from acute MI. Optimal treatment including aggressive lifestyle modifications and concomitant medical therapy should be implemented in all patients to maximize benefits from either PCI or CABG. Future prospective randomized controlled trials with newer second or third generation DES and bioabsorbable DES are necessary to determine if PCI may be non-inferior to CABG in the future.

Outcomes following cardiac surgery in patients with preoperative renal dialysis

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was that whether patients who are dependent on chronic dialysis have higher morbidity and mortality rates than the general population when undergoing cardiac surgery. These patients often require surgery in view of their heightened risk of cardiac disease. Altogether 278 relevant papers were identified using the below mentioned search, 16 papers represented the best evidence to answer the question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses were tabulated. Dialysis-dependent (DD) patients undergoing coronary artery bypass grafting (CABG) or valve replacement have higher morbidity but acceptable outcomes. There is some evidence to show that outcomes after off-pump coronary artery bypass grafting (OPCAB) are better than after on-pump coronary artery bypass grafting (ONCAB) and that results are worse in DD patients with diabetic nephropathy. Patients undergoing combined procedures have a higher mortality.

Management of cardiovascular disease in patients with kidney disease

The burden of cardiovascular disease is high in patients with chronic kidney disease or end-stage renal disease. The presence of kidney dysfunction affects the cardiovascular system in multiple ways, including accelerated progression of atherosclerosis and valvular disease, the exacerbation of congestive heart failure, and the development of pericardial disease. This comorbidity results not only from the concordance of shared risk factors, but also from other issues specific to this population, such as systemic inflammation and vascular calcification. Furthermore, both the sensitivity and specificity of noninvasive testing modalities, and the efficacy of several pharmacotherapeutic strategies, are diminished in this population. The exclusion of patients with severe kidney disease from many clinical trials of cardiac interventions raises various therapeutic uncertainties, and kidney disease itself is likely to alter the underlying cardiovascular physiology. In this Review, we discuss aspects of the epidemiology, pathophysiology, and diagnosis of cardiovascular disease in patients with kidney disease, and propose specific, evidence-based recommendations for pharmacological and surgical treatment.

Implications of Hemodialysis in Patients Undergoing Coronary Artery Bypass Grafting

BACKGROUND

Cardiovascular disease is the leading cause of morbidity and mortality in patients on hemodialysis. To our knowledge, no studies have examined long-term outcomes of hemodialysis patients following coronary artery bypass grafting (CABG) in a predominately rural, low-income, and racially dichotomous population.

METHODS

Long-term survival of hemodialysis patients undergoing non-emergent, isolated CABG was compared with non-hemodialysis patients. Survival probabilities were computed using the Kaplan-Meier product limit method and stratified by hemodialysis. Hazard ratios (HR) and 95% confidence intervals (95%CI) were computed using a Cox regression model.

RESULTS

Hemodialysis patients (n=220) had shorter long-term survival than non-hemodialysis patients (median survival=3.3 versus 14 years, p<0.0001). The survival difference remained statistically significant after adjusting for clinically relevant variables (HR=5.2, 95%CI=4.4-6.2).

CONCLUSION

Hemodialysis patients had significantly shorter long-term survival compared with non-hemodialysis patients after CABG. Further research is needed to address the cost and policy implications of our findings, especially among priority populations.

Mortality and morbidity in dialysis-dependent patients undergoing spinal surgery: analysis of a national administrative database in Japan

BACKGROUND

The impact of dialysis dependence on perioperative risks following spinal surgery is not fully understood. The purposes of the present study were to determine the perioperative risks in dialysis-dependent patients treated with spinal surgery and to examine whether the presence of destructive spondyloarthropathy further increases perioperative risks.

METHODS

We examined abstracted data from the Diagnosis Procedure Combination database in a retrospective analysis of a nationally representative inpatient database. The survey of the database is conducted annually for a six-month period between July 1 and December 31. The data from 2007 and 2008 were used for this study. We included all patients who had undergone any combination of laminectomy, laminoplasty, discectomy, and/or spinal arthrodesis. For analysis, dialysis-dependent patients were further classified into subgroups with or without destructive spondyloarthropathy.

RESULTS

We identified 51,648 eligible patients (30,743 men and 20,905 women; mean age, sixty-two years), including 869 (1.7%) who were dialysis-dependent. Of the latter, ninety-five had destructive spondyloarthropathy. Overall in-hospital mortality was 0.41%. Dialysis-dependent patients had a significantly higher in-hospital mortality rate than non-dialysis-dependent patients. After adjustment, dialysis-dependent patients remained at a tenfold higher risk for in-hospital death. Dialysis-dependent patients were also at significantly greater risk for postoperative major complications. The rate of complications in dialysis-dependent patients with destructive spondyloarthropathy was 65% higher than that in those without destructive spondyloarthropathy, but this difference did not reach significance.

CONCLUSIONS

Dialysis-dependent patients had a tenfold higher risk of in-hospital death than did non-dialysis-dependent patients. Dialysis-dependent patients were also more likely to have major complications such as cardiac events, sepsis, and respiratory complications. Our data also indicate that the presence of destructive spondyloarthropathy is associated with a higher rate of postoperative complications in dialysis-dependent patients.

Management of coronary artery disease in end-stage renal disease

Despite a substantial number of patients with end-stage renal disease who have coronary artery disease, the comparative effectiveness of revascularization procedures such as coronary artery bypass grafting and percutaneous coronary intervention remain unclear. Innovations in the field of coronary artery revascularization and concomitant changes in the standard of practice have improved outcomes in general. However, meaningful clinical decision-making remains difficult because it requires clinicians to extrapolate evidence derived from studies in the general population to patients with kidney disease for whom there is limited information from intervention trials. In non-randomized studies, this high-risk population for cardiovascular morbidity and mortality appear to derive substantial benefits from coronary revascularization. However, specific treatment decisions are often made based upon individual circumstances and contexts that are not well captured in these studies. This article reviews the available evidence, and its limitations, for deciding between various revascularization strategies for patients with end-stage renal disease. Several considerations that arise while making such decisions are discussed.

Cardiovascular disease in chronic kidney disease. A clinical update from Kidney Disease: Improving Global Outcomes (KDIGO)

Cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD) is high, and the presence of CKD worsens outcomes of cardiovascular disease (CVD). CKD is associated with specific risk factors. Emerging evidence indicates that the pathology and manifestation of CVD differ in the presence of CKD. During a clinical update conference convened by the Kidney Disease: Improving Global Outcomes (KDIGO), an international group of experts defined the current state of knowledge and the implications for patient care in important topic areas, including coronary artery disease and myocardial infarction, congestive heart failure, cerebrovascular disease, atrial fibrillation, peripheral arterial disease, and sudden cardiac death. Although optimal strategies for prevention, diagnosis, and management of these complications likely should be modified in the presence of CKD, the evidence base for decision making is limited. Trials targeting CVD in patients with CKD have a large potential to improve outcomes.

Cardiovascular disease in end-stage renal disease: the challenge of assessing and managing cardiac disease in dialysis patients

Cardiovascular disease (CVD) is the leading cause of mortality in end-stage renal disease (ESRD), approximating a 10- to 20-fold higher risk of death in dialysis patients than in the general population. Despite this, dialysis patients often undergo fewer investigations, receive less invasive procedures, and are prescribed fewer medications compared with age-matched non-ESRD patients. A lack of randomized control trials for evidence-based treatment strategies in this population may explain some of these discrepancies, but there is concern that an attitude of "therapeutic nihilism" may be impacting on the medical care of these patients. In this review, we will explore CVD in the ESRD population. Specifically, we will try to address the following issues in patients with ESRD: (1) mechanisms of CVD, (2) cardiac evaluation and the role of coronary revascularization with percutaneous or coronary artery bypass procedures, and (3) cardiac pharmacotherapy use.

Coronary artery bypass grafting in patients on maintenance dialysis: is peritoneal dialysis a risk factor of operative mortality?

BACKGROUND

Increasing numbers of patients on dialysis are undergoing coronary artery bypass grafting (CABG). We undertook this retrospective study to identify risk factors of operative mortality in dialysis patients who underwent CABG.

PATIENTS AND METHODS

We performed retrospective analysis of 105 patients who were on dialysis for at least two months before surgery and who underwent CABG in Toronto General Hospital from 1997 to 2006. Using prospectively collected data from the Division of Cardiovascular Surgery Database of Toronto General Hospital, we collected data on comorbidities, procedures, modality change during hospitalization, and operative outcomes. Logistic regression was used to assess risk factors of operative mortality.

RESULTS

One hundred and five maintenance dialysis patients (40 PD and 65 HD) who met the inclusion criteria were studied. Overall in-hospital mortality was 7.6%. Atrial fibrillation and pneumonia occurred in 16.2 and 9.5%, respectively, of all dialysis patients. Among PD patients, rates of post-operative dialysate leak and peritonitis were 10 and 12.5%, respectively. Among HD patients, 4.6% experienced post-operative AV access thrombosis. Logistic regression showed older age (>or=70 years) and peritoneal dialysis are independent risk factors of operative mortality.

CONCLUSION

In this retrospective study, older patients on PD had higher operative mortality than HD patients. These findings suggest extra care should be taken when CABG is considered for PD patients over 70 years old. In this study we could not identify the reason(s) for the high mortality of elderly peritoneal dialysis patients undergoing CABG.

Coronary revascularization in end-stage renal disease

Advanced coronary artery disease and acute cardiac events are the most common causes of death in patients with end-stage renal disease. Because of their heightened risk, end-stage renal disease patients are frequently referred for coronary revascularization. However, these patients are almost always excluded from trials examining various innovations in medical and revascularization interventions for cardiovascular conditions. Extrapolation of trial conclusions regarding dialysis patients can be misleading because the risk-benefit ratios of various interventions in this patient population can be markedly different. Thus, clinical decisions regarding the need for (and type of) coronary revascularization are based on retrospective outcome analyses from various databases. This article reviews the data available in the literature on the morbidity, mortality, and outcomes of dialysis patients undergoing surgical or percutaneous revascularization, particularly with the addition of drug-eluting stents to the available therapeutic options.