Coronary Artery Bypass Surgery in End-Stage Renal Disease Patients

Impact of Chronic Kidney Disease on Clinical Outcomes during Hospitalization and Five-Year Follow-Up after Coronary Artery Bypass Grafting

Background

Chronic kidney disease (CKD) is often associated with multiple comorbidities including diabetes mellitus, and each has its own complications and impact after cardiac surgery including coronary revascularization. The objective of this work was to study the impact of CKD on clinical outcomes after coronary artery bypass grafting (CABG) and to compare outcomes in patients with different grades of renal functions. We retrospectively reviewed all patients who underwent CABG from January 2016 to August 2020 at our tertiary care hospital using electronic medical records.

Results

The study included 410 patients with a median age of 60 years, and 28.6% of them had CKD and hospital mortality of 2.7%. About 71.4% of the patients had GFR > 60 mL/min per 1.73 m2, 18.1% had early CKD (GFR 30-60), 2.7% had late CKD (GFR < 30), and 7.8% of them had end-stage renal disease (ESRD) requiring dialysis. The CKD group had significantly more frequent hospital mortality (p = 0.04), acute cerebrovascular stroke (p = 0.03), acute kidney injury (AKI) (p < 0.001), longer ICU stay (p = 0.002), post-ICU stay (p = 0.001), and sternotomy wound debridement (p = 0.03) compared to the non-CKD group. The frequencies of new need for dialysis were 2.4% vs. 14.9% vs. 45.5% (p < 0.001) in the patients with GFR > 60 mL/min per 1.73 m2, early CKD, and late CKD, respectively. Acute cerebral stroke (OR: 10.29, 95% CI: 1.82-58.08, and p = 0.008), new need for dialysis (OR: 25.617, 95% CI: 13.78-85.47, and p < 0.001), and emergency surgery (OR: 3.1, 95% CI: 1.82-12.37, and p = 0.036) were the independent predictors of hospital mortality after CABG. The patients with CKD had an increased risk of strokes (HR: 2.14, 95% CI: 1.20-3.81, and p = 0.01) but insignificant mortality increase (HR: 1.44, 95% CI: 0.42-4.92, and p = 0.56) during follow-up.

Conclusion

The patients with CKD, especially the late grade, had worse postoperative early and late outcomes compared to non-CKD patients after CABG. Patients with dialysis-independent CKD had increased risks of needing dialysis, hospital mortality, and permanent dialysis after CABG.

Reconstruction Technique Options for Achieving Total Arterial Revascularization and Multiple Arterial Grafting

Ischemic heart disease is the leading cause of morbidity and mortality worldwide and may require coronary revascularization when more severe or symptomatic. Coronary artery bypass grafting (CABG) is the most common cardiac surgical procedure and can be performed with different bypass conduits and anastomotic techniques. Saphenous vein grafts (SVGs) are the most frequently used conduits for CABG, in addition to the left internal thoracic artery. Outcomes with a single internal thoracic artery and SVGs are favorable, and the long-term patency of SVGs may be improved through novel harvesting techniques, preservation methods, and optimal medical therapy. However, increasing evidence points towards the superiority of arterial grafts, especially in the form of multiple arterial grafting (MAG). Nevertheless, the uptake of MAG remains limited and variable, both as a result of technical complexity and a scarcity of conclusive randomized controlled trial evidence. Here, we present an overview of CABG techniques, harvesting methods, and anastomosis types to achieve total arterial revascularization and adopt MAG. We further narratively summarize the available evidence for MAG versus single arterial grafting to date and highlight remaining gaps and questions that require further study to elucidate the role of MAG in CABG.

Coronary artery bypass grafting vs. percutaneous coronary intervention in coronary artery disease patients with advanced chronic kidney disease: A Chinese single-center study

Objectives

Aims to compare the contemporary and long-term outcomes of coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) in coronary artery disease (CAD) patients with advanced chronic kidney disease (CKD).

Methods

823 CAD patients with advanced CKD (eGFR < 30 ml/min/1.73 m²) were collected, including 247 patients who underwent CABG and 576 patients received PCI from January 2014 to February 2021. The primary endpoint was all-cause death. The secondary endpoints included major adverse cardiac and cerebrovascular events (MACCEs), myocardial infarction (MI), stroke and revascularization.

Results

Multivariable Cox regression models were used and propensity score matching (PSM) was also performed. After PSM, the 30-day mortality rate in the CABG group was higher than that in the PCI group but without statistically significant (6.6% vs. 2.4%, p = 0.24). During the first year, patients referred for CABG had a hazard ratio (HR) of 1.42 [95% confidence interval (CI), 0.41-3.01] for mortality compared with PCI. At the end of the 5-year follow-up, CABG group had a HR of 0.58 (95%CI, 0.38-0.86) for repeat revascularization, a HR of 0.77 (95%CI, 0.52-1.14) for survival rate and a HR of 0.88(95%CI, 0.56-1.18) for MACCEs as compared to PCI.

Conclusions

Among patients with CAD and advanced CKD who underwent CABG or PCI, the all-cause mortality and MACCEs were comparable between the two groups in 30 days, 1-year and 5 years. However, CABG was only associated with a significantly lower risk for repeat revascularization compared with PCI at 5 years follow-up.

The outcomes of ultrafiltration in on-pump versus off-pump coronary artery bypass grafting in patients with renal impairment

OBJECTIVE

In chronic kidney disease (CKD), using cardiopulmonary bypass (CPB) may contribute to renal dysfunction. Off-pump coronary artery bypass grafting (OPCAB) is one technique that preserved renal function, but the procedure may not be possible in certain situations. The ultrafiltration (UF) can remove excess fluid and inflammatory mediators that result from exposure to the CPB. Coronary artery bypass grafting (CABG) with UF could be an alternative way to preserve renal function.

METHOD

A retrospective study of CKD patients who underwent CABG. The renal outcomes were compared between the patients who underwent CABG with UF and OPCAB. A repeated measure adjusted by propensity score was used for comparing the renal outcome. Univariable and multivariable logistic regression was used to identify the risk factors for acute renal failure (AKI) and adverse outcomes.

RESULTS

From January 2009 and June 2020, there were 220 CKD patients, 109 (49.55%) patients underwent CABG with UF, and 111 (50.45%) patients underwent OPCAB. There were statistically significant differences in the change of the average level of creatinine between CABG with UF (increased + 0.09 mg/dl) and OPCAB (decreased - 0.05 mg/dl) (p = 0.043). Also, patients who underwent CABG with UF had a significantly increased risk for AKI (OR 5.38, 95%CI 1.09, 26.5).

CONCLUSION

The UF adjunct technique in CABG with CPB tends to provide a lower protective effect for renal function and had a significantly higher incidence of post-cardiac surgery AKI when compared to OPCAB. If technically feasible, OPCAB would be a preferable choice for CKD patients.

STUDY REGISTRATION NUMBER

SUR-2562-06607/Research ID: 6607.

Rapid decline in cardiac function in diabetic patients with calcified coronary artery disease undergoing hemodialysis: two case reports

BACKGROUND

Clinical symptoms of patients on dialysis do not match the signs of coronary disease progression, making the prediction of the true progression of their medical condition in clinical settings difficult. Emergency and concomitant surgeries are significant risk factors of mortality following open-heart surgery in patients on hemodialysis.

CASE PRESENTATION

We report two cases of successful coronary artery bypass grafting (CABG) in patients on dialysis with a history of cardiac surgery. The first case describes a 65-year-old woman who had undergone aortic valve replacement 2 years ago and was hospitalized urgently, because of a sudden decline in heart function and hypotension. She had moderate mitral regurgitation with right ventricular pressure of 66 mmHg and poor left ventricular function [left ventricular ejection fraction (LVEF), 40%]. Cineangiography revealed an increase in the rate of stenosis in the left main trunk, from 25 to 99% at admission, in addition to 100% occlusion in proximal left anterior descending artery (LAD) and 99% stenosis in the proximal left circumflex artery (LCX). We inserted an intra-aortic balloon pump preoperatively and performed emergency surgery (Euro II risk score, 61.7%; Society of Thoracic Surgeons (STS) risk score, 56.3%). The second case described a 78-year-old man who had undergone surgery for left atrial myxoma 4 years ago and was hospitalized urgently due to dyspnea, chest discomfort, and an LVEF of 44% (Euro II risk score, 40.7%; STS risk score, 33.2%). Cineangiography revealed an increase in the rate of stenosis in the proximal LAD, from 25% (4 years ago) to 90% at admission, in addition to 99% stenosis in proximal LCX and 95% stenosis in the posterolateral branch of LCX. Both patients underwent emergency CABG due to unstable hemodynamics and decreased left ventricular function despite regular dialysis. The surgeries were successful, and the patients were discharged without any complications.

CONCLUSIONS

In patients with multiple comorbidities and those who undergo dialysis treatment, calcified lesions in coronary arteries can progress severely and rapidly without any symptoms, including chest pain. Close outpatient management involving nephrologists and the cardiovascular team is necessary for patients on dialysis.

Comparison of coronary artery bypass graft versus drug-eluting stents in dialysis patients: an updated systemic review and meta-analysis

INTRODUCTION

As percutaneous coronary intervention (PCI) technologies have been far improved, we hence conducted an updated systemic review and meta-analysis to determine the comparability between coronary artery bypass graft (CABG) and PCI with drug-eluting stent (DES) in ESRD patients.

METHODS

We comprehensively searched the databases of MEDLINE, EMBASE, PUBMED and the Cochrane from inception to January 2020. Included studies were published observational studies that compared the risk of cardiovascular outcomes among dialysis patients with CABG and DES. Data from each study were combined using the random-effects, generic inverse variance method of DerSimonian and Laird to calculate risk ratios and 95% confidence intervals. Subgroup analyses and meta-regression were performed to explore heterogeneity.

RESULTS

Thirteen studies were included in this analysis, involving total 56 422 (CABG 21 740 and PCI 34 682). Compared with DES, our study demonstrated CABG had higher 30-day mortality [odds ratio (OR) 3.85, P = 0.009] but lower cardiac mortality (OR 0.78, P < 0.001), myocardial infarction (OR 0.5, P < 0.001) and repeat revascularization (OR 0.35, P < 0.001). No statistical differences were found between CABG and DES for long-term mortality (OR 0.92, P = 0.055), composite outcomes (OR 0.88, P = 0.112) and stroke (OR 1.49, P = 0.457). Meta-regression suggested diabetes and the presence of left main coronary artery disease as an effect modifier of long-term mortality.

CONCLUSION

PCI with DES shared similar long-term mortality, composite outcomes and stroke outcomes to CABG among dialysis patients but still was associated with an improved 30-day survival. However, CABG had better rates of myocardial infarction, repeat revascularization and cardiac mortality.

Long-term prognosis in patients with end-stage renal disease after coronary artery bypass grafting

Background

Cardiovascular disease is a major cause of morbidity and mortality in patients with end-stage renal disease (ESRD). Coronary artery bypass grafting (CABG) is beneficial in selected patients with ESRD. This study investigates the survival outcomes and prognostic factors in ESRD patients who underwent CABG.

Methods

A retrospective analysis was performed for 149 patients with ESRD who underwent isolated CABG between 2006 and 2015.

Results

Mean age was 59.4±8.7 years and 106 patients (71.1%) were male. Operative mortality occurred in 20 patients (13.4%). Overall survival was 81.1%±3.2% at 1 year, 41.5%±4.3% at 5 years and 19.2%±4.2% at 10 years. Median survival was 4.3 years. Multivariable analysis identified age [P=0.001, odds ratio (OR): 1.15 per 1-year increase, 95% confidence interval (CI): 1.06-1.25], preoperative left ventricular ejection fraction (LVEF) (P=0.020, OR: 0.94, 95% CI: 0.89-0.99) and non-elective status of operation (P=0.049, OR: 3.34, 95% CI: 1.00-11.1) as predictors of operative mortality. Cox regression analysis identified age [P<0.001, hazard ratio (HR): 1.05 per 1-year increase, 95% CI: 1.03-1.08], New York Heart Association (NYHA) class III or IV status (P=0.010, HR: 1.75, 95% CI: 1.15-2.67) and the use of a left internal mammary artery (LIMA) to left anterior descending artery (LIMA-LAD) graft (P=0.029, HR: 0.42, 95% CI: 0.19-0.92) as factors influencing long-term survival.

Conclusions

CABG is associated with high operative mortality and poor long-term survival in ESRD patients. Age and NYHA class influenced late survival. LIMA-LAD grafting conferred a long-term survival advantage.

Predictors and Outcomes of Cardiac Events following Thoracic Endovascular Aortic Repair in Descending Thoracic Aortic Aneurysm and Dissection

BACKGROUND

 Cardiac events following thoracic endovascular aortic repair (TEVAR) have been associated with significant morbidity and mortality. However, predictors of post-TEVAR cardiac events in descending thoracic aortic aneurysm or dissection are poorly understood.

METHODS

 A retrospective analysis of completed TEVAR procedures performed from 2010 to 2016 was conducted using the ACS-NSQIP (American College of Surgeons National Surgical Quality Improvement Program) participant user file database. Adult patients (≥18 years) who underwent TEVAR for descending thoracic aortic aneurysm or dissection were identified and 30-day outcomes were examined. An initial univariate analysis was performed to determine associations between all patient variables and cardiac events, defined as myocardial infarction or cardiac arrest that occurred ≤30 days of surgery. Multivariate logistic regression was subsequently performed to identify independent risk factors for cardiac events following TEVAR.

RESULTS

 The study identified 150 out of 2,905 (5.2%) patients who underwent TEVAR for descending thoracic aortic aneurysm or dissection who developed cardiac events. No significant difference in incidence of cardiac events was noted among patients presenting with aortic aneurysm or dissection (p = 0.339). The overall 30-day mortality rate for all patients was 9.1%. Independent preoperative predictors of post-TEVAR cardiac events included emergency procedure (odds ratio [OR] 2.80, 95% confidence interval [CI] 1.9-4.1, p < 0.01); American Society of Anesthesiologists score >3 (OR 1.71, 95% CI 1.1-2.6, p = 0.01), ventilator dependence (OR 2.33, 95% CI 1.3-4.2, p < 0.01), renal failure (OR 2.53, 95% CI 1.50-4.3, p < 0.01), blood transfusion (OR 1.84, 95% CI 1.1-3.2, p = 0.03), and preoperative leukocytosis (OR 2.45, 1.6-3.8, p < 0.01). After TEVAR, unplanned reintubation (OR 5.52, 95% CI 3.5-8.8, p < 0.01), prolonged mechanical ventilation (OR 1.94, 95% CI 1.2-3.2, p = 0.011), and postoperative blood transfusion (OR 4.02, 95% CI 2.70-6.0, p < 0.01) were independent predictors of cardiac events. Cardiac events greatly increased mortality (60.7 vs. 5.5%), total length of hospital stay (13.2 ± 14.7 days vs. 8.3 ± 9.3 days), and readmission rates (19.3 vs. 8.2%, p < 0.01).

CONCLUSIONS

 Cardiac events following TEVAR are associated with significant mortality. Patients with these risk factors should be appropriately monitored to improve outcomes.

Coronary Artery Bypass Graft Patency and Survival in Patients on Dialysis

BACKGROUND

Little is known about graft patency after coronary artery bypass grafting (CABG) performed in patients on dialysis. Our aim was to assess patency of internal thoracic artery (ITA) grafts and saphenous vein grafts (SVGs) in these patients.

METHODS

From 1/1997 to 1/2018, 500 patients on dialysis underwent primary CABG with or without concomitant procedures at Cleveland Clinic, 40 of whom had 48 postoperative angiograms for recurrent ischemic symptoms. Complete follow-up was obtained on all but 1 patient lost to follow-up 1 y after CABG. Thirty-six ITA grafts and 65 SVGs were evaluable for stenosis and occlusion.

RESULTS

Two of 40 patients (5%) had emergency CABG; 3 (7.5%) with calcified aortas had a change in operative strategy to avoid ascending aortic manipulation, 2 (5%) had poor conduit quality, and 12 (30%) had severe diffuse atherosclerotic disease with calcification of the coronary targets causing technical difficulties. Thirty-three patients (82%) were bypassed with an in situ ITA and 3 (7.5%) had a free ITA graft. Three of 36 ITA grafts were occluded at 0.78, 1.8, and 9.4 y (too few to model). SVG patency was 52% and 37% at 1 and 2 y, respectively.

CONCLUSIONS

Among patients on dialysis who underwent CABG, coronary angiography for ischemic symptoms in a select subset revealed that SVG patency was lower than expected from published reports in the general CABG population and may contribute to the poor prognosis of this cohort. Further work is needed to guide graft selection and improve graft patency in dialysis patients.

Outcomes and Patency of Complex Configurations of Composite Grafts Using Bilateral Internal Thoracic Arteries

Background

It is generally agreed that using a bilateral internal thoracic artery (BITA) composite graft improves long-term survival after coronary artery bypass grafting (CABG). Although the left internal thoracic artery (LITA)-based Y-composite graft is widely adopted, technical or anatomical difficulties necessitate complex configurations. We aimed to investigate whether BITA configuration impacts survival or patency in patients undergoing coronary revascularization.

Methods

Between January 2006 and June 2017, 1,161 patients underwent CABG at Seoul National University Bundang Hospital, where the standard technique is a LITA-based Y-composite graft with the right internal thoracic artery (RITA) sequentially anastomosed to non-left anterior descending (LAD) targets. Total of 160 patients underwent CABG using BITA with modifications. Their medical records and imaging data were reviewed retrospectively to investigate technical details, clinical outcomes, and graft patency.

Results

Modifications of the typical Y-graft (group 1, n=90), LITA-based I-graft (group 2, n=39), and RITA-based composite graft (group 3, n=31) were used due to insufficient RITA length (47%), problems using LITA (28%), and target vessel anatomy (25%). The overall 30-day mortality rate was 1.9%. Among 116 patients who underwent computed tomography or conventional angiography at a mean interval of 29.9±33.1 months postoperatively, the graft patency rates were 98.7%, 95.3%, and 83.6% for the LAD, left circumflex artery, and right coronary artery territories, respectively. Patency rates for the inflow, secondary, and tertiary grafts were 98.2%, 90.5%, and 80.4%, respectively. The RITA-based graft (group 3) had the lowest patency rate of the various configurations (p<0.011).

Conclusion

LITA-based Y composite graft, showed satisfactory clinical outcomes and patency whereas modifications of RITA-based composite graft had the lowest patency and 5-year survival rates. Therefore, when using RITA-based composite graft, other options should be considered before proceeding atypical configurations.

Comparison between three different equations for the estimation of glomerular filtration rate in predicting mortality after coronary artery bypass

Background

This study was undertaken to compare the accuracy of chronic kidney disease-epidemiology collaboration (eGFR_CKD-EPI) to modification of diet in renal disease (eGFR_MDRD) and the Cockcroft-Gault formulas of Creatinine clearance (C_CG) equations in predicting post coronary artery bypass grafting (CABG) mortality.

Methods

Data from 4408 patients who underwent isolated CABG over a 11-year period were retrieved from one institutional database. Discriminatory power was assessed using the c-index and comparison between the scores’ performance was performed with DeLong, bootstrap, and Venkatraman methods. Calibration was evaluated with calibration curves and associated statistics.

Results

The discriminatory power was higher in eGFR_CKD-EPI than eGFR_MDRD and C_CG (Area under Curve [AUC]:0.77, 0.55 and 0.52, respectively). Furthermore, eGFR_CKD-EPI performed worse in patients with an eGFR ≤29 ml/min/1.73m² (AUC: 0.53) while it was not influenced by higher eGFRs, age, and body size. In contrast, the MDRD equation was accurate only in women (calibration statistics p = 0.72), elderly patients (p = 0.53) and subjects with severe impairment of renal function (p = 0.06) whereas C_CG was not significantly biased only in patients between 40 and 59 years (p = 0.6) and with eGFR 45–59 ml/min/1.73m² (p = 0.32) or ≥ 60 ml/min/1.73m² (p = 0.48).

Conclusions

In general, CKD-EPI gives the best prediction of death after CABG with unsatisfactory accuracy and calibration only in patients with severe kidney disease. In contrast, the CG and MDRD equations were inaccurate in a clinically significant proportion of patients.

Surgical outcomes of acute type A aortic dissection in dialysis patients

BACKGROUND

Acute type A aortic dissection (ATAAD) is relatively uncommon in dialysis patients, and characteristics and repair outcomes are not fully understood.

PATIENTS AND METHODS

Patients with ATAAD (n = 960) were divided into a dialysis group (n = 19) and non-dialysis group (n = 941), depending on whether they required dialysis for preoperative end-stage renal disease (ESRD). Hospital charts and imaging data were reviewed, and characteristics and outcomes were compared between the groups. Segmental aortic wall or intima/media flap calcification in the thoracic and abdominal aorta was assessed in the dialysis patients.

RESULTS

The leading primary causes of ESRD were polycystic kidney disease (n = 5) and chronic glomerulonephritis (n = 5). There were no significant differences (dialysis group vs. non-dialysis group) in age (60.5 vs. 64.5 years), preoperative hemodynamics, or organ ischemia. Dialysis patients were more likely to have an entry tear in the aortic arch (42% vs. 15%, p = 0.003). These patients showed moderate-to-severe calcification (multiple focal or single focal calcification > 10 mm) in the ascending aorta (17%), aortic arch (61%), descending aorta (67%), and abdominal aorta (83%). Arch replacement was common in this group (37% vs. 18%, p = 0.030). Although in-hospital mortality was increased in this group (21% vs. 7%, p = 0.059), morbidities did not differ significantly. Six-year survival was 60.3 ± 13.4% and 78.8 ± 1.6%, respectively (p = 0.01).

CONCLUSIONS

Dialysis patients tend to have aortic calcification and a primary tear in the aortic arch. Outcomes are acceptable.