Influence of chronic kidney disease on early clinical outcomes after off-pump coronary artery bypass grafting

Long-term mortality after isolated coronary artery bypass grafting and risk factors for mortality

BACKGROUND

Patients requiring coronary artery bypass grafting (CABG) have multiple co-morbidities which need to be considered in totality when determining surgical risks. The objective of this study is to evaluate short-term and long-term mortality rates of CABG surgery, as well as to identify the most significant risk factors for mortality after isolated CABG.

METHODS

All patients with complete dataset who underwent isolated CABG between January 2008 and December 2017 were included. Univariate and multivariate Cox regression was performed to determine the risk factors for all-cause mortality. Classification and regression tree analysis was performed to identify the relative importance of these risk factors.

RESULTS

3,573 patients were included in the study. Overall mortality rate was 25.7%. In-hospital mortality rate was 1.62% overall. 30-day, 1-year, 5-year, 10-year and 14.5-year mortality rates were 1.46%, 2.94%, 9.89%, 22.79% and 36.30% respectively. Factors associated with death after adjustment for other risk factors were older age, lower body mass index (BMI), hypertension, diabetes mellitus, chronic obstructive pulmonary disease, pre-operative renal failure on dialysis, higher last pre-operative creatinine level, lower estimated glomerular filtration rate (eGFR), heart failure, lower left ventricular ejection fraction and New York Heart Association class II, III and IV. Additionally, female gender and logistic EuroSCORE were associated with death on univariate Cox analysis, but not associated with death after adjustment with multivariate Cox analysis. Using CART analysis, the strongest predictor of mortality was pre-operative eGFR < 46.9, followed by logistic EuroSCORE ≥ 2.4.

CONCLUSION

Poorer renal function, quantified by a lower eGFR, is the best predictor of post-CABG mortality. Amongst other risk factors, logistic EuroSCORE, age, diabetes and BMI had a relatively greater impact on mortality. Patients with chronic kidney disease stage 3B and above are at highest risk for mortality. We hope these findings heighten awareness to optimise current medical therapy in preserving renal function upon diagnosis of any atherosclerotic disease and risk factors contributing to coronary artery disease.

Stroke outcomes following cardiac and aortic surgery are improved by the involvement of a stroke team

OBJECTIVES

Post-cardiac and aortic surgery stroke is often underreported. We detail our single-centre experience the following introduction of comprehensive consultant-led daily stroke service, to demonstrate the efficacy of a stroke team in recovery from stroke following cardiac and aortic surgeries.

METHODS

This retrospective, single-centre observational cohort study analysed consecutive patients undergoing cardiac and aortic surgery at our institution from August 2014 to December 2020. Main outcomes included stroke rate, predictors of stroke, and neurological deficit resolution or persistence at discharge and clinic follow-up.

RESULTS

A total of 12,135 procedures were carried out in the reference period. Among these, 436 (3.6%) suffered a stroke. Overall survival to discharge and follow-up were 86.0% and 84.0% respectively. Independent risk factors for post-operative stroke included advanced age (OR 1.033, 95% CI [1.023, 1.044], p < .001), female sex (OR 1.491, 95% [1.212, 1.827], p < .001), history of previous cardiac surgeries (OR 1.670, 95% CI [1.239, 2.218], p < .001), simultaneous coronary artery bypass graft + valve procedures (OR 1.825, 95% CI [1.382, 2.382], p < .001) and CPB time longer than 240 min (OR 3.384, 95% CI [2.413, 4.705], p < .001). Stroke patients managed by the multidisciplinary team demonstrated significantly higher rates of survival at discharge (87.3% vs. 61.9%, p = .001).

CONCLUSIONS

Perioperative stroke can be debilitating immediately long term. The involvement of specialist stroke teams plays a key role in reducing the long-term burden and mortality of this condition.

A model for predicting postoperative persistent acute kidney injury (AKI) in AKI after cardiac surgery patients with normal baseline renal function

BACKGROUND

Persistent acute kidney injury (AKI) after cardiac surgery is not uncommon and linked to poor outcomes.

HYPOTHESIS

The purpose was to develop a model for predicting postoperative persistent AKI in patients with normal baseline renal function who experienced AKI after cardiac surgery.

METHODS

Data from 5368 patients with normal renal function at baseline who experienced AKI after cardiopulmonary bypass cardiac surgery in our hospital were retrospectively evaluated. Among them, 3768 patients were randomly assigned to develop the model, while the remaining patients were used to validate the model. The new model was developed using logistic regression with variables selected using least absolute shrinkage and selection operator regression.

RESULTS

The incidence of persistent AKI was 50.6% in the development group. Nine variables were selected for the model, including age, hypertension, diabetes, coronary heart disease, cardiopulmonary bypass time, AKI stage at initial diagnosis after cardiac surgery, postoperative serum magnesium level of <0.8 mmol/L, postoperative duration of mechanical ventilation, and postoperative intra-aortic balloon pump use. The model's performance was good in the validation group. The area under the receiver operating characteristic curve was 0.761 (95% confidence interval: 0.737-0.784). Observations and predictions from the model agreed well in the calibration plot. The model was also clinically useful based on decision curve analysis.

CONCLUSIONS

It is feasible by using the model to identify persistent AKI after cardiac surgery in patients with normal baseline renal function who experienced postoperative AKI, which may aid in patient stratification and individualized precision treatment strategy.

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.

Left Main Coronary Artery Revascularization in Patients with Impaired Renal Function: Percutaneous Coronary Intervention versus Coronary Artery Bypass Grafting

INTRODUCTION

The evidence about the optimal revascularization strategy in patients with left main coronary artery (LMCA) disease and impaired renal function is limited. Thus, we aimed to compare the outcomes of LMCA disease revascularization (percutaneous coronary intervention [PCI] vs. coronary artery bypass grafting [CABG]) in patients with and without impaired renal function.

METHODS

This retrospective cohort study included 2,138 patients recruited from 14 centers between 2015 and 2,019. We compared patients with impaired renal function who had PCI (n= 316) to those who had CABG (n = 121) and compared patients with normal renal function who had PCI (n = 906) to those who had CABG (n = 795). The study outcomes were in-hospital and follow-up major adverse cardiovascular and cerebrovascular events (MACCE).

RESULTS

Multivariable logistic regression analysis showed that the risk of in-hospital MACCE was significantly higher in CABG compared to PCI in patients with impaired renal function (odds ratio [OR]: 8.13 [95% CI: 4.19-15.76], p < 0.001) and normal renal function (OR: 2.59 [95% CI: 1.79-3.73]; p < 0.001). There were no differences in follow-up MACCE between CABG and PCI in patients with impaired renal function (HR: 1.14 [95% CI: 0.71-1.81], p = 0.585) and normal renal function (HR: 1.12 [0.90-1.39], p = 0.312).

CONCLUSIONS

PCI could have an advantage over CABG in revascularization of LMCA disease in patients with impaired renal function regarding in-hospital MACCE. The follow-up MACCE was comparable between PCI and CABG in patients with impaired and normal renal function.

Single-port versus multiport partial nephrectomy: a propensity-score-matched comparison of perioperative and short-term outcomes

The objective of this study was to compare the perioperative and short-term functional and oncological outcomes of single-port and multiport robotic-assisted laparoscopic partial nephrectomy using propensity-score analysis. We evaluated all patients who underwent robotic partial nephrectomy at our institution between January 2019 and October 2020. Patient demographics, intraoperative data, and postoperative outcomes were collected and analyzed. Propensity-score matching was performed on age, sex, body mass index, prior abdominal surgery, and nephrometry score using the optimal matching method. A post hoc sensitivity analysis was performed to examine the robustness of the results. In total, 48 and 238 patients underwent single-port and multiport robotic partial nephrectomy, respectively. Following propensity-score matching, 48 multiport cases were matched 1:1 to single-port cases. The single-port cohort had lower median opioid use at postoperative day 1 (4.6 vs 9.8 MME, p = 0.0209) and cumulative hospital stay (5.1 vs 9.3 MME, p = 0.0357). Single port also had a shorter median length of stay (1.4 vs 1.6 days, p = 0.0045), although the post hoc sensitivity analysis showed no difference between the groups [- 0.13 (95% CI; - 0.580, 0.315, p = 0.5607). There were no significant differences in operative time, estimated blood loss, ischemia time, transfusions received, or positive margin rates. In conclusion, based on our early experience, single-port robotic partial nephrectomy is a safe and acceptable alternative to multiport robotic partial nephrectomy, providing comparable perioperative and postoperative outcomes while reducing inpatient opioid use.

Predictors and clinical outcomes of post-coronary artery bypass grafting cerebrovascular strokes

Background

Despite the improved medical and surgical managements, still there is a significant risk of developing acute cerebrovascular strokes after coronary artery bypass grafting (CABG). Our objectives were to study the immediate and long-term outcomes after CABG and to identify the possible predictors of post-CABG strokes.

Results

Between January 2016 and August 2020, 410 adult patients, mostly males (82.2%), were retrospectively enrolled after CABG. Acute postoperative strokes occurred in 31 (7.5%) patients; of them, 30 (96.8%) patients had ischemic stroke, while 1 (3.2%) had hemorrhagic stroke. Mechanical thrombectomy was done in two cases. The patients who developed acute cerebral stroke had significantly higher admission (p = 0.02) and follow-up (p < 0.001) SOFA scores, higher arterial blood lactate level (p < 0.001), longer hospitalization (p < 0.001) and more hospital mortality (p < 0.001) compared with the patients who did not develop stroke. Kaplan–Meier curves for 5-year mortality showed increased risk in those patients with postoperative stroke (HR: 23.03; 95% CI: 6.10–86.92, p < 0.001). After multivariate regression, the predictors of early postoperative stroke were carotid artery stenosis (CAS), postoperative atrial fibrillation, cardiopulmonary bypass time, prior cerebral stroke, admission SOFA score and chronic kidney disease (CKD). The predictors of late cerebrovascular stroke were CAS, combined CABG and valve surgery, CKD, atrial fibrillation, prior stroke and HbA1c.

Conclusions

The development of post-CABG acute cerebrovascular stroke is associated with longer hospitalization, multiple morbidities and increased mortality. Careful assessment and management of risk factors especially atrial fibrillation and carotid artery stenosis should be implemented to decrease this substantial complication after CABG.

Coronary Artery Bypass Grafting in Patients with Chronic Kidney Disease: Chronic Kidney Disease Has an Independent Adverse Effect on the Long-Term Outcome of Coronary Artery Bypass Grafting

We examined short- and long-term outcomes of coronary artery bypass grafting (CABG) in patients with ischemic heart disease and the effect of renal function on these outcomes. We included 2783 patients who underwent primary elective CABG at a single institution between 2002 and 2020 (age: 67.6 ± 10.2 years; male: 2281 male). They were stratified based on their preoperative estimated glomerular filtration rate and underwent off-pump CABG (completion rate, 98.1%); 57.6% cases used bilateral internal thoracic arteries (BITA). In-hospital mortality rate was 1.0%. Logistic regression analysis revealed that low left ventricular function (<40%), but not chronic kidney disease (CKD) severity, was an independent predictive risk factor for postoperative hospital mortality. Significant differences existed in respiratory complications, infections, and hospitalization duration according to CKD severity. Deep sternal wound infection rate was 0.5%. The mean follow-up period was 7.1 (0–18.5) years. Estimated 10-year survival rates were negatively correlated with CKD severity; in the Cox hazard model, severe CKD was an independent predictor of long-term survival. We examined the relationship between preoperative and intraoperative factors and their effects on long-term survival using propensity score matching by dividing the renal function severity into G1–2 and G3–5. Renal function severity, age, and operative time were independent risk factors. No prognostic improvement was observed with BITA grafts; graft patency was superior in the right internal thoracic artery (52/52; 100%) than in the great saphenous vein (48/59; 81.4%) in G5. Post-CABG in-hospital mortality was unrelated to renal function, but CKD severity strongly influenced long-term survival. Operation time was an important predictor of long-term prognosis in patients with impaired renal function. Treatment plans, including graft and anastomosis-site selections, should be designed to shorten the operation time. In conclusion, using the right internal thoracic artery in CABG is more beneficial in patients with CKD and cardiovascular comorbidities.

Outcomes of off-pump coronary artery bypass grafting in non-dialysis-dependent patients with stage 2 and stage 3 chronic kidney disease

Purpose

To assess the short-term outcomes in non-dialysis-dependent patients with stage 2 and stage 3 chronic kidney disease (CKD), undergoing off-pump coronary artery bypass (OPCAB). To examine whether there was a difference in mortality between stage 2 and stage 3 CKD patients and whether mortality in diabetics was different compared to non-diabetics. Outcomes would be judged on the basis of possible cardiovascular, pulmonary, infective, neurological and renal complications, duration of stay at the intensive therapy unit (ITU), and overall duration of stay at the hospital. A comparative study of outcomes between stage 2 and stage 3 CKD would be undertaken. Also, given the impact of diabetes mellitus in this patient population, a comparative study of outcomes would be made between diabetics and non-diabetics.

Methods

Three hundred fifteen consecutive patients undergoing OPCAB were included in this observational prospective study. Of them, 201 (64%) had stage 3 CKD and 114 (36%) had stage 2 CKD. Nearly half of the study group (49.52%) were diabetics. Data was collected from patients' files, patient observation charts at the ITU, and patient interviews. Continuous variables were expressed as mean ± standard deviation or median (Q1, Q3) as appropriate and qualitative variables presented with the frequency and corresponding percentage. Comparison between diabetic and non-diabetic patients was performed by the Student's t test or chi-square test as appropriate. And when assumptions of parametric test failed, then an appropriate non-parametric test was performed. Repeated measures ANOVA (analysis of variance) was used to see the trend of estimated glomerular filtration rate (eGFR) values. Statistical analysis was done by using SPSS version 19.0 (SPSS Inc., Chicago, IL, USA). All p values <0.05 were considered statistically significant.

Results

The eGFR was measured pre-operatively, on the day following OPCAB and at the time of discharge and the mean eGFR, remained more or less the same throughout (mean of 55.86 ml/min/1.73 m² pre-operatively, 58.39 ml/min/1.73 m² on the day following OPCAB and 58.39 ml/min/1.73 m² at discharge). One patient with stage 2 CKD (0.9%) required hemodialysis post-operatively while 3 patients (1.5%) required the same in the stage 3 CKD group, which was not statistically significant. Nineteen patients (6.03%) required re-intubation for hypoxia in the post-operative period. Post-operative myocardial infarction developed in 12 patients (3.81%). Twenty patients (6.35%) patients needed an intra-aortic balloon pump (IABP) insertion in the peri-operative period owing to hemodynamic compromise. Fifteen patients (4.76%) were re-explored for bleeding following surgery and fifteen patients (4.76%) had a deep sternal wound infection in the post-operative period. New-onset atrial fibrillation was found to be present in 42 stage 3 CKD patients (11%) while it occurred in 21 stage 2 CKD patients (9.6%) (p value = 0.014), which was statistically significant. The mean duration of ITU stay was 84 ± 6.22 h in the stage 2 CKD group and 92.9 ± 8.18 h in the stage 3 CKD group (p value = 0.01), which was statistically significant. Mean duration of ITU stay was 94 ± 10.12 h in the diabetic group while it was 86.7 ± 11.08 h in the non-diabetic group (p value = 0.008) which was statistically significant. Duration of post-operative hospital stay was a mean of 8 ±0.08 days in the diabetic group whereas it was 7 ± 0.04 days in the non-diabetic group (p value = 0.012), which was statistically significant. Surgical mortality was 6 out of 315 patients (1.9%).

Conclusion

OPCAB is a safe and effective revascularization strategy in patients with stage 2 and stage 3 CKD. Short-term outcomes of OPCAB have been good in the patient population in this study, in terms of both surgical morbidity and mortality. Surgical mortality was 1.9%. New-onset atrial fibrillation was found in eleven patients (9.6%) in the stage 2 CKD group and 42 patients (21%) in the stage 3 CKD group (p value =0.014) which was statistically significant. The results of this study reflect the reno-protective nature of OPCAB. The duration of ITU stay and the post-operative duration of stay at the hospital were found to be significantly more in diabetics than in non-diabetics.