Long-term outcomes after coronary artery bypass grafting: Preoperative kidney function is prognostic

Health-related quality of life impacts upon 5-year survival after coronary artery bypass surgery

BACKGROUND

Poor preoperative health-related quality of life (HRQoL) has been associated with reduced short-term survival after coronary artery bypass graft (CABG) surgery; however, its impact on long-term mortality is unknown. This study's objective was to determine if baseline HRQoL status predicts 5-year post-CABG mortality.

METHODS

This prespecified, randomized on/off bypass follow-up study (ROOBY-FS) subanalysis compared baseline patient characteristics and HRQoL scores, obtained from the Seattle Angina Questionnaire (SAQ) and Veterans RAND Short Form-36 (VR-36), between 5-year post-CABG survivors and nonsurvivors. Standardized subscores were calculated for each questionnaire. Multivariable logistic regression assessed whether HRQoL survey subcomponents independently predicted 5-year mortality (p ≤ .05).

RESULTS

Of the 2203 ROOBY-FS enrollees, 2104 (95.5%) completed baseline surveys. Significant differences between 5-year post-CABG deaths (n = 286) and survivors (n = 1818) included age, history of chronic obstructive pulmonary disease, stroke, peripheral vascular disease, renal dysfunction, diabetes, lower left ventricular ejection fraction, atrial fibrillation, depression, non-White race/ethnicity, lower education status, and off-pump CABG. Adjusting for these factors, baseline VR-36 physical component summary score (p = .01), VR-36 mental component summary score (p < .001), and SAQ physical limitation score (p = .003) were all associated with 5-year all-cause mortality.

CONCLUSIONS

Pre-CABG HRQoL scores may provide clinically relevant prognostic information beyond traditional risk models and prove useful for patient-provider shared decision-making and enhancing pre-CABG informed consent.

Cardiac Surgery-associated Acute Kidney Injury in Patients with Preserved Baseline Renal Function

INTRODUCTION

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a powerful predictor of perioperative outcomes. We evaluated the burden of CSA-AKI in patients with preserved baseline renal function.

METHODS

The data of 2,162 adult patients who underwent cardiac surgery from January 2005 to December 2020 were analyzed. Logistic regression models were used to determine predictors of CSA-AKI and their associations with hospital mortality up to 30 days.

RESULTS

The prevalence of acute kidney injury was 43.0%, and 2.0% of patients required renal replacement therapy. Hospital mortality rate was 5.6% (non-acute kidney injury = 2.0% vs. CSA-AKI = 10.4%, P&lt;0.001), and any degree of CSA-AKI was associated with a significant increase in death rates (stage 1 = 4.3%, stage 2 = 23.9%, stage 3 = 59.7%). Multivariable logistic regression analysis identified age, obesity, left ventricular dysfunction, previous cardiac surgery, and cardiopulmonary bypass duration as predictors of CSA-AKI. Moreover, CSA-AKI was confirmed as independent predictor of hospital mortality for stage 1 (odds ratio, 2.02; 95% confidence interval, 1.16 to 3.51; P=0.013), stage 2 (odds ratio, 9.18; 95% confidence interval, 4.54 to 18.58; P&lt;0.001), and stage 3 (odds ratio, 37.72; 95% confidence interval, 18.87 to 75.40; P&lt;0.001) patients.

CONCLUSION

Age, obesity, left ventricular dysfunction, previous cardiac surgery, and cardiopulmonary bypass duration are independent predictors of CSA-AKI in patients with preserved baseline renal function. The development of CSA-AKI is significantly associated with worse outcomes, and there is a dose-response relationship between acute kidney injury stages and hospital mortality.

Impact of Preoperative Occult Renal Dysfunction on Early and Late Outcomes After Off-Pump Coronary Artery Bypass

BACKGROUND

Renal dysfunction is independently associated with increased early and late mortality after coronary artery bypass graft (CABG) surgery. Off-pump CABG (OPCABG) avoids postoperative complications from the cardiopulmonary bypass, but it is unclear how it is impacted by occult renal dysfunction (ORD). This study aimed to investigate the effects of ORD on early and late outcomes after OPCABG.

METHODS

This retrospective and observational cohort study reviewed data on 1,188 patients who underwent first isolated OPCABG with normal serum creatinine (SCr) levels. According to preoperative estimated creatinine clearance (eCrCl) by the Cockcroft-Gault formula, the patients were divided into an ORD group (n=260, eCrCl <60 mL/min/1.73 m²) and a control group (n=928, eCrCl ≥60 mL/min/1.73 m²).

RESULTS

The ORD patients presented with older age, higher incidence of small body surface area, hypertension, low preoperative eCrCl, cerebrovascular accident, peripheral vascular disease, New York Heart Association (NYHA) Ⅲ, and high risk score. The prevalence of hospital mortality, postoperative acute kidney injury (AKI), peak postoperative SCr, and prolonged hospital stay were greater in the ORD patients than the control patients. Multivariable logistic regression analysis showed that the ORD patients were at significantly higher risk of postoperative AKI (OR, 2.702; 95% CI, 1.994-3.662) and in-hospital mortality (OR, 2.884; 95% CI, 1.293-6.432). Multivariate Cox proportional hazard models confirmed that ORD was significantly associated with high later mortality (HR, 2.847; 95% CI, 1.262-6.425).

CONCLUSIONS

Occult renal dysfunction is an independent risk factor for postoperative AKI in-hospital and later mortality in patients undergoing OPCABG with normal SCr levels.

Renal Disease Is Associated With Poor Outcomes Following Isolated Coronary Artery Bypass Grafting

BACKGROUND

People with renal disease have a markedly higher risk of cardiovascular disease as well as morbidity and mortality after cardiac surgery. Little is known regarding the post-operative adverse outcomes following isolated coronary artery bypass graft (CABG) in the Australian population with renal disease.

OBJECTIVES

The aim of this study was to examine the effect of different stages of renal disease on patients' risk of post-operative mortality and complications following isolated CABG in an Australian cohort.

METHODS

Using the ANZSCTS (Australian and New Zealand Society of Cardiac and Thoracic Surgeons) registry, data from 44,968 patients who underwent isolated CABG between 2001 and 2014 were used. The effect of renal disease stages on short- and long-term outcomes were examined using multivariable logistic and Cox's regression methods respectively.

RESULTS

Three of 4 Australian patients (74.6%) who underwent isolated CABG had some degree of renal disease: 50.2% mild; 20.9% moderate; 2.1% severe; and 1.6% dialysis-dependent. Adjusted risk of 30-day mortality increased with deteriorating renal disease from mild (1.6-fold) to dialysis-dependent (4.6-fold). Worsening renal disease was also associated with higher risk of post-operative complications. Hazard ratio for long-term survival shows steady increase of mortality risk with worsening renal disease categories from 1.1-fold for mild to 3.9-fold for patients on dialysis.

CONCLUSIONS

Pre-existing renal disease is significantly associated with 30-day and long-term mortality, length of intensive care unit and hospital stay as well as several other post-operative complications.

Prevalence of renal artery disease and its prognostic significance in patients undergoing coronary bypass grafting

Several studies demonstrated the prognostic importance of renal failure and peripheral artery disease in patients undergoing coronary artery bypass grafting (CABG), but data regarding the prognostic value of renal artery disease in this context are scarce. We aimed to study the prevalence and prognostic value of renal artery disease in patients undergoing CABG. We assessed by duplex ultrasound the renal arteries of 429 consecutive patients who underwent CABG, of whom 401 had satisfactory imaging quality to detect >60% renal artery stenosis (RAS) and/or an elevated resistive index (ERI>0.80). Of the 401 subjects included (age 68±10 years, 83% men), 40 (10%) had RAS and 35 (9%) had ERI. Nine patients (2.2%) had both conditions. Patients were followed up for 12.4±7.0 months. The primary outcome was composite, including 30-day death, stroke, and/or myocardial infarction. In a multivariate model adjusted for age, gender, cardiovascular (CV) risk factors, renal function, chronic obstructive pulmonary disease, the use of off-pump CABG, CV co-morbidities, and drugs, the presence of ERI was strongly associated with the occurrence of the composite outcome (odds ratio 4.3, 95% confidence interval 1.7 to 9.9, p=0.0006). Similarly, ERI, not RAS, was significantly associated with the 30-day acute kidney disease and the midterm mortality, as well as fatal and nonfatal CV events. In conclusion, regardless of renal function and other factors, the renal resistive index is a strong predictor of CV and renal events after CABG. Renal duplex ultrasound can identify a subgroup of patients at high risk of CABG.

Preoperative estimates of glomerular filtration rate as predictors of outcome after surgery: a systematic review and meta-analysis

BACKGROUND

Kidney dysfunction is a strong determinant of prognosis in many settings.

METHODS

A systematic review and meta-analysis was undertaken to explore the relationship between estimated glomerular filtration rate (eGFR) and adverse outcomes after surgery. Cohort studies reporting the relationship between eGFR and major outcomes, including all-cause mortality, major adverse cardiovascular events, and acute kidney injury after cardiac or noncardiac surgery, were included.

RESULTS

Forty-six studies were included, of which 44 focused exclusively on cardiac and vascular surgery. Within 30 days of surgery, eGFR less than 60 m l · min · 1.73 m(-2) was associated with a threefold increased risk of death (multivariable adjusted relative risk [RR] 2.98; 95% confidence interval [CI] 1.95-4.96) and acute kidney injury (adjusted RR 3.13; 95% CI 2.22-4.41). An eGFR less than 60 ml · min · 1.73(-2) m was associated with an increased risk of all-cause mortality (adjusted RR 1.61; 95% CI 1.38-1.87) and major adverse cardiovascular events (adjusted RR 1.49; 95% CI 1.32-1.67) during long-term follow-up. There was a nonlinear association between eGFR and the risk of early mortality such that, compared with patients having an eGFR more than 90 ml · min · 1.73m(-2) the pooled RR for death at 30 days in those with an eGFR between 30 and 60 ml · min · 1.73 m(-2) was 1.62 (95% CI 1.43-1.80), rising to 2.85 (95% CI 2.49-3.27) in patients with an eGFR less than 30 ml · min · 1.73 m(-2) and 3.75 (95% CI 3.44-4.08) in those with an eGFR less than 15 ml · min · 1.73 m(-2).

CONCLUSION

: There is a powerful relationship between eGFR, and both short- and long-term prognosis after, predominantly cardiac and vascular, surgery.

Early results of human atrial natriuretic peptide infusion in non-dialysis patients with chronic kidney disease undergoing isolated coronary artery bypass grafting: the NU-HIT trial for CKD-II

BACKGROUND

Chronic kidney disease (CKD) is an important risk factor for cardiac surgery. In the most recently reported NU-HIT trial for CKD with CKD patients underwent coronary artery bypass grafting (CABG) as subjects, carperitide was reported to be effective in terms of renal function. In the present study, a subanalysis was performed on patients registered in the NU-HIT trial for CKD from the standpoint of renin-angiotensin system, natriuresis and renal function.

METHODS

303 patients with CKD who underwent isolated CABG were divided into a group that received carperitide infusion and another group without carperitide. The renin activity, angiotensin-II, aldosterone, urine-sodium, urine- creatinine, fractional sodium excretion, renal failure index, and BNP levels.

RESULTS

There were significant lower in hANP group than the placebo group, in angiotensin-II at one day postoperatively, and in aldosterone from 0 day to one month postoperatively. FENa was significantly lower in the hANP group at 3 day and one week postoperatively.

CONCLUSIONS

In on pump isolated CABG patients with CKD, carperitide showed a potent natriuretic action and inhibited the renin-angiotensin system, suggesting that it prevented deterioration of postoperative renal function. Our findings raise new possibilities for the perioperative and postoperative management of patients undergoing surgery with cardiopulmonary bypass.

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.

Prognostic impact of chronic kidney disease on 10-year clinical outcomes among patients with acute coronary syndrome

BACKGROUND

Chronic kidney disease (CKD) is closely associated with a higher risk of cardiovascular disease. However, whether patients with acute coronary syndrome (ACS) and CKD are at increased risk for long-term mortality after coronary revascularization remains unknown.

METHODS AND RESULTS

Data from consecutive patients with ACS who had undergone coronary revascularization, including percutaneous coronary intervention (PCI) and coronary artery bypass surgery (CABG) were analyzed. The estimated glomerular filtration rate (eGFR) was calculated using the current Japanese equation and CKD was defined as eGFR < 60 mL/min/1.73 m(2). Among 375 enrolled patients with ACS, 75 (20.0%) had CKD. During a follow-up period of 10.0 ± 3.4 years, the total number of deaths was 80 (21.3%), of which 36 (9.6%) were due to cardiovascular causes. Kaplan-Meier analysis showed that the presence of CKD was associated with a significant increase in mortality from all causes (log-rank test, p<0.001) and cardiovascular mortality (p<0.001). Cox proportional-hazard analysis revealed that CKD increased the risk of mortality with a hazard ratio of 2.31 (95% confidence interval (CI): 1.25-4.29, p=0.008) and of cardiovascular death with a hazard ratio of 3.76 (95% CI: 1.60-8.80, p=0.002) in patients with ACS.

CONCLUSIONS

CKD is a powerful determinant of long-term all-cause and cardiovascular mortality after ACS.

Advances in acute kidney injury associated with cardiac surgery: the unfolding revolution in early detection

Cardiac surgery-associated acute kidney injury (CSA-AKI) is important because it remains common and serious. A major limitation in the management of CSA-AKI has been ongoing delayed diagnosis by standard clinical approaches, including serum creatinine and calculated glomerular filtration rate. Recent advances in the understanding of CSA-AKI have highlighted the utility of novel biomarkers that diagnose CSA-AKI within the first 24 hours. The biomarkers that have been evaluated in clinical trials include neutrophil gelatinase-associated lipocalin (NGAL), cystatin C, kidney injury molecule 1 and interleukin-18. The biomarker with the greatest clinical promise is NGAL. Although it has multiple advantages over serum creatinine, it is still not the ideal biomarker for CSA-AKI. It is likely that a panel of early biomarkers will be developed to facilitate rapid and reliable detection of CSA-AKI, combining their different characteristics to optimize patient management. Future clinical trials likely will focus on whether these biomarkers predict adverse outcomes independent of serum creatinine fluctuations and whether therapies guided by biomarker profiles improve renal salvage and overall clinical outcomes. Given their clinical utility, these novel biomarkers have been evaluated beyond cardiac surgery for AKI in multiple clinical environments, including the emergency department, the operating room, the cardiac catheterization laboratory, and the intensive care unit. Their integration into clinical practice seems likely in the near future.

Primary coronary artery bypass surgery in the presence of decreasing preoperative renal function: effect on short-term outcomes

BACKGROUND

This study evaluated the impact of decreasing renal function on short-term outcomes in patients undergoing primary coronary artery bypass grafting (CABG).

METHODS

The study period was from February 1999 to February 2009. Data on 4050 patients undergoing primary CABG were prospectively collected and analyzed retrospectively. The study population was divided into 3 groups: the CABG:N group, patients with preoperative serum creatinine levels <2 mg/dL (n = 3947); the CABG:RF group, patients with preoperative creatinine levels >2 mg/dL (n = 87); and the CABG:D group, patients on dialysis (n = 16).

RESULTS

The significant differences between the groups (CABG:D > CABG:RF > CABG:N) in short-term outcomes were with respect to blood product use (P < .001), postoperative acute myocardial infarction (P < .001), pulmonary complications (P .001), infection (P < .001), and death (P < .001). The risk of short-term death (30 days) in the CABG:D group (4/16, 25%) was 25 times greater than that in the CABG:N group (38/3947, 0.96%).

CONCLUSION

CABG in the presence of renal failure is associated with significant morbidity and mortality.

Review article: Coronary artery stenoses: detection and revascularization in renal disease

Cardiovascular events are markedly elevated in those with all degrees of renal impairment compared to the general population. There are well established guidelines in the general population for the management of coronary artery disease, however, similar guidelines have not been established in the renal population. This review examines the current published work on the detection of coronary artery stenoses in addition to summarizing the outcomes of revascularization in patients with kidney disease. Testing for coronary artery disease in the renal population most commonly occurs in dialysis patients as part of their assessment for renal transplantation. While a positive myocardial stress test for the detection of significant coronary artery stenoses is associated with an increased risk of cardiac events, there is no clear information currently showing that cardiovascular testing itself reduces the rate of adverse cardiac events after transplantation. Revascularization of coronary artery stenoses is associated with higher morbidity and mortality in all groups with kidney disease than in the general population, with the exception of renal transplant recipients where the mortality is likely to be similar to that of the general population. There appears to be a benefit in coronary artery bypass surgery compared to percutaneous intervention in those on dialysis and after renal transplant. Currently, there is little data to support coronary artery intervention prior to transplantation in those with asymptomatic coronary artery disease.

Acute kidney injury is associated with increased long-term mortality after cardiothoracic surgery

BACKGROUND

Long-term survival after acute kidney injury (AKI) is poorly studied. We report the relationship between long-term mortality and AKI with small changes in serum creatinine during hospitalization after various cardiothoracic surgery procedures.

METHODS AND RESULTS

This was a retrospective study of 2973 patients with no history of chronic kidney disease who were discharged from the hospital after cardiothoracic surgery between 1992 and 2002. AKI was defined by the RIFLE classification (Risk, Injury, Failure, Loss, and End stage), which requires at least a 50% increase in serum creatinine and stratifies patients into 3 grades of AKI: Risk, injury, and failure. Patient survival was determined through the National Social Security Death Index. Long-term survival was analyzed with a risk-adjusted Cox proportional hazards regression model. Survival was worse among patients with AKI and was proportional to its severity, with an adjusted hazard ratio of 1.23 (95% CI 1.06 to 1.42) for the least severe RIFLE risk class and 2.14 (95% CI 1.73 to 2.66) for the RIFLE failure class compared with patients without AKI. Survival was worse among all subgroups of cardiothoracic surgery with AKI except for valve surgery. Patients with complete renal recovery after AKI still had an increased adjusted hazard ratio for death of 1.28 (95% CI 1.11 to 1.48) compared with patients without AKI.

CONCLUSIONS

The risk of death associated with AKI after cardiothoracic surgery remains high for 10 years regardless of other risk factors, even for those patients with complete renal recovery. Improved renal protection and closer postdischarge follow-up of renal function may be warranted.

The influence of coronary artery bypass graft harvest site on women's pain, functional status, and health services utilization throughout the first post-operative year: a longitudinal study

BACKGROUND

Coronary artery bypass graft surgery is a commonly performed procedure aimed at managing coronary symptoms and prolonging life. Researchers have typically examined morbidity and mortality outcomes of predominantly male populations. Less is known about the influence of graft harvest site on recovery outcomes such as surgery-related pain, functional status, and health services utilization, especially in women.

OBJECTIVES

We aimed to examine the relationships between coronary artery bypass graft harvest site (saphenous vein, internal mammary arteries or both) and surgery-related pain, functional status, health services use at 6 weeks, 12 weeks and 12 months post-operatively.

DESIGN

Longitudinal extension survey following participation in a clinical trial.

SETTING

Ten Canadian centres.

PARTICIPANTS

Women (222) who participated in the Women's Recovery from Sternotomy Trial, underwent coronary artery bypass graft surgery with or without heart valve surgery, and completed the 12-month follow-up interview.

METHODS

Harvest site data were collected by health record audit at the time of hospital discharge. Surgery-related pain, functional status, pain medication use and health services use data were collected by standardized interview over the telephone at 6 weeks, 12 weeks and 12 months post-operatively. Surgery-related pain and functional status were measured using the short Health Assessment Questionnaire. Health services use was measured by questionnaire and recorded as reported by the participants.

RESULTS

Surgery-related pain, functional disability and health services use decreased over the first post-operative year. Participants who had left internal mammary artery grafts were more likely to have surgery-related pain (Adjusted Odds Ratio (AOR)=2.79; 95% Confidence Interval (CI) 1.40-5.70) and use pain medication (AOR=4.32; 95% CI 1.44-12.91) than those who had saphenous vein grafts. Conversely, participants who had saphenous vein grafts reported significantly more functional disability (AOR=2.63; 95% CI 1.16-6.25) over 12 months post-surgery than those with left internal mammary artery grafts. Participants who had pain over the course of follow-up were more likely to visit their family physician or nurse practitioner (p=0.017), visit another type of provider (i.e., naturopath or chiropractor, p=0.004), or use any health care service (p<0.0001).

CONCLUSIONS

Following coronary artery bypass graft surgery, women who had left internal mammary artery grafts reported more pain and health services use while those who had saphenous vein grafts were more functionally disabled. Women who reported surgery-related pain also used more health services.