Long-term cardiovascular outcomes in patients with chronic kidney disease undergoing coronary artery bypass graft surgery for acute coronary syndromes

Unraveling Chronic Cardiovascular and Kidney Disorder through the Butterfly Effect

Chronic Cardiovascular and Kidney Disorder (CCKD) represents a growing challenge in healthcare, characterized by the complex interplay between heart and kidney diseases. This manuscript delves into the "butterfly effect" in CCKD, a phenomenon in which acute injuries in one organ lead to progressive dysfunction in the other. Through extensive review, we explore the pathophysiology underlying this effect, emphasizing the roles of acute kidney injury (AKI) and heart failure (HF) in exacerbating each other. We highlight emerging therapies, such as renin-angiotensin-aldosterone system (RAAS) inhibitors, SGLT2 inhibitors, and GLP1 agonists, that show promise in mitigating the progression of CCKD. Additionally, we discuss novel therapeutic targets, including Galectin-3 inhibition and IL33/ST2 pathway modulation, and their potential in altering the course of CCKD. Our comprehensive analysis underscores the importance of recognizing and treating the intertwined nature of cardiac and renal dysfunctions, paving the way for more effective management strategies for this multifaceted syndrome.

Single versus bilateral internal thoracic artery grafting in patients with impaired renal function

OBJECTIVE

The optimal strategy for surgical revascularization in patients with impaired renal function is inconclusive. We compared early and late outcomes between bilateral internal thoracic artery (BITA) and single ITA (SITA) grafting in patients with renal dysfunction.

METHODS

This is a retrospective analysis of all the patients with multivessel disease and impaired renal function (estimated glomerular filtration rate <60mL/min/1.73m2) who underwent isolated coronary artery bypass graft (CABG) in our center during 1996-2011, utilizing either BITA or SITA revascularization.

RESULTS

Of the 5301 patients with multivessel disease who underwent surgical revascularization during the study period, 391 were with impaired renal function: 212 (54.2%) underwent BITA, 179 (45.8%) underwent SITA. Patients who underwent BITA were less likely to have comorbidities. Statistically significant differences were not observed between the BITA and SITA groups in 30-day mortality (5.6% vs. 9.0%, p = 0.2) and in rates of early stroke, myocardial infarction, and sternal infection (4.5% vs. 6.1%, p = 0.467; 1.7% vs. 2.8%, p = 0.517; and 2.2% vs. 5.7%, p = 0.088, respectively). Long-term survival of the BITA group was better: median 8.36 vs. 4.14 years, p<0.001. In multivariable analysis, BITA revascularization was associated with decreased late mortality (HR = 0.704, 95% CI: 0.556-0.89, p = 0.003). In analysis of a matched cohort (134 pairs), early outcomes did not differ between the groups; however, in multivariable analysis, BITA revascularization was associated with decreased late mortality ‎‎(HR = 0.35 (95%CI 0.18-0.68), p = 0.002)‎.

CONCLUSIONS

BITA revascularization did not impact early outcome in patients with CRF, but demonstrated a significant protective effect on long-term survival ‎in the unmatched and matched cohorts.

Estimated glomerular filtration rate derived from different formulas and prognosis in acute coronary syndrome: Findings from the improving care for cardiovascular disease in China-acute coronary syndrome project

BACKGROUND

The optimal formula for the estimation of glomerular filtration rate (GFR) in patients with acute coronary syndrome (ACS) in terms of predicting in-hospital mortality and adverse events remains unclear.

METHODS

A nationwide registry study, Improving CCC (Care for Cardiovascular Disease in China) ACS project, was launched in 2014 as a collaborative study of the American Heart Association and Chinese Society of Cardiology. The Cockcroft-Gault, modification of diet in renal disease (MDRD) formula for Chinese (C-MDRD), Mayo, and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas were used to calculate estimated GFR in 61,545 ACS patients (38,734 with ST-segment elevation myocardial infarction [STEMI] and 22,811 with non-ST-segment-elevation ACS [NSTE-ACS]).

RESULTS

Prevalence of moderate to severe renal dysfunction was inconsistent among four formulas, ranging from 11.6% to 22.4% in NSTE-ACS and from 8.3% to 16.8% in STEMI, respectively. The in-hospital mortality rate in patients with ACS was inversely associated with estimated GFR. In STEMI, the Mayo-derived eGFR exhibited the highest predictive power for in-hospital death compared with the Cockcroft-Gault-derived eGFR (area under the curve [AUC]: 0.782 vs. 0.768, p=0.004), C-MDRD-derived eGFR (AUC: 0.782 vs. 0.740, p<0.001) and CKD-EPI-derived eGFR (AUC: 0.782 vs. 0.767, p<0.001). In NSTE-ACS, the Mayo-derived eGFR exhibited a similar predictive value with the Cockcroft-Gault (AUC: 0.781 vs. 0.787, p>0.05) and CKD-EPI-derived eGFR (AUC: 0.781 vs. 0.784, p>0.05).

CONCLUSIONS

The Mayo formula was superior to Cockcroft-Gault, C-MDRD, and CKD-EPI formulas for predicting in-hospital mortality in ACS patients, especially for STEMI. The Mayo-derived eGFR may serve as a risk-stratification tool for in-hospital adverse events in ACS patients.

CLINICAL TRIAL REGISTRATION

URL: http://www.

CLINICALTRIALS

gov. Unique identifier: NCT02306616.

Single Versus Multiple Arterial Revascularization in Patients With Reduced Renal Function: Long-term Outcome Comparisons in 23,406 CABG Patients From Ontario, Canada

OBJECTIVE

To compare the long-term outcomes of MAR versus SAR in patients with renal insufficiency.

SUMMARY OF BACKGROUND DATA

Previous studies have been insufficiently powered to address whether MAR confers long-term benefit over SAR in patients with renal dysfunction who require CABG.

METHODS

We conducted retrospective cohort study in Ontario, Canada of patients who underwent isolated CABG (n = 23,406). The primary outcome was MACE, defined as the composite of stroke, myocardial infarction, and repeat revascularization. We compared patients by matching them on the propensity to have received SAR versus MAR, within groups with preoperative glomerular filtration rate (GFR) ≥60 mL/min/1.73 m2; GFR between 30 and 60; and GFR <30.

RESULTS

In patients with GFR ≥60, the use of MAR versus SAR was associated with a lower rate of MACE [hazard ratio (HR) 0.87 (0.80-0.94)], and a lower rate of long-term mortality [HR 0.87 (0.79-0.97)]. In those with GFR between 30 and 60, MAR was not associated with a difference in MACE [HR 1.04 (0.87-1.26)], and a lower rate of long-term mortality [HR 0.75 (0.65-0.87)] was observed. In those with GFR <30, MAR was not associated with a difference in outcomes.

CONCLUSIONS

MAR versus SAR does not correlate with a difference in MACE amongst patients with GFR between 30 and 60 and better survival raises the possibility of indication bias. Furthermore, MAR did not confer a benefit in those with severely reduced renal function. These data suggest that the potential long-term benefits of using MAR in CABG patients with renal insufficiency may be offset by competing health risks.

A retrospective comparison of preoperative estimated glomerular filtration rate as a predictor of postoperative cardiac surgery associated acute kidney injury

Background:

Cardiac surgery-associated acute kidney injury (CSA-AKI) remains common with distressingly high mortality. Over time, risk scorings systems have been developed to predict it and preoperative low estimated glomerular filtration rate (eGFR) has been regarded as one of the predicting risk factors.

Objectives:

The present study is aimed at assessing the relation of different ranges of preoperative eGFR with an incidence of CSA-AKI defined by the AKI network (AKIN) criteria.

Materials and Methods:

Files of 134 patients with eGFR of >40 cc/min/1.73 m² body surface area (BSA) who underwent cardiac surgeries on cardiopulmonary bypass were screened for data collection. Occurrences of CSA-AKI were evaluated as per the AKIN criteria over the course of 3 postoperative days. The relationships of different ranges of preoperative eGFR with CSA-AKI were analyzed by appropriate statistical tests using Instat software and P < 0.05 was considered statistically significant.

Results:

A total of 60 males and 74 females with a mean + standard deviation (SD) age of 37.98 ± 12.50 years and mean + SD preoperative eGFR of 70.20 ± 20.89 cc/min/1.73 m² were analyzed in this study. About 49.25% of patients suffered from CSA-AKI by the 3^rd postoperative day. The crude risk of CSA-AKI in patients with eGFR 40–60 cc/min/1.73 m² was not higher (odds ratio 0.29) as compared to patients in patients with eGFR >100 cc/min/1.73 m². The CSA-AKI trend with different eGFR was also statistically insignificant (P > 0.05).

Conclusion:

In patients with preoperative eGFR >40 cc/min/1.73 m² BSA, a lower preoperative eGFR (40–60 cc/min/1.73 m²) does not predict higher incidence of CSA-AKI as defined by AKIN criteria as compared to higher preoperative eGFR (>100 cc/min/1.73 m²). Lower height is independently associated with higher incidence of CSA-AKI in such patients.

Six-month prognostic impact of hemodynamic profiling by short minimally invasive monitoring after cardiac surgery

Introduction: Studies have shown that a hemodynamic-guided therapy improves the post operative outcomes of high-risk patients.This study, evaluated if a short period through minimally invasive hemodynamic monitoring, pressure recording analytical method (PRAM), on admission to a post-cardiac surgery step-down unit (SDU), may identify patients at higher risk of 6-month adverse events after cardiac surgery. Methods: From December 2016-May 2017,173 patients were admitted in SDU within 24-48 hours of major cardiac surgery procedure, and submitted to clinical, laboratoristic and echocardiographic evaluation and a 1-hour PRAM recording to obtain a "biohumoral snapshot" of individual patient's.156 173 patients (17 patients were lost at follow-up) were phone interviewed six months after surgery,to evaluate, as a composite end-point, the adverse events during follow-up. A multivariable logistic regression analysis was used to identify a model clinical-biohumoral (CBM) and clinical-biohumoral hemodynamics (CBHM). Results: No data from past clinical history and no conventional risk score (EuroScore II, STS score)independently predicted the risk of 6-month major events in our study. The risk of adverse events at six-month follow-up was directly related, in the CBM, to sustained post-operative cardiac arrhythmias, higher values of NT-proBNP and of arterial pH; inversely related to values of hs-C-reactive protein (hs-CRP) and, in the CBHM, to low values of cardiac cycle efficiency (CCE) and dP/dt_max. Conclusion: Our study although limited by its observational nature and by the limited number of patients enrolled, showed that a short period of minimally invasive hemodynamic monitoring increased the accuracy to identify patients at major risk of mid-term events after cardiac surgery.

Outcome of Percutaneous Coronary Intervention During Non-ST-Segment-Elevation Myocardial Infarction in Elderly Patients With Chronic Kidney Disease

Background

There is a paucity of data on the benefit of revascularization by percutaneous coronary intervention (PCI) during non–ST‐segment–elevation myocardial infarction in patients aged >80 years with concurrent chronic kidney disease.

Methods and Results

Patients aged >80 years with chronic kidney disease, defined as an estimated glomerular filtration rate (eGFR) <60 mL/min per 1.73 m² with non–ST‐segment–elevation myocardial infarction, during 2011 to 2014 in Sweden retrieved from the SWEDEHEART (Swedish Web‐System for Enhancement and Development of Evidence‐Based Care in Heart Disease Evaluated According to Recommended Therapies) Registry. Cox regression was used to estimate adjusted hazard ratios with 95% CIs for all‐cause mortality in patients with PCI versus no PCI treatment, stratified for eGFR. Logistic regression was used to evaluate adjusted odds for reinfarction and bleeding during hospitalization. Propensity score weighting analysis was also done as sensitivity analysis. In total, 12 821 patients were included, of whom 47%, 45%, and 8% had an eGFR of >60, 30 to 60, and 15 to <30 mL/min per 1.73 m², respectively. Patients with eGFR 30 to 60 and 15 to <30 mL/min per 1.73 m², 22%, and 10%, respectively, underwent PCI, compared with 36% among patients with eGFR >60 mL/min per 1.73 m². During a mean follow‐up of 3.2 years, the absolute risk of death was 42%, 56%, and 76% in patients with eGFR >60, 30 to 60, and 15 to <30 mL/min per 1.73 m², respectively. Patients who underwent PCI had a lower risk of death in all groups of eGFR (0.47 [95% CI, 0.42–0.53], 0.50 [95% CI, 0.45–0.56], and 0.44 [95% CI, 0.33–0.59], respectively). Patients with eGFR 15 to <30 mL/min per 1.73 m² had a higher risk of bleeding with PCI. Propensity score weighting showed similar outcomes for mortality risk as the unweighted analysis in all the eGFR groups.

Conclusions

PCI is rarely used in non–ST‐segment–elevation myocardial infarction elderly patients with chronic kidney disease, and it appears to offer a survival benefit.

Renal insufficiency and severe coronary artery disease: should coronary artery bypass grafting, off-pump coronary artery bypass grafting or percutaneous coronary intervention be performed?

PURPOSE OF REVIEW

Chronic kidney disease (CKD) is an important determinant of long-term survival. However, the optimal revascularization strategy for patients with CKD is still controversial. Herein we review the impact of different treatment modalities on the outcomes of patients with CKD.

RECENT FINDINGS

CABG could confer better long-term outcomes than PCI in patients with CKD, irrespective of CKD severity. CABG as compared with PCI may be associated with improved long-term survival albeit higher short-term risk. Off-pump as compared with on-pump CABG may be associated with better short-term outcomes but no demonstrable long-term benefit. In CKD patients who are treated with PCI, the use of drug-eluting stents may be associated with better intermediate-term outcomes than bare metal stents.

SUMMARY

There is insufficient evidence to inform the optimal revascularization strategy for patients with CKD and severe coronary artery disease. CABG as compared with PCI confers greater long-term benefit but higher upfront risk. A multidisciplinary, team-based evaluation based on individual patient comorbidity, frailty and anatomical disease burden, is recommended when making treatment decisions.

Kidney transplantation and cardiomyopathy: Concepts and controversies in clinical decision-making

Increasing comorbidities and an aging population have led to a tremendous increase in the burden of both kidney and cardiac dysfunction. Concomitant cardiomyopathy exposes the patients with kidney disease to further physiological, hemodynamic, and pathologic alterations. Kidney transplantation imposes lesser anesthetic and surgical complexities compared to another solid organ transplant. The surgical decision-making remains an unsettled issue in these conditions. The surgical choices, techniques, and sequences in kidney transplant and cardiac surgery depend on the pathophysiological perturbations and perioperative outcomes. The absence of randomized controlled trials eludes us from suggesting definite management protocol in patients with end-stage kidney disease with cardiomyopathy. Nevertheless, in this review, we extracted data from published literature to understand the pathophysiologic interactions between end-stage renal diseases with cardiomyopathy and also proposed the management algorithm in this challenging scenario. The proposed management algorithm would ensure consensus across all stakeholders involved in decision-making. Our simplistic evidence-based approach would augur future randomized trials and would further ensure refinement in our management approach after the emergence of more definitive evidence.

Increased concentrations of platelet- and endothelial-derived microparticles in patients with myocardial infarction and reduced renal function- a descriptive study

Background

Patients with chronic kidney disease (CKD) have a high risk of recurring thrombotic events following acute myocardial infarction (AMI). Microparticles (MPs) are circulating small vesicles shed from various cells. Platelet microparticles (PMPs) reflect platelet activation and endothelial microparticles (EMPs) reflect endothelial activation or dysfunction. Both increase following AMI, and may mediate important biological effects. We hypothesized that AMI patients with CKD have further elevated PMPs and EMPs compared with non-CKD patients, despite concurrent antithrombotic treatment.

Methods

We performed a descriptive study of patients with AMI. Fasting blood samples were acquired from 47 patients on dual antiplatelet treatment. Patients were stratified by renal function: normal (H; n = 19) mean eGFR 88; moderate CKD (CKD3; n = 15) mean eGFR 47, and severe CKD (CKD4–5; n = 13) mean eGFR 20 mL/min/1.73 m².

MPs were measured by flow-cytometry and phenotyped according to size (< 1.0 μm) and expression of CD41 (GPIIb; PMPs) and CD62E (E-selectin; EMPs). In addition, expression of platelet activation markers P-selectin (CD62P) and CD40ligand (CD154) were also investigated.

Results

PMPs expressing CD40 ligand were higher in CKD4–5: 210 /μl (174–237); median and interquartile range; vs. group H; 101 /μl (71–134; p < 0.0001) and CKD 3: 142 /μl (125–187; p = 0.006). PMPs expressing P-selectin were higher in CKD4–5 compared with H, but not in CKD3. EMPs were higher in CKD4–5; 245 /μl (189–308) compared with H; 83 /μl (53–140; p < 0.0001) and CKD3; 197 /μl (120–245; p < 0.002).

Conclusions

In AMI patients, PMPs and EMPs from activated platelets and endothelial cell are further elevated in CKD patients. This indicate impaired endothelial function and higher platelet activation in CKD patients, despite concurrent antiplatelet treatment.

Kidney function is associated with short-term, mid-term and long-term clinical outcome after coronary angiography and intervention

BACKGROUND

Patients with kidney dysfunction are at risk of developing ischaemic heart disease. We investigated the association between eGFR and early-, mid- and long-term clinical outcome in patients undergoing coronary angiography and intervention.

METHODS

Retrospective study on 4968 patients with complete data on eGFR, 65% male and aged 32-80 years, admitted to Danderyd University Hospital, Stockholm, Sweden for coronary angiography and intervention from 2006 to 2008. Data were censored at 0-30 days, 31-365 days and 366-1825 days of follow-up.

RESULTS

Baseline eGFR was strongly associated with all-cause mortality at all three time periods studied with each 10 ml/min per 1.73 m² increase in eGFR being associated with a ∼30% (p < .001), 25% (p = .002) and 20% (p < .001) decrease in all-cause mortality at 30, 365 and 1825 days respectively. Each 10 ml/min per 1.73 m² increase in eGFR was associated with a ∼21% (p < .001) decrease in re-hospitalisation for MI at 365 days and a 6% decrease (p = .03) at day 30 for re-vascularisation.

CONCLUSIONS

We report a strong association between kidney function and all-cause mortality at both early, mid- and long-term follow-up in patients undergoing coronary angiography and intervention, with eGFR significantly associated with MI-related mortality after one month of follow-up. Kidney function was also shown to be associated with risk for re-vascularisation at one month, indicating mostly procedural-related risk and with new MI at mid-term follow-up. Further research is warranted to explore the mechanisms linking kidney function and cardiovascular disease to improve both the short- and long-term care of these patients.

Any grade of relative overhydration is associated with long-term mortality in patients with Stages 4 and 5 non-dialysis chronic kidney disease

Background

Overhydration (OH) is associated with mortality in chronic kidney disease (CKD). A relative overhydration adjusted for extracellular water (OH/ECW) measured by bioimpedance >15% has shown an increased mortality risk in haemodialysis but few studies have been developed in advanced CKD. Our objective was to evaluate the effect of OH on mortality in patients with Stage 4 or 5 non-dialysis CKD.

Methods

We performed a prospective study of 356 patients enrolled in 2011 and followed up until 2016. At baseline we collected general characteristics, serum inflammatory and nutrition markers, cardiovascular events (CVEs) and body composition using bioimpedance spectroscopy. During a median follow-up of 50 (24–66) months we collected mortality data.

Results

The mean creatinine was 3.5 ± 1.3 mg/dL, median proteinuria was 0.5 [interquartile range (IQR) 0.2–1.5] g/24 h, median OH was 0.6 (IQR −0.4–1.5) L and mean relative OH (OH/ECW) was 2.3 ± 0.8%. We found that 32% of patients died. The univariate Cox analysis showed an association between mortality and age, diabetes, previous CVEs, Charlson comorbidity index, low albumin and pre-albumin, high C-reactive protein (CRP), low lean tissue and high OH/ECW. Multivariate Cox analysis confirmed an association between mortality and age {exp(B) 1.1 [95% confidence interval (CI) 1.0–1.3]; P = 0.001}, Charlson comorbidity index [exp(B) 1.1 (95% CI 1.0–1.2); P = 0.01], CRP [exp(B) 1.1 (95% CI 1.0–1.2); P = 0.04], OH/ECW [exp(B) 3.18 (95% CI 2.09–4.97); P = 0.031] and low lean tissue [exp(B) 0.82 (95% CI 0.69–0.98); P = 0.002]. Kaplan–Meier analysis confirmed higher mortality in patients with OH/ECW >0% (log rank 11.1; P = 0.001).

Conclusion

Any grade of relative OH measured by OH/ECW >0% is associated with long-term mortality in patients with Stage 4 or 5 non-dialysis CKD.

Relationship between sleep-disordered breathing and renal dysfunction in acute coronary syndrome

BACKGROUND

Sleep-disordered breathing (SDB) is associated with cardiovascular complications. However, the effect of SDB on renal function in patients with acute coronary syndrome (ACS) treated by percutaneous coronary intervention (PCI) remains unclear.

METHODS

We enrolled 154 consecutive ACS patients without heart failure. A sleep study was performed immediately after PCI.

RESULTS

The mean apnea-hypopnea index (AHI) was 16.4±13.1, and 33 patients (21%) had severe SDB, defined as AHI≥25. Estimated glomerular filtration rate (eGFR) values on admission (60±12mL/min/1.73m² vs. 67±17mL/min/1.73m², p=0.046) and at discharge (54±15mL/min/1.73m² vs. 63±15mL/min/1.73m², p=0.002) were lower in patients with severe SDB than in those patients without severe SDB. Multiple linear regression analysis showed that AHIs were significantly correlated with absolute changes in eGFR values from admission to discharge (β=0.201, p=0.004). Median 24-h urinary noradrenaline excretion measured on the same day of the sleep study was higher [297 (interquartile range {IQR}: 232-472) vs. 174 (IQR: 107-318)μg/day, p=0.021] in patients with severe SDB. On multivariate logistic regression analysis, the presence of severe SDB was a significant predictor (adjusted odds ratio 3.76, 95% confidence interval 1.06-13.9, p=0.047) for eGFR of less than 45mL/min/1.73m² at discharge. This association was independent of age, eGFR on admission, and a presentation of ST-segment elevation myocardial infarction.

CONCLUSION

In patients with ACS who undergo PCI, severe SDB is associated with impaired renal function on admission and its deterioration during hospitalization. Further studies will be needed to conclude that SDB would be a therapeutic target in ACS.

Impact of renal function impairment assessed by CKDEPI estimated glomerular filtration rate on early and late outcomes after coronary artery bypass grafting

BACKGROUND

We explore the association between short- and long- term adverse outcomes following coronary artery bypass grafting (CABG) and the degree of preoperative renal dysfunction classified on glomerular fraction estimated with Chronic Kidney Disease-Epidemiology Collaboration equation (eGFR_CKD-EPI). We also try to identify cut-off values of eGFR_CKD-EPI able to predict post-CABG unfavorable events and assess whether a reclassification with new thresholds is necessary.

METHODS

One-thousand-one-hundred-eighty-six consecutive patients undergoing CABG between 2005 and 2014 were categorized in 4 groups according to the eGFR_CKD-EPI: Group 1 (≥60ml/min/1.73m²; n=1199), Group 2 (45-59ml/min/1.73m²; n=358), Group 3 (30-44ml/min/1.73m²; n=171) and Group 4 (≤29ml/min/1.73m²; n=126). Median follow-up was 66months [IQR 46-84].

RESULTS

eGFR_CKD-EPI ≤30ml/min/1.73m², ≤41ml/min/1.73m², ≤27ml/min/1.73m² and ≤29ml/min/1.73m² were strong predictors of early mortality (OR 5.88 [95% CI 2.59-11.25]), stroke (2.59 [1.43-3.71]), prolonged length of stay (3.49 [1.24-5.92]) and postoperative dialysis (3.68 [1.34-4.91]), respectively. In addition, eGFR_CKD-EPI ≤26ml/min/1.73m², ≤25ml/min/1.73m², ≤35ml/min/1.73m² and ≤29ml/min/1.73m² predicted all-cause death (hazard ratio 2.74 [95% CI 2.10-3.92] cardiovascular death (sub-hazard ratio 2.11 [95% CI 1.42-3.90]), myocardial infarction (2.01 [1.32-3.70]) and heart failure (2.24 [1.41-3.93]), respectively. Analyses corrected by age and left ventricular ejection fraction confirmed these findings.

CONCLUSIONS

In our experience, the use of the eGFR_CKD-EPI equation led to categorization with a significantly lower number of patients at risk for post-CABG complications. This might have important clinical repercussions on allocation of healthcare resources and more targeted prevention and management of CABG complications.

Coronary artery bypass grafting in patients 50 years or younger: a Swedish nationwide cohort study

BACKGROUND

There are limited data regarding long-term results after coronary artery bypass grafting (CABG) in young adults. We performed a nationwide population-based cohort study to analyze long-term survival, major adverse cardiovascular events, and factors associated with elevated risk in young adults undergoing CABG.

METHODS AND RESULTS

We included all adult patients ≤50 years of age who underwent primary isolated CABG in Sweden between 1997 and 2013 from the Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART) register. Patient data were linked from national Swedish health data registers to create a study database. We identified 4086 young adults with a mean age of 46 years and 18% women. During a median follow-up time of 10.9 years (interquartile range, 6.4-14.1) 490 (12%) patients died. Survival at 5, 10, and 15 years was 96% (95% CI, 95-96), 90% (95% CI, 89-91), and 82% (95%CI, 80-83), respectively, which was significantly better in comparison with patients aged 51 to 70 years and >70 years who underwent CABG during the same period. The cumulative incidence of death or a major adverse cardiovascular event during 17 years after CABG was mainly driven by myocardial infarction or the need for repeat revascularization. The most important risk factors for all-cause mortality were chronic kidney disease, reduced left ventricular ejection fraction, peripheral vascular disease, or chronic obstructive pulmonary disease.

CONCLUSIONS

Long-term survival and freedom from major cardiovascular events after CABG was better in young adults than in older patients. Factors significantly associated with an elevated long-term risk of death or adverse outcome were similar to well-known risk factors for older age groups following CABG.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02276950.

Effects of acute kidney injury and chronic kidney disease on long-term mortality after coronary artery bypass grafting

BACKGROUND

Both acute kidney injury (AKI) and chronic kidney disease (CKD) are important issues in patients undergoing coronary artery bypass grafting (CABG), particularly with regard to mortality. However, their synergistic or discrete effects on long-term mortality remain unresolved.

METHODS

A total of 1,899 patients undergoing CABG were retrospectively analyzed. The adjusted hazard ratios for all-cause mortality were calculated after stratifying the timeframes. To evaluate the synergistic effects between AKI and CKD, the relative excess risk due to interaction was applied.

RESULTS

The presence of AKI, CKD, or both increased the hazard ratios for mortality, compared with the absence of both: AKI alone, 1.84 (1.464-2.319); CKD alone, 2.46 (1.735-3.478); and AKI and CKD together, 3.21 (2.301-4.488). However, the relationships with mortality were different between AKI and CKD, according to the timeframes: AKI primarily affected early mortality, particularly within 3 years, whereas CKD had a relatively constant effect on both the early and late periods. When the parameters from the relative excess risk due to interaction were obtained, there was a synergistic additive effect on early mortality between AKI and CKD.

CONCLUSIONS

The relationships with mortality after CABG were different between AKI and CKD. However, their effects were not exclusive but synergistic.