Multiple arterial vs. single arterial coronary artery bypass grafting: sex-related differences in outcomes

BACKGROUND AND AIMS

Uncertainty exists over whether multiple arterial grafting has a sex-related association with survival after coronary artery bypass grafting. This study aims to compare the long-term survival of using multiple arterial grafting vs. single arterial grafting in women and men undergoing coronary artery bypass grafting.

METHODS

The retrospective study used the Australian and New Zealand Society of Cardiothoracic Surgical Database with linkage to the National Death Index. Patients from 2001 to 2020 were identified. Sex-stratified, inverse probability weighted Cox proportional hazard model was used to facilitate survival comparisons. The primary outcome was all-cause mortality.

RESULTS

A total number of 54 275 adult patients receiving at least two grafts in primary isolated bypass operations were analysed. The entire study cohort consisted of 10 693 (19.7%) female patients and 29 711 (54.7%) multiple arterial grafting procedures. At a median (interquartile range) postoperative follow-up of 4.9 (2.3-8.4) years, mortality was significantly lower in male patients undergoing multiarterial than single arterial procedures (adjusted hazard ratio 0.82; 95% confidence interval 0.77-0.87; P < .001). The survival benefit was also significant for females (adjusted hazard ratio 0.83; 95% confidence interval 0.76-0.91; P < .001) at a median (interquartile range) follow-up of 5.2 (2.4-8.7) years. The interaction model from Cox regression suggested insignificant subgroup effect from sex (P = .08) on the observed survival advantage. The survival benefits associated with multiple arterial grafting were consistent across all sex-stratified subgroups except for female patients with left main coronary disease.

CONCLUSIONS

Compared to single arterial grafting, multiple arterial revascularization is associated with improved long-term survival for women as well as men.

Risk factors of in-hospital mortality for isolated on-pump coronary artery bypass graft surgery in the northeast of Iran from 2007 to 2016

BACKGROUND AND OBJECTIVE

Coronary artery bypass graft (CABG) surgery is the most common cardiac surgery worldwide. The reported mortality rates for this operation vary greatly. We aimed to determine the risk factors of in-hospital mortality for isolated on-pump CABG surgery.

METHODS

This was a large-scale retrospective cohort study of two heart centers in Golestan province. Patients over the age of 18 from both genders who underwent isolated on-pump CABG procedures from 2007 to 2016 were included. The study outcome was in-hospital mortality, which was determined according to the clinical records of study patients.

RESULTS

A total of 3704 patients were included in the study, and 63% were men. In-hospital mortality occurred in 2.8% (n=103) of the patients. The median (IQR) age of survived and not-survived patients were 59 (53-65) and 62 (55-75) years, respectively. 44% of the mortalities occurred in patients older than 65, while 28% of the survivors were older than 65. Multivariable logistic regression indicated that emergency CABG (OR 4.52, 95% CI, 1.45, 14.02; P = 0.009) and cardiopulmonary bypass time (CPB) (OR 1.004, 95% CI 1.001, 1.008; P = 0.034) were the risk factors of in-hospital mortality. The area under the receiver operating characteristic (ROC) curve (AUC) of the model consisting of operative and preoperative variables was 0.70 (acceptable performance).

CONCLUSION

Our study revealed an acceptable mortality proportion for CABG surgeries conducted in the region. Emergency CABG and CPB time were the main risk factors for in-hospital mortality after CABG.

Outcomes of Coronary Artery Bypass Graft Surgery in Africa: A Systematic Review and Meta-Analysis

Coronary artery bypass graft (CABG) surgery has been in practice for many decades, and it is one of the most commonly performed cardiac surgeries worldwide. While there are several studies reporting data on perioperative outcomes following CABG in developed countries, there is a staggering paucity of data and evidence reporting the outcomes in developing areas such as Africa. Thus, it is important to study the practice and outcome of CABG in Africa to establish its clinical efficacy and safety in this region and identify factors that might be limiting its practice. The overall aim of this study is to identify all relevant clinical data on CABG in Africa and report on the perioperative outcomes and practice of CABG in the African population. Electronic search was performed using three online databases, PubMed, African Journal Online, and Research Gate, from inception to June 2023. The preferred reporting items for systematic reviews and meta-analysis (PRISMA) guideline was utilised for this study. Relevant studies fulfilling predefined eligibility criteria were included in the study. Intraoperative details, such as the number of grafts performed, operative, bypass, and cross-clamp time, were reported. The primary endpoint assessed were early mortality and overall mortality. The secondary endpoints included length of hospital stay, intensive care unit stay, and postoperative complications, such as renal impairment, atrial fibrillation, and surgical site infection. The data were pooled together and meta-analyzed using a random effect model for proportions and mean for meta-analysis with R software (version 4.3.1 (2023-06-16); R Development Core Team, Vienna, Austria). This systematic review identified 42 studies that fulfilled the study eligibility criteria, including 21 randomised controlled trials, 20 observational studies, and one cross-sectional study. Only four out of the 54 countries in Africa had studies carried out that met the criteria for this review; they included Algeria, Egypt, Nigeria, and South Africa, with a majority from Egypt. Meta-analysis reported a pooled early mortality and pooled overall mortality of 3.51% and 3.73%, respectively, for the total cohort of patients. The result of this meta-analysis suggests that mortality outcomes following CABG in Africa are relatively higher than those in developed nations. Several issues, such as lack of financial resources and poor infrastructure, continue to hinder the optimal practice of CABG procedures in many parts of Africa. Further studies focused on finding factors associated with outcomes following CABG should be done. Though there were a few limitations to the study largely from a lack of data from several regions and countries in Africa, the result from this meta-analysis can serve as a benchmark for future studies until more relevant data are reported.

Atrial fibrillation in patients with coronary heart disease: current state of the problem

Atrial fibrillation is one of the most common types of cardiac arrhythmia observed in clinical practice. Despite advances in the diagnosis and treatment, atrial fibrillation remains one of the leading causes of cardiovascular mortality and morbidity. In addition, atrial fibrillation is quite often combined with other pathologies of the cardiovascular system and is a marker of an unfavorable outcome. Several previous studies have demonstrated reduced survival in patients with coronary artery disease and atrial fibrillation who have not undergone surgery for arrhythmia. According to other data, the presence of preoperative atrial fibrillation among patients undergoing isolated coronary artery bypass grafting was associated with significantly higher rates of major postoperative complications. Nowadays, no one doubts the fact that atrial fibrillation during a coronary artery bypass surgery is a risk factor for increased hospital mortality, postoperative morbidity and leads to a decrease in the long-term survival. The studies confirm the necessity of surgical ablation for atrial fibrillation during coronary revascularization to reduce both short-term and long-term postoperative mortality and late complications.

Management of Atrial Fibrillation in Patients Undergoing Coronary Artery Bypass Grafting: Review of the Literature

Untreated atrial fibrillation is associated with an increased risk of all-cause mortality and morbidity. Despite the current guidelines recommending surgical ablation of atrial fibrillation at the time of coronary artery bypass surgery, most patients with concomitant atrial fibrillation and coronary artery disease do not receive surgical ablation for their atrial fibrillation. This review reports the efficacy of different surgical ablation techniques used for the treatment of atrial fibrillation during coronary artery bypass. PubMed was systematically searched for studies reporting outcomes of concomitant surgical ablation in coronary artery bypass patients between January 2002 and March 2018. Data were independently extracted and analyzed by two investigators. Twenty-four studies were included. Twelve studies exclusively reported outcomes of surgical ablation in patients undergoing coronary artery bypass, whereas the remaining 12 reported outcomes of concomitant cardiac surgery with subgroup analysis. Only four studies performed the concomitant Cox-Maze procedure. Freedom from atrial tachyarrhythmia was reported as high as 98% at 1 year and 76% at 5 years with Cox-Maze procedure, whereas lesser lesion sets had more variable outcomes, ranging from 35% to 93%. In most studies, the addition of surgical ablation was not associated with increased morbidity and mortality. Although the Cox-Maze procedure had the greatest short- and long-term success rates, most studies comprising the evidence documenting the safety and efficacy of adding surgical ablation were of low or moderate quality. There was a great deal of heterogeneity among study populations, follow-up times, methods, and definition of failure. To establish a consensus regarding a surgical ablation technique for atrial fibrillation in coronary artery bypass population, larger multicenter randomized controlled studies need to be designed.

Biomarkers and mortality in severe Chagas cardiomyopathy

BACKGROUND

Chagas cardiomyopathy is a chronic sequela of infection by the parasite, Trypanosoma cruzi. Advanced cardiomyopathy is associated with a high mortality rate, and clinical characteristics have been used to predict mortality risk. Though multiple biomarkers have been associated with Chagas cardiomyopathy, it is unknown how these are related to survival.

OBJECTIVES

This study aimed to identify biomarkers associated with mortality in individuals with severe Chagas cardiomyopathy in an urban Bolivian hospital.

METHODS

The population included individuals with and without T. cruzi infection recruited in an urban hospital in Santa Cruz, Bolivia. Baseline characteristics, electrocardiogram findings, medications, and serum cardiac biomarker levels (B-type natriuretic peptide [BNP], N-terminal pro-B-type natriuretic peptide [NT-proBNP], creatine kinase-myocardial band [CK-MB], troponin I, matrix metalloproteinase [MMP]-2, MMP-9, tissue inhibitor of metalloproteinases [TIMP] 1 and 2, transforming growth factor [TGF] beta 1 and 2) were ascertained. Echocardiograms were performed on those with cardiac symptoms or electrocardiogram abnormalities at baseline. Participants were contacted approximately 1 year after initial evaluation; deaths were reported by family members. Receiver-operating characteristic curves (ROC) were used to optimize cutoff values for each marker. For markers with area under the curve (AUC) >0.55, Cox proportional hazards models were performed to determine the hazards ratio (HR) and 95% confidence interval (CI) for the association of each marker with mortality.

RESULTS

The median follow-up time was 14.1 months (interquartile range 12.5, 16.7). Of 254 individuals with complete cardiac data, 220 (87%) had follow-up data. Of 50 patients with severe Chagas cardiomyopathy at baseline, 20 (40%) had died. Higher baseline levels of BNP (HR: 3.1, 95% CI: 1.2 to 8.4), NT-proBNP (HR: 4.4, 95% CI: 1.8 to 11.0), CK-MB (HR: 3.3, 95% CI: 1.3 to 8.0), and MMP-2 (HR: 4.2, 95% CI: 1.5 to 11.8) were significantly associated with subsequent mortality.

CONCLUSIONS

Severe Chagas cardiomyopathy is associated with high short-term mortality. BNP, NT-proBNP, CK-MB, and MMP-2 have added predictive value for mortality, even in the presence of decreased ejection fraction and other clinical signs of congestive heart failure.

Do age, diabetes and left ventricular function affect the outcomes of ischemic mitral valve repair?

INTRODUCTION

It is well documented that older age, chronic concomitant diseases (such as diabetes mellitus, chronic obstructive lung disease, etc.), and poor left ventricular function can increase the postoperative complication rate and worsen the general outcomes of coronary artery bypass (CABG) and concomitant repair of ischemic mitral regurgitation (MR).

MATERIAL AND METHODS

Retrospective data of 394 patients after CABG and mitral valve (MV) repair (mainly annuloplasty) were analyzed. Patients were grouped according to age, diabetes mellitus (DM), and left ventricular ejection fraction (LVEF). Echocardiography data, the rate of postoperative complications (cardiogenic shock, preoperative myocardial infarction, bleeding from the gastrointestinal tract, cognitive disorders, stroke, sepsis, deep wound infection), and early and late mortality were compared between paired groups.

RESULTS

There were no differences between age groups in reverse positive remodeling of LV. A significantly higher incidence of sepsis and deep wound infection in younger patients was observed. Patients with DM had no change in the pre-postoperative NYHA class and a higher rate of perioperative MI (10.3% vs. 3.1% respectively, p < 0.05) in comparison to patients with no DM. In all LVEF groups, MR was significantly decreased, but reverse positive remodeling of LV was pronounced only in those with "poor" and "moderately lowered" LVEF. Postoperative complications did not differ among these three groups.

CONCLUSIONS

Elderly age, concomitant DM and lowered LVEF do not influence either early or late mortality, including early postoperative outcomes after MV repair for ischemic MR following CABG. Concomitant DM increases the rate of perioperative MI and impairs reverse remodeling of LV.

Feasibility, efficacy, and safety of a simple insulin infusion protocol in a large volume cardiac surgery unit in India

AIM

Inpatient hyperglycemia management is essential, but difficult to achieve especially in a large volume cardiac surgery setup, thus necessitating use of nurse-led insulin protocols. A rapid flux of nurses dealing with a huge workload has been a cause for traditionally not using nurse-led protocols in most Indian institutes. The challenges we faced were to have a simple protocol for the nurses to accept it without compromising on glycemic control. Therefore, this observational study was planned to measure the efficacy and safety of the insulin infusion protocol in cardiac surgery patients.

MATERIALS AND METHODS

Insulin protocol was implemented, using seven fixed columns of infusion with the nurse making decisions to initiate and titrate doses based on simple rules. Blood glucose (BG) data captured from blood gas analyzers (glucometrics) in the intervention group (i.e., after protocol implementation) were compared to control group (i.e., before the protocol implementation).

RESULTS

The mean BG for the first 48 h was lower in the intervention group as compared to control group, without an increase in the episodes of hypoglycemia. The nurses found the protocol easy to understand, less time-consuming and there was no protocol deviation over 8 months after implementation.

CONCLUSION

A small change in the process, allowing nurses to titrate insulin doses based on some rules and having seven fixed columns of insulin infusion rates, improved glycemic control and efficiency.

The importance of intraoperative selenium blood levels on organ dysfunction in patients undergoing off-pump cardiac surgery: a randomised controlled trial

INTRODUCTION

Cardiac surgery is accompanied by an increase of oxidative stress, a significantly reduced antioxidant (AOX) capacity, postoperative inflammation, all of which may promote the development of organ dysfunction and an increase in mortality. Selenium is an essential co-factor of various antioxidant enzymes. We hypothesized a less pronounced decrease of circulating selenium levels in patients undergoing off-pump coronary artery bypass (OPCAB) surgery due to less intraoperative oxidative stress.

METHODS

In this prospective randomised, interventional trial, 40 patients scheduled for elective coronary artery bypass grafting were randomly assigned to undergo either on-pump or OPCAB-surgery, if both techniques were feasible for the single patient. Clinical data, myocardial damage assessed by myocard specific creatine kinase isoenzyme (CK-MB), circulating whole blood levels of selenium, oxidative stress assessed by asymmetric dimethylarginine (ADMA) levels, antioxidant capacity determined by glutathionperoxidase (GPx) levels and perioperative inflammation represented by interleukin-6 (IL-6) levels were measured at predefined perioperative time points.

RESULTS

At end of surgery, both groups showed a comparable decrease of circulating selenium concentrations. Likewise, levels of oxidative stress and IL-6 were comparable in both groups. Selenium levels correlated with antioxidant capacity (GPx: r = 0.720; p<0.001) and showed a negative correlation to myocardial damage (CK-MB: r =  -0.571, p<0.001). Low postoperative selenium levels had a high predictive value for the occurrence of any postoperative complication.

CONCLUSIONS

OPCAB surgery is not associated with less oxidative stress and a better preservation of the circulating selenium pool than on-pump surgery. Low postoperative selenium levels are predictive for the development of complications.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01409057.

Medanta insulin protocols in patients undergoing cardiac surgery

Hyperglycemia is common in patients undergoing cardiac surgery and is associated with poor outcomes. This is a review of the perioperative insulin protocol being used at Medanta, the Medicity, which has a large volume cardiac surgery setup. Preoperatively, patients are usually continued on their preoperative outpatient medications. Intravenous insulin infusion is intiated postoperatively and titrated using a column method with a choice of 7 scales. Insulin dose is calculated as a factor of blood glucose and patient's estimated insulin sensitivity. A comparison of this protocol is presented with other commonly used protocols. Since arterial blood gas analysis is done every 4 hours for first two days after cardiac surgery, automatic data collection from blood gas analyzer to a central database enables collection of glucose data and generating glucometrics. Data auditing has helped in improving performance through protocol modification.

A novel treatment strategy of new onset atrial fibrillation after cardiac surgery: an observational prospective study

OBJECTIVE

The aim of this prospective observational study was to evaluate the efficiency of a new escalating treatment strategy with vernakalant, flecainide and electrical cardioversion (EC) in patients with new onset atrial fibrillation (AF) after cardiac surgery.

MATERIAL AND METHODS

24 patients with new onset AF after aortic valve surgery, coronary artery bypass surgery or combined procedures were evaluated in this study. Additional including criteria were age between 18 and 80, duration of AF less than four days, body weight less than 100 kg and no previous treatment with class I or III antiarrhythmic drugs. Exclusion criteria were poor left ventricular ejection fraction (LVEF < 40%) and history of myocardial infarction within 30 days. The patients were divided into converters and non-converters according to their response to combination treatment with vernakalant and flecainide, and the groups were compared.

RESULTS

The mean age of the population was 69.6 ± 6.3 years and 26.1% of patients were female. There were no statistically significant differences between the two groups in terms of height, weight, gender distribution, comorbidities, preoperative medication, left ventricular function and left atrium diameter. Interventricular septum (IVS) in the non-converted group was significantly thicker compared to the converted group: 14.0 ± 1.00 vs. 10.40 ± 2.59 mm (p = 0.036). While 14 patients (60.9%) were successfully converted into stable sinus rhythm by pharmacological treatment with vernakalant and flecainide, 9 patients (39.1%, non-converted group) remained in AF. However, seven of them could be converted after additional EC.

CONCLUSION

The combination of vernakalant and flecainide improves the conversion rate into a stable sinus rhythm in postcardiotomy patients with new onset AF compared to single drug therapy. Furthermore it might be an excellent precondition for successful EC in patients who are not converted after using both antiarrhtythmic drugs. Furthermore, left ventricular hypertrophy might be a potential negative predictor of successful pharmacological cardioversion.

The effect of patient sex on survival in patients undergoing isolated coronary artery bypass surgery receiving a radial artery

OBJECTIVES

To determine whether patient sex makes a difference to in-hospital mortality and survival in patients undergoing isolated coronary artery bypass graft surgery (CABG) receiving a radial artery graft.

METHODS

Analysis of consecutive patients on a validated prospective cardiac surgery database was performed for patients undergoing isolated CABG. Uni- and multivariate analyses were performed for in-hospital mortality and long-term survival. A propensity analysis was also performed.

RESULTS

Overall mortality was 2.1% (n = 284) for all cases, n = 13 369. Median follow-up was 7.0 (interquartile range 4.1-10.1) years. Of the cases 28.2% of males (n = 384) and 29.7% of females (n = 764) had a radial artery utilized. Univariate analysis demonstrated that in-hospital mortality was significantly lower in male patients, P < 0.001, and radial artery use was associated with increased survival in males, P < 0.0001, but not in females, P = 0.82. In male patients, multivariate analysis failed to identify the radial artery as a risk factor for in-hospital death. The radial artery was identified as a significant prognostic factor, associated with improved long-term survival (hazard ratio [HR] 0.78, 95% confidence interval [CI] 0.69-0.88, P = 0.0001). Propensity analysis confirmed this finding (HR 0.76, 95% CI 0.67-0.86, P < 0.0001). In female patients, multivariate analysis failed to identify the radial artery as a significant factor determining in-hospital mortality or long-term survival. Propensity analysis confirmed these findings.

CONCLUSION

Males derive a significant survival advantage if they receive a radial artery graft when undergoing isolated CABG. The radial artery makes no difference to long-term survival in female patients. Radial artery use does not affect in-hospital mortality regardless of patient sex.

Virchow’s triad and intestinal ischemia post cardiac surgery

Background

Intestinal ischemia is associated with a very high mortality rate. We combined the principles of Virchow’s triad to produce preoperative and postoperative models for the development of intestinal ischemia.

Methods

A single institutional study was undertaken involving 18,325 consecutive patients from April 1997 to March 2012. Univariate and multivariate analysis was performed.

Results

Mortality was 87% in 91 patients who developed bowel ischemia. Multivariate logistic regression demonstrated that age, peripheral vascular disease, intraaortic balloon pump support, female sex, and preexisting renal failure were significant determinates of intestinal ischemia preoperatively. Logistic regression demonstrated that age, peripheral vascular disease, creatine kinase-MB level, reoperation for bleeding, and blood product usage were significant determinates of intestinal ischemia postoperatively.

Conclusions

Potentially remedial causes of intestinal ischemia include blood product usage, reoperation for bleeding, and creatine kinase-MB release. Age, female sex, peripheral vascular disease, intraaortic balloon pump usage, and preexisting renal failure are fixed risk factors. Despite the continuing trend of reduced blood product usage in the field of cardiac surgery, the increase in patients’ risk factors will mean that incidences of intestinal ischemia may increase in the future.

Long-term survival of non-smokers undergoing coronary artery bypass surgery

OBJECTIVES

We sought to investigate long-term survival of non-smokers undergoing coronary artery bypass surgery (CABG).

METHODS

A prospective database of consecutive patients was retrospectively analysed and cross correlated with the UK strategic tracking service to evaluate survival after primary CABG. Univariate, multivariate and a propensity analyses were performed.

RESULTS

We analysed 13 337 primary CABG procedures. Median follow-up was 7 years. Kaplan-Meier survival curves demonstrate that non-smokers have a significantly improved long-term survival compared with ex- and current smokers, P < 0.0001. Cox regression analysis identified smoking status, age, diabetes, ejection fraction (EF), body mass index, cerebrovascular disease, dialysis, left internal mammary artery (LIMA) non-usage, postoperative creatinine kinase muscle-brain isoenzyme (CKMB), radial artery usage, preoperative rhythm, forced vital capacity (FVC) and logistic EuroSCORE as significant risk factors determining long-term survival. Propensity matching resulted in 3575 non-smokers being matched 1:1, with ex-smokers. After matching, univariate analysis demonstrated the significantly worse long-term survival of ex-smokers compared with non-smokers, P < 0.0001. Cox regression analysis identified smoking status, age, postoperative CKMB, cerebrovascular disease, dialysis, diabetes, EF, FVC, LIMA non-usage, radial artery used, sinus rhythm and logistic EuroSCORE as significant risk factors determining long-term survival. Survival by smoking status plotted at the mean of the covariates, prepropensity matching, demonstrated that non-smokers had a significantly better long-term survival than ex-smokers, P < 0.0001; however, after propensity matching, non-smokers under 65 years of age had a significantly worse long-term survival compared with ex-smokers, P < 0.0001.

CONCLUSIONS

Non-smokers under the age of 65 years of age have significantly worse long-term survival compared with ex-smokers after risk factor adjustment. We speculate that this is because ex-smokers have had the causative factor, smoking, removed, but non-smokers have not.

Statins and long-term survival after isolated valve surgery: the importance of valve type, position and procedure

OBJECTIVES

To investigate whether valve position, type and procedure are important factors in determining the beneficial effects of statin therapy with regard to long-term survival in patients undergoing isolated single valve surgery.

METHODS

A prospective single-institution cardiac surgery database was analysed. Univariate, multivariate stepwise linear, logistic and Cox regression analysis and propensity matching were performed to identify if statins were associated with increased survival post-valve surgery.

RESULTS

Overall mortality was 3.4% (n = 172) for all cases, n = 5013. The median follow-up was 5.8 years. Kaplan-Meier survival analysis indicated that statin therapy was beneficial for all patients undergoing isolated valve surgery, n = 5013, P = 0.03 and isolated aortic valve surgery, n = 3220, P = 0.03, but not isolated mitral valve surgery n = 1793, P = 0.4. Cox regression analysis of the study cohort revealed that statin therapy was a significant factors determining long-term survival in the study cohort, postisolated aortic valve replacement and postisolated biological aortic valve replacement. Statins therapy was not associated with an increased long-term survival post-mitral valve replacement or repair. Propensity matching resulted in 1555 patients receiving statins being matched 1:1 with those not receiving statins. The results after propensity matching concurred with that of the Cox regression analyses, demonstrating that statin therapy was significantly associated with reduced in-hospital mortality, hospital length of stay and postoperative creatinine kinase, muscle-brain isoenzyme release.

CONCLUSIONS

Previous publications have not distinguished valve type, position and repair as possible factors influencing statin-therapy outcomes. Statin therapy is associated with increased long-term survival postaortic valve replacement with a biological valve only. Statin therapy had no survival benefit in patients undergoing mitral valve repair or a mechanical valve replacement. A randomized trial is necessary to confirm or refute our findings.