Clinical outcomes in randomized trials of off- vs. on-pump coronary artery bypass surgery: systematic review with meta-analyses and trial sequential analyses

Cardiopulmonary bypass associated acute kidney injury: better understanding and better prevention

Cardiopulmonary bypass (CPB) is a common technique in cardiac surgery but is associated with acute kidney injury (AKI), which carries considerable morbidity and mortality. In this review, we explore the range and definition of CPB-associated AKI and discuss the possible impact of different disease recognition methods on research outcomes. Furthermore, we introduce the specialized equipment and procedural intricacies associated with CPB surgeries. Based on recent research, we discuss the potential pathogenesis of AKI that may result from CPB, including compromised perfusion and oxygenation, inflammatory activation, oxidative stress, coagulopathy, hemolysis, and endothelial damage. Finally, we explore current interventions aimed at preventing and attenuating renal impairment related to CPB, and presenting these measures from three perspectives: (1) avoiding CPB to eliminate the fundamental impact on renal function; (2) optimizing CPB by adjusting equipment parameters, optimizing surgical procedures, or using improved materials to mitigate kidney damage; (3) employing pharmacological or interventional measures targeting pathogenic factors.

Prolonged Systemic Inflammatory Response Syndrome After Cardiac Surgery

OBJECTIVES

Cardiac surgery induces systemic inflammatory response syndrome (SIRS), leading to higher morbidity and mortality. There are no individualized predictors for worse outcomes or biomarkers for the multifactorial, excessive inflammatory response. The interest of this study was to evaluate whether a systematic use of the SIRS criteria could be used to predict postoperative outcomes beyond infection and sepsis, and if the development of an exaggerated inflammation response could be observed preoperatively.

DESIGN

The study was observational, with prospectively enrolled patients.

SETTING

This was a single institution study in a hospital setting combined with laboratory findings.

PARTICIPANTS

The study included a cohort of 261 volunteer patients.

INTERVENTIONS

Patients underwent cardiac surgery with cardiopulmonary bypass, and were followed up to 90 days. Biomarker profiling was run preoperatively.

MEASUREMENTS AND MAIN RESULTS

Altogether, 17 of 261 (6.4%) patients had prolonged SIRS, defined as fulfilling at least 2 criteria on 4 consecutive postoperative days. During hospitalization, postoperative atrial fibrillation (POAF) was found in 42.2% of patients, and stroke and transient ischemic attack in 3.8% of patients. Prolonged SIRS was a significant predictor of POAF (odds ratio [OR] 4.5, 95% CI 1.2-17.3), 90-day stroke (OR 4.5, 95% CI 1.1-18.0), and mortality (OR 10.7, 95% CI 1.7-68.8). Biomarker assays showed that preoperative nerve growth factor and interleukin 5 levels were associated with prolonged SIRS (OR 5.6, 95%, CI 1.4-23.2 and OR 0.7, 95%, CI 0.4-1.0, respectively).

CONCLUSIONS

Nerve growth factor and interleukin 5 can be used to predict prolonged systemic inflammatory response, which is associated with POAF, stroke, and mortality.

Association of Calpain10 polymorphisms with polycystic ovarian syndrome susceptibility: a systematic review and meta-analysis with trial sequential analysis

Insulin resistance plays an important role in the pathogenesis of polycystic ovarian syndrome (PCOS). Calpain10 (CAPN10) gene was the first identified susceptibility gene for type 2 diabetes mellitus and closely related to insulin sensitivity. A lot of research attention has been attracted on the relationship between CAPN10 polymorphisms and PCOS risk, but they didn't reach a consistent conclusion. We therefore performed this systematic review and meta-analysis to assess the association of CAPN10 common variants with PCOS susceptibility. A total of 21 studies were eligible for inclusion. Meta-analyses were done for 5 variants that had at least two data sources: UCSNP-19, -43, -44, -56 and -63. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated under five genetic models. Subgroup analyses by ethnicity, PCOS diagnostic criteria, and source of controls were conducted. Moreover, false-positive report probability (FPRP) test and trial sequential analysis (TSA) were performed to assess the significant associations. The results showed a possible negative association between UCSNP-19 and PCOS risk (ins/ins vs. del/del + del/ins: OR = 0.84, 95% CI: 0.72-0.98). In subgroup analyses, FPRP test indicated that noteworthy associations were observed in mixed ethnicities for UCSNP-43 (A vs. G: OR = 1.81, 95% CI: 1.17-2.79; AA + AG vs. GG: OR = 2.14, 95% CI: 1.20-3.80) and in Asians for UCSNP-44 (CC vs. TT: OR = 2.07, 95% CI: 1.21-3.51; CC vs. CT + TT: OR = 2.19, 95% CI: 1.31-3.69), but TSA plots showed that the accumulated sample sizes of these associations were insufficient to draw firm conclusions. In summary, our study suggested that UCSNP-19, UCSNP-43, and UCSNP-44 in CAPN10 gene may be involved in PCOS susceptibility. These findings warrant further studies.

Acute clinical and financial outcomes of on- versus off-pump coronary artery bypass grafting in octogenarians

BACKGROUND

Coronary artery bypass surgery in octogenarians is associated with increased postoperative morbidity. Off-pump coronary artery bypass surgery eliminates potential complications of cardiopulmonary bypass, but its use remains controversial. This study aimed to evaluate the clinical and financial impact of off-pump coronary artery bypass surgery compared to conventional coronary artery bypass surgery among this high-risk population.

METHODS

Patients ≥80 years undergoing first-time, isolated, elective coronary artery bypass surgery were identified using the 2010-2019 Nationwide Readmissions Database. Patients were grouped into off-pump or conventional coronary artery bypass surgery cohorts. Multivariable models were developed to assess the independent associations between off-pump coronary artery bypass surgery and key outcomes.

RESULTS

Of ∼56,158 patients, 13,940 (24.8%) underwent off-pump coronary artery bypass surgery. On average, the off-pump cohort was more likely to undergo single-vessel bypass (37.3 vs 19.7%, P < .001). After adjustment, undergoing off-pump coronary artery bypass surgery was associated with similar odds of in-hospital mortality (adjusted odds ratio 0.90, 95% confidence interval 0.73-1.12) relative to conventional bypass. Additionally, the off-pump and conventional coronary artery bypass surgery groups were comparable in odds of postoperative stroke (adjusted odds ratio 1.03, 95% confidence interval 0.78-1.35), cardiac arrest (adjusted odds ratio 0.99, 95% confidence interval 0.71-1.37), ventricular fibrillation (adjusted odds ratio 0.89, 95% confidence interval 0.60-1.31), tamponade (adjusted odds ratio 1.21, 95% confidence interval 0.74-1.97), and cardiogenic shock (adjusted odds ratio 0.94, 95% confidence interval 0.75-1.17). However, the off-pump coronary artery bypass surgery cohort was linked with an increased likelihood of ventricular tachycardia (adjusted odds ratio 1.23, 95% confidence interval 1.01-1.49) and myocardial infarction (adjusted odds ratio 1.34, 95% confidence interval 1.16-1.55). Furthermore, those undergoing off-pump coronary artery bypass surgery demonstrated reduced odds of non-home discharge (adjusted odds ratio 0.91, 95% confidence interval 0.83-0.99) and a decrement in hospitalization expenditures ($-1,290, 95% confidence interval -$2,370 to $200).

CONCLUSION

Off-pump coronary artery bypass surgery was linked with increased odds of ventricular tachycardia and myocardial infarction, but no difference in mortality. Our findings point to the safety of conventional coronary artery bypass surgery in octogenarians. Yet, future work is needed to consider long-term outcomes in this complex surgical cohort.

Potential Markers of Neurocognitive Disorders After Cardiac Surgery: A Bibliometric and Visual Analysis

Background

Identifying useful markers is essential for diagnosis and prevention of perioperative neurocognitive disorders (PNDs). Here, we attempt to understand the research basis and status, potential hotspots and trends of predictive markers associated with PNDs after cardiac surgery via bibliometric analysis.

Methods

A total of 4,609 original research articles and reviews that cited 290 articles between 2001 and 2021 were obtained from the Web of Science Core Collection (WoSCC) as the data source. We used the software CiteSpace to generate and analyze visual networks of bibliographic information, including published years and journals, collaborating institutions, co-cited references, and co-occurring keywords.

Results

The number of annual and cumulative publications from 2001 to 2021 has been increasing on the whole. The Harvard Medical School was a very prolific and important institution in this field. The journal of Ann Thorac Surg (IF 4.33) had the most publications, while New Engl J Med was the most cited journal. Neuron-specific enolase (NSE), S100b and kynurenic acid (KYNA) were frequently discussed as possible markers of PNDs in many references. Cardiopulmonary bypass (CPB) was a keyword with high frequency (430) and sigma (6.26), and inflammation was the most recent burst keyword.

Conclusion

Potential markers of PNDs has received growing attention across various disciplines for many years. The research basis mainly focuses on three classic biomarkers of S100b, NSE, and KYNA. The most active frontiers are the inflammation-related biomarkers (e.g., inflammatory cells, cytokines, or mediators) and surgery-related monitoring parameters (e.g., perfusion, oxygen saturation, and the depth of anesthesia).

Influence of ADRB1, ADRB2, and COMT Genetic Polymorphisms on Postoperative Outcomes of Patients Undergoing Cardiac Valve Surgery

PURPOSE

The aim of this study is to prospectively investigate the influence of ADRB and COMT gene polymorphisms on postoperative outcomes of patients undergoing cardiac surgery.

METHODS

This prospective cohort study included 223 patients undergoing elective cardiac valve surgery using cardiopulmonary bypass. Demographic information, intraoperative data, postoperative data, and blood samples were collected. Patients were genotyped for single-nucleotide polymorphisms (SNPs) of ADRB1 rs1801253, ADRB2 rs1042713, and COMT rs4680. Major adverse cardiovascular and cerebrovascular events (MACCEs) were used as the primary outcome to evaluate the postoperative prognosis of patients. Secondary outcomes included the duration of mechanical ventilatory support, intensive care unit stay, postoperative hospital stay, and postoperative need of inotropic or vasoactive agents.

FINDINGS

The overall incidence of MACCEs was 15.2%. Among 3 SNP loci, only different genotyped carriers of ADRB2 rs1042713 had statistically significant differences in the incidence of MACCEs (P = 0.005), especially for acute kidney injury (P = 0.023). The proportions of postoperative norepinephrine demand of patients carrying the AA genotype of ADRB2 rs1042713 (P = 0.016) and the AG genotype of COMT rs4680 (P = 0.018) were low. The duration of mechanical ventilatory support (P = 0.034) and postoperative hospital stay (P = 0.045) of patients carrying the AG genotype of COMT rs4680 was shortest. After multiple logistic regression analysis, we found that the G allele carriers of ADRB2 rs1042713 had a higher risk of MACCEs (AG vs AA genotype: odds ratio [OR] = 4.348; 95% CI, 1.529-12.359, P = 0.006; GG vs AA genotype: OR = 3.722; 95% CI, 1.060-13.071; P = 0.040), in particular with acute kidney injury (AG vs AA genotype: OR = 5.273; 95% CI, 1.093-25.451; P = 0.038; GG vs AA genotype: OR = 7.533; 95% CI, 1.275-44.522; P = 0.026). There was no SNP-SNP interaction found among the 3 SNPs with multifactor dimensionality reduction analysis.

IMPLICATION

The ADRB2 rs1042713 polymorphism might be related to prognosis of patients undergoing cardiac surgery. Patients carrying the G allele of ADRB2 rs1042713 had a higher risk of developing MACCEs, especially acute kidney injury. chictr.org.com identifier: ChiCTR1800015105.

Current Impact of Cardiopulmonary Bypass in Coronary Artery Bypass Grafting in São Paulo State

BACKGROUND

Previous results on the use of cardiopulmonary bypass (CPB) have generated difficulties in choosing the best treatment for each patient undergoing myocardial revascularization surgery (CABG) in the current context.

OBJECTIVE

Evaluate the current impact of CPB in CABG in São Paulo State.

METHODS

A total of 2905 patients who underwent CABG were consecutively analyzed in 11 São Paulo State centers belonging to the São Paulo Registry of Cardiovascular Surgery (REPLICCAR) I. Perioperative and follow-up data were included online by trained specialists in each hospital. Associations of the perioperative variables with the type of procedure and with the outcomes were analyzed. The study outcomes were morbidity and operative mortality. The expected mortality was calculated using EuroSCORE II (ESII). The values of p <5% were considered significant.

RESULTS

There were no significant differences concerning the patients' age between the groups (p=0.081). 72.9% of the patients were males. Of the patients, 542 underwent surgery without CPB (18.7%). Of the preoperative characteristics, patients with previous myocardial infarction (p=0.005) and ventricular dysfunction (p=0.031) underwent surgery with CPB. However, emergency or New York Heart Association (NYHA) class IV patients underwent surgery without CPB (p<0.001). The ESII value was similar in both groups (p=0.427). In CABG without CPB, the radial graft was preferred (p<0.001), and in CABG with CPB the right mammary artery was the preferred one (p<0.001). In the postoperative period, CPB use was associated with reoperation for bleeding (p=0.012).

CONCLUSION

Currently in the REPLICCAR, reoperation for bleeding was the only outcome associated with the use of CPB in CABG. (Arq Bras Cardiol. 2020; 115(4):595-601).

The effect of systemic corticosteroids on the incidence of gastrointestinal bleeding in critically ill adults: a systematic review with meta-analysis

PURPOSE

To assess the effect of systemic corticosteroids on the incidence of gastrointestinal bleeding in adult critically ill patients.

METHODS

We systematically reviewed randomised clinical trials comparing systemic corticosteroids administered for more than 24 h with placebo/no treatment in adult critically ill patients. Trial selection, data abstraction and risk of bias assessments were performed in duplicate. We used trial sequential analysis (TSA) to assess the risk of random errors and the grading of recommendations, assessment, development, and evaluations (GRADE) approach to assess the quality of evidence. The primary outcome was the incidence of clinically important gastrointestinal bleeding within 90 days. The secondary outcome was the incidence of gastrointestinal bleeding of any severity within 90 days.

RESULTS

Twenty-five trials (n = 14,615) reported data for the primary outcome and 55 trials (n = 21,792) for the secondary outcome. The pooled incidence of clinically important gastrointestinal bleeding was 2.3% in the corticosteroid group and 1.8% in the control group (RR, 1.26; 95% CI, 1.01-1.57; I² = 0%, TSA-adjusted CI 0.51-3.14). We observed no difference in the risk of gastrointestinal bleeding of any severity (RR, 1.10; 95% CI, 0.92-1.32; I² = 0%, TSA-adjusted CI 0.87-1.38). The GRADE quality of evidence was low (risk of bias and imprecision).

CONCLUSIONS

We observed an overall low incidence of clinically important gastrointestinal bleeding among adult critically ill patients. Corticosteroids may slightly increase the incidence of clinically important gastrointestinal bleeding, but not bleeding of any severity. Rarity of events, infrequent trial reporting and high risk of bias reduced the quality of evidence.

Meta-Analysis of Repeat Revascularization of Off-Pump and On-Pump Coronary Artery Bypass Surgery

BACKGROUND

There is an ongoing debate focusing on clinical outcomes after off-pump coronary artery bypass graft surgery (OPCABG) and on-pump coronary artery bypass graft surgery (ONCABG). The objective of the present meta-analysis is to update and compare repeat revascularization rates between OPCABG and ONCABG procedures.

METHODS

Data sources including PubMed, EMBASE, Cochrane Library, and ISI Web of Knowledge were searched between 1966 and October 2017. Studies considered for inclusion should conform to the following criteria: prospective randomized clinical trials comparing OPCABG and ONCABG. Outcome should include repeat revascularization rate at the time of 1-month, 1-year, or 5-year follow-up.

RESULTS

A literature search yielded 11 randomized controlled trials, and a total of 11,246 patients were randomly allocated to OPCABG or ONCABG procedures. Pooled analysis demonstrated a statistically significant 53% increase in repeat revascularization rate at 1-year follow-up with OPCABG relative to ONCABG in the fixed effects model (odds ratio 1.53, 95% confidence interval: 1.17 to 2.00, p = 0.002), whereas there was no significant difference in repeat revascularization rate at 5-year follow-up between OPCABG and ONCABG in the fixed effects model (OR 1.16, 95% confidence interval: 0.95 to 1.41, p = 0.14). In general, exclusion of any single trial did not affect repeat revascularization rate at 1-year and 5-year follow-up. There was no evidence of significant publication bias.

CONCLUSIONS

The result of our meta-analysis suggests that compared with ONCABG, OPCABG increases repeat revascularization rate at 1-year follow-up, but does not affect that of 5-year follow-up.

Use of cardiopulmonary pump support during coronary artery bypass grafting in the high-risk: a meta-analysis

BACKGROUND

Data from randomized trials evaluating the efficacy of on- versus off-pump coronary artery bypass grafting remain inconclusive, particularly in high-risk populations.

AIMS

The aim of this study is to compare the outcomes associated with on- versus off-pump coronary artery bypass grafting among high-risk patients.

METHODS

We performed a meta-analysis of randomized control trials comparing on- versus off-pump coronary artery bypass grafting, focusing on high-risk populations. Studies focusing on "high-risk" features: European System of Cardiac Operative Risk Evaluation (EuroSCORE) ≥ 5, age > 70 years, preexisting renal insufficiency, history of stroke(s), and the presence of left ventricular dysfunction were included. MEDLINE, Scopus, and Embase were searched for all publications between January 1, 2000 and August 1, 2016, using the following terms: on-pump, off-pump, coronary artery bypass, high-risk, left ventricular dysfunction, elderly, aged, and renal insufficiency. Endpoints included cardiovascular and all-cause mortality, non-fatal myocardial infarction, stroke, need for revascularization, renal failure, and length of hospital stay.

RESULTS

Nine studies incorporating 11,374 patients with a mean age of 70 years were selected. There was no statistical difference in cardiovascular mortality, all-cause mortality, non-fatal myocardial infarction, and renal failure between the two groups. There was a decrease in further revascularization at 1 year with on-pump (OR 0.67 (0.50-0.89)). However, there was an increase in length of hospital stay by 2.24 days (p = 0.03) among the on-pump group with no difference in stroke (OR 1.34 (1.00-1.80)).

CONCLUSIONS

On-pump is associated with a decreased risk of additional revascularization by 1 year. However, this appears to be a cost of longer hospitalization.

The impact of BMI on sperm parameters and the metabolite changes of seminal plasma concomitantly

The development of male infertility increased rapidly worldwide, which coinciding with the epidemic of obesity. However, the impact of weight abnormalities on sperm quality is still contestable. To assess the correlation between BMI and sperm parameters, we searched relevant articles in PubMed, Embase, Web of science, and Wanfang database published until June 2015 without language restriction. Otherwise, we also recruited some participants who attended fertility clinic as well as some general populations in this report. We performed a systematic review and meta-analysis about BMI and sperm parameters containing total sperm count, concentration, semen volume and sperm motility (overall and progressive). Metabolomic analysis of seminal plasma was performed to explore the mechanism from a new perspective. This study found standardized weighted mean differences (SMD) in sperm parameters (total sperm count, sperm concentration, and semen volume) of abnormal weight groups decreased to different degree compared to normal weight. Dose-response analysis found SMD of sperm count, sperm concentration and semen volume respectively fell 2.4%, 1.3% and 2.0% compared with normal weight for every 5-unit increase in BMI. Metabolomic analysis of seminal plasma showed that spermidine and spermine were likely to play a vital role in the spermatogenesis progress. This systematic review with meta-analysis has confirmed there was a relationship between BMI and sperm quality, suggesting obesity may be a detrimental factor of male infertility.

Myocardial revascularization without extracorporeal circulation; Why hasn't it convinced yet?

Extracorporeal circulation has led to a great development in cardiovascular surgery during the last five decades. Its time-proven efficacy and safety have made on-pump coronary artery bypass grafting (CABG) the gold standard method of surgical revascularization. However, coronary revascularization on cardiopulmonary bypass and the accompanying aortic manipulation are related to plenty of deleterious complications. Therefore, off-pump CABG surgery was established to avoid complications. Nevertheless, despite the initial enthusiasm on this technique, only 20% of myocardial revascularization procedures worldwide are performed off-pump. Not only are off-pump cardiac procedures more technically difficult but also they do not provide better results in terms of graft patency, completeness of revascularization, repeat revascularization requirement, cost, and quality of life. Completeness of revascularization and anastomotic quality should not be compromised to avoid cardiopulmonary bypass.

Impact of off-pump coronary artery bypass grafting on survival: current best available evidence

The superiority of either off-pump (OPCAB) or on-pump (ONCAB) coronary artery bypass grafting (CABG) remains unclear despite a large body of literature evidence comparing the two approaches. The potential advantages of avoiding cardiopulmonary bypass (CPB), minimizing aortic manipulation and maintaining pulsatile flow may be associated with reduced inflammatory responses and embolic events. Numerous studies compared OPCAB with ONCAB and the cumulative data have been presented in meta-analyses of both randomized and observational studies. Although there is an abundance of data with respect to the operative morbidity and mortality and the short-term outcomes associated with these two strategies, not much is known about how they impact long-term survival and recurrence of myocardial ischaemic events. Recent studies and meta-analyses have focused on long-term survival and major secondary outcomes in OPCAB vs. ONCAB within the general population. Significant limitations in methodology, however, have raised concerns about the strength of several randomized trials with restrictive inclusion criteria that reduced the populations to those at low risk only, thus creating result bias. Here, we present a review of the best available evidence with a focus on long-term outcomes.

Off-pump coronary artery bypass grafting in octogenarians

Enhanced life expectancy has confronted cardiac surgery with a rapidly growing population of octogenarians needing coronary artery bypass grafting (CABG). Octogenarians are deemed a high-risk patient population with increased postoperative morbidity and mortality following conventional CABG using cardiopulmonary bypass (CPB). In such patients reducing the invasiveness of the surgical procedure by avoiding CPB may be tried in an attempt to improve outcomes. The increasing performance of off-pump coronary artery bypass (OPCAB) grafting within certain centers reflects surgeon preference to avoid the inherent risks of CPB and cardioplegic arrest including hemodilution, nonpulsatile arterial flow, global myocardial ischemia, atherosclerotic embolization from aortic manipulation, and systemic inflammatory response. Although OPCAB grafting is a well-established surgical myocardial revascularization strategy, its actual benefits in terms of morbidity and mortality remain questionable in the general population. In the higher risk octogenarian patients, however, there is a potential for more tangible clinical benefits when CPB is avoided. This review article provides an overview of the impact of OPCAB grafting on postoperative mortality and morbidity in octogenarians.

Early outcomes of on-pump versus off-pump coronary artery bypass grafting

Objectives:

To see the early post-operative outcomes of off-pump versus on-pump coronary artery bypass graft surgery.

Methods:

This retrospective analytical study was conducted at Ch. Pervaiz Elahi Institute of Cardiology Multan, Pakistan. Our Primary outcome variables were; necessity of inotropic support, nonfatal myocardial infarction, ICU stay, nonfatal stroke, new renal failure requiring dialysis and death within 30 days after operation. There were two groups of patients; Group-I (On-pump group) and Group-II (Off-pump Group). SPSS V17 was used for data analysis. Independent sample t-test and Mann Whitney U test were used to compare quantitative Variables. Chi-square test and Fisher’s exact test were used to analyze qualitative variables. P-value ≤ 0.05 was considered significant.

Results:

Three hundred patients were included in this study. There were no significant difference regarding risk factors except hyper-cholestrolemia which was high in off pump group (p-value 0.05). Angiographic and Echocardiographic characteristics e.g. preoperative ejection fraction, LV function grade and severity of CAD was same between the groups. Mortality risk scores and Priority status for surgery were also same. Regarding post-operative outcomes; Post-op CKMB Levels, need and duration of inotropic support, mechanical ventilation time and ICU stay was significantly less in Off-Pump group (p-value 0.001, <0.0001, 0.006, 0.025 and 0.001 resp.). Peri-operative chest drainage was significantly high in On-pump CABG group (p-value 0.027). Incidence of post-op complications was not statistically different between the groups.

Conclusions:

At 30 days follow-up, Incidence of myocardial infarction, necessity and duration of inotropic support, ICU stay period and peri-operative bleeding were significantly less in off-pump group. The incidence of neurologic, pulmonary and renal complications was same between the off-pump and on-pump groups.

How Strong Is the Evidence for Sodium Bicarbonate to Prevent Contrast-Induced Acute Kidney Injury After Coronary Angiography and Percutaneous Coronary Intervention?

Hydration with sodium bicarbonate is one of the strategies to prevent contrast-induced acute kidney injury (CI-AKI). The purpose of this study was to determine how strong is the evidence for sodium bicarbonate to prevent CI-AKI after coronary angiography (CAG) and/or percutaneous coronary intervention (PCI).We conducted PubMed, EMBASE, and CENTRAL databases to search for randomized controlled trials (RCTs) comparing the efficacy of sodium bicarbonate with sodium chloride to prevent CI-AKI after CAG and/or PCI. Relative risk (RR), standardized mean difference (SMD), or weighted mean difference (WMD) with 95% confidence intervals (CIs) was calculated. Heterogeneity, publication bias, and study quality were evaluated, sensitivity analyses, cumulative analyses, and subgroup analyses were performed. The risk of random errors was assessed by trial sequential analysis (TSA).Sixteen RCTs (3537 patients) met the eligibility criteria. Hydration with sodium bicarbonate showed significant beneficial effects in preventing CI-AKI (RR 0.67; 95% CI: 0.47-0.96, P = 0.029), decreasing the change in serum creatinine (SCr) (SMD -0.31 95% CI: -0.55 to -0.07, P = 0.011) and estimated glomerular filtration rate (eGFR) (SMD -0.17 95% CI: -0.30 to -0.04, P = 0.013). But no significant differences were observed in the requirement for dialysis (RR 1.11; 95% CI: 0.60-2.07, P = 0.729), mortality (RR 0.71; 95% CI: 0.41-1.21, P = 0.204) and reducing the length of hospital stay (LHS) (WMD -1.47; 95% CI: -4.14 to 1.20, P = 0.279). The result of TSA on incidence of CI-AKI showed the required information size (RIS = 6614) was not reached and cumulative z curve did not cross TSA boundary. The result of TSA on the requirement for dialysis and mortality demonstrated the required information sizes (RIS = 170,510 and 19,516, respectively) were not reached, and the cumulative z-curve did not cross any boundaries.The evidence that sodium bicarbonate reduces the incidence of CI-AKI is encouraging but more well-designed randomized controlled trails are required to allow definitive firm conclusion to be drawn.

Current randomized control trials, observational studies and meta analysis in off-pump coronary surgery

The off-pump literature is divided into three eras: the "early phase" with results favouring off-pump surgery supported with randomized control trials (RCTs) mainly from Bristol, UK; an "intermediate phase" dominated by the results of the ROOBY trial and finally a more "contemporary phase" whereby the off/on-pump argument is unsettled. Although the literature has failed to project an overall superiority of off-pump versus on-pump surgery, nevertheless, small randomized control trials and large meta-analysis studies are concluding that the incidence of a stroke is less than 1 % when an aortic off-pump techniques (especially the non-touch technique) are advocated in patients with diseased ascending aorta. Furthermore, off-pump combined with hybrid procedures may lead to a reduction of adverse outcome in the aged high-risk population with concomitant poor left ventricular function and co-morbidities.The current review attempts to bring an insight onto the last ten years knowledge on the on/off-pump debate, with an aim to draw some clear conclusions in order to allow practitioners to reflect on the subject.

The impact of off-pump surgery in end-organ function: practical end-points

Most surgeons perform coronary bypass surgery with the aid of cardiopulmonary bypass, which inflicts a massive systemic inflammatory response to the body leading to adverse clinical outcome. In an attempt to make CABG less invasive, interest have been diverted to the off pump technique.The current review attempts to bring an insight onto the last ten years knowledge on the off-pump impact in end organ function, with an aim to draw some clear conclusions in order to allow practitioners to reflect on the subject.

Off-pump coronary artery bypass grafting improves short-term outcomes in high-risk patients compared with on-pump coronary artery bypass grafting: Meta-analysis

OBJECTIVES

To assess the benefits and risks of off-pump coronary artery bypass (OPCAB) versus coronary artery bypass grafting (CABG) through a meta-analysis of randomized controlled trials (RCTs), and to investigate the relationship between outcomes and patient risk profile.

METHODS

PubMed, Embase, the Cumulative Index of Nursing and Allied Health Literature, Scopus, Web of Science, Cochrane Library, and major conference proceedings databases were searched for RCTs comparing OPCAB and CABG and reporting short-term (≤ 30 days) outcomes. Endpoints assessed were all-cause mortality, myocardial infarction (MI), and cerebral stroke.

RESULTS

The meta-analysis included 100 studies, with a total of 19,192 subjects. There was no difference between the 2 techniques with respect to all-cause mortality and MI (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.71-1.09; P = .25; I(2) = 0% and OR, 0.90; 95% CI, 0.77-1.05; P = .19; I(2) = 0%, respectively). OPCAB was associated with a significant 28% reduction in the odds of cerebral stroke (OR, 0.72; 95% CI, 0.56-0.92; P = .009; I(2) = 0%). A significant relationship between patient risk profile and benefits from OPCAB was found in terms of all-cause mortality (P < .01), MI (P < .01), and cerebral stroke (P < .01).

CONCLUSIONS

OPCAB is associated with a significant reduction in the odds of cerebral stroke compared with conventional CABG. In addition, benefits of OPCAB in terms of death, MI, and cerebral stroke are significantly related to patient risk profile, suggesting that OPCAB should be strongly considered in high-risk patients.

Long-term follow-up of off-pump and on-pump coronary artery bypass grafting

OBJECTIVE

Despite increasing recognition of the benefits of off-pump coronary artery bypass grafting (CABG), concerns persist regarding its impact on long-term mortality and freedom from reintervention. In this study, we assessed the impact of off-pump CABG on long-term outcomes.

METHODS

From January 2002 to December 2002, a total of 307 consecutive patients who underwent isolated multivessel off-pump CABG at our institution were compared with a control group of 397 patients who underwent multivessel on-pump CABG during the same period. Perioperative data were prospectively collected and compared. In addition, univariate and risk-adjusted comparisons between the two groups were performed at 10 years.

RESULTS

After adjusting for clinical covariates, off-pump CABG did not emerge as a significant independent predictor of long-term mortality [hazard ratio (HR), 0.91; 95% confidence interval (CI), 0.70-1.12], readmission to hospital for cardiac cause (HR, 0.96; 95% CI, 0.78-1.10), or the need for reintervention (HR, 0.93; 95% CI, 0.87-1.05).

CONCLUSIONS

At long-term follow-up, off-pump CABG remains a safe and effective myocardial revascularization strategy with no adverse impact on survival or freedom from reintervention.

A multistudy analysis investigating systematic differences in cardiovascular trial results between Europe and Asia

OBJECTIVE

To assess whether there are differences in the results of cardiovascular trials between Europe and Asia using data from an extensive collection of randomised controlled trials.

STUDY DESIGN AND SETTING

All meta-analyses containing randomised controlled trials (RCT's) for the treatment or prevention of cardiovascular diseases were searched for in The Cochrane Library (2000-2008) and MEDLINE (2005-2008). Analysis was then conducted within and over each meta-analysis which satisfied given criteria. Separate estimates of treatment effect were calculated for Europe and Asia in each meta-analysis and then compared. Estimates of a common inter-continental difference over all meta-analyses were also calculated and meta-regression was performed. This was performed for both fatal and non-fatal end points.

RESULTS

The literature search identified 59 meta-analyses that satisfied the inclusion criteria. After exclusion, the number of meta-analyses reporting greater effect sizes in Asia than in Europe was significantly more than would be expected by chance (fatal 12/14, p=0.013; non-fatal 23/32, p=0.020).

CONCLUSIONS

This study provides some evidence that for cardiovascular interventions treatment effect estimation differs between Europe and Asia, with respect to both fatal and non-fatal end points.

[Epidemiology of cerebral perioperative vascular accidents]

OBJECTIVES

Stroke is a well-described postoperative complication, after carotid and cardiac surgery. On the contrary, few studies are available concerning postoperative stroke in general non-cardiac non-carotid surgery. The high morbid-mortality of stroke justifies an extended analysis of recent literature.

ARTICLE TYPE

Systematic review.

DATA SOURCES

Firstly, Medline and Ovid databases using combination of stroke, cardiac surgery, carotid surgery, general non-cardiac non-carotid surgery as keywords; secondly, national and European epidemiologic databases; thirdly, expert and French health agency recommendations; lastly, reference book chapters.

RESULTS

In cardiac surgery, with an incidence varying from 1.2 to 10% according to procedure complexity, stroke occurs peroperatively in 50% of cases and during the first 48 postoperative hours for the others. The incidence of stroke after carotid surgery is 1 to 20% according to the technique used as well as operator skills. Postoperative stroke is a rare (0.15% as mean, extremes around 0.02 to 1%) complication in general surgery, it occurs generally after the 24-48th postoperative hours, exceptional peroperatively, and 40% of them occurring in the first postoperative week. It concerned mainly aged patient in high-risk surgeries (hip fracture, vascular surgery). Postoperative stroke was associated to an increase in perioperative mortality in comparison to non-postoperative stroke operated patients.

CONCLUSION

Postoperative stroke is a quality marker of the surgical teams' skill and has specific onset time and induces an increase of postoperative mortality.

Is the evidence from first time off-pump coronary artery bypass graft surgery transferable to re-operative off-pump surgery?

On-pump coronary artery surgery remains the gold standard treatment for multi-vessel disease. The technique of off-pump surgery has evolved since its first use; however, currently less than 20% of all cases worldwide are performed this way. This poor uptake has been both the cause and the effect of widespread scepticism regarding the validity of the data on the technique, as well as criticism regarding the conversion-related adverse outcomes, graft patency and completeness of revascularisation. Consequently, there has been focus on patient selection from subgroups most likely to benefit from the technique. Re-operative patients, by virtue of their advanced age, complex co-morbidities and the technical challenges of re-operation, fall into this category. In this review, the authors will discuss the outcomes of off-pump surgery in comparison to on-pump, explore the potential beneficial effects of off-pump in re-operative surgery and formulate a decision-making strategy in patients undergoing reoperative coronary artery surgery.

On-pump versus off-pump coronary artery bypass graft surgery: what do the evidence show?

The main purpose of the off-pump coronary artery bypass surgery is to reduce morbidity and mortality due cardiopulmonary bypass. However, even though many studies have shown that off-pump coronary artery bypass is feasible and provides hospital morbidity and mortality similar to the on-pump coronary artery bypass graft surgery, probably better in some aspects, its long-term results have been questioned, since some trials have shown reduced survival with off-pump coronary artery bypass. It is likely that incomplete revascularization and/or poor graft patency with off-pump coronary artery bypass probably are responsible for such unfavorable outcome.

Are cardiovascular trial results systematically different between North America and Europe? A study based on intra-meta-analysis comparisons

BACKGROUND

It is often assumed that differences in the efficacy of treatments between countries (or regions) will be neither negligible nor minor and therefore cannot be overlooked when assessing the potential benefit of treatments in one country (or region) on the basis of trials conducted in another country (or region).

AIM

To assess differences in the results of cardiovascular trials between Europe and North America on the basis of data from an extensive collection of trials.

METHODS

A systematic search was conducted of Medline (from the year 2005 to 2008) and the Cochrane Library (from 2000 to 2008) for all meta-analyses of randomized controlled trials aimed at treating and preventing cardiovascular disease. Within each meta-analysis that satisfied given criteria, trial results were compared between Europe and North America with respect to a fatal and/or non-fatal endpoint by forming separate estimates of treatment efficacy for each of these continents.

RESULTS

The literature search found 59 meta-analyses that satisfied all the inclusion criteria. For most meta-analyses, it was the case that relative to the control, the intervention was more favoured in trials conducted in Europe than in North America with regard to both fatal endpoints (28 out of 43 meta-analyses) and non-fatal endpoints (28 out of 40 meta-analyses). However, it was only with regard to non-fatal endpoints that this imbalance turned out to be statistically significant at the 5% level (P=0.017). Also, the lack of statistically significant differences in trial results between Europe and North America within individual meta-analyses meant that it was not possible to determine for which types of intervention these intercontinental differences are likely to be more pronounced than others.

CONCLUSION

There is some evidence to support the theory that, relative to controls, interventions are more favoured in cardiovascular trials conducted in Europe than in North America, when treatment efficacy is measured in terms of a non-fatal endpoint. However, the overall support for systematic differences in cardiovascular trial results between Europe and North America is weak, which may be surprising given the amount of data collected.

Coronary artery bypass grafting: Part 1--the evolution over the first 50 years

Surgical treatment for angina pectoris was first proposed in 1899. Decades of experimental surgery for coronary artery disease finally led to the introduction of coronary artery bypass grafting (CABG) in 1964. Now that we are approaching 50 years of CABG experience, it is appropriate to summarize the advancement of CABG into a procedure that is safe and efficient. This review provides a historical recapitulation of experimental surgery, the evolution of the surgical techniques and the utilization of CABG. Furthermore, data on contemporary clinical outcomes are discussed.

Association between DAZL polymorphisms and susceptibility to male infertility: systematic review with meta-analysis and trial sequential analysis

Several studies have investigated the association between polymorphisms in the Deleted in AZoospermia-Like (DAZL) gene and male infertility risk, but with inconsistent results. We aimed to derive a more precise estimation of the relationship, therefore a meta-analysis was performed. A total of 13 case-control studies, including 2556 cases and 1997 controls, were selected. Two polymorphisms in DAZL were investigated, namely T12A (Thr12 → Ala) and T54A (Thr54 → Ala). Our meta-analysis showed that A > G is a risk factor for male infertility (P = 0.047, OR = 1.262, 95%CI = 1.003-1.587). However, when using trial sequential analysis (TSA) to confirm, we found that A > G risk effect turned out to be false positive. In addition, significant association was found between the T54A polymorphism and male infertility under co-dominant model (AG vs. AA: OR = 4.364, 95%CI = 2.207-8.630, P < 0.001) and dominant model (OR = 4.584, 95%CI = 2.320-9.058, P < 0.001). Stratified analysis showed that significantly strong association between T54A polymorphism and male infertility was present only in Asians, but not in Caucasians. Further studies of T12A and T54A with their biological functions are needed to understand the role of these polymorphisms in the development of male infertility.

New-onset atrial fibrillation predicts long-term newly developed atrial fibrillation after coronary artery bypass graft

BACKGROUND

New-onset postoperative atrial fibrillation (POAF) is associated with poor short- and long-term outcomes after isolated coronary artery bypass graft (CABG). This study evaluated whether new-onset POAF is independently associated with long-term (>1 year) atrial fibrillation (AF) and mortality.

METHODS

Among 1,171 consecutive patients who had undergone CABG, AF and mortality were compared between patients with POAF (POAF group, n = 244) and those without POAF (no-POAF group, n = 927) after propensity score matching.

RESULTS

During the follow-up period of 41 ± 23 months (range 0-87 months), the POAF group had a higher incidence of total (20/927 [2.2%] vs 46/244 [18.9%], P < .001) and long-term AF recurrence (13/927 [1.4%] vs 25/244 [10.2%], P < .001). Even after propensity score matching, the POAF group still showed a higher incidence of total (7/244 [2.9%] vs 46/224 [18.9%], P < .001) and long-term AF recurrence (4/244 [1.6%] vs 25/224 [10.2%], P < .001). In addition, the POAF group had a lower cumulative survival free of long-term AF than the no-POAF group (P < .001). In competing risk regression, POAF was an independent predictor of long-term newly developed AF (hazard ratio 4.99, 95% CI 1.68-14.84, P = .004). Cumulative survival free of death was worse in patients with POAF (P = .01).

CONCLUSIONS

New-onset POAF was shown to be a predictor of long-term newly developed AF in CABG patients. The results of this study suggest that patients who develop POAF should undergo strict surveillance and routine screening for AF during follow-up after surgery.

Off-pump versus on-pump revascularization in females: a meta-analysis of observational studies

BACKGROUND

Coronary revascularization in female patients presents several challenges, including smaller target vessels and smaller conduits. Furthermore, late presentation and more co-morbidities than males may increase complication rates. The aim of this study was to assess whether off-pump coronary artery bypass (OPCAB) improves outcomes when compared to on-pump coronary artery bypass (ONCAB) in the female population.

METHODS

A systematic literature review identified six observational studies, incorporating 23313 patients (n=9596 OPCAB, 13717 ONCAB). These were meta-analyzed using random effects modeling. Heterogeneity, subgroup analysis, quality scoring and publication bias were assessed. The primary endpoints were 30-day mortality and major cardiac, respiratory and renal complications. Secondary endpoints were the number of grafts per patient.

RESULTS

No statistically significant difference was observed in 30-day mortality between the OPCAB and ONCAB groups (4.8% vs. 0.7%; OR 0.96; 95% CI [0.41, 2.24], p=0.92). Significant inter-study heterogeneity was also present (I2=94%) and was not explained by study size or quality. Peri-operative myocardial infarction (OR 0.65; 95% CI [0.51, 0.84], p=0.0009) was significantly lower with OPCAB without significant heterogeneity; however, OPCAB did not significantly alter other morbidity outcomes. OPCAB was associated with a trend towards fewer grafts per patient than ONCAB.

CONCLUSIONS

OPCAB is a safe alternative to ONCAB in the surgical revascularisation of female patients and may reduce post-operative myocardial infarction (MI). However, this does not translate into a reduction in 30-day mortality and OPCAB does not significantly improve other cardiovascular, renal or neurological outcomes. Late outcome data remains lacking and a well-structured, randomized trial is required to answer vital questions regarding the effect of OPCAB on women in the long-term.

A review with meta-analysis of observational studies for survival following off-pump coronary artery bypass versus drug-eluting stent implantation

To determine whether off-pump coronary artery bypass (OPCAB) improves survival over drug-eluting stent (DES) implantation, we performed a review with meta-analysis of exclusive OPCAB versus DES. Databases including MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials were searched through October 2013 using Web-based search engines (PubMed and OVID). Studies that met the following criteria were considered for inclusion: the design was a randomized controlled trial or observational comparative study; the study population was patients with any coronary artery disease; patients were assigned to OPCAB versus DES and outcomes included all-cause mortality at ≥1 years. Our exhaustive search identified no randomized trial and 10 observational studies of OPCAB versus DES. A pooled analysis demonstrated no statistically significant difference in all-cause mortality between OPCAB and DES (hazard ratio, 0.94; 95% confidence interval, 0.76-1.15; P = 0.55). In general, exclusion of any single study from the analysis did not substantially alter the overall result of our analysis. There was no evidence of significant publication bias. In conclusion, OPCAB may not improve survival over DES despite greater number of treated vessels in OPCAB than in DES or greater number of distal anastomosis in OPCAB than that of implanted stents in DES.

Off-pump surgery: is it beneficial in patients with left ventricular dysfunction?

On-pump coronary artery bypass surgery remains the gold standard for complex multivessel disease. Off-pump revascularization has matured as a technique over the last twenty years, but is used in less than 20% of cases worldwide. The poor uptake has been attributed to the significant learning curve in learning the procedure and conflicting evidence reports, together with concerns over mortality related conversion, graft patency and completeness of revascularization. Given these concerns, patient selection continues to be paramount and the subgroups that benefit most are hotly debated. Patients with left ventricular dysfunction constitute a high-risk subgroup which is enlarging in size. There is some evidence to suggest that avoidance of cardiopulmonary bypass in this group may lead to superior results in terms of early mortality, non-cardiac complications and organ dysfunction. Even with the theoretical risk of incomplete revascularization, the technique may be an attractive option in managing high-risk patients.

Does off-pump coronary artery bypass grafting negatively impact long-term survival and freedom from reintervention?

Recently published evidence has raised concerns about worse late mortality and increasing need for reintervention after off-pump coronary artery bypass grafting. We undertook this study to assess the impact of off-pump coronary artery bypass grafting on survival and freedom from reintervention at 10 years. From January 2002 to December 2002, 307 consecutive patients who had isolated multivessel off-pump coronary artery bypass grafting at our institution were compared to a control group of 397 patients that underwent multivessel on-pump coronary artery bypass grafting during the same period. In addition, univariate and risk-adjusted comparisons between the two groups were performed at 10 years. Kaplan-Meier survival was similar for the two cohorts. After adjusting for clinical covariates, off-pump coronary artery bypass grafting did not emerge as a significant independent predictor of long-term mortality (Hazard Ratio 0.91; 95% Confidence Interval 0.70-1.12), readmission to hospital for cardiac cause (Hazard Ratio 0.96; 95% Confidence Interval 0.78-1.10), or the need for reintervention (Hazard Ratio 0.93; 95% Confidence Interval 0.87-1.05). Off-pump coronary artery bypass grafting compared with on-pump coronary artery bypass grafting does not adversely impact survival or freedom from reintervention at a 10-year follow-up.

A meta-analysis of randomized trials for repeat revascularization following off-pump versus on-pump coronary artery bypass grafting

To determine whether repeat revascularization rates are increased following off-pump coronary artery bypass grafting (CABG), we performed a meta-analysis of randomized controlled trials of off-pump vs on-pump CABG. Databases including MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials were searched through March 2013 using web-based search engines (PubMed, OVID). Studies considered for inclusion met the following criteria: the design was a prospective randomized controlled clinical trial; the study population was patients undergoing CABG; patients were randomly assigned to off-pump vs on-pump CABG and outcomes included repeat revascularization rates at ≥1 year. Our exhaustive search identified 12 prospective randomized controlled trials of off-pump vs on-pump CABG. Pooled analysis demonstrated a statistically significant 38% increase in repeat revascularization rates with off-pump relative to on-pump CABG in the fixed-effects model (odds ratio, 1.38; 95% confidence interval, 1.09-1.76; P = 0.008). In general, exclusion of any single trial from the analysis did not substantively alter the overall result of our analysis. There was no evidence of significant publication bias. The results of our analysis suggest that off-pump CABG may increase repeat revascularization rates by 38% over on-pump CABG.

Comparison of frequency of postoperative stroke in off-pump coronary artery bypass grafting versus on-pump coronary artery bypass grafting versus percutaneous coronary intervention

The stroke rate after coronary artery bypass grafting (CABG) compared to percutaneous coronary intervention (PCI) is generally considered high because cardiopulmonary bypass and aortic manipulations are often associated with cerebrovascular complications. However, an increasing number of CABGs performed without cardiopulmonary bypass (OPCAB) may improve those outcomes. Of 6,323 patients with multivessel and/or left main coronary artery disease, 3,877 patients underwent PCI, 1,381 conventional on-pump CABG, and 1,065 OPCAB. Median follow-up was 3.4 years. Stroke types were classified as early (onset of stroke within 24 hours after revascularization), delayed (within 30 days), and late (after 30 days). Propensity score analysis showed that the incidences of early, delayed, and late stroke did not differ between PCI and OPCAB (0.65, 95% confidence interval 0.08 to 5.45, p = 1.00; 0.36, 0.10 to 1.29, p = 0.23; 0.81, 0.52 to 1.27, p = 0.72, respectively). In contrast, incidence of early stroke after on-pump CABG was higher than after OPCAB (7.22, 1.67 to 31.3, p = 0.01), but incidences of delayed and late stroke were not different (1.66, 0.70 to 3.91, p = 0.50; 1.18, 0.83 to 1.69, p = 0.73). In conclusion, occurrence of stroke was not found to differ in patients after PCI versus OPCAB regardless of onset of stroke. Occurrence of early stroke after OPCAB was lower than that after on-pump CABG, yet occurrences of delayed and late strokes were similar for the 3 revascularization strategies.

Atrial fibrillation following cardiac surgery: risk analysis and long-term survival

Background

We studied potential risk factors for postoperative atrial fibrillation (POAF) in a large cohort of patients who underwent open-heart surgery, evaluating short- and long-term outcome, and we developed a risk-assessment model of POAF.

Methods

A retrospective study of 744 patients without prior history of AF who underwent CABG (n = 513), OPCAB (n = 207), and/or AVR (n = 156) at Landspitali Hospital in 2002–2006. Logistic regression analysis was used to study risk factors for POAF, comparing patients with and without POAF.

Results

The rate of POAF was 44%, and was higher following AVR (74%) than after CABG (44%) or OPCAB (35%). In general, patients with POAF were significantly older, were more often female, were less likely to be smokers, had a lower EF, and had a higher EuroSCORE. The use of antiarrythmics was similar in the groups but patients who experienced POAF were less likely to be taking statins. POAF patients also had longer hospital stay, higher rates of complications, and operative mortality (5% vs. 0.7%). In multivariate analysis, AVR (OR 4.4), a preoperative history of cardiac failure (OR 1.8), higher EuroSCORE (OR 1.1), and advanced age (OR 1.1) were independent prognostic factors for POAF. Overall five-year survival was 83% and 93% for patients with and without POAF (p <0.001).

Conclusion

POAF was detected in 44% of patients, which is high compared to other studies. In the future, our assessment score will hopefully be of use in identifying patients at high risk of POAF and lower complications related to POAF.

Anaortic coronary bypass surgery

Review of the benefits and techniques for anaortic coronary bypass surgery.