The effect of off-pump coronary artery bypass on mortality after acute coronary syndrome: A meta-analysis

Gut microbiota and metabolomics profiles in patients with chronic stable angina and acute coronary syndrome

Cardiovascular disease (CVD) is the leading cause of death worldwide. The gut microbiota and its associated metabolites may be involved in the development and progression of CVD, although the mechanisms and impact on clinical outcomes are not fully understood. This study investigated the gut microbiome profile and associated metabolites in patients with chronic stable angina (CSA) and acute coronary syndrome (ACS) compared with healthy controls. Bacterial alpha diversity in stool from patients with ACS or CSA was comparable to healthy controls at both baseline and follow-up visits. Differential abundance analysis identified operational taxonomic units (OTUs) assigned to commensal taxa differentiating patients with ACS from healthy controls at both baseline and follow-up. Patients with CSA and ACS had significantly higher levels of trimethylamine N-oxide compared with healthy controls (CSA: 0.032 ± 0.023 mmol/L, P < 0.01 vs. healthy, and ACS: 0.032 ± 0.023 mmol/L, P = 0.02 vs. healthy, respectively). Patients with ACS had reduced levels of propionate and butyrate (119 ± 4 vs. 139 ± 5.1 µM, P = 0.001, and 14 ± 4.3 vs. 23.5 ± 8.1 µM, P < 0.001, respectively), as well as elevated serum sCD14 (2245 ± 75.1 vs. 1834 ± 45.8 ng/mL, P < 0.0001) and sCD163 levels (457.3 ± 31.8 vs. 326.8 ± 20.7 ng/mL, P = 0.001), compared with healthy controls at baseline. Furthermore, a modified small molecule metabolomic and lipidomic signature was observed in patients with CSA and ACS compared with healthy controls. These findings provide evidence of a link between gut microbiome composition and gut bacterial metabolites with CVD. Future time course studies in patients to observe temporal changes and subsequent associations with gut microbiome composition are required to provide insight into how these are affected by transient changes following an acute coronary event.NEW & NOTEWORTHY The study found discriminative microorganisms differentiating patients with acute coronary syndrome (ACS) from healthy controls. In addition, reduced levels of certain bacterial metabolites and elevated sCD14 and sCD163 were observed in patients with ACS compared with healthy controls. Furthermore, modified small molecule metabolomic and lipidomic signatures were found in both patient groups. Although it is not known whether these differences in profiles are associated with disease development and/or progression, the findings provide exciting options for potential new disease-related mechanism(s) and associated therapeutic target(s).

Optimal Timing of Coronary Artery Bypass Grafting in Haemodynamically Stable Patients after Myocardial Infarction

During the acute phase of myocardial infarction, the culprit artery must be revascularized quickly with angioplasty. Surgery then completes the procedure in a second stage. If emergency surgery is performed, the resulting death rate is high; 15-20% of patients are operated on within the first 48 h after the myocardial infarction. The timing of surgical revascularization and the patient's preoperative state influence the mortality rate. We aimed to evaluate the impact of surgery delay on morbimortality. Between 2007 and 2017, a retrospective monocentric study was conducted including 477 haemodynamically stable patients after myocardial infarction who underwent an urgent coronary bypass. Three groups were described, depending on the timing of the surgery: during the first 4 days (Group 1, n = 111, 23%), 5 to 10 days (Group 2, n = 242, 51%) and after 11 days (Group 3, n = 124, 26%). The overall thirty-day mortality was 7.1% (n = 34). The death rate was significantly higher in Group 1 (n = 16; 14% vs. n = 10; 4.0% vs. n = 8; 6%, p < 0.01). The mortality risk factors identified were age (OR: 1.08; CI 95%: 1.04-1.12; p < 0.001), peripheral arteriopathy (OR: 3.31; CI 95%: 1.16-9.43; p = 0.024), preoperative renal failure (OR: 6.39; CI 95%: 2.49-15.6; p < 0.001) and preoperative ischemic recurrence (OR: 3.47; CI 95%: 1.59-7.48; p < 0.01). Ninety-two patients presented with preoperative ischemic recurrence (19%), with no difference between the groups. The optimal timing for the surgical revascularization of MI seems to be after Day 4 in stable patients. However, timing is not the only factor influencing the death rate: the patient's health condition and disease severity must be considered in the individual management strategy.

Coronary artery bypass surgery for acute coronary syndrome: A network meta-analysis of on-pump cardioplegic arrest, off-pump, and on-pump beating heart strategies

BACKGROUND

Coronary artery bypass grafting (CABG) in the setting of an acute coronary syndrome is a high-risk procedure, and the best strategy for myocardial revascularisation remains debated. This study compares the 30-day mortality benefit of on-pump CABG (ONCAB), off-pump CABG (OPCAB), and on-pump beating heart CABG (OnBHCAB) strategies.

METHODS

A systematic search of three electronic databases was conducted for studies comparing ONCAB with OPCAB or OnBHCAB in patients with acute coronary syndrome (ACS). The primary outcome, 30-day mortality, was compared using a Bayesian hierarchical network meta-analysis (NMA). A random effects consistency model was applied, and direct and indirect comparisons were made to determine the relative effectiveness of each strategy on postoperative outcomes.

RESULTS

One randomised controlled trial and eighteen observational studies fulfilling the inclusion criteria were identified. A total of 4320, 5559, and 1962 patients underwent ONCAB, OPCAB, and OnBHCAB respectively. NMA showed that OPCAB had the highest probability of ranking as the most effective treatment in terms of 30-day mortality (odds ratio [OR], 0.50; 95% credible interval [CrI], 0.23-1.00), followed by OnBHCAB (OR, 0.62; 95% CrI, 0.20-1.57), however the 95% CrI crossed or included unity. A subgroup NMA of nine studies assessing only acute myocardial infarction (AMI) patients demonstrated a 72% reduction in likelihood of 30-day mortality after OPCAB (CrI, 0.07-0.83). No significant increase in rate of stroke, renal dysfunction or length of intensive care unit stay was found for either strategy.

CONCLUSIONS

Although no single best surgical revascularisation approach in ACS patients was identified, the significant mortality benefit with OPCAB seen with AMI suggests high acuity patients may benefit most from avoiding further myocardial injury associated with cardiopulmonary bypass and cardioplegic arrest.

Surgical revascularization for acute coronary syndromes: a report from the North Rhine-Westphalia surgical myocardial infarction registry

OBJECTIVES

The aim of this was to analyse current outcomes in patients referred to coronary artery bypass grafting (CABG) for acute coronary syndromes (ACSs), including ST-elevation or non-ST-elevation ACS (non-ST-segment elevation myocardial infarction) or unstable angina.

METHODS

Patients (n = 2432) undergoing CABG for ACS between January 2010 and December 2017 were prospectively entered into a surgical myocardial infarction registry in North Rhine-Westphalia, Germany. Key end points were in-hospital all-cause mortality (IHM) and major adverse cardio-cerebral events (MACCE). Predictors for IHM and MACCE were analysed by multivariable logistic regression.

RESULTS

Patients (78% males) were referred for CABG for unstable angina (25%), non-ST-segment elevation myocardial infarction (50%), and ST-segment elevation myocardial infarction (25%). The mean patient age was 68 ± 11 years, logistic EuroSCORE was 19 ± 18% and three-vessel and left main stem diseases were diagnosed in 81% and 45% of patients, respectively. On-pump CABG with cardiac arrest or beating heart was performed in 92% and 2%, respectively, with only 6% off-pump surgery and 6% multiple arterial revascularization (3.1 ± 1.0 grafts, 93% left internal thoracic artery). Emergency CABG was performed in 23% of patients (42% in ST-segment elevation myocardial infarction; P < 0.001). The total IHM and MACCE rates were 8.1% and 17.5% and were highest in ST-segment elevation myocardial infarction patients with 12.6% and 28.5%, respectively (P < 0.001). Key predictors for IHM and MACCE were female gender, elevated troponin, left ventricular ejection fraction, inotropic support, logistic EuroSCORE, cardiopulmonary bypass and aortic clamp time and the need for emergency CABG.

CONCLUSIONS

Surgical myocardial revascularization in patients with ACS is still linked to substantial in-hospital mortality. Emergency CABG for patients with ACS was associated with poorer outcomes.

Surgical Outcomes of Isolated Coronary Artery Bypass Grafting for Acute Coronary Syndrome - Based on the Japan Adult Cardiovascular Surgery Database

BACKGROUND

The present study aimed to clarify the current use and outcomes of coronary artery bypass grafting (CABG) for acute coronary syndrome (ACS) based on the Japan Adult Cardiovascular Surgery Database (JACVSD) in stratified risk categories, and also to provide guidance on selection of optimal surgical strategies for ACS.Methods and Results:From January 2008 through December 2012, 7,867 isolated CABG procedures for ACS were identifiedfrom the JACVSD. Patients were stratified into 3 subgroups (<2%, 2-9.9%, ≥10%) according to preoperative risk estimations based on this database. Off- and on-pump CABG surgical outcomes were evaluated in each subgroup. Off-pump CABG (OPCAB) was the predominant surgical strategy in all subgroups. The proportion of on-pump beating CABG increased in the higher-risk groups. Although average observed mortality rates were compatible with preoperative estimated risk in all subgroups, those after OPCAB were significantly lower in the medium (2-9.9%) risk group with lower incidence of major complications. In the low (<2%) and high (≥10%) risk groups, observed mortality rates did not show statistically significant differences between off- and on-pump CABG.

CONCLUSIONS

In this study in Japan, OPCAB was mainly performed in patients with ACS, particularly those with estimated risk <10%, with lower mortality rates, whereas on-pump beating CABG was selected for higher-risk patients with ACS, with reasonable mortality rates.

Current outcomes of off-pump coronary artery bypass grafting: evidence from real world practice

Coronary artery bypass grafting (CABG) can be performed conventionally using cardiopulmonary bypass (CPB) and aortic clamping or on a beating heart (BH) without the use of CPB, the so-called off-pump CABG. Some surgeons, who are proponents of off-pump CABG, preferentially use this technique for the majority of operations, whereas others use it only in certain situations which warrant avoidance of CPB. Ever since the conception of off-pump CABG, the never-ending debate about which technique of CABG is safe and efficacious continues to date. Several randomized controlled trials (RCTs) have been conducted that have either favored on-pump CABG or have failed to show a significant difference in outcomes between the two techniques. However, these RCTs have been fraught with claims that they do not represent the majority of patients undergoing CABG in real world practice. Therefore, assessment of the benefits and drawbacks of each technique through observational and registry studies would be more representative of patients encountered in daily practice. The present review examines various retrospective studies and meta-analyses of observational studies that compare the early and long-term outcomes of off- and on-pump CABG, which assesses their safety and efficacy. Additionally, their outcomes in older patients, females, and those with diabetes mellitus, renal dysfunction, presence of ascending aortic disease, and/or acute coronary syndrome (ACS) have also been discussed separately. The general consensus is that early results of off-pump CABG are comparable to or in some cases better than on-pump CABG. However, on-pump CABG provides a survival benefit in the long term according to a majority of publications in literature.