Stroke prevention strategies for cardiac surgery: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Stroke is a much-feared complication of cardiac surgery, but existing literature on preventive strategies is fragmented. Hence, a systematic review and meta-analysis of stroke prevention strategies for cardiac surgery was conducted. METHODS: An electronic literature search was conducted to retrieve randomized controlled trials (RCTs) investigating perioperative interventions for cardiac surgery, with stroke as an outcome. Random-effects meta-analyses were conducted to generate risk ratios (RRs), 95% confidence intervals (95% CI), and forest plots. Descriptive analysis and synthesis of literature was conducted for interventions not amenable to meta-analysis, focusing on risks of stroke, myocardial infarction and study-defined major adverse cardiovascular events (MACE). RESULTS: Fifty-six RCTs (61 894 patients) were retrieved. Many included trials were underpowered to detect differences in stroke risk. Among pharmacological therapies, only preoperative amiodarone was shown to reduce stroke risk in one trial. Concomitant left atrial appendage closure (LAAC) significantly reduced stroke risk (RR = 0.55, 95% CI = 0.36-0.84, P = 0.006) in patients with preoperative atrial fibrillation, and there was no difference in on-pump versus off-pump coronary artery bypass grafting (CABG) (RR = 0.94, 95% CI = 0.64-1.37, P = 0.735). Much controversy exists in literature on the timing of carotid endarterectomy relative to CABG in patients with severe carotid stenosis. The use of preoperative remote ischemic preconditioning was not found to reduce rates of stroke or MACE. CONCLUSION: This review presents a comprehensive synthesis of existing interventions for stroke prevention in cardiac surgery, and identifies gaps in research which may benefit from future, large-scale RCTs. LAAC should be considered to reduce stroke incidence in patients with preoperative atrial fibrillation.

N-Acetylcysteine's Renoprotective Effect in Cardiac Surgery: A Systematic Review and Meta-Analysis.

OBJECTIVE: To examine N-acetylcysteine's (NAC's) renoprotective effect in adult cardiac surgeryMethods: PubMed, Ovid Medline, and Embase were searched for randomized controlled trials published between January 1990 and May 2021 that investigated the effect of NAC in preventing acute kidney injury (AKI) in patients undergoing cardiac surgery. The inclusion criterion was studies that assessed the effect of NAC in comparison to placebo by measuring the incidence of AKI. RESULTS: Overall meta-analytic estimates of all 10 included trials showed that NAC did not have a significant effect (odds ratio [OR]: 0.84, 95% confidence interval [CI]: 0.64-1.10) on AKI. Further subgroup analysis did not show a significant benefit of NAC in preventing AKI. CONCLUSION: This meta-analysis suggests that NAC does not have a significant effect in reducing the incidence of AKI. However, there is notable heterogeneity among the included studies that could possibly account for the non-significant effect observed. It is worth noting that only one trial administered NAC high dosages perioperatively, and it is the only included trial to show a significant benefit in reducing the incidence of AKI (OR: 0.30, 95% CI: 0.11-0.81). Further studies on this dosage and duration of administration should be conducted to best elucidate the effect of administering NAC.

Anticoagulation After Isolated Mitral Valve Repair: A Systematic Review and Meta-Analysis of Clinical Outcomes.

Recommendations from international guidelines on optimal thromboprophylaxis after mitral repair are controversial and based on underpowered observational studies. This study aimed to evaluate the prophylactic use of warfarin after isolated mitral valve repair (MVr). A PubMed, EMBASE and Scopus search for studies in English on postoperative thromboprophylaxis for isolated MVr published to February 2020 was performed. The analysis excluded all studies with combined operations, mitral valve replacement and preoperative or postoperative atrial fibrillation. Clinical endpoints that were studied were thromboembolic events, bleeding complications and mortality. Random effects meta-analyses of the effect of postoperative warfarin use as compared with no warfarin use across all clinical endpoints was conducted. Warfarin use did not confer benefit in terms of thromboembolic prophylaxis after isolated MVr in patients without atrial fibrillation (OR, 0.97; 95% CI, 0.72-1.31). At the same time, it did not increase the risk of bleeding complications (OR, 1.10; 95% CI, 0.53-2.30) or affect overall survival during the follow-up period of the included studies (OR, 1.06; 95% CI, 0.28-4.05). To conclude, warfarin use is not necessary for patients after isolated MVr who remain in sinus rhythm. Recommendations from international guidelines may need to be revisited for this group of patients.

Left heart bypass versus circulatory arrest for open repair of thoracoabdominal aortic pathologies.

BACKGROUND: Most large-volume centres use left heart bypass (LHB) as their preferred organ protection strategy during repair of descending thoracic aortic (DTA) and thoracoabdominal aortic (TAA) pathologies. We investigate the use of hypothermic circulatory arrest (HCA) for similar pathologies and compare the outcomes of both. METHODS: A PubMed, Embase and Scopus search for studies in English on LHB versus HCA for repair of DTA and TAA pathologies published from inception till February 2020 was performed. Our analysis excluded studies without direct comparison of the two organ protection strategies. Clinical endpoints that were studied were 30-day mortality, post-operative stroke, spinal cord deficit, renal failure and respiratory failure. Random effects meta-analyses of the effect of the two strategies across all clinical endpoints were conducted. RESULTS: HCA is non-inferior to LHB across all clinical endpoints. In terms of 30-day mortality (odds ratio (OR) 1.19, 95% confidence interval (CI) 0.31-4.59, P = 0.14, I2 = 49%), stroke (OR 0.41, 95% CI 0.12-1.39, P = 0.97, I2 = 0%), spinal cord deficit (OR 0.56, 95% CI 0.22-1.45, P = 0.78, I2 = 0%), renal failure (OR 1.33, 95% CI 0.37-4.76, P = 0.98, I2 = 0%) and respiratory failure (OR 0.86, 95% CI 0.37-1.97, P = 0.16, I2 = 46%), there was no statistically significant difference between the two cohorts. CONCLUSION: Evidence is limited, but suggests that HCA alone provides adequate organ protection during repair of DTA and TAA pathologies, and has equivalent outcomes when compared to LHB.

Assessing the Impact of a Pulmonary Embolism Response Team and Treatment Protocol on Patients Presenting With Acute Pulmonary Embolism.

BACKGROUND: Pulmonary embolism (PE) care has traditionally been fragmented. The newly introduced Pulmonary Embolism Response Team (PERT) model provides streamlined care based on expedient, multi-disciplinary decision-making. This study aimed to quantify the impact of PERT, as part of a hospital-wide PE treatment protocol, on clinical outcomes. METHODS: Consecutive adult patients with acute PE diagnosed via computed tomography pulmonary angiogram (CTPA) were included. The PERT and treatment protocol were introduced in January 2015. Patient characteristics, therapies, quality measures of CTPA reporting, and clinical outcomes of PE patients treated for 2 years before and after implementation of these changes were evaluated. Primary endpoints were median length of stay in intensive care (ICU) and survival to discharge. RESULTS: A total of 321 consecutive PE patients were enrolled, of which 154 (treated in 2013-2014) and 167 (2015-2016) patients formed the historical control and study groups, respectively. Implementation of the algorithm was associated with less variance in anticoagulation and improved reporting of right heart strain parameters on CTPA. The ICU stay was reduced from a median of 5 to 2 days (p < 0.01). Eligible massive PE patients receiving reperfusion increased from 30% to 92% (p = 0.01), with mean delay from diagnosis to reperfusion decreasing from 763 to 181 minutes (p < 0.01). Bleeding complications were not increased, but overall survival to discharge remained unchanged. CONCLUSIONS: Introducing a PERT and treatment protocol reduced ICU stay, enhanced quality measures, and improved access of massive PE patients to reperfusion therapies, without increasing bleeding complications or health care costs.

Meta-analysis of the benefit of beta-blockers for the reduction of isolated atrial fibrillation incidence after cardiac surgery.

Objectives: Postoperative atrial fibrillation (POAF) is a common problem of cardiac surgery. Beta-blockers are recognized as effective prophylactic agents available for POAF management. To better understand its effect on isolated atrial fibrillation after cardiac surgery, a meta-analysis was conducted. Methods: Randomized controlled trials (RCTs) were searched and filtered by comparing the efficacy of beta-blockers and control users in isolated POAF for cardiac surgery. Seventeen RCTs were identified and analyzed by typical meta-analysis methods. The search was performed from inception to May 31, 2020. Subgroup analyses were conducted for type of surgery and beta-blocker, starting time and route of administration of beta-blocker, and dosage of intravenous landiolol hydrochloride. Results: Beta-blockers were effective in reducing isolated POAF risk (risk ratio [RR], 0.52 [0.41, 0.66], P = .31, I2 = 12%). In subgroup analyses, beta-blocker administration during postoperative period (RR, 0.43 [0.29, 0.62], P = .84, I2 = 0%) and on-pump coronary artery bypass graft (RR, 0.34 [0.04, 3.15], P = .56, I2 = 0%) had lowest risk of isolated POAF incidence. Intravenous landiolol hydrochloride at 2 µg/kg/min also had low risk of isolated POAF occurrence. Conclusions: Beta-blocker treatment helps to reduce isolated atrial fibrillation incidence after cardiac surgery. Our subgroup analyses also reveal postoperative beta-blocker administration after on-pump coronary artery bypass graft surgery is most effective in reducing isolated POAF risk. Intravenous landiolol hydrochloride at a dosage of 2 µg/kg/min has also displayed favorable results. Further trials may be required to explore these factors.

Building a Longitudinal National Integrated Cardiovascular Database　- Lessons Learnt From SingCLOUD.

Background: Real world data on clinical outcomes and quality of care for patients with coronary artery disease (CAD) are fragmented. We describe the rationale and design of the Singapore Cardiovascular Longitudinal Outcomes Database (SingCLOUD). Methods and Results: We designed a health data grid to integrate clinical, administrative, laboratory, procedural, prescription and financial data from all public-funded hospitals and primary care clinics, which provide 80% of health care in Singapore. Here, we explain our approach to harmonize real-world data from diverse electronic medical and non-medical platforms to develop a robust and longitudinal dataset. We present pilot data on patients with myocardial infarction (MI) treated with percutaneous coronary intervention (PCI) between 2012 and 2014. The initial data set had 53,395 patients. Of these, 35,203 had CAD confirmed on coronary angiography, of whom 21,521 had PCI. Eventually, limiting to 2012-2014, 3,819 patients had MI with PCI, while 5,989 had MI. Compared with the quality improvement registry, Singapore Cardiac Data Bank, which had 189 fields for analysis, the SingCLOUD platform generated an additional 313 additional data fields, and was able to identify an additional 250 heart failure events, 664 major adverse cardiovascular events at 2 years, and low-density lipoprotein levels to 1 year for 3,747 patients. Conclusions: By integrating multiple incongruent data sources, SINGCLOUD enables in-depth analysis of real-world cardiovascular "big data".

Coronary and arch hybrid surgery in a patient with infrarenal aortic occlusion.

A 65-year-old gentleman with claudication underwent contrast-enhanced computed tomography. The scan showed occlusion of the infrarenal abdominal aorta and a 6.0 × 3.7 cm saccular zone-3 arch aneurysm. The left ventricular ejection fraction was 35% and a coronary angiogram revealed triple-vessel disease. In view of the patient's high risk with EuroSCORE II 20.34%, coronary artery surgery was combined with hybrid type I arch aneurysm repair. An endovascular stent was delivered in an antegrade manner. Open heart surgery and a hybrid type I arch intervention can be performed simultaneously through a midline sternotomy approach.

Mid-term study of transcatheter aortic valve implantation in an Asian population with severe aortic stenosis: two-year Valve Academic Research Consortium-2 outcomes.

INTRODUCTION: Transcatheter aortic valve implantation (TAVI) is an effective treatment for high-risk or inoperative patients with severe aortic stenosis. Given the unique characteristics of Asian populations, questions regarding mid-term outcomes in Asians undergoing TAVI have yet to be addressed. We evaluated the two-year clinical outcomes of TAVI in an Asian population using Valve Academic Research Consortium-2 definitions. METHODS: This prospective study recruited 59 patients from a major academic medical centre in Singapore. The main outcomes were two-year survival rates, peri-procedural complications, symptom improvement, valvular function and assessment of learning curve. RESULTS: Mean age was 76.8 years (61.0% male), mean body surface area 1.6 m2 and mean logistic EuroSCORE 18.7%. Survival was 93.2%, 86.0% and 79.1% at 30 days, one year and two years, respectively. At 30 days post TAVI, the rate of stroke was 1.7%, life-threatening bleeding 5.1%, acute kidney injury 25.0%, major vascular complication 5.1%, and new permanent pacemaker implantation 6.8%. 29.3% of TAVI patients were rehospitalised (47.1% cardiovascular-related) within one year. These composite outcomes were measured: device success (93.2%); early safety (79.7%); clinical efficacy (66.1%); and time-related valve safety (84.7%). Univariate analysis found these predictors of two-year all-cause mortality: logistic EuroSCORE (hazard ratio [HR] 1.07; p < 0.001); baseline estimated glomerular filtration rate (HR 0.97; p = 0.048); and acute kidney injury (HR 5.33; p = 0.022). Multivariate analysis identified non-transfemoral TAVI as a predictor of cardiovascular-related two-year mortality (HR 14.64; p = 0.008). CONCLUSION: Despite the unique clinical differences in Asian populations, this registry demonstrated favourable mid-term clinical and safety outcomes in Asians undergoing TAVI.

Unravelling the proteome of degenerative human mitral valves.

Degenerative mitral valve disease (DMVD), which includes the syndromes of mitral valve prolapse (MVP) and flail leaflet, is a common valvular condition which can be complicated by mitral regurgitation and adverse cardiovascular outcomes. Although several genetic and other studies of MVP in dog models have provided some information regarding the underlying disease mechanisms, the proteins and molecular events mediating human MVP pathogenesis have not been unraveled. In this study, we report the first large-scale proteome profiling of mitral valve tissue resected from patients with MVP. A total of 1134 proteins were identified, some of which were validated using SWATH-MS and western blotting. GO annotation of these proteins confirmed the validity of this proteome database in various cardiovascular processes. Among the list of proteins, we found several structural and extracellular matrix proteins, such as asporin, biglycan, decorin, lumican, mimecan, prolargin, versican, and vinculin, that have putative roles in the pathophysiology of MVP. These proteins could also be involved in the cardiac remodeling associated with mitral regurgitation. All MS data have been deposited in the ProteomeXchange with identifier PXD000774 (http://proteomecentral.proteomexchange.org/dataset/PXD000774).

Sutureless aortic valve implantation: first experience in Asia.

Age-related degenerative calcification is currently the most common cause of aortic stenosis (AS) in adults and the most frequent reason for aortic valve replacement in patients with AS. With the increased life expectancy, a large proportion of elderly patients with AS is undergoing cardiac surgery, although many are not offered conventional aortic valve replacement due to the risks involved. However, sutureless aortic valve replacement provides an alternative for this group of elderly patients. This case series reports the first experience in Asia of sutureless aortic valve implantation in seven patients at our institution.

Transcatheter aortic valve implantation: implications for Asian patients.

BACKGROUND: transcatheter aortic valve implantation is now an accepted therapy for patients with severe aortic valve stenosis who are deemed inoperable, and it is a reasonable alternative for patients with high surgical risk. This study assessed the clinical outcomes of this procedure and the implications of transcatheter aortic valve implantation for such patients. METHODS: 14 consecutive patients with severe aortic valve stenosis, who underwent transcatheter aortic valve implantation, were assessed. Baseline clinical characteristics, procedural information, and clinical outcomes and complications were compared at baseline and at follow-up. Thirty-day mortality was also assessed. RESULTS: the mean age of the patients was 81 ± 8 years (35% females). The mean Society of Thoracic Surgeons score was 6.8 ± 3.7. Most patients had chronic kidney disease with an estimated glomerular filtration rate of 44.5 ± 14.9 mL·kg(-1)·min(-1). The mean annulus diameter was 21.9 ± 1.7 mm, and 8 (57%) patients received 23-mm valves. After transcatheter aortic valve implantation, the mean transaortic gradient and aortic valve area improved from 42.9 ± 19.4 to 8.9 ± 3.1 mm Hg (p < 0.001) and 0.7 ± 0.1 to 1.5 ± 0.3 cm(2) (p < 0.001), respectively. The 30-day mortality for this cohort was 7%. CONCLUSION: transcatheter aortic valve implantation can be performed successfully in carefully selected Asian patients. The decision to undertake this procedure should be guided by the surgical team.

Pulmonary metastasectomy in colorectal cancer: a systematic review and quantitative synthesis.

OBJECTIVES: Surgical removal of pulmonary metastases from colorectal cancer is undertaken increasingly but the practice is variable. There have been no randomized trials of effectiveness. We needed evidence from a systematic review to plan a randomized controlled trial. DESIGN: A formal search for all studies concerning the practice of pulmonary metastasectomy was undertaken including all published articles using pre-specified keywords. Abstracts were screened, reviewed and data extracted by at least two of the authors. Information across studies was collated in a quantitative synthesis. RESULTS: Of 101 articles identified, 51 contained sufficient quantitative information to be included in the synthesis. The reports were published between 1971 and 2007, and reported on 3504 patients. There was little change over time in patient characteristics such as age, sex, the time elapsed since resection of the primary cancer, its site or stage. The proportion with multiple metastases or elevated carcinoma embryonic antigen (CEA) did not change over time but there was an apparent increase in the proportion of patients who also had hepatic metastasectomy. Differences in 5-year survival between groups defined by CEA or by single versus multiple metastases persisted over time. Few data were available concerning postoperative morbidity, postoperative lung function or change in symptoms. CONCLUSION: The quality of evidence available concerning pulmonary metastasectomy in colorectal cancer is not sufficient to draw inferences concerning the effectiveness of this surgery. There is great variety in what was reported and its utility. Given the burdensome nature of the surgery involved, better evidence, ideally in the form of a randomized trial, is required for the continuance of this practice.