Mortality Reduction With β-Blockers in Ischemic Cardiomyopathy Patients Undergoing Coronary Artery Bypass Grafting

Effect of β-blocker on patients with moderate functional mitral regurgitation undergoing surgical aortic valve replacement

AIMS

The optimal treatment for severe aortic valve disease complicated with moderate function mitral regurgitation (FMR) remains controversial. Although isolated surgical aortic valve replacement (SAVR) is reasonable, previous studies also show that moderate FMR might deteriorate after surgical treatment and result in poorer prognosis. Because the left ventricular remodelling plays a critical role in the development of FMR, these patients might potentially benefit from the administration of β-blocker (BB). Unfortunately, relevant clinical evidence is lacking. This study aimed to investigate the impact of post-operative administration of BB on the outcomes of moderate FMR patients undergoing isolated SAVR.

METHODS

In this single-centre cohort study, patients who underwent isolated SAVR and complicated with pre-operative moderate FMR during 2010 and 2019 at our centre were retrospectively recruited. Patients were divided into two groups according to postoperative administration of BB (BB group vs. control group). The cumulative survival rates were calculated using the Kaplan-Meier method and tested by the log-rank test, followed by inverse probability treatment weighting (IPTW) analysis to further control the between-group imbalances. The primary outcome was the major adverse cardiovascular and cerebrovascular events (MACCE), a composite endpoint of all-cause death, repeat heart valve surgery, non-fatal myocardial infarction, stroke, and hospitalization for heart failure.

RESULTS

A total of 165 patients were enrolled, 57 (34.6%) of whom were female, and the mean age was 59.2 ± 12.2 years. Eighty (48.5%) patients received post-operative BB therapy. The median follow-up time was 18.4 months. The administration of BB was not associated with lower risk of MACCE [hazard ratio (HR): 0.68, 95% confidence interval (CI): 0.29-1.62, P = 0.388] or all-cause death (HR: 1.03, 95% CI: 0.30-0.56, P = 0.967). In the IPTW dataset, the total number of patients were 326.89, and the outcomes regarding the risk of MACCE (HR: 0.79, 95% CI: 0.31-1.97, P = 0.607) and all-cause death (HR: 1.33, 95% CI:0.35-5.05, P = 0.674) were in line with the unmatched analysis. The follow-up echocardiographic results were available for 72.2% of the overall cohort, and the use of BB was observed to be associated with higher improvement rate of follow-up FMR according to the IPTW analysis (92.2% vs. 98.3%, P = 0.033).

CONCLUSIONS

The administration of BB after SAVR was not associated with lower risk of MACCE for patients of severe aortic valve disease complicated with moderate FMR, but was potentially beneficial for improving FMR.

Factors affecting mortality after coronary bypass surgery: a scoping review

Objectives

Previous research reports numerous factors of post-operative mortality in patients undergoing isolated coronary artery bypass graft surgery. However, this evidence has not been mapped to the conceptual framework of care improvement. Without such mapping, interventions designed to improve care quality remain unfounded.

Methods

We identified reported factors of in-hospital mortality post isolated coronary artery bypass graft surgery in adults over the age of 19, published in English between January 1, 2000 and December 31, 2019, indexed in PubMed, CINAHL, and EMBASE. We grouped factors and their underlying mechanism for association with in-hospital mortality according to the augmented Donabedian framework for quality of care.

Results

We selected 52 factors reported in 83 articles and mapped them by case-mix, structure, process, and intermediary outcomes. The most reported factors were related to case-mix (characteristics of patients, their disease, and their preoperative health status) (37 articles, 27 factors). Factors related to care processes (27 articles, 12 factors) and structures (11 articles, 6 factors) were reported less frequently; most proposed mechanisms for their mortality effects.

Conclusions

Few papers reported on factors of in-hospital mortality related to structures and processes of care, where intervention for care quality improvement is possible. Therefore, there is limited evidence to support quality improvement efforts that will reduce variation in mortality after coronary artery bypass graft surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-01784-z.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered.

STRUCTURE

Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

Secondary Prevention Medications Post Coronary Artery Bypass Grafting Surgery-A Literature Review

Secondary prevention after coronary artery bypass graft (CABG) surgery is imperative in slowing the progression of atherosclerosis in both native and grafted vessels. Aspirin and statins remain the key medications for all patients without significant contraindications. The evidence for dual antiplatelet therapy with clopidogrel is less convincing, but there is hope for newer antiplatelet agents, such as ticagrelor. Meanwhile, β-blockers and angiotensin converting enzyme inhibitors might only offer benefits to specific sub-groups. Post-CABG patients appear to have different medication needs to the general cardiovascular patient and respond differently. In this review, we cover the drug regimens proposed by recent guidelines and the evidence behind their use. Assessing the evidence behind these recommendations, we find that there is an unmet need in some areas for robust population-specific evidence. We hope that future research will address this gap.

Comparing the effectiveness of revascularization interventions with medical therapy in patients with ischemic cardiomyopathy: A systematic review and meta-analysis

Background: Determining the effectiveness of cardiovascular interventions plays an important role in reimbursement decisions, health care pricing, and providing clinical guidance on the use of existing clinical technologies. This study aimed to review and analyze the effectiveness of revascularization interventions (CABG and PCI) compared to medical therapy in patients with ischemic cardiomyopathy.

Methods: Different databases were searched up to December 2017. The articles were selected based on inclusion and exclusion criteria. Quality of all studies was evaluated by Jadad score and relevant checklists. The I2 test was used to test heterogeneity. Also, to integrate the results of similar studies, meta-analysis was done using STATA software.

Results: A total of 18 studies were included. Based on the random effects model, the overall results of comparing the effectiveness of revascularization interventions with medical therapy were as follow: 38.94 [95% CI: 26.95-50.94, p<0.001, I² = 99.6%, p<0.001], [75.31, 95% CI: 74.06-76.57, p<0.001, I²= 88.8, p<0.001], and 75.76 [95% CI: 71.99-79.53, p<0.001, I2= 99.2, p<0.001] for cardiac mortality rate, quality of life, and 5-year survival, respectively. Also, in patient satisfaction index, revascularization interventions were shown to be more effective than medical therapy.

Conclusion: This study showed that revascularization interventions in all studied indices were more effective than medical therapy. Also, between revascularization interventions, PCI was more effective in cardiovascular mortality and 5-year survival than CABG in terms of quality of life. Moreover, CABG was more effective than PCI. In patient satisfaction index, the results of the 2 included studies were contradictory.

Rationale for administering beta-blocker therapy to patients undergoing coronary artery bypass surgery: a systematic review

INTRODUCTION

Secondary preventative therapies are essential for patients undergoing coronary artery bypass graft (CABG) surgery to optimize perioperative and long-term outcomes. Beta-blockers are commonly used to treat patients with coronary artery disease and congestive heart failure (CHF), but their role for CABG patients remains unclear. The goal of this systematic review was to evaluate the rationale for administering beta-blockers to the CABG population and to assess their efficacy before and after coronary surgical revascularization.

AREAS COVERED

A systematic literature review was performed to retrieve relevant articles from the PubMed database published between 1985 and 2017.

EXPERT OPINION

Outside of the surgical field, strong evidence supports the use of beta-blockers for patients with a history of previous myocardial infarction (MI) or CHF. For the CABG population, studies have suggested that perioperative beta-blocker therapy is beneficial, with an associated reduction in mortality, particularly among those with a history of previous MI or CHF. Beta-blocker administration has also clearly been shown to lower the rate of new-onset postoperative atrial fibrillation after CABG. Among the different types of beta-blockers, perioperative carvedilol appears to be the most beneficial. In the absence of contraindications, nearly all CABG patients are candidates for perioperative beta-blocker therapy.

Efficacy of β-blocker therapy for secondary prevention for patients undergoing coronary artery bypass grafting surgery

PURPOSE OF REVIEW

The efficacy and safety of β-blockers in the treatment of cardiovascular diseases, such as ischemic heart disease, cardiac arrhythmias, and heart failure, have been well established for decades. In this article, we review the current opinions on the application of β-blockers for secondary prevention in patients undergoing coronary artery bypass grafting (CABG) surgery.

RECENT FINDINGS

As the average age of patients treated surgically for coronary artery disease (CAD) is increasing, it is not uncommon to have candidates for CABG presenting with concomitant atrial fibrillation, heart failure or hypertension, most of which were caused by excessive activation of the adrenergic nervous system. In a recent decade, a number of national quality-improvement efforts using a variety of techniques have been made to increase the use of β-blocker therapy before or following the CABG. Results from recent large observational studies among patients with CAD showed that β-blockers were associated with a lower risk of cardiac events only among those with heart failure or recent myocardial infarction. However, the consistent use of β-blockers could benefit those with or without prior myocardial infarction who underwent CABG and discharged alive.

SUMMARY

In real-world clinical practice, β-blockers are effective and safe to control heart rate and symptoms in patients with CAD, especially for those concomitant with left ventricular systolic dysfunction or prior myocardial infarction. Current evidence supports the preoperative use of β-blocker therapy for patients undergoing CABG as a prevention of new-onset atrial fibrillation. It is reasonable to continue β-blockers as chronic therapy in all CABG patients without contraindications after hospital discharge. Further strategies should be developed to understand and improve discharge prescription of β-blockers and long-term patient adherence.

Effects of five preoperative cardiovascular drugs on mortality after coronary artery bypass surgery: A retrospective analysis of an observational study of 16, 192 patients

BACKGROUND

Statins reduce risk from coronary artery bypass graft (CABG) surgery, but the influence of angiotensin-converting enzyme inhibitors, alpha-2 adrenergic agonists, calcium channel blockers and beta-blockers is less clear.

OBJECTIVES

We investigated the association of each of these drugs with perioperative risk, accounting for different confounders, and evaluated the class, dose-response and long-term protective effect of statins.

DESIGN

A retrospective analysis of observational data.

SETTING

United Kingdom.

PATIENTS

Sixteen thousand one hundred and ninety-two patients who underwent CABG surgery during the period 01 January 2004 to 31 December 2013 and contributed data to Primary Care Clinical Practice Research Datalink.

EXPOSURE VARIABLES

Cardiovascular drugs.

OUTCOME MEASURE

Perioperative mortality within 30 days of surgery.

STATISTICAL ANALYSIS

Five multivariable logistic regression models and a further Cox regression model were used to account for preexisting cardiovascular and other comorbidities along with lifestyle factors such as BMI, smoking and alcohol use.

RESULTS

Exposure to statins was most prevalent (85.1% of patients), followed by beta-blockers (72.8%), angiotensin-converting enzyme inhibitors (60.5%), calcium channel blockers (42.8%) and alpha-2 adrenergic agonists (1.2%). The mortality rate was 0.8% in patients not prescribed statins and 0.4% in those on statins. Statins were associated with a statistically significant reduced perioperative mortality in all five logistic regression models with adjusted odds ratios (OR) (95% confidence interval, 95% CI) ranging from 0.26 (0.13 to 0.54) to 0.35 (0.18 to 0.67). Cox regression for perioperative mortality [adjusted hazard ratio (95% CI) 0.40 (0.20 to 0.80)] and 6-month mortality [adjusted hazard ratio (95% CI) 0.63 (0.42 to 0.92)] produced similar results. Of the statin doses tested, only simvastatin 40 mg exerted protective effects. The other cardiovascular drugs lacked consistent effects across models.

CONCLUSION

Statins appear consistently protective against perioperative mortality from CABG surgery in multiple models, an effect not shared by the other cardiovascular drugs. Further data are needed on whether statins exert class and dose-response effects.