Differential Effect of β-Blockers According to Heart Rate in Acute Myocardial Infarction Without Heart Failure or Left Ventricular Systolic Dysfunction: A Cohort Study

Therapeutic appraisal in protracted heart failure

Data from pivotal randomized controlled trials established the four pillars of guideline-directed medical therapy in heart failure with reduced ejection fraction. The randomized controlled trials enrolled stable patients with New York Heart Association functional class II-III and a low incidence of cardiovascular death and hospitalization for heart failure. Whether the four pillars retain therapeutic value when a patient's symptoms worsen and life expectancy decreases has received scarce attention. We review the observational studies that point to the fading benefit of neurohormonal modulation and cardiac afterload reduction in the late stages of cardiovascular or renal diseases. We then propose a pragmatic approach for collecting evidence-based data on sequential withdrawal of the four pillars in patients with heart failure and reduced ejection fraction after years of guideline-directed medical therapy.

Beta-Blockers for Secondary Prevention following Myocardial Infarction in Patients Without Reduced Ejection Fraction or Heart Failure: An Updated Meta-Analysis

AIM

The 2023 ESC guidelines for acute coronary syndrome note that contemporary data are heterogenous regarding beta-blockers (BB) use post-myocardial infarction (MI) in patients without reduced ejection fraction (EF) or heart failure (HF). We aimed to address the heterogeneity in contemporary data around BB post-MI in this population.

METHODS

We searched 6 databases from Jan 1, 2000 to Sep 1, 2024 to identify contemporary studies enrolling MI patients without reduced EF (≤40%) or history of HF receiving BB at index MI, and comparing outcomes between BB users and non-users. The primary outcome was all-cause mortality. Secondary outcomes included major adverse cardiac and cerebrovascular events (MACCE) and cardiovascular (CV) mortality. Random-effects meta-analysis was conducted using the restricted maximum likelihood method.

RESULTS

There were 24 studies including 290,349 patients enrolled in the contemporary era. Overall, BB use was associated with a significant 11% reduction in all-cause mortality (HR, 0.89; 95% CI, 0.81 to 0.97; I2 = 40%; Figure 1), however with moderate-to-high statistical heterogeneity. Prespecified subgroup analyses demonstrate comparable all-cause mortality (HR, 0.99; 95% CI, 0.94 to 1.06; I2 = 0%), CV mortality (HR, 0.99; 95% CI, 0.85 to 1.15; I2 = 0%), and MACCE (HR, 1.24; 95% CI, 1.01 to 1.52; I2 = 0%) in patients with a 1-year event-free period, defined as no death, recurrent MI, or HF while on BB following index MI. In patients with no event-free period, meta-regression revealed that BB mortality benefits were modified by the study inclusion period (P = 0.01), reflecting a temporal trend of decreasing BB mortality benefits over time. Based on the temporal trend, in patients with preserved EF post-2010, BB exhibited no reduction in all-cause mortality (HR, 0.97; 95% CI, 0.90 to 1.04; I2 = 0%), but a non-significant trend towards increased CV mortality (HR, 1.29; 95% CI, 0.96 to 1.72; I2 = 0%) and a significant increase in MACCE (HR, 1.24; 95% CI, 1.01 to 1.52; I2 = 0%).

CONCLUSION

In the contemporary reperfusion era, BB may not confer additional mortality benefits beyond a 1-year event-free period post-MI in patients without reduced EF. Moreover, post-MI BB use was associated with detrimental effects in patients with preserved EF.

Beta Blockers in Contemporary Cardiology: Is It Better to Cast Them Out?

Beta blockers are one of the commonest prescription drugs in medicine and they have been thought to revolutionize the treatment of heart failure (HF) with reduced ejection fraction (HFrEF) in the last century. In addition to HFrEF, they are prescribed for a variety of diseases in cardiology from hypertension to HF, angina, and stable coronary artery disease (CAD). The increased prescription of beta blockers in conditions like HF with preserved ejection fraction (HFpEF), and stable CAD may be doing more harm than good as per the data we have so far. The available data shows that beta blockers are associated with increased stroke risk and atrial fibrillation (AF) in hypertension and in patients with HFpEF, they have been associated with decreased exercise capacity. In patients with stable CAD and patients with myocardial infarction with normal systolic functions, beta blockers don't offer any mortality benefit. In this article, we critically review the common indications and the uses of beta blockers in patients with HFpEF, CAD, hypertension and AF and we propose that beta blockers are over-prescribed under the shadow of their beneficial effects in patients with HFrEF.

Association of β-blocker use at discharge and prognosis of oldest old with acute myocardial infarction: a prospective cohort study

PURPOSE

It is uncertain whether β-blockers are beneficial for long-term prognosis in older patients following acute myocardial infarction (AMI). Thus, this study sought to examine the effect of β-blockers on long-term cardiovascular mortality (CVM) in the oldest old (≥ 80 years) with AMI.

METHODS

In this prospective, consecutive, non-randomized study, a total of 1156 patients with AMI admitted within 24 h after onset of symptoms were enrolled from January 2012 to February 2020. Univariate and multivariate Cox regression analyses were performed to examine the impact of β-blocker use on prognosis. Furthermore, one-to-one propensity score matching (PSM) and inverse probability treatment weighting (IPTW) analyses were used to control for systemic differences between groups. The primary outcome was long-term CVM.

RESULTS

Among the enrolled subjects, 972 (85.9%) were prescribed with β-blockers at discharge. Over a mean follow-up of 26.3 months, 224 cardiovascular deaths were recorded. Both univariate [hazard ratio (HR), 1.41, 95% confidence interval (CI) 0.93-2.13] and multivariate (HR, 1.29, 95% CI 0.79-2.10) Cox regression analyses showed that β-blocker use had no significant association with the long-term CVM, which was further demonstrated by PSM (HR, 1.31, 95% CI 0.75-2.28) and IPTW (HR, 1.41, 95% CI 0.73-2.69) analyses. Subgroup analyses according to sex, heart rate, hypertension, diabetes, revascularization, left ventricular ejection fraction, and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers use showed consistent results as well.

CONCLUSION

Our findings first suggested that the use of β-blockers at discharge in oldest old with AMI was not useful for reducing post-discharge CVM, which need to be further verified by randomized controlled trials.

Potential Influential Factors of In-Hospital Myocardial Reinfarction in ST-Segment Elevation Myocardial Infarction (STEMI) Patients: Finding from the Improving Care for Cardiovascular Disease in China- (CCC-) Acute Coronary Syndrome (ACS) Project

In this study, 39915 inpatients with a discharge diagnosis of STEMI from the CCC-ACS project phase I and II were included. The prevalence of the medical history, clinical complications on admission and treatment during hospitalization in the STEMI inpatients with and without in-hospital reinfarction was presented. The factors that were differentially distributed and of critical clinical significance (e.g., age, sex, heart rate, smoking, MI history, HF history, COPD history, stroke, hypertension, diabetes, PCI treatment, administration of DAPT, and statins) were entered into standard Cox regression model and competing risk model for potential influential factors of in-hospital reinfarction. Patients with a higher heart rate (OR 1.018; 95% CI 1.003 to 1.033) were more susceptible to in-hospital reinfarction. Myocardial infarction history (OR 2.840; 95% CI 1.160 to 6.955) was a risk factor of in-hospital reinfarction independent of hypertension, diabetes, and dyslipidaemia.

2020 Focused Update of the 2012 Guidelines of the Taiwan Society of Cardiology for the Management of ST-Segment Elevation Myocardial Infarction

One of the major missions of the Taiwan Society of Cardiology is to publish practice guidelines that are suitable for local use in Taiwan. The ultimate purpose is to continuously improve cardiovascular health care from the implementation of the recommendations in the guidelines. Despite recent improvement of medical care, patients with ST-segment elevation myocardial infarction (STEMI) still carry a high morbidity and mortality. There have been many changes in the concepts of STEMI diagnosis and treatment in recent years. The 2020 focused update of the 2012 guidelines of the Taiwan Society of Cardiology for the management of STEMI is an amendment of the 2012 guidelines based on the newest published scientific data. The recommendations in this focused update provide the diagnosis and treatment strategy for STEMI that should be generally implemented in Taiwan. Nevertheless, guidelines never completely replace clinical judgment and medical decision still should be determined individually.