Long-Term Beta-Blocker Therapy after Myocardial Infarction in the Reperfusion Era: A Systematic Review

Chinese expert consensus on the diagnosis and treatment of coronary microvascular diseases (2023 Edition)

Since the four working groups of the Chinese Society of Cardiology issued first expert consensus on coronary microvascular diseases (CMVD) in 2017, international consensus documents on CMVD have increased rapidly. Although some of these documents made preliminary recommendations for the diagnosis and treatment of CMVD, they did not provide classification of recommendations and levels of evidence. In order to summarize recent progress in the field of CMVD, standardize the methods and procedures of diagnosis and treatment, and identify the scientific questions for future research, the four working groups of the Chinese Society of Cardiology updated the 2017 version of the Chinese expert consensus on CMVD and adopted a series of measures to ensure the quality of this document. The current consensus has raised a new classification of CMVD, summarized new epidemiological findings for different types of CMVD, analyzed key pathological and molecular mechanisms, evaluated classical and novel diagnostic technologies, recommended diagnostic pathways and criteria, and therapeutic strategies and medications, for patients with CMVD. In view of the current progress and knowledge gaps of CMVD, future directions were proposed. It is hoped that this expert consensus will further expedite the research progress of CMVD in both basic and clinical scenarios.

Adherence with cardiovascular medications and the outcomes in patients with coronary arterial disease: "Real-world" evidence

BACKGROUND

Cardiovascular medications are vital for the secondary prevention of coronary arterial disease (CAD). However, the effect of cardiovascular medication may depend on the optimal adherence of the patients. This meta-analysis aims to determine the magnitude of adherence to vascular medications that influences the absolute and relative risks (RRs) of mortality in patients with CAD in real-world settings.

METHODS

The Cochrane Library, PubMed, and EMBASE databases were searched through March 1, 2022. Prospective studies reporting association as RR and 95% confidence interval between cardiovascular medication adherence and any cardiovascular events and/or all-cause mortality in patients with CAD were included. A one-stage robust error meta-regression method was used to summarize the dose-specific relationships.

RESULTS

A total of 18 studies were included. There is a significant inverse linear association between cardiovascular medication adherence and cardiovascular events (p_nonlinearity  = .68) or mortality (p_nonlinearity  = .82). The exposure-effect analysis showed that an improvement of 20% cardiovascular medication adherence was associated with 8% or 12% lower risk of any cardiovascular events or mortality, respectively. In subgroup analysis, the benefit was observed in adherence of stain (RR: 0.90, for cardiovascular events, RR: 0.85, for mortality), angiotensin-converting enzyme inhibitors (ACEI)/angiotensin II receptor blockers (ARB)(RR: 0.90, for mortality), and antiplatelet agent (RR: 0.89 for mortality) but not in beta-blocker (RR: 0.90, p = .14, for cardiovascular events, RR: 0.97, p = .32 for mortality). Estimated absolute differences per 1 million individuals per year for mortality associated with 20% improvement were 175 cases for statin, 129 cases for antiplatelet, and 117 cases for ACEI/ARB.

CONCLUSION

Evidence from the real word showed poor adherence to vascular medications contributes to a considerable proportion of all cardiovascular disease events and mortality in patients with CAD.

Beta-Blocker Use after Discharge in Patients with Acute Myocardial Infarction in the Contemporary Reperfusion Era

Background and objectives: The effect of beta-blocker use after discharge on patients with acute myocardial infarction (AMI) in the contemporary reperfusion era remains ambiguous. By applying meta-analysis, we sought to assess the role of beta-blockers in the contemporary reperfusion era. Materials and Methods: Randomized controlled trials (RCT) and observational studies using propensity score matching, comparing use of beta-blockers with non-use of beta-blockers, in patients with AMI after discharge. The primary outcome was all-cause mortality. Odds ratios (OR) and associated 95% confidence intervals (CI) were calculated. Results: One RCT and eight observational studies, containing 47,339 patients with AMI, were included. Compared with non-use of beta-blockers, beta-blocker use after discharge may have reduced the risk of all-cause mortality (OR: 0.70, 95% CI: 0.61 to 0.80, I² = 14.4%), cardiac death (OR: 0.63, 95% CI: 0.44 to 0.91, I² = 22.8%), myocardial infarction (OR: 0.73, 95% CI: 0.62 to 0.86, I² = 0), and revascularization (OR: 0.92, 95% CI: 0.85 to 0.99, I² = 0). No significant differences were found in major adverse cardiovascular events (MACE, OR: 0.88, 95% CI: 0.66 to 1.17, I² = 78.4%), heart failure (OR: 0.56, 95% CI: 0.29 to 1.08, I² = 0) or stroke (OR: 1.13, 95% CI: 0.92 to 1.39, I² = 0). For patients with preserved left ventricular function, beta-blocker use after discharge may have also reduced the risk of all-cause mortality (OR: 0.61, 95% CI: 0.44 to 0.84, I² = 0). Conclusions: Use of beta-blockers after discharge may still be beneficial for AMI patients in the contemporary reperfusion era, with or without preserved left ventricular function.

Harnessing RKIP to Combat Heart Disease and Cancer

Cancer and heart disease are leading causes of morbidity and mortality worldwide. These diseases have common risk factors, common molecular signaling pathways that are central to their pathogenesis, and even some disease phenotypes that are interdependent. Thus, a detailed understanding of common regulators is critical for the development of new and synergistic therapeutic strategies. The Raf kinase inhibitory protein (RKIP) is a regulator of the cellular kinome that functions to maintain cellular robustness and prevent the progression of diseases including heart disease and cancer. Two of the key signaling pathways controlled by RKIP are the β-adrenergic receptor (βAR) signaling to protein kinase A (PKA), particularly in the heart, and the MAP kinase cascade Raf/MEK/ERK1/2 that regulates multiple diseases. The goal of this review is to discuss how we can leverage RKIP to suppress cancer without incurring deleterious effects on the heart. Specifically, we discuss: (1) How RKIP functions to either suppress or activate βAR (PKA) and ERK1/2 signaling; (2) How we can prevent cancer-promoting kinase signaling while at the same time avoiding cardiotoxicity.

Effects of Metoprolol on Periprocedural Myocardial Infarction After Percutaneous Coronary Intervention (Type 4a MI): An Inverse Probability of Treatment Weighting Analysis

Background: Metoprolol is the most used cardiac selective β-blocker and has been recommended as a mainstay drug in the management of acute myocardial infarction (AMI). However, the evidence supporting this regimen in periprocedural myocardial infarction (PMI) is limited.

Methods: This study identified 860 individuals who suffered PMI following percutaneous coronary intervention (PCI) procedure and median followed up for 3.2 years. Subjects were dichotomized according to whether they received chronic oral sustained-release metoprolol succinate following PMI. After inverse probability of treatment weighting (IPTW) adjustment, logistic regression analysis, Kaplan-Meier curve, and Cox regression analysis were performed to estimate the effects of metoprolol on major adverse cardiovascular events (MACEs) which composed of cardiac death, myocardial infarction (MI), stroke, and revascularization. Moreover, an exploratory analysis was performed according to hypertension, cardiac troponin I (cTnI) elevation, and cardiac function. A double robust adjustment was used for sensitivity analysis.

Results: Among enrolled PMI subjects, 456 (53%) patients received metoprolol treatment and 404 (47%) patients received observation. After IPTW adjustment, receiving metoprolol was found to reduce the subsequent 3-year risk of MACEs by nearly 7.1% [15 vs. 22.1%, absolute risk difference (ARD) = 0.07, number needed to treat (NNT) = 14, relative risk (RR) = 0.682]. In IPTW-adjusted Cox regression analyses, receiving metoprolol was related to a reduced risk of MACEs (hazard ratio [HR] = 0.588, 95%CI [0.385–0.898], P = 0.014) and revascularization (HR = 0.538, 95%CI [0.326–0.89], P = 0.016). Additionally, IPTW-adjusted logistic regression analysis showed that receiving metoprolol reduced the risk of MI at the third year (odds ratio [OR] = 0.972, 95% CI [0.948–997], P = 0.029). Exploratory analysis showed that the protective effect of metoprolol was more pronounced in subgroups of hypertension and cTnI elevation ≥1,000%, and was remained in patients without cardiac dysfunction. The benefits above were consistent when double robust adjustments were performed.

Conclusion: In the real-world setting, receiving metoprolol treatment following PCI-related PMI has decreased the subsequent risk of MACEs, particularly the risk of recurrent MI and revascularization.

Usefulness of universal beta-blocker therapy in patients after ST-elevation myocardial infarction

The use of beta-blockers (BB) in the context of ST-segment elevation myocardial infarction (STEMI) was a universal practice in the pre-reperfusion era. Since then, evidence of their use for secondary prevention after STEMI is scarce. Our aim is to determine treatment results associated with BB therapy after a STEMI at 1-year follow-up in a contemporary nationwide cohort.A prospective analysis involving 49 national centers, including patients admitted with STEMI, enrolled between October 2010 and September 2019 was conducted. The primary outcome was defined as the composite of all-cause mortality or hospital re-admission for a cardiovascular (CV) cause in the first year after STEMI. The patients were distributed into 2 groups, depending on whether they received therapy with BB at hospital discharge or not (BB and NB group, respectively).A total of 3145 patients were included in the analysis, of which 2526 (80.3%) in the BB group. A total of 12.2% of patients reached the primary outcome. Regarding the univariate Cox regression analysis, the BB group presented lower mortality or re-admission for CV cause at 1-year follow-up [hazard ratio (HR) 0.69, confidence interval (CI) 95% 0.55-0.87, P = .001]. However, after adjustment for significant covariates, this association was lost (HR 0.73, CI 95% 0.51-1.04, P = .081). In patients with preserved (HR 0.73, CI 95% 0.51-1.04, P = .081) and mid-range (HR 1.01, CI 95% 0.64-1.61, P = .959) left ventricular ejection fraction (LVEF), the primary outcome was similar between the 2 groups, while in patients with reduced LVEF, the BB group presented a better prognosis, with fewer patients reaching the primary outcome (HR 0.431, CI 95% 0.262-0.703, P = .001).BB universal therapy after STEMI has not proved useful, but it seems to be beneficial in patients with reduced LVEF.

Chronotropic incompetence could negatively influence post-operative risk assessment in patients before lung cancer surgery

Background

Cardiopulmonary exercise testing (CPET) is a standard part of preoperative evaluation in patients before lung surgical resection. According to current guidelines the risk of such a procedure is estimated according to maximum oxygen consumption (VO₂max). Chronotropic incompetence (CI) is a prevalent condition which could possibly influence cardiopulmonary fitness. The aim of this study was to assess the prevalence of CI in patients before surgical lung resections and its influence on CPET results.

Methods

This study enrolled 154 patients (97 men) of average age 66.4±8.3 with newly diagnosed lung cancer indicated for surgical lung resections. All patients underwent CPET (cycle ergometry). Age predicted maximal HR was calculated using the traditional equation (220 – age). Three levels of CI were defined as, 85% HR_pred, 80% HR_pred and 70% HR_pred. The influence of CI on CPET results was evaluated.

Results

CI was present in the following ratios: 85% HR_pred—48.7%; 80% HR_pred—39.6% and 70% HR_pred—16.9%. A significant negative correlation was also found between VO₂max, maximal heart rate (HR) and maximal work load among all CI groups (P<0.0001). The presence of CI significantly correlated with beta-blocker treatment (P<0.0001).

Conclusions

CI significantly decreases VO₂max in patients before lung cancer surgery. It is strongly associated with beta-blocker treatment which could negatively influence risk assessment. It is thus a matter for future discussion, as to whether the evaluation of CI should be part of preoperative care guidelines.

[Frequency of use and Indications for Beta-Blockers in Heart Failure with Preserved Ejection Fraction]

Aim      To evaluate trends in beta-blocker prescribing and incidence of possible reasons for beta-blocker administration, including arterial hypertension (AH), atrial fibrillation (AF), ischemic heart disease (IHD), and myocardial infarction, in participants of clinical studies enrolling patients with chronic heart failure with preserved ejection fraction (CHF-PEF).Material and methods  A systematic literature search was performed in the PubMed and EMBASE databases. The study included RCSs of pharmacological therapies for patients with CHF-PEF conducted from 1993 through 2019. Studies of beta-blocker efficacy or those including a specific population (CHF-PEF+IHD or CHF-PEF+AH, etc.) were excluded from the analysis. Baseline characteristics of patients, incidence rate of beta-blocker prescribing, and prevalence of AH, AF, IHD, and MI were recorded. Trends in prevalence of concomitant diseases and the proportion of patients using beta-blockers by the year of enrollment to the study were analyzed with the Mann-Kendall test.Results 14 RCSs of 718 selected publications completely met the inclusion and exclusion criteria. Beta-blocker prescribing significantly increased between 1993 and 2019 (tau=0.51; p=0.014) and reached 80 % in recent studies. Furthermore, prevalence of IHD, MI, AH, and AF did not significantly change among the RCS participants (p&gt;0.05 for all). However, while for AH and AF, a tendency toward an increasing prevalence (tau=0.4; p=0.055 and tau=0.043; p=0.063, respectively) could be considered and became statistically significant for AF when the ALDO-DHF study was excluded from the analysis (tau=0.5; p=0.042), the MI prevalence tended to decrease (tau= -0.73; p=0.06).Conclusion      Beta-blocker prescribing to patients upon inclusion into RCSs for CHF-PEF has significantly increased for the recent 20 years while the incidence of formal reasons for beta-blocker administration (AF, AH, MI, IHD) did not significantly change.

Association Between β-Blockers and Outcome of Coronary Artery Bypass Grafting: Before and After 1 Year

BACKGROUND

We evaluated the long-term outcomes of coronary artery bypass grafting (CABG) according to β-blocker therapy using landmark analysis. Although β-blockers have been shown to improve outcomes for ischemic heart disease, the long-term effects and optimal treatment duration of use after CABG remain unknown.

METHODS

From January 2001 to December 2014, 5382 CABG patients were stratified into 2 groups according to β-blocker therapy at discharge (β-blocker group: 3677 [68.3%], no β-blocker group: 1705 [31.7%]).

RESULTS

The primary outcome was all-cause death during 48 months of follow-up. Using propensity score-matched analysis, β-blocker therapy was associated with all-cause death during the 48-month follow-up (hazard ratio [HR], 0.62; 95% confidence interval [CI], 0.41-0.95; P = .03). The landmark analysis demonstrated that the effect of β-blockers on all-cause death was particularly significant within the first 12 months of therapy (HR, 0.37; 95% CI, 0.19-0.80; P = .01) but not after 12 months (HR, 0.92; 95% CI, 0.56-1.53; P = .77).

CONCLUSIONS

The benefits of postdischarge β-blockers may be limited to 1 year after CABG, but further studies are required to confirm this finding.

Design and rationale of the Danish trial of beta-blocker treatment after myocardial infarction without reduced ejection fraction: study protocol for a randomized controlled trial

Background

Treatment with beta-blockers is currently recommended after myocardial infarction (MI). The evidence relies on trials conducted decades ago before implementation of revascularization and contemporary medical therapy or in trials enrolling patients with heart failure or reduced left ventricular ejection fraction (LVEF ≤ 40%). Accordingly, the impact of beta-blockers on mortality and morbidity following acute MI in patients without reduced LVEF or heart failure is unclear.

Methods/design

The Danish trial of beta-blocker treatment after myocardial infarction without reduced ejection fraction (DANBLOCK) is a prospective, randomized, controlled, open-label, non-blinded endpoint clinical trial designed to evaluate the efficacy of beta-blocker treatment in post-MI patients in the absence of reduced LVEF or heart failure. We will randomize 3570 patients will be randomized within 14 days of index MI to beta-blocker or control for a minimum of 2 years. The primary endpoint is a composite of all-cause mortality, recurrent MI, acute decompensated heart failure, unstable angina pectoris, or stroke. The primary composite endpoint will be assessed through locally reported and adjudicated endpoints supplemented by linkage to the Danish national registers. A number of secondary endpoints will be investigated including patient reported outcomes and cardiovascular mortality. Data from similar ongoing trials in Norway and Sweden will be pooled to perform an individual patient data meta-analysis.

Discussion

DANBLOCK is a randomized clinical trial investigating the effect of long-term beta-blocker therapy after myocardial infarction in patients without heart failure and reduced LVEF. Results from the trial will add important scientific evidence to inform future clinical guidelines.

Trial registration

Clinicaltrials.gov, NCT03778554. Registered on 19 December 2018.

European Clinical Trials Database, 2018-002699-42, registered on 28 September 2018.

Comparison of Preventive Cardiovascular Pharmacotherapy in Surgical vs Percutaneous Coronary Revascularization

Background

Data suggest that patients who undergo coronary artery bypass grafting (CABG) have a lower rate of secondary preventive cardiovascular pharmacotherapy use compared with patients who undergo percutaneous coronary intervention (PCI). This study sought to assess the rate of use of preventive pharmacotherapy at discharge in patients who underwent CABG vs PCI post–acute coronary syndrome (ACS).

Methods

A prospective cohort study was conducted at St Paul’s Hospital in Vancouver, Canada. Patients aged ≥ 18 years who presented with an ACS and underwent CABG or PCI between January and November 2018 were included. Data on preventive pharmacotherapy use and reasons for justified nonuse (eg, intolerance, contraindication) were collected.

Results

A total of 275 patients were included. Mean age was 65 years, and 83% were male. Overall, 141 patients (51%) underwent CABG and 134 patients (49%) underwent PCI. All patients received acetylsalicylic acid, but more patients who underwent CABG received 325 mg (vs 80-81 mg) compared to PCI (25% vs 1%, P < 0.01). Use of P2Y12 inhibitors was higher in patients who underwent PCI (primarily ticagrelor) compared with patients who underwent CABG (primarily clopidogrel) (99% vs 26%, P < 0.01). All patients who underwent CABG received a β-blocker vs 96% of patients who underwent PCI (P = 0.017). Use of angiotensin-modulating agents was higher in patients who underwent PCI (98% vs 65%, P < 0.01). Statin use was similar between groups (99% vs 99%, P = 0.96), but more patients who underwent PCI received maximum-dose therapy (89% vs 64%, P < 0.01).

Conclusions

Use of acetylsalicylic acid, β-blockers, and statins in patients post-ACS was high regardless of revascularization strategy, whereas P2Y12 inhibitors and angiotensin-modulating agents were underused in patients who underwent CABG even after adjusting for justified nonuse.

Sudden Cardiac Death (SCD) - risk stratification and prediction with molecular biomarkers

Sudden cardiac death (SCD) is a sudden, unexpected death that is caused by the loss of heart function. While SCD affects many patients suffering from coronary artery diseases (CAD) and heart failure (HF), a considerable number of SCD events occur in asymptomatic individuals. Certain risk factors for SCD have been identified and incorporated in different clinical scores, however, risk stratification using such algorithms is only useful for health management rather than for early detection and prediction of future SCD events in high-risk individuals. In this review, we discuss different molecular biomarkers that are used for early detection of SCD. This includes genetic biomarkers, where the majority of them are genomic variants for genes that encode for ion channels. Meanwhile, protein biomarkers often denote proteins that play roles in pathophysiological processes that lead to CAD and HF, notably (i) atherosclerosis that involves oxidative stress and inflammation, as well as (ii) cardiac tissue damage that involves neurohormonal and hemodynamic regulation and myocardial stress. Finally, we outline existing challenges and future directions including the use of OMICS strategy for biomarker discovery and the multimarker panels.

Synergism of myocardial β-adrenoceptor blockade and I1-imidazoline receptor-driven signaling: Kinase-phosphatase switching

Recently identified imidazoline receptors of the first type (I₁Rs) on the cardiomyocyte's sarcolemma open a new field in calcium signaling research. In particular, it is interesting to investigate their functional interaction with other well-known systems, such as β-adrenergic receptors. Here we investigated the effects of I₁Rs activation on L-type voltage-gated Ca²⁺-currents under catecholaminergic stress induced by the application of β-agonist, isoproterenol. Pharmacological agonist of I₁Rs (I₁-agonist), rilmenidine, and the putative endogenous I₁-ligand, agmatine, have been shown to effectively reduce Ca²⁺-currents potentiated by isoproterenol. Inhibitory analysis shows that the ability to suppress voltage-gated Ca²⁺-currents by rilmenidine and agmatine is fully preserved in the presence of the protein kinase A blocker (PKA), which indicates a PKA-independent mechanism of their action. The blockade of NO synthase isoforms with 7NI does not affect the intrinsic effects of agmatine and rilmenidine, which suggests NO-independent signaling pathways triggered by I₁Rs. A nonspecific serine/threonine protein phosphatase (STPP) inhibitor, calyculin A, abrogates effects of rilmenidine or agmatine on the isoproterenol-induced Ca²⁺-currents. Direct measurements of phosphatase activity in the myocardial tissues showed that activation of the I₁Rs leads to stimulation of STPP, which could be responsible for the I₁-agonist influences. Obtained data clarify peripheral effects that occur during activation of the I₁Rs under endogenous catecholaminergic stress, and can be used in clinical practice for more precise control of heart contractility in some cardiovascular pathologies.