Beta-Blockers after Myocardial Infarction and Preserved Ejection Fraction.

BACKGROUND: Most trials that have shown a benefit of beta-blocker treatment after myocardial infarction included patients with large myocardial infarctions and were conducted in an era before modern biomarker-based diagnosis of myocardial infarction and treatment with percutaneous coronary intervention, antithrombotic agents, high-intensity statins, and renin-angiotensin-aldosterone system antagonists. METHODS: In a parallel-group, open-label trial performed at 45 centers in Sweden, Estonia, and New Zealand, we randomly assigned patients with an acute myocardial infarction who had undergone coronary angiography and had a left ventricular ejection fraction of at least 50% to receive either long-term treatment with a beta-blocker (metoprolol or bisoprolol) or no beta-blocker treatment. The primary end point was a composite of death from any cause or new myocardial infarction. RESULTS: From September 2017 through May 2023, a total of 5020 patients were enrolled (95.4% of whom were from Sweden). The median follow-up was 3.5 years (interquartile range, 2.2 to 4.7). A primary end-point event occurred in 199 of 2508 patients (7.9%) in the beta-blocker group and in 208 of 2512 patients (8.3%) in the no-beta-blocker group (hazard ratio, 0.96; 95% confidence interval, 0.79 to 1.16; P = 0.64). Beta-blocker treatment did not appear to lead to a lower cumulative incidence of the secondary end points (death from any cause, 3.9% in the beta-blocker group and 4.1% in the no-beta-blocker group; death from cardiovascular causes, 1.5% and 1.3%, respectively; myocardial infarction, 4.5% and 4.7%; hospitalization for atrial fibrillation, 1.1% and 1.4%; and hospitalization for heart failure, 0.8% and 0.9%). With regard to safety end points, hospitalization for bradycardia, second- or third-degree atrioventricular block, hypotension, syncope, or implantation of a pacemaker occurred in 3.4% of the patients in the beta-blocker group and in 3.2% of those in the no-beta-blocker group; hospitalization for asthma or chronic obstructive pulmonary disease in 0.6% and 0.6%, respectively; and hospitalization for stroke in 1.4% and 1.8%. CONCLUSIONS: Among patients with acute myocardial infarction who underwent early coronary angiography and had a preserved left ventricular ejection fraction (≥50%), long-term beta-blocker treatment did not lead to a lower risk of the composite primary end point of death from any cause or new myocardial infarction than no beta-blocker use. (Funded by the Swedish Research Council and others; REDUCE-AMI ClinicalTrials.gov number, NCT03278509.).

Napex acupoint thread-embedding combined with metoprolol tartrate tablet for prophylactic treatment of migraine without aura: a randomized controlled trial. / æž•é¡¹éƒ¨åŸ‹çº¿æ³•è”åˆé ’çŸ³é ¸ç¾Žæ‰˜æ´›å°”ç‰‡é¢„é˜²æ€§æ²»ç–—æ— å ˆå †åå¤´ç—›ï¼šéšæœºå¯¹ç §è¯•éªŒ.

OBJECTIVES: To observe the efficacy of napex acupoint thread-embedding combined with metoprolol tartrate tablet for prophylactic treatment of migraine without aura, and to compare its efficacy with simple napex acupoint thread-embedding and simple metoprolol tartrate tablet. METHODS: A total of 105 patients with migraine without aura were randomized into a combination group (35 cases, 5 cases dropped out), a thread-embedding group (35 cases, 4 cases dropped out) and a western medication group (35 cases, 2 cases dropped out). In the thread-embedding group, napex acupoint thread-embedding was applied at bilateral Fengchi (GB 20) and points of 1.5 cun nearby to the lower edge of spinous process of cervical 2. In the western medication group, metoprolol tartrate tablet was given orally, 12.5 mg a time, twice a day. In the combination group, napex acupoint thread-embedding combined with oral metoprolol tartrate tablet was delivered. The treatment of 8 weeks was required in the 3 groups. The days of headache attacks, frequency of headache attacks, headache severity (visual analogue scale [VAS] score) and the migraine specific quality of life questionnaire version 2.1 (MSQ) score were observed during baseline period (4 weeks before treatment to before treatment), observation period (1-4 weeks and 5-8 weeks in treatment) and follow-up period (1-4 weeks after treatment completion) respectively, the proportions of the days of headache attacks/frequency of headache attacks relieved by 50% were calculated, and the safety was evaluated in the 3 groups. RESULTS: During the observation period and the follow-up period, the days of headache attacks, frequency of headache attacks and headache VAS scores in the 3 groups were reduced compared with those of the baseline period (P<0.05). During the observation period and the follow-up period, the days of headache attacks and the frequency of headache attacks in the combination group were lower than those in the thread-embedding group and the western medication group (P<0.05); during the observation period (1-4 weeks in treatment), the headache VAS scores in the combination group and the thread-embedding group were lower than that in the western medication group (P<0.05); during the observation period (5-8 weeks in treatment) and the follow-up period, the headache VAS scores in the combination group were lower than those in the thread-embedding group and the western medication group (P<0.05). During the observation period and the follow-up period, the scores of role restriction, role prevention and emotion function of MSQ in the combination group were increased compared with those of the baseline period (P<0.05); during the observation period (5-8 weeks in treatment) and the follow-up period, the role prevention scores of MSQ in the thread-embedding group and the western medication group were increased compared with those of the baseline period (P<0.05); during the follow-up period, the emotion function scores of MSQ in the thread-embedding group and the western medication group were increased compared with those of the baseline period (P<0.05). During the observation period and the follow-up period, the scores of role restriction, role prevention and emotion function of MSQ in the combination group were higher than those in the thread-embedding group and the western medication group (P<0.05). There was no statistical difference in the proportions of the days of headache attacks/frequency of headache attacks relieved by 50% among the 3 groups (P>0.05), and there were no serious adverse reactions in the 3 groups. CONCLUSIONS: Napex acupoint thread-embedding combined with metoprolol tartrate tablet, simple napex acupoint thread-embedding and simple metoprolol tartrate tablet all can reduce the days of headache attacks and the frequency of headache attacks, relieve headache severity and improve the quality of life in patients with migraine without aura. Napex acupoint thread-embedding combined with metoprolol tartrate tablet has a better effect.

Probable interacción farmacológica entre sulfonilurea y betabloqueante en paciente con DM-II. Un reporte de caso / Probable pharmacological interaction between sulfonylurea and beta blocker in patients with DM-II. A case report

El estudio presenta el caso de una mujer de 47 años con diabetes tipo 2 (DM-II), hipertensión y anemia, tratada con metformina, glibenclamida, metoprolol y hierro/ácido fólico. Se identificó una interacción farmacológica entre glibenclamida y metoprolol, causando síntomas de hipoglucemia por la tarde. La evaluación mediante la Escala de Probabilidad de Interacciones Farmacológicas (EPIF) de Horn sugirió una interacción probable. El análisis farmacocinético reveló que el tiempo en el cual se alcanzan las concentraciones máximas de ambos fármacos coincidía con el inicio de los síntomas. Se implementó un nuevo horario de medicación que resolvió los síntomas. La interacción farmacológica se atribuyó al bloqueo de los efectos adrenérgicos por el metoprolol, comprometiendo la capacidad de contrarrestar la acción de la insulina liberada por la glibenclamida. Se resalta la importancia de la vigilancia, la toma de decisiones informadas y la implementación de estrategias preventivas para garantizar la seguridad y eficacia del tratamiento farmacológico en pacientes con condiciones clínicas específicas, como la DM-II y enfermedades cardiovasculares concomitantes.(AU)

Mechanism-Based Inactivation of CYP2D6 by Phellopterin and Related Drug-Drug Interaction with Metoprolol.

Phellopterin (PLP) is a linear furanocoumarin widely found in citrus fruits and herbal medicines. The study aims to comprehensively investigate the mechanism of inhibition of CYP2D6 enzyme activity by PLP and its alteration of metoprolol pharmacokinetics. PLP was found to irreversibly inhibit CYP2D6 in time-, concentration-, and nicotinamide adenine dinucleotide phosphate-dependent manners. Coincubation with quinidine, which is a competitive inhibitor of CYP2D6, attenuated this time-dependent inhibition. Glutathione (GSH) and catalase/superoxide dismutase failed to reverse the PLP-induced CYP2D6 inactivation. GSH trapping experiments provided strong evidence that PLP metabolic activation produces epoxide or γ-ketoaldehyde intermediates. In addition, pretreatment with PLP resulted in significant increases in Cmax and area under curve of plasma metoprolol in rats.

Which should you choose for post operative atrial fibrillation, carvedilol or metoprolol? A systemic review and meta-analysis.

BACKGROUND: Postoperative atrial fibrillation (POAF) is the most common arrhythmic complication following cardiac surgery. Current guidelines suggest beta-blockers for the prevention of POAF. In comparing metoprolol succinate with carvedilol, the later has sparked interest in its usage as an important medication for POAF prevention. METHODS: We considered randomized controlled studies (RCTs) and retrospective studies that evaluated the efficacy of carvedilol versus metoprolol for the prevention of POAF. After literature search, data extraction, and quality evaluation, pooled data were analyzed using either the fixed-effect or random-effect model using Review Manager 5.3. The Cochrane risk of bias tool was used to assess the bias of included studies. The incidence of POAF was the primary endpoint, while mortality rate and bradycardia were secondary outcomes. RESULTS: In meta-analysis 5 RCTs and 2 retrospective studies with a total of 1000 patients were included. The overall effect did not favor the carvedilol over metoprolol groups in terms of mortality rate [risk ratio 0.45, 95 % CI (0.1-1.97), P=0.29] or incidence of bradycardia [risk ratio 0.63, 95 % CI (0.32-1.23), P=0.17]. However, the incidence of POAF was lower in patients who received carvedilol compared to metoprolol [risk ratio 0.54, 95 % CI (0.42-0.71), P < 0.00001]. CONCLUSION: In patients undergoing cardiac surgery, carvedilol may minimize the occurrence of POAF more effectively than metoprolol. To definitively establish the efficacy of carvedilol compared to metoprolol and other beta-blockers in the prevention of POAF, a large-scale, well-designed randomized controlled trials are required.

Intravenous Diltiazem Versus Metoprolol in Acute Rate Control of Atrial Fibrillation/Flutter and Rapid Ventricular Response: A Meta-Analysis of Randomized and Observational Studies.

BACKGROUND: Atrial fibrillation (AF) and/or atrial flutter (AFL) with rapid ventricular response (RVR) is a condition that often requires urgent treatment. Although guidelines have recommendations regarding chronic rate control therapy, recommendations on the best choice for acute heart rate (HR) control in RVR are unclear. METHODS: A systematic search across multiple databases was performed for studies evaluating the outcome of HR control (defined as HR less than 110 bpm and/or 20% decrease from baseline HR). Included studies evaluated AF and/or AFL with RVR in a hospital setting, with direct comparison between intravenous (IV) diltiazem and metoprolol and excluded cardiac surgery and catheter ablation patients. Hypotension (defined as systolic blood pressure less than 90 mmHg) was measured as a secondary outcome. Two authors performed full-text article review and extracted data, with a third author mediating disagreements. Random effects models utilizing inverse variance weighting were used to calculate odds ratios (OR) and 95% confidence intervals (CI). Heterogeneity was assessed using the I2 test. RESULTS: A total of 563 unique titles were identified through the systematic search, of which 16 studies (7 randomized and 9 observational) were included. In our primary analysis of HR control by study type, IV diltiazem was found to be more effective than IV metoprolol for HR control in randomized trials (OR 4.75, 95% CI 2.50-9.04 with I2 = 14%); however, this was not found for observational studies (OR 1.26, 95% CI 0.89-1.80 with I2 = 55%). In an analysis of observational studies, there were no significant differences between the two drugs in odds of hypotension (OR 1.12, 95% CI 0.51-2.45 with I2 = 18%). CONCLUSION: While there was a trend toward improved HR control with IV diltiazem compared with IV metoprolol in randomized trials, this was not seen in observational studies, and there was no observed difference in hypotension between the two drugs.

Effect of Carvedilol Versus Metoprolol on Contrast-Induced Nephropathy in Patients with Acute Coronary Syndrome Undergoing Percutaneous Intervention Therapy.

Carvedilol can inhibit inflammation, vasoconstriction, and oxidative stress, which play important roles in the development and progression of contrast-induced nephropathy (CIN). To the best of our knowledge, no studies have investigated the potential effect of carvedilol on the prevalence of CIN after percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). The present study aimed to determine whether carvedilol use is associated with the development of CIN. A total of 319 patients (mean age, 59.2 ± 12.4 years; 77.7% male) with ACS who underwent urgent PCI at our institution between May 2019 and May 2022 were included prospectively. Overall, 100 and 219 patients were assigned to the carvedilol and metoprolol groups, respectively. The prevalence of CIN was significantly lower in the carvedilol group (6.0%) than in the metoprolol group (18.3%; P = .003). Multivariate analysis revealed that carvedilol use (odds ratio [OR] .250, 95% confidence interval [CI] .092-.677, P = .006), amount of contrast agent (OR 1.004, 95% CI 1.000-1.008, P = .031), and admission estimated glomerular filtration rate (OR .978, 95% CI 0.960-.995, P = .014) were independently associated with the development of CIN. The use of carvedilol may be a promising option for the prevention of CIN in patients with ACS undergoing urgent PCI.

Influence of Weight and Body Size on the Pharmacokinetics of Heart Failure Pharmacotherapy: A Systematic Review.

OBJECTIVE: To conduct a review of studies evaluating the influence of body size and weight (WT) on the pharmacokinetics (PK) of drugs recommended for heart failure (HF) treatment. DATA SOURCES: A systematic search of the MEDLINE (1946 to April 2023) and EMBASE (1974 to April 2023) databases was conducted for articles that focused on the impact of WT or body size on the PK of drugs of interest used in HF patients. STUDY SELECTION AND DATA EXTRACTION: Articles written in English or French related to the aim of our study were retained for analysis. DATA SYNTHESIS: Of 6493 articles, 20 were retained for analysis. Weight was associated with the clearance of digoxin, carvedilol, enalapril, and candesartan as well as the volume of distribution of eplerenone and bisoprolol. There was no documented direct impact of WT on the PK of furosemide, valsartan, and metoprolol, although these studies were limited or confounded by the small sample size, adjustment of PK factors by WT, or the use of the Cockroff-Gault equation for the evaluation of creatinine clearance, which includes WT. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: This review highlights and summarizes the available data on the importance of WT on the PK of HF treatment. CONCLUSION: Considering the significant impact of WT on most HF drugs in this review, it may be important to further investigate it in the context of personalized therapy, particularly in patients presenting extreme WTs.

Effects of Moracizine Combined with Metoprolol on Hemodynamic Indices of the Left Atrium and Quality of Life in Patients with Atrial Fibrillation.

BACKGROUND: Drugs are the first choice of treatment for atrial fibrillation (AF), but there is currently a lack of efficient drug treatment options. The aim of this study was to investigate a combination drug treatment plan which may serve as a reference for the treatment of AF. METHODS: A total of 316 AF patients admitted to Jiaozhou Central Hospital in Qingdao from October 2020 to October 2022 were selected for this retrospective study. They were divided into a control group (CG, metoprolol, n = 156) and an observation group (OG, moracizine combined with metoprolol, n = 160) based on the treatment they received. The CG and OG groups were compared for clinical efficacy, occurrence of AF, cardiac output (CO), cardiac indexes (CI), stroke volume (SV), stroke indexes (SI) and improvement in QOL. RESULTS: The OG had a better effective rate of treatment, higher levels of CO, CI, SV and SI, and higher QOL scores compared to the CG, as well as a lower AF recurrence rate and AF burden (all p < 0.05). CONCLUSION: Moracizine combined with metoprolol is an effective treatment for AF patients. This drug combination was found to reduce the AF recurrence rate and burden in AF patients, and to improve their hemodynamic indices and QOL.

Improved Cardiac Performance and Decreased Arrhythmia in Hypertrophic Cardiomyopathy With Non-ß-Blocking R-Enantiomer Carvedilol.

BACKGROUND: Hypercontractility and arrhythmia are key pathophysiologic features of hypertrophic cardiomyopathy (HCM), the most common inherited heart disease. ß-Adrenergic receptor antagonists (ß-blockers) are the first-line therapy for HCM. However, ß-blockers commonly selected for this disease are often poorly tolerated in patients, where heart-rate reduction and noncardiac effects can lead to reduced cardiac output and fatigue. Mavacamten, myosin ATPase inhibitor recently approved by the US Food and Drug Administration, has demonstrated the ability to ameliorate hypercontractility without lowering heart rate, but its benefits are so far limited to patients with left ventricular (LV) outflow tract obstruction, and its effect on arrhythmia is unknown. METHODS: We screened 21 ß-blockers for their impact on myocyte contractility and evaluated the antiarrhythmic properties of the most promising drug in a ventricular myocyte arrhythmia model. We then examined its in vivo effect on LV function by hemodynamic pressure-volume loop analysis. The efficacy of the drug was tested in vitro and in vivo compared with current therapeutic options (metoprolol, verapamil, and mavacamten) for HCM in an established mouse model of HCM (Myh6R403Q/+ and induced pluripotent stem cell (iPSC)-derived cardiomyocytes from patients with HCM (MYH7R403Q/+). RESULTS: We identified that carvedilol, a ß-blocker not commonly used in HCM, suppresses contractile function and arrhythmia by inhibiting RyR2 (ryanodine receptor type 2). Unlike metoprolol (a ß1-blocker), carvedilol markedly reduced LV contractility through RyR2 inhibition, while maintaining stroke volume through α1-adrenergic receptor inhibition in vivo. Clinically available carvedilol is a racemic mixture, and the R-enantiomer, devoid of ß-blocking effect, retains the ability to inhibit both α1-receptor and RyR2, thereby suppressing contractile function and arrhythmias without lowering heart rate and cardiac output. In Myh6R403Q/+ mice, R-carvedilol normalized hyperdynamic contraction, suppressed arrhythmia, and increased cardiac output better than metoprolol, verapamil, and mavacamten. The ability of R-carvedilol to suppress contractile function was well retained in MYH7R403Q/+ iPSC-derived cardiomyocytes. CONCLUSIONS: R-enantiomer carvedilol attenuates hyperdynamic contraction, suppresses arrhythmia, and at the same time, improves cardiac output without lowering heart rate by dual blockade of α1-adrenergic receptor and RyR2 in mouse and human models of HCM. This combination of therapeutic effects is unique among current therapeutic options for HCM and may particularly benefit patients without LV outflow tract obstruction.

Effect of Carvedilol vs Metoprolol on Atrial and Ventricular Arrhythmias Among Implantable Cardioverter-Defibrillator Recipients.

BACKGROUND: Both selective and nonselective beta-blockers are used to treat patients with heart failure (HF). However, the data on the association of beta-blocker type with risk of atrial arrhythmia and ventricular arrhythmia (VA) in HF patients with a primary prevention implantable cardioverter-defibrillator (ICD) are limited. OBJECTIVES: This study sought to evaluate the effect of metoprolol vs carvedilol on the risk of atrial tachyarrhythmia (ATA) and VA in HF patients with an ICD. METHODS: This study pooled primary prevention ICD recipients from 5 landmark ICD trials (MADIT-II, MADIT-CRT, MADIT-RIT, MADIT-RISK, and RAID). Fine and Gray multivariate regression models, stratified by study, were used to evaluate the risk of ATA, inappropriate ICD shocks, and fast VA (defined as ventricular tachycardia ≥200 beats/min or ventricular fibrillation) by beta-blocker type. RESULTS: Among 4,194 patients, 2,920 (70%) were prescribed carvedilol and 1,274 (30%) metoprolol. The cumulative incidence of ATA at 3.5 years was 11% in patients treated with carvedilol vs 15% in patients taking metoprolol (P = 0.003). Multivariate analysis showed that carvedilol treatment was associated with a 35% reduction in the risk of ATA (HR: 0.65; 95% CI: 0.53-0.81; P < 0.001) when compared to metoprolol, and with a corresponding 35% reduction in the risk of inappropriate ICD shocks (HR: 0.65; 95% CI: 0.47-0.89; P = 0.008). Carvedilol vs metoprolol was also associated with a 16% reduction in the risk of fast VA. However, these findings did not reach statistical significance (HR: 0.84; 95% CI: 0.70-1.02; P = 0.085). CONCLUSIONS: These findings suggests that HF patients with ICDs on carvedilol treatment experience a significantly lower risk of ATA and inappropriate ICD shocks when compared to treatment with metoprolol.

Transportability of two heart failure trials to a disease registry using individual patient data.

OBJECTIVES: Randomized controlled trials are the gold-standard for determining therapeutic efficacy, but are often unrepresentative of real-world settings. Statistical transportation methods (hereafter transportation) can partially account for these differences, improving trial applicability without breaking randomization. We transported treatment effects from two heart failure (HF) trials to a HF registry. STUDY DESIGN AND SETTING: Individual-patient-level data from two trials (Carvedilol or Metoprolol European Trial (COMET), comparing carvedilol and metoprolol, and digitalis investigation group trial (DIG), comparing digoxin and placebo) and a Scottish HF registry were obtained. The primary end point for both trials was all-cause mortality; composite outcomes were all-cause mortality or hospitalization for COMET and HF-related death or hospitalization for DIG. We performed transportation using regression-based and inverse odds of sampling weights (IOSW) approaches. RESULTS: Registry patients were older, had poorer renal function and received higher-doses of loop-diuretics than trial participants. For each trial, point estimates were similar for the original and IOSW (e.g., DIG composite outcome: OR 0.75 (0.69, 0.82) vs. 0.73 (0.64, 0.83)). Treatment effect estimates were also similar when examining high-risk (0.64 (0.46, 0.89)) and low-risk registry patients (0.73 (0.61, 0.86)). Similar results were obtained using regression-based transportation. CONCLUSION: Regression-based or IOSW approaches can be used to transport trial effect estimates to patients administrative/registry data, with only moderate reductions in precision.

The influence of metoprolol in patients with sepsis-induced cardiomyopathy: A retrospective study.

OBJECTIVES: To focus on evaluating the clinical influence of metoprolol on sepsis-induced cardiomyopathy (SICM). METHODS: A total of 90 patients with SICM was enrolled from December 2018 to February 2021 and divided into 2 groups according to the use of metoprolol during hospitalization in Suzhou Municipal Hospital in Suzhou, China. We compared them with the cardiac function, sequential organ failure assessment score, and clinical outcomes. RESULTS: Between the 2 groups, the oxygenation indices and Glasgow coma scale in the metoprolol group were higher on the first day of treatment, with Glasgow coma scale higher on the third day of treatment. However, the doses of norepinephrine in patients with metoprolol showed no significant differences with the control group. The all-causemortality at 28 days in the metoprolol group was lower, and the time of removing from ventilator support as well as the number of failured organs also significantly differed between the 2 groups. CONCLUSION: Metoprolol can reduce the 28-day mortality and shorten the duration of mechanical ventilation in SICM. It can also reduce the number of organ failures and improve the oxygenation index and Glasgow coma scale of these patients. Meanwhile, metoprolol did not affect the norepinephrine dose in patients with SICM.

IL-6 translation is a therapeutic target of human cytokine release syndrome.

Chimeric antigen receptor (CAR) T therapies have achieved remarkable success for treating hematologic malignancies, yet are often accompanied by severe cytokine release syndrome (CRS). Here, an accidental clinical observation raised the possibility that metoprolol, an FDA-approved ß1 adrenergic receptor blocker widely used for cardiovascular conditions, may alleviate CAR T-induced CRS. Metoprolol effectively blocked IL-6 production in human monocytes through unexpected mechanisms of action of targeting IL-6 protein translation but not IL6 mRNA expression. Mechanistically, metoprolol diminished IL-6 protein synthesis via attenuating eEF2K-eEF2 axis-regulated translation elongation. Furthermore, an investigator-initiated phase I/II clinical trial demonstrated a favorable safety profile of metoprolol in CRS management and showed that metoprolol significantly alleviated CAR T-induced CRS without compromising CAR T efficacy. These results repurposed metoprolol, a WHO essential drug, as a potential therapeutic for CRS and implicated IL-6 translation as a mechanistic target of metoprolol, opening venues for protein translation-oriented drug developments for human inflammatory diseases.

Preemptive Pharmacogenetic-Guided Metoprolol Management for Postoperative Atrial Fibrillation in Cardiac Surgery: The Preemptive Pharmacogenetic-Guided Metoprolol Management for Atrial Fibrillation in Cardiac Surgery Pilot Trial.

OBJECTIVES: To test the hypothesis that implementation of a cytochrome P-450 2D6 (CYP2D6) genotype-guided perioperative metoprolol administration will reduce the risk of postoperative atrial fibrillation (AF), the authors conducted the Preemptive Pharmacogenetic-Guided Metoprolol Management for Atrial Fibrillation in Cardiac Surgery pilot study. DESIGN: Clinical pilot trial. SETTING: Single academic center. PARTICIPANTS: Seventy-three cardiac surgery patients. MEASUREMENTS AND MAIN RESULTS: Patients were classified as normal, intermediate, poor, or ultrarapid metabolizers after testing for their CYP2D6 genotype. A clinical decision support tool in the electronic health record advised providers on CYP2D6 genotype-guided metoprolol dosing. Using historical data, the Bayesian method was used to compare the incidence of postoperative AF in patients with altered metabolizer status to the reference incidence. A logistic regression analysis was performed to study the association between the metabolizer status and postoperative AF while controlling for the Multicenter Study of Perioperative Ischemia AF Risk Index. Of the 73 patients, 30% (n = 22) developed postoperative AF; 89% (n = 65) were normal metabolizers; 11% (n = 8) were poor/intermediate metabolizers; and there were no ultrarapid metabolizer patients identified. The estimated rate of postoperative AF in patients with altered metabolizer status was 30% (95% CI 8%-60%), compared with the historical reference incidence (27%). In the risk-adjusted analysis, there was insufficient evidence to conclude that modifying metoprolol dosing based on poor/intermediate metabolizer status was associated significantly with the odds of postoperative AF (odds ratio 0.82, 95% CI 0.15-4.55, p = 0.82). CONCLUSIONS: A CYP2D6 genotype-guided metoprolol management was not associated with a reduction of postoperative AF after cardiac surgery.

The influence of sex on the treatment of postural tachycardia syndrome in children.

There are differences in postural tachycardia syndrome (POTS) incidence and manifestations in children between the sexes. However, there is limited evidence on how the gender affects the prognosis of POTS in children. This study is aimed at exploring the differences between the sexes regarding the prognosis of children with POTS. A retrospective study was conducted on children (n = 53; aged 6-14 years) who were diagnosed with POTS. All the POTS patients were given health education and autonomic function training, their water and salt intake was increased (oral rehydration salt III, 250 mL, Bid), and they were administered oral metoprolol (1 mg/kg per day) for 3 months. The prognosis was defined by the head-up tilt test results after treatment. It was observed that male and female children exhibited different trends in POTS prognosis. Further, the sex showed a stable independent effect on prognostic in children with POTS. To elaborate, females had a 503% increased risk of poor prognosis compared to males. We hence hypothesize that there is an association between the sex and the POTS prognosis in children. Female patients have a significantly higher risk of poor prognosis compared to males. A slight increase in the dose of oral rehydration salt could help lower the risk of poor prognosis in children with POTS. A higher absorption of total metoprolol, lower local concentrations, and slower metabolic excretion are documented in research in female POTS patients during treatment. It is recommended that the optimal dose of metoprolol should be lowered in female children undergoing treatment, to limit the risk of poor prognosis.

[A pregnant woman with de novo atrial fibrillation]. / Atriumfibrilleren bij een zwangere vrouw.

BACKGROUND: De novo atrial fibrillation (AF) is rare in pregnancy. The exact pathophysiology of AF is unclear; it might be caused by several cardiovascular and hemodynamic changes that occur in pregnancy, leading to an increased stretch in myocardial cells of the atrial wall. CASE DESCRIPTION: A 26-year-old primigravida with a thus far uncomplicated pregnancy presents with symptoms of heart palpitations, shortness of breath and chest pain. The CTG was normal but an ECG showed de novo atrial fibrillation. The patient was given two doses of digoxin 0.25mg after which sinus rhythm was achieved. No anatomical substrate was found; hence it was seen as most likely caused by increased hemodynamic demands in pregnancy. The delivery and postpartum period were uncomplicated. CONCLUSION: AF is rarely seen in pregnancy. Treatment favours rate and/or rhythm control with metoprolol and digoxin, respectively. Anticoagulation is not indicated in lone AF during pregnancy. Vaginal birth is preferred.

Pharmacogenomic markers of metoprolol and α-OH-metoprolol concentrations: a genome-wide association study.

Aim: Few genome-wide association studies (GWASs) have been conducted to identify predictors of drug concentrations. The authors therefore sought to discover the pharmacogenomic markers involved in metoprolol pharmacokinetics. Patients & methods: The authors performed a GWAS of a cross-sectional study of 993 patients from the Montreal Heart Institute Biobank taking metoprolol. Results: A total of 391 and 444 SNPs reached the significance threshold of 5 × 10-8 for metoprolol and α-OH-metoprolol concentrations, respectively. All were located on chromosome 22 at or near the CYP2D6 gene, encoding CYP450 2D6, metoprolol's main metabolizing enzyme. Conclusion: The results reinforce previous findings of the importance of the CYP2D6 locus for metoprolol concentrations and confirm that large biobanks can be used to identify genetic determinants of drug pharmacokinetics at a GWAS significance level.

Beta1-receptor blockade attenuates atherosclerosis progression following traumatic brain injury in apolipoprotein E deficient mice.

Traumatic brain injury (TBI) is associated with cardiovascular mortality in humans. Enhanced sympathetic activity following TBI may contribute to accelerated atherosclerosis. The effect of beta1-adrenergic receptor blockade on atherosclerosis progression induced by TBI was studied in apolipoprotein E deficient mice. Mice were treated with metoprolol or vehicle following TBI or sham operation. Mice treated with metoprolol experienced a reduced heart rate with no difference in blood pressure. Six weeks following TBI, mice were sacrificed for analysis of atherosclerosis. Total surface area and lesion thickness, analyzed at the level of the aortic valve, was found to be increased in mice receiving TBI with vehicle treatment but this effect was ameliorated in TBI mice receiving metoprolol. No effect of metoprolol on atherosclerosis was observed in mice receiving only sham operation. In conclusion, accelerated atherosclerosis following TBI is reduced with beta-adrenergic receptor antagonism. Beta blockers may be useful to reduce vascular risk associated with TBI.

Impact of Diabetes Mellitus on Benefit of ß-Blocker Therapy After Myocardial Infarction.

Beta blockers are uniformly recommended for all patients after myocardial infarction (MI), including those with diabetes mellitus (DM). This study assesses the impact of ß-blocker type and dosing on survival in patients with DM after MI. A cohort of 6,682 patients in the Outcomes of Beta-blocker Therapy After Myocardial INfarction registry were discharged after MI. In this cohort, 2,137 patients had DM (32%). Beta-blocker dose was indexed to the target daily dose used in randomized clinical trials and reported as percentage. Dosage groups were: no ß blocker, >0% to 12.5%, >12.5% to 25%, >25% to 50%, and >50% of the target dose. The overall mean discharge ß-blocker dose in patients with DM was 42.7 ± 34.1% versus 35.9 ± 27.4% in patients without DM (p <0.0001). Patients with DM were prescribed carvedilol at a higher rate than those without DM (27.8% vs 19.6%). The 3-year mortality estimates were 24.4% and 12.8% for patients with DM versus without DM (p <0.0001), respectively, with an unadjusted hazard ratio = 1.820 (confidence interval 1.587 to 2.086, p <0.0001). Patients with DM in the >12.5% to 25% dose category had the highest survival rates, whereas patients in the >50% dose had the lowest survival rate among patients discharged on ß blockers (p <0.0001). In the multivariable analysis among patients with DM after MI, all ß-blocker dose categories demonstrated lower mortality than no therapy; however, only the >12.5% to 25% dose had a statistically significant hazard ratio 0.450 (95% confidence interval 0.224 to 0.907, p = 0.025). In patients with DM, there was no statistically significant difference in 3-year mortality among those treated with metoprolol versus carvedilol. In conclusion, our analysis in patients with DM after MI suggested a survival benefit from ß-blocker therapy, with no apparent advantage to high- versus low-dose ß-blocker therapy; although, physicians tended to prescribe higher doses in patients with DM. There was no survival benefit for carvedilol over metoprolol in patients with DM.