Effects of propranolol, atenolol, and chlordesmethyldiazepam on response to mental stress in patients with recent myocardial infarction

Beta-blockers in patients without heart failure after myocardial infarction

BACKGROUND

Cardiovascular disease is the number one cause of death globally. According to the World Health Organization (WHO), 7.4 million people died from ischaemic heart disease in 2012, constituting 15% of all deaths. Beta-blockers are recommended and are often used in patients with heart failure after acute myocardial infarction. However, it is currently unclear whether beta-blockers should be used in patients without heart failure after acute myocardial infarction. Previous meta-analyses on the topic have shown conflicting results. No previous systematic review using Cochrane methods has assessed the effects of beta-blockers in patients without heart failure after acute myocardial infarction.

OBJECTIVES

To assess the benefits and harms of beta-blockers compared with placebo or no treatment in patients without heart failure and with left ventricular ejection fraction (LVEF) greater than 40% in the non-acute phase after myocardial infarction.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS, Science Citation Index - Expanded, BIOSIS Citation Index, the WHO International Clinical Trials Registry Platform, ClinicalTrials.gov, European Medicines Agency, Food and Drug Administration, Turning Research Into Practice, Google Scholar, and SciSearch from their inception to February 2021.

SELECTION CRITERIA

We included all randomised clinical trials assessing effects of beta-blockers versus control (placebo or no treatment) in patients without heart failure after myocardial infarction, irrespective of publication type and status, date, and language. We excluded trials randomising participants with diagnosed heart failure at the time of randomisation.

DATA COLLECTION AND ANALYSIS

We followed our published protocol, with a few changes made, and methodological recommendations provided by Cochrane and Jakobsen and colleagues. Two review authors independently extracted data. Our primary outcomes were all-cause mortality, serious adverse events, and major cardiovascular events (composite of cardiovascular mortality and non-fatal myocardial reinfarction). Our secondary outcomes were quality of life, angina, cardiovascular mortality, and myocardial infarction during follow-up. We assessed all outcomes at maximum follow-up. We systematically assessed risks of bias using seven bias domains and we assessed the certainty of evidence using the GRADE approach.

MAIN RESULTS

We included 25 trials randomising a total of 22,423 participants (mean age 56.9 years). All trials and outcomes were at high risk of bias. In all, 24 of 25 trials included a mixed group of participants with ST-elevation myocardial infarction and non-ST myocardial infarction, and no trials provided separate results for each type of infarction. One trial included participants with only ST-elevation myocardial infarction. All trials except one included participants younger than 75 years of age. Methods used to exclude heart failure were various and were likely insufficient. A total of 21 trials used placebo, and four trials used no intervention, as the comparator. All patients received usual care; 24 of 25 trials were from the pre-reperfusion era (published from 1974 to 1999), and only one trial was from the reperfusion era (published in 2018). The certainty of evidence was moderate to low for all outcomes. Our meta-analyses show that beta-blockers compared with placebo or no intervention probably reduce the risks of all-cause mortality (risk ratio (RR) 0.81, 97.5% confidence interval (CI) 0.73 to 0.90; I² = 15%; 22,085 participants, 21 trials; moderate-certainty evidence) and myocardial reinfarction (RR 0.76, 98% CI 0.69 to 0.88; I² = 0%; 19,606 participants, 19 trials; moderate-certainty evidence). Our meta-analyses show that beta-blockers compared with placebo or no intervention may reduce the risks of major cardiovascular events (RR 0.72, 97.5% CI 0.69 to 0.84; 14,994 participants, 15 trials; low-certainty evidence) and cardiovascular mortality (RR 0.73, 98% CI 0.68 to 0.85; I² = 47%; 21,763 participants, 19 trials; low-certainty evidence). Hence, evidence seems to suggest that beta-blockers versus placebo or no treatment may result in a minimum reduction of 10% in RR for risks of all-cause mortality, major cardiovascular events, cardiovascular mortality, and myocardial infarction. However, beta-blockers compared with placebo or no intervention may not affect the risk of angina (RR 1.04, 98% CI 0.93 to 1.13; I² = 0%; 7115 participants, 5 trials; low-certainty evidence). No trials provided data on serious adverse events according to good clinical practice from the International Committee for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH-GCP), nor on quality of life.

AUTHORS' CONCLUSIONS

Beta-blockers probably reduce the risks of all-cause mortality and myocardial reinfarction in patients younger than 75 years of age without heart failure following acute myocardial infarction. Beta-blockers may further reduce the risks of major cardiovascular events and cardiovascular mortality compared with placebo or no intervention in patients younger than 75 years of age without heart failure following acute myocardial infarction. These effects could, however, be driven by patients with unrecognised heart failure. The effects of beta-blockers on serious adverse events, angina, and quality of life are unclear due to sparse data or no data at all. All trials and outcomes were at high risk of bias, and incomplete outcome data bias alone could account for the effect seen when major cardiovascular events, angina, and myocardial infarction are assessed. The evidence in this review is of moderate to low certainty, and the true result may depart substantially from the results presented here. Future trials should particularly focus on patients 75 years of age and older, and on assessment of serious adverse events according to ICH-GCP and quality of life. Newer randomised clinical trials at low risk of bias and at low risk of random errors are needed if the benefits and harms of beta-blockers in contemporary patients without heart failure following acute myocardial infarction are to be assessed properly. Such trials ought to be designed according to the SPIRIT statement and reported according to the CONSORT statement.

β-Adrenergic Contributions to Emotion and Physiology During an Acute Psychosocial Stressor

OBJECTIVE

β-Adrenergic receptor signaling, a critical mediator of sympathetic nervous system influences on physiology and behavior, has long been proposed as one contributor to subjective stress. However, prior findings are surprisingly mixed about whether β-blockade (e.g., propranolol) blunts subjective stress, with many studies reporting no effects. We reevaluated this question in the context of an acute psychosocial stressor with more comprehensive measures and a larger-than-typical sample. We also examined the effects of β-blockade on psychophysiological indicators of sympathetic and parasympathetic nervous system reactivity, given that β-blockade effects for these measures specifically under acute psychosocial stress are not yet well established.

METHODS

In a double-blind, randomized, placebo-controlled study, 90 healthy young adults received 40 mg of the β-blocker propranolol or placebo. Participants then completed the Trier Social Stress Test, which involved completing an impromptu speech and difficult arithmetic in front of evaluative judges. Self-reported emotions and appraisals as well as psychophysiology were assessed throughout.

RESULTS

Propranolol blunted Trier Social Stress Test preejection period reactivity (b = 9.68, p = .003), a marker of sympathetic nervous system activity, as well as salivary α-amylase reactivity (b = -0.50, p = .006). Critically, propranolol also blunted negative, high arousal emotions in response to the stressor (b = -0.22, p = .026), but cognitive appraisals remained intact (b values < -0.17, p values > .10).

CONCLUSIONS

These results provide updated experimental evidence that β-adrenergic blockade attenuates negative, high arousal emotions in response to a psychosocial stressor while also blunting sympathetic nervous system reactivity. Together, these findings shed light on the neurophysiological mechanisms by which stressors transform into the subjective experience we call "stress."Trial Registration: ClinicalTrials.gov Identifier: NCT02972554.

Treatment of Anxiety in Patients With Coronary Heart Disease: A Systematic Review

BACKGROUND

Anxiety is common in patients with coronary heart disease (CHD) and is associated with an increased risk for adverse outcomes. There has been a relative paucity of studies concerning treatment of anxiety in patients with CHD.

OBJECTIVE

We conducted a systematic review to organize and assess research into the treatment of anxiety in patients with CHD.

METHODS

We searched CCTR/CENTRAL, MEDLINE, EMBASE, PsycINFO, and CINAHL for randomized clinical trials conducted before October 2016 that measured anxiety before and after an intervention for patients with CHD.

RESULTS

A total of 475 articles were subjected to full text review, yielding 112 publications that met inclusion criteria plus an additional 7 studies from reference lists and published reviews, yielding 119 studies. Sample size, country of origin, study quality, and demographics varied widely among studies. Most studies were conducted with nonanxious patients. The Hospital Anxiety and Depression Scale and State-Trait Anxiety Inventory were the most frequently used instruments to assess anxiety. Interventions included pharmacological, counseling, relaxation-based, educational, or "alternative" therapies. Forty (33% of total) studies reported that the interventions reduced anxiety; treatment efficacy varied by study and type of intervention. Elevated anxiety was an inclusion criterion in only 4 studies, with inconsistent results.

CONCLUSION

Although there have been a number of randomized clinical trials of patients with CHD that assessed anxiety, in most cases anxiety was a secondary outcome, and only one-third found that symptoms of anxiety were reduced with treatment. Future studies need to target anxious patients and evaluate the effects of treatment on anxiety and relevant clinical endpoints.

Clinical pharmacokinetics of buffered propranolol sublingual tablet (Promptol™)-application of a new "physiologically based" model to assess absorption and disposition

Sublingual administration of certain buffered propranolol may improve the rate and extent of absorption compared to oral administration. The main objectives of this study were to (1) compare the plasma propranolol concentrations (Cp-prop) following sublingual administration of a specially buffered formulation (Promptol™) to that following oral administration of Inderal(®) and (2) evaluate the utility of a special pharmacokinetic model in describing the Cp-prop following sublingual administration. Eighteen healthy volunteers received 10 mg sublingual Promptol™ or oral Inderal(®). Multiple Cp-prop were determined and their pharmacokinetics compared. Additional data following sublingual 40 mg Promptol™ or Inderal(®) were utilized for evaluation of a special advanced compartmental absorption and transit (ACAT) model. For model simulation, the physicochemical parameters were imported from AMET predictor, whereas the pharmacokinetic parameters were calculated and optimized by Gastroplus(®). Based on this model, the quantity of drug absorbed via buccal/sublingual mucosa was estimated. Cp-prop was higher at earlier times with 3-fold greater relative bioavailability following sublingual Promptol™ compared to that from oral Inderal(®). The special ACAT model provided excellent goodness of fit of Cp-prop-time curve and estimated a 56.6% increase in absorption rate from Promptol™ and higher initial Cp-prop compared to the regular formulation. The modified ACAT model provided a useful approach to describe sublingual absorption of propranolol and clearly demonstrated an improvement of absorption of Promptol™. The sublingual 10 mg Promptol™ achieved not only a similar systemic exposure as 30 mg oral Inderal(®) but an earlier effective Cp-prop which may be advantageous for certain clinical conditions.

The use of benzodiazepines in the treatment of chest pain: a review of the literature

Benzodiazepines, although not listed in the American Heart Association's guidelines for the treatment of chest pain, are often used to provide symptomatic relief to patients who experience chest pain. To investigate the utility of benzodiazepines in the treatment of chest pain, the pharmacologic actions and cardiovascular effects of benzodiazepines were reviewed. In addition, a literature search regarding the use of benzodiazepines to treat patients with chest pain was conducted. The results indicated that benzodiazepines reduce anxiety, pain, and cardiovascular activation. Benzodiazepines amplify gamma-aminobutyric acid (GABA) throughout the central nervous system, and act more peripherally to reduce catecholamines. In addition, preliminary evidence indicates that benzodiazepines may cause coronary vasodilatation, prevent dysrhythmias, and block platelet aggregation, though further study is needed. Both non-cardiac chest pain (associated with musculoskeletal, esophageal, neurologic, and psychiatric conditions) and cardiac chest pain (associated with acute and chronic myocardial ischemia) seem to be effectively treated with benzodiazepines. Benzodiazepines are safe and well tolerated when administered alone or in combination with other medications. Moreover, the risk of dependence is minimal when benzodiazepines are prescribed on a short-term basis. Further study of benzodiazepines in the treatment of acute chest pain is needed to confirm these favorable actions and better define their use in the acute medical setting.

Effect of mental stress throughout the day on cardiac autonomic control

Although many laboratory studies have demonstrated changes in cardiac autonomic control during psychological stress, few have attempted to demonstrate this effect in ambulatory subjects. To address this issue, 24-h electrocardiographic recordings of 33 healthy subjects were analyzed for RR interval and heart period variability (HPV) responses associated with periodic diary entries measuring physical position, negative effect, and time of day. A total of 362 diary entries were made during the 24-h sessions, each in response to a device which signaled on an average of once per hour. HPV was analyzed in the frequency domain, yielding estimates of spectral power in low (LF) and high (HF) frequency bands, as well as the LF/HF ratio. Because of the high correlations of the measures of negative affect (alpha = 0.91), they were combined to create a single index of stress. Multivariate analysis was used to assess the effect of individual subject differences, physical position, and stress on RR interval and HPV. Results revealed significant effects of individual differences, stress, and physical position on RR interval, with increases in stress associated with decreases in RR interval as expected. HF power was significantly lower and the LF/HF ratio significantly higher in the standing compared with the sitting position. Psychological stress was significantly associated with an increase in the LF/HF ratio, suggesting increases in the relative predominance of sympathetic nervous system activity during stressful periods of the day. Overall, these findings suggest that in ambulatory normal subjects, cardiac autonomic control varies throughout the day as a function of self-reported stress.

Cardiovascular reactivity to psychosocial stressors. A review of the effects of beta-blockade

Fifty-nine studies examining the effects of beta-blockers on cardiovascular reactivity to psychosocial stressors are reviewed. Across all classifications of beta-blockers, heart rate reactivity was reduced (p less than 0.0001), while there were no significant changes in either systolic or diastolic blood pressure reactivity. Nonselective beta-blockers were more often associated with a reduction in heart rate reactivity than selective blockers (p less than 0.05). There was no evidence that drug lipophilicity or intrinsic sympathomimetic activity differentially affected blood pressure or heart rate reactivity; nor was there evidence that the reactivity of hypertensive subjects was differentially affected by blockade compared to the reactivity of normotensive subjects. While beta-blockers are effective in reducing resting blood pressure, they are not effective agents in reducing blood pressure reactivity to mild psychosocial stressors.

Depression and anxiety among chronically ill heart patients: age differences in risk and predictors

Anxiety and depression for 399 survivors of a 1,102-member heart disease cohort were assessed 8 to 9 years post-hospitalization. Approximately one-third reported symptoms of emotional distress and one-fourth were on anti-anxiety drugs. Predictors of anxiety and depression were analyzed through logistic regression. Subjects age 65 and over were less likely than younger patients to report anxiety or depression and also reported less heart-associated disability, the strongest predictor of distress for both age groups. Other significant predictors included a previous history of distress, low income, female sex, and beta blocker use.