Impact of clinical trials on the use of beta blockers after acute myocardial infarction and its relation to other risk indicators for death and 1-year mortality rate

Effects of β-blockers on all-cause mortality in patients with diabetes and coronary heart disease: A systematic review and meta-analysis

Beta-blockers have been considered as an effective treatment in secondary prevention of coronary heart disease (CHD). However, there is still disputed whether β-blockers can increase all-cause mortality in patients with coronary heart disease and diabetes mellitus (DM). Here, our systematic review and meta-analysis is aiming to assess the effects of β-blockers on all-cause mortality in patients with coronary heart disease and diabetes mellitus. Four databases (PubMed, Embase, Cochrane Library and Web of Science) and other sources were searched to collect randomized controlled trials (RCTs) and cohort studies related to the treatment of β-blockers for coronary heart disease and diabetes mellitus patients. We further evaluated quality of evidence using the grading of recommendations assessment, development, and evaluation (GRADE) approach. Finally, a total of 16,188 records were identified, and four randomized controlled trials and six cohort studies (206,490 patients) were included. Random effects analysis revealed that β-blockers combined with routine treatment (RT) significantly decreased all-cause mortality in patients with coronary heart disease and diabetes mellitus compared with RT in control group (RR 0.59, 95% CI 0.47 to 0.75; p < 0.000 01; I² = 72%). Subgroup analysis of all-cause mortality by the subtype of diabetes mellitus and definite MI patients (RR 0.54, 95% CI 0.45 to 0.65, p < 0.000 01, I² = 29%) and the subtype of randomized controlled trials (RR 0.49, 95% CI 0.32 to 0.76, p = 0.001, I² = 0%) indicated a relatively small heterogeneity and stable results. β-blockers application significantly reduced cardiovascular death as well (RR 0.56, 95% CI 0.42 to 0.74; p < 0.000 1; I² = 0%). Our meta-analysis provided critical evidence of β-blockers treatment for patients with coronary heart disease (especially MI type) and diabetes mellitus, and discussed the advantages and potential metabolic risks for the clinical use of β-blockers. This study suggested that β-blockers application may improve all-cause mortality and cardiovascular death in coronary heart disease (especially MI type) and diabetes mellitus patients. However, given a small number of included studies, the aforementioned conclusion should be confirmed in a multi-center, large-scale, and strictly designed trial.

Effect of Beta-blockers on Tachycardia in Patients with Pulmonary Embolism

Hypothesis Beta-blockers (BBs) lower the heart rate, which may mask the diagnosis of pulmonary embolism (PE) since one of the main clinical diagnoses of PE is tachycardia. The endpoint of our retrospective study is to determine if the pre-existing use of (BB) significantly affects the utility of these scoring criteria in diagnosing PE. Introduction Diagnosing PE is a challenge because of the non-specificity of its symptoms and signs. The initial step is to assess the patient's likelihood of having a PE. This involves using a scoring system to stratify patients into different levels of risk of having PE (for example, as 'low,' 'moderate,' or 'high' risk). Some of the commonly used criteria are Wells' Score, Geneva Score, and Pulmonary Embolism Rule-out Criteria (PERC) Rule (Charlotte Rule). Methodology This retrospective study was conducted at St. Francis Medical Center. Subjects were taken from a patient population with a new diagnosis of PE (between 2010 and 2017) on the basis of computed tomography angiography (CTA) of the chest. Patients with sepsis or septic shock, heart block, atrioventricular (AV) nodal ablation, pacemaker placement, or taking more than one AV nodal blocker were excluded from the study. Subjects were categorized on the basis of beta-blocker consumption. Result Out of a total of 170 cases, 71 patients were taking beta-blockers and 99 patients were not taking beta-blockers. Among the participants taking BBs, 30.4% had a heart rate <60 and 55.8% had a heart rate between 60 and 100. Conclusion BBs significantly obviate tachycardia in patients with PE. It falsely decreases the Wells' Score and the Geneva Score and results in the inappropriate fulfilling of PERC criteria.

Do physician outcome judgments and judgment biases contribute to inappropriate use of treatments? Study protocol

BACKGROUND

There are many examples of physicians using treatments inappropriately, despite clear evidence about the circumstances under which the benefits of such treatments outweigh their harms. When such over- or under- use of treatments occurs for common diseases, the burden to the healthcare system and risks to patients can be substantial. We propose that a major contributor to inappropriate treatment may be how clinicians judge the likelihood of important treatment outcomes, and how these judgments influence their treatment decisions. The current study will examine the role of judged outcome probabilities and other cognitive factors in the context of two clinical treatment decisions: 1) prescription of antibiotics for sore throat, where we hypothesize overestimation of benefit and underestimation of harm leads to over-prescription of antibiotics; and 2) initiation of anticoagulation for patients with atrial fibrillation (AF), where we hypothesize that underestimation of benefit and overestimation of harm leads to under-prescription of warfarin.

METHODS

For each of the two conditions, we will administer surveys of two types (Type 1 and Type 2) to different samples of Canadian physicians. The primary goal of the Type 1 survey is to assess physicians' perceived outcome probabilities (both good and bad outcomes) for the target treatment. Type 1 surveys will assess judged outcome probabilities in the context of a representative patient, and include questions about how physicians currently treat such cases, the recollection of rare or vivid outcomes, as well as practice and demographic details. The primary goal of the Type 2 surveys is to measure the specific factors that drive individual clinical judgments and treatment decisions, using a 'clinical judgment analysis' or 'lens modeling' approach. This survey will manipulate eight clinical variables across a series of sixteen realistic case vignettes. Based on the survey responses, we will be able to identify which variables have the greatest effect on physician judgments, and whether judgments are affected by inappropriate cues or incorrect weighting of appropriate cues. We will send antibiotics surveys to family physicians (300 per survey), and warfarin surveys to both family physicians and internal medicine specialists (300 per group per survey), for a total of 1,800 physicians. Each Type 1 survey will be two to four pages in length and take about fifteen minutes to complete, while each Type 2 survey will be eight to ten pages in length and take about thirty minutes to complete.

DISCUSSION

This work will provide insight into the extent to which clinicians' judgments about the likelihood of important treatment outcomes explain inappropriate treatment decisions. This work will also provide information necessary for the development of an individualized feedback tool designed to improve treatment decisions. The techniques developed here have the potential to be applicable to a wide range of clinical areas where inappropriate utilization stems from biased judgments.

Prescription patterns in patients with systolic heart failure at hospital discharge: why beta blockers are underprescribed or prescribed at low dose in real life?

Systolic heart failure (SHF) is associated with increased morbidity and mortality. Beta-blockers (BB) were shown to provide mortality benefit in patients with SHF, and currently indicated in all stages of patients with SHF. We evaluated the factors influencing the prescription of BBs at discharge in patients hospitalised with HF. Hospital discharge records of consecutive 1418 patients (996 men, 422 women) with a mean age of 57 +/- 15 years, hospitalised and treated for SHF (EF < 45%), were retrospectively reviewed. Mean age of female (n = 422) and male patients (n = 996) was similar (58 +/- 15 years vs. 58 +/- 14 years, p = 0.654). Mean EF was 33 +/- 7%, and not different for each sex (p = 0.288). BBs were present in 47.4% of patients at hospital discharge, and female patients were more frequently prescribed than men (51.7% vs. 45.7%, p = 0.036). Patients who were prescribed BBs at discharge were younger than those who were not (p = 0.034). Patients who were prescribed BBs at discharge had significantly higher EF than those who were not (p = 0.019). Older patients were prescribed low-dose BBs. Besides, creatinine level was significantly higher in the group who were prescribed low-dose BBs than those who were prescribed high dose. However, EF was significantly lower in the group, who were prescribed low-dose BBs than in those prescribed moderate-high dose (33 +/- 7% vs. 35 +/- 7%, p = 0.023). There exist several factors associated with underuse of this highly recommended medication in patients with HF.

Changes in rates of beta-blocker use in community hospital patients with acute myocardial infarction

OBJECTIVE

To examine changes in the rate of beta-blocker (BB) use at admission, in hospital, and at discharge between 1994 and 1995 (MICH I) and 1997 (MICH II) in patients with acute myocardial infarction (AMI).

DESIGN

Comparison of two prospectively enrolled cohorts.

SETTING

Five mid-Michigan community hospitals.

PATIENTS

We studied 287 MICH I patients and 121 MICH II patients with AMI who had no contraindications to BB use from cohorts of consecutively admitted cases of AMI (814 in MICH I; 500 in MICH II).

RESULTS

Prescription of BBs to ideal patients with AMI increased in patients with previous history of myocardial infarction on arrival at the hospital (12.5% vs 36.0%; P= .01), in hospital (47.0% vs 76%; P < .01), and at discharge (34.0% vs 61.9%; P < .01). Neither race nor gender was a predictor of BB use. Younger age predicted BB prescription at discharge (odds ratio [OR], 2.07; 95% confidence interval [CI], 1.32 to 3.23). Later study cohort was the most important predictor of BB use in hospital (OR, 3.4; 95% CI, 2.09 to 5.25).

CONCLUSION

BB use improved dramatically over the study period, but additional work is needed to improve use of BB after discharge and among elderly patients with AMI.

The gap between knowledge and practice in the treatment and prevention of cardiovascular disease

There is a gap between the current knowledge of the treatment of cardiac conditions derived from evidence-based medicine and the widespread application of this knowledge. The use of ACE inhibitors for patients with congestive heart failure, beta blockers in postmyocardial infarction patients, anticoagulation in patients with chronic atrial fibrillation, cholesterol medications for either primary or secondary prevention of coronary artery disease, and antihypertensive treatment, are of proven benefit, yet all are underutilized by cardiologists, as well as other medical practitioners. There is evidence that there are methods to improve the prescribing of medication, but further studies are required to identify the best ways of doing this. A challenge for the future will be to identify and apply the best educational programs to improve the quality and efficiency of medical care. (c) 2000 by CHF, Inc.

Which factors determine the long-term outcome among patients with a very small or unconfirmed AMI

AIM

To describe various factors associated with the very long-term prognosis for patients with a very small or an unconfirmed acute myocardial infarction (AMI).

METHODS

Patients below 76 years of age, hospitalized due to suspected AMI who either developed a very small AMI (enzyme elevation<twice upper normal limit and maximum serum (S) aspartate aminotransferase (S-ASAT)<1.4 ukat/l) or an unconfirmed AMI (a suspected ischemic event with no signs of myocardial necrosis) were evaluated at our out-patient clinic. The 10-year mortality was related to the clinical history, age and sex, metabolic factors, diagnosis at hospital discharge, various psychosocial factors, use of medication, current symptoms, underlying reason to the symptoms, maximal working capacity and other observations at bicycle exercise test including signs of myocardial ischemia.

RESULTS

In all, 714 patients (33% women) with a median age of 63 years were included in the analyses. The following appeared as independent risk indicators for 10-year mortality: S-gammaglutamyl transpeptidase (GT) (P<0.0001), age (P<0.0001), current smoking (P<0.0001), a history of previous AMI (P<0.0001), maximal working capacity at bicycle exercise test (P=0.002), and current treatment with digitalis (borderline significance; P=0.022).

CONCLUSION

Among patients with a suspected acute myocardial ischemic event with no or minimal myocardial necrosis, various factors reflecting their age, history of cardiac disease and smoking, liver function, working capacity and possibly use of medication affected their very long-term prognosis.

Changes in the use of medications after acute myocardial infarction: possible impact on mortality after myocardial infarction and long-term outcome

OBJECTIVE

To describe the change in the use of medication after acute myocardial infarction (AMI) and discuss its possible impact on risk and risk indicators for death.

PATIENTS

All patients discharged alive after hospitalization for AMI at Sahlgrenska Hospital (covering half the community of Göteborg, i.e. 250,000 of 500,000 inhabitants) during 1986-1987 (period I) and at Sahlgrenska Hospital and Ostra Hospital (covering the whole community of Göteborg, 500,000 inhabitants) during 1990-1991 (period II).

METHODS

Overall mortality was retrospectively evaluated during 5 years of follow-up.

RESULTS

In all, 740 patients were included in the study during period I and 1448 during period II. The 5-year mortalities were 44.1% for period I patients and 39.3% for period II patients (P = 0.036). The relative risk of death for period II patients was 0.78 [95% confidence interval (CI) 0.67-0.89, P = 0.0005] after adjustment for differences at baseline. There was a significant interaction with a history of congestive heart failure; improvement in duration of survival was found only for patients without such a history. During period I, only 3% of patients were administered fibrinolytic agents, compared with 33% of patients during period II (P < 0.0001). During period I, aspirin was prescribed for 13% of patients discharged from hospital compared with 79% during period II. Other changes in treatment on going from period I to period II included increases in prescription of beta-blockers and angiotensin converting enzyme inhibitors. After adjustment for various risk indicators for death, relative risk of death for those administered fibrinolytic agents was 0.60 (95% CI 0.18-2.02) for patients in the period-I cohort and 0.68% (95% CI 0.51-0.91) for those in the period-II cohort. Adjusted relative risk of death for those prescribed aspirin upon discharge from hospital was 0.81 (95% CI 0.52-1.25) for period-I patients and 0.71 (95% CI 0.56-0.91) for period-II patients. The adjusted relative risk of death for those administered beta-blockers was 0.72 (95% CI 0.55-0.96) for period-I patients and 0.70 (95% CI 0.55-0.90) for period-II patients.

CONCLUSION

Increased use of fibrinolytic agents and aspirin for AMI as well as a moderate increase in use of beta-blockers and angiotensin converting enzyme inhibitors was associated with a parallel reduction in age-adjusted mortality during the 5 years after discharge from hospital. However, this improvement was seen only for patients without histories of congestive heart failure.

Assimilating new therapeutic interventions into clinical practice: how does hypertension compare with other therapeutic areas?

Medical research has helped to clarify the benefits of some therapies for improving the treatment or outcome associated with cardiovascular disease. However, the adoption of these approaches into routine clinical practice is, in many cases, inadequate. Consequently, there are many missed opportunities to reduce the burden of morbidity and mortality from cardiovascular disease. This review summarizes the factors that may prevent modified behavior in medical practice and the effectiveness of interventions that influence change. There are many barriers that may prevent or slow the adoption of new therapeutic advances into routine clinical practice. As a result, the use of well-proven, efficacious therapy can be suboptimal. Because of this underuse, the realized benefits of treatment are below the potential benefits. Adoption of new therapies is highly dependent on the use of interventions to promote clinical change. However, the effectiveness of different types of interventions varies greatly. Nevertheless, there is a wide range of strategies available that can be used to induce real changes in practice performance and potentially improve patient outcomes. It is essential that future intervention strategies focus on improving adoption of new therapies into clinical practice. The physician must be encouraged to prescribe proven treatments to those patients who stand to benefit most. In addition, better systems of care should be developed that improve the identification of patients as suitable candidates for proven treatments and sustain their long-term commitment to therapy.

Thrombolytic Therapy in Acute Myocardial Infarction Part II: 1997 Update

Thrombolytic therapy has become an established treatment for acute myocardial infarction. Streptokinase was first demonstrated in 1988 to reduce mortality rates. In 1993, tissue plasminogen activator was shown to have a slight superiority over streptokinase in reducing mortality rates (approximately 1%). Reteplase is a second generation thrombolytic agent that is given in two bolus injections intravenously over 30 minutes. Studies demonstrated slightly better and more rapid improvement in myocardial perfusion with reteplase compared to tissue plasminogen activator. However, recent studies showed 30-day mortality rates in patients treated with reteplase were similar as those treated with tissue plasminogen activator. The use of angioplasty, aspirin, beta blockers, angiotensin converting enzyme inhibitors, and lipid lowering agents also contribute to the reduction of mortality from acute myocardial infarction.

Postinfarction use of beta-blockers in elderly patients

beta-Adrenoceptor antagonists (beta-blockers) reduce mortality and recurrent myocardial infarction (MI) in older patients after both Q-wave MI and non-Q-wave MI. The effects of beta-blockers are to: (i) reduce complex ventricular arrhythmias, including ventricular tachycardia; (ii) increase the ventricular fibrillation threshold; (iii) reduce myocardial ischaemia; (iv) decrease sympathetic tone; (v) markedly attenuate the circadian variation of complex ventricular arrhythmias: (vi) abolish the circadian variation of myocardial ischaemia; and (vii) abolish the circadian variation of sudden cardiac death or MI. beta-Blockers reduce mortality in patients with MI and complex ventricular arrhythmias. In addition, they are excellent antianginal agents. Older persons with hypertension who have had an MI should be treated initially with a beta-blocker. beta-Blockers reduce mortality in patients with: (i) diabetes mellitus who have had an MI; (ii) MI and congestive heart failure with an abnormal or normal left ventricular ejection fraction; and (iii) MI and an asymptomatic abnormal left ventricular ejection fraction. Severe congestive heart failure, severe peripheral arterial disease with threatening gangrene, greater than first degree atrioventricular block, hypotension, bradycardia, lung disease with bronchospasm, and bronchial asthma are contraindications to treatment with beta-blockers.

Pharmacologic therapies after myocardial infarction

Despite the availability and use of effective methods for limiting infarct size with thrombolytic agents and primary angioplasty, patients experiencing a myocardial infarction (MI) are at increased risk for a second cardiac event in the post-MI period (e.g., reinfarction, heart failure, and sudden death). For this reason, postinfarction risk management is crucial. An extensive data base has firmly established the efficacy of beta blockers in reducing cardiovascular risk following acute MI. The full advantages of angiotensin-converting enzyme (ACE) inhibitors have only recently begun to emerge as the result of a growing understanding of the mechanisms of adverse outcomes following MI. The importance of lipid-lowering agents, in particular the "statins," should be considered in all post-MI patients, especially since recent studies have conclusively shown improved survival and reduced rates of MI and coronary artery bypass surgery in this population with this therapy. Aspirin is now considered a standard part of the early management of the acute infarct patient as well as for secondary prevention in post-MI patients. At present, chronic anticoagulation with warfarin should be reserved for selected patients. The nondihydropyridine calcium antagonists diltiazem and verapamil can be considered for post-MI use only in patients in whom beta blockers are contraindicated and who have preserved systolic function and/or those without clinical heart failure. In contrast, the dihydropyridine calcium antagonists, particularly nifedipine, have no role in secondary prevention. Although long-term benefits are minimal, nitrates continue to be useful in post-MI patients with residual ischemia (angina or silent ischemia), heart failure (systolic or diastolic), or postinfarction hypertension. Antiarrhythmic agents, except amiodarone, are relatively contraindicated in post-MI patients. Recent data show that vitamin E reduces the rate of nonfatal MI. Its role in cardiovascular death and overall mortality remains to be clarified. Despite their demonstrated value, agents used in secondary prevention generally appear to be underutilized. In addition, when pharmacologic therapies are administered for secondary prevention, they are often prescribed at lower doses than those tested and proved in trials. A greater appreciation for the efficacy and safety profiles of these agents could lead to more widespread use and more pronounced reductions in morbidity and mortality among post-MI patients.