Early beta-blocker therapy for acute myocardial infarction in elderly patients

BACKGROUND: Despite the evidence supporting the importance of early beta-blocker therapy, this intervention has received little attention as an indicator of quality of care. OBJECTIVES: To determine how often beta-blockers are administered as early treatment of acute myocardial infarction in patients 65 years of age or older, to identify predictors of the decision to use beta-blockers, and to evaluate the association between the early use of beta-blockers and in-hospital mortality. DESIGN: Observational study. SETTING: Nongovernment, acute care hospitals in the United States. PATIENTS: Medicare beneficiaries who were 65 years of age or older, were hospitalized with an acute myocardial infarction in 1994 and 1995, and did not have a contraindication to beta-blocker therapy. MEASUREMENTS: Medical chart review to obtain information about the use of beta-blockers, contraindications to these drugs, patient demographics, and clinical factors. RESULTS: Of the 58 165 patients (from a total of 4414 hospitals), 28 256 (49%) received early beta-blocker therapy. Patients with the highest risk for in-hospital death were the least likely to receive therapy. Patients who received beta-blockers had a lower in-hospital mortality rate than patients who did not receive beta-blockers (odds ratio, 0.81 [95% CI, 0.75 to 0.87]), even after adjustment for baseline differences in demographic, clinical, and treatment characteristics between the two groups. CONCLUSIONS: Early beta-blocker therapy was not used for 51% of elderly patients who were hospitalized with an acute myocardial infarction and did not have a contraindication to this therapy. Increasing the early use of beta-blockers for these patients would provide an excellent opportunity to improve their care and outcomes.     

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.     

Anticoagulant therapy after acute myocardial infarction

The use of anticoagulant therapy for patients who have had an acute myocardial infarction is still controversial, mainly because early major studies had conflicting findings, but reanalysis of the data did produce evidence that anticoagulation had clinically and statistically significant benefits. Now more evidence, including the results of a 10-day in-hospital study of low- and high-dose calcium heparin, has been gathered to support using anticoagulants for these patients. The study used the development of left ventricular mural thrombosis, a frequent complication of acute myocardial infarction that carries a high risk for systemic embolic complications, to assess clinical outcome: A reduced incidence of mural thrombosis would be taken to indicate reduced chances that patients would have major systemic emboli. Two-dimensional echocardiography was used to detect thrombi. In the study, the incidence of left ventricular mural thrombosis was significantly lower in the high--than in the low-dose group. Among patients in the high-dose group in whom a mural thrombosis did develop, plasma heparin concentrations were significantly lower and activated partial thromboplastin times were shorter. These data suggest that monitoring plasma heparin levels and anticoagulant response can ensure maximal treatment effectiveness. No significant differences in other outcomes--such as bleeding complications, nonhemorrhagic strokes and mortality--were found between the high- and low-dose treatment groups.     

Effects of prior beta-blocker therapy on clinical outcomes after primary coronary angioplasty for acute myocardial infarction

We hypothesized that pretreatment with beta blockers may improve clinical outcomes after primary angioplasty for acute myocardial infarction. We pooled clinical, angiographic, and outcomes data on 2,537 patients enrolled in the Primary Angioplasty in Myocardial Infarction (PAMI), PAMI-2, and Stent PAMI trials. We classified patients into a beta group (n = 1,132) if they received beta-blocker therapy before primary angioplasty or a no-beta group (n = 1,405) if they did not. We evaluated procedural complications and in-hospital and 1-year outcomes (death and major adverse cardiac events [death, reinfarction, target vessel revascularization, or stroke]) between groups. Beta patients were younger, had higher systolic blood pressure and heart rate, and were more likely to be in Killip class I at admission. They had lower left ventricular ejection fraction, greater door-to-balloon time, greater likelihood of having a left anterior descending artery culprit lesion, but a similar incidence of Thrombolysis In Myocardial Infarction 3 flow after angioplasty (92.6% vs 92.7%, p = 0.91). The beta group had less procedural complications (23% vs 34%, p <0.0001) and a lower incidence of death (1.8% vs 3.7%, p = 0.0035) and major adverse cardiac events (5.5% vs 7.8%, p = 0.027) during hospitalization. At 1 year, mortality remained lower in beta patients (4.9% vs 6.7%, log-rank p = 0.055). After adjustment for baseline differences, beta patients had significantly lower in-hospital mortality (odds ratio 0.41; 95% confidence interval 0.20 to 0.84; p <0.0148) and nonsignificantly lower 1-year mortality (odds ratio 0.72; 95% confidence interval 0.47 to 1.08; p = 0.11). Thus, pretreatment with beta blockers has an independent beneficial effect on short-term clinical outcomes in patients undergoing primary angioplasty for acute myocardial infarction.     

Impact of acute beta-blocker therapy for patients with non-ST-segment elevation myocardial infarction

Purpose

Early use of beta-blockers is a quality indicator for the treatment of patients with non-ST-segment elevation myocardial infarction (NSTEMI), despite limited data from randomized clinical trials in this population. We sought to determine the impact of acute beta-blocker therapy on outcomes in patients with NSTEMI.

Subjects and Methods

We examined acute (<24 hours) beta-blocker use in 72,054 patients with NSTEMI from the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the American College of Cardiology/American Heart Association Guidelines (CRUSADE) initiative at 509 US hospitals from 2001-2004. We analyzed patient and provider factors associated with beta-blocker use and the impact of beta-blocker therapy on unadjusted, risk-adjusted, and propensity matched outcomes in the overall sample and among selected high-risk subgroups.

Results

A total of 82.5% of patients without documented contraindications received acute beta-blocker therapy. Factors strongly associated with acute beta-blocker use included prior beta-blocker use, higher presenting systolic blood pressure, lower heart rate, lack of signs of heart failure, and cardiology care. Acute beta-blocker use was associated with lower in-hospital mortality (unadjusted 3.9% vs 6.9%, P <.001, adjusted odds ratio 0.66, 95% confidence interval 0.60-0.72), lower adjusted mortality among most of 6 subgroups determined by propensity to receive acute beta-blockers, and lower adjusted mortality in patients with and without signs of heart failure and in those <80 years and those ≥80 years old.

Conclusions

The majority of NSTEMI patients receive acute beta-blocker therapy. Certain patient subgroups remain undertreated. Because treatment with acute beta-blockers was associated with improved clinical outcomes in nearly all patient subgroups assessed, broader use in patients with NSTEMI appears warranted.     

Medical therapy after acute myocardial infarction.

Several therapeutic agents have been tested for secondary prevention after acute myocardial infarction. Each patient presents a clinical challenge and gives the physician an opportunity to use the tests and therapy most likely to benefit the clinical course. The presence of other associated medical conditions, the type of myocardial infarction, the presence or absence of accompanying ischemia, left ventricular dysfunction, intracardiac thrombus, or ventricular arrhythmias dictate the choices that are to be made. It is apparent from this review that no single class of agents can be considered a cure, although beta-adrenergic blocking agents come the closest to this role. Analysis of these drugs helps individualize drug therapy and provides a physiologic probe to understanding the pathophysiologic processes that characterize the period after myocardial infarction. To address the impact of developing technology and drug availability on the practice and cost of medical care, the American College of Cardiology and the American Heart Association have developed guidelines for the management of patients with myocardial infarction. The clinical trial remains the best test for the assessment of therapeutic choices and can also expand our knowledge of the natural history of the disease process. Nevertheless, the issue of appropriate therapy is ever-changing, affected by the explosion of new technology and the continued investigation into the pathophysiology of coronary artery disease.     

Predicting return to work after acute myocardial infarction. Significance of clinical data, exercise test variables and beta-blocker therapy

Among 66 full-time employed men surviving an acute myocardial infarction (AMI) and participating in the Norwegian postinfarction study with timolol, 50 (75.7%) resumed their previous work within 12 months, and 16 (24.3%) retired. Stepwise logistic regression analysis of clinical data and of results from an exercise test 3 months post AMI revealed the following factors of independent predictive value for enhanced return to work: previous labor characterized as light or moderately heavy (p = 0.001), low age at the time of infarction (p = 0.001), timolol treatment (p = 0.009), ability to stop smoking post AMI (p = 0.006), and a high exercise capacity on the exercise test (p = 0.016). It is concluded that the clinical history and an exercise test 3 months after AMI can identify patients who are more likely to resume work, and that post-AMI beta-blocker treatment with timolol and ability to stop smoking are predictive of an enhanced return to work.     

Adjunctive therapy after reperfusion therapy in acute myocardial infarction

The current era has witnessed dramatic improvement in the treatment of acute myocardial infarction, due in large part to the more widespread use of thrombolytic therapy aimed at quickly restoring perfusion in the infarct-related artery. This review addresses the role of adjunctive pharmacologic therapy in the thrombolytic era, recognizing that much of the available clinical trial data supporting the role of adjunctive pharmacologic treatment strategies was conducted in patient populations not widely exposed to reperfusion therapy. This review, therefore, explores the data supporting the incremental benefit of therapy with beta blockers, nitrates, angiotensin-converting enzyme inhibitors, or magnesium in addition to thrombolytic therapy. Heparin and aspirin will not be discussed.     

Effectiveness of beta-blocker therapy after acute myocardial infarction in elderly patients with chronic obstructive pulmonary disease or asthma

OBJECTIVES

We hypothesized that aspirin (ASA) might alter the beneficial effect of beta-blockers on left ventricular ejection fraction (LVEF) in patients with chronic heart failure.

BACKGROUND

Aspirin blunts the vasodilation caused by both angiotensin-converting enzyme (ACE) inhibitors and beta-blockers in hypertensive patients and in patients with heart failure. Several studies suggest that ASA also blunts some of beneficial effects of ACE inhibitors on mortality in patients with heart failure. To our knowledge, there have been no data evaluating the possible interaction of ASA and beta-blockers on left ventricular remodeling in patients with heart failure.

METHODS

We retrospectively evaluated patients entered into the Multicenter Oral Carvedilol Heart failure Assessment (MOCHA) trial, a 6-month, double-blind, randomized, placebo-controlled, multicenter, dose-response evaluation of carvedilol in patients with chronic stable symptomatic heart failure. Multivariate analysis was performed to determine if aspirin independently influenced the improvement in LVEF.

RESULTS

Over all randomized patients (n = 293), LVEF improved 8.2 ± 0.8 ejection fraction (EF) units in ASA nonusers and 4.5 ± 0.7 EF units in ASA users (p = 0.005). In subjects randomized to treatment with carvedilol (n = 231), LVEF improved 9.5 ± 0.9 EF units in ASA nonusers and 5.8 ± 0.8 EF units in ASA users (p = 0.02). In subjects randomized to treatment with placebo (n = 62), LVEF improved 2.8 ± 1.2 EF units in ASA nonusers and 0.5 ± 1.4 EF units in ASA users (p = 0.20). Aspirin did not significantly affect the heart rate or systolic blood pressure response in either the placebo or carvedilol groups. The effect of ASA became more significant on multivariate analysis. The change in LVEF was also influenced by carvedilol dose, etiology of heart failure, baseline heart rate, EF and coumadin use. The detrimental effect of ASA on the improvement in LVEF was dose-related and was present in both placebo and carvedilol groups, although the effect was statistically significant only in the much larger carvedilol group.

CONCLUSIONS

Aspirin significantly affects the changes in LVEF over time in patients with heart failure and systolic dysfunction treated with carvedilol. The specific mechanism(s) underlying this interaction are unknown and further studies are needed to provide additional understanding of the molecular basis of factors influencing reverse remodeling in patients with heart failure.     

Coronary angiography after thrombolytic therapy for acute myocardial infarction

PURPOSE: To review the status of emergency, urgent, routine, and selective angiography after intravenous thrombolytic therapy. DATA SOURCES: Relevant English-language articles published from January 1985 to July 1990 were identified through MEDLINE. STUDY SELECTION: For emergency angiography, four major randomized studies were reviewed and data from nine studies that incorporated rescue coronary angioplasty were pooled for meta-analysis. For urgent angiography, two controlled trials were reviewed. Comparisons of routine and selective angiography were done using data from two dedicated, large-scale, controlled trials and the ancillary findings of four other studies of reperfusion that incorporated angiography. DATA EXTRACTION: The review emphasizes the findings from multicenter, randomized, controlled trials. DATA SYNTHESIS: Emergency coronary angiography is done primarily in preparation for primary or rescue angioplasty; the value of rescue angioplasty has yet to be assessed in a randomized trial, but technical success and reocclusion improve significantly after therapy with nonspecific plasminogen activators compared with relatively specific agents (success rate, 86% compared with 75%, respectively; P = 0.03; reocclusion rate, 10.9% compared with 26.8%, respectively; P less than 0.001). Urgent coronary angiography has value for treating recurrent ischemia, but patients who develop this complication after thrombolysis are likely to have a suboptimal outcome despite aggressive care. Studies support the use of either selective or routine angiography in uncomplicated patients after thrombolytic therapy; either approach is acceptable, but the former is more practical and may prove to be cost effective. CONCLUSIONS: Optimal follow-up for patients with evolving myocardial infarction who receive thrombolysis may incorporate coronary angiography at various stages. Although our ability to noninvasively detect reperfusion, reocclusion, or viable but ischemic myocardium is limited at present, available data may assist in selecting a catheterization strategy.     

急性心肌梗死介入治疗术后的康复运动疗法研究进展

急性心肌梗死(acute myocardial infarction,AMI)是临床上常见的急危重症,发病率呈现逐年升高的趋势,死亡率均随年龄的增加而增加。经皮腔内冠状动脉介入治疗（percutaneous coronary intervention PCI）术成为AMI的重要治疗手段。但PCI没有改变动脉粥样硬化的进程,且支架本身还存在再狭窄和支架内血栓等并发症,因此,冠心病的康复治疗也从传统的心肌梗死后的康复发展到AMI介入性治疗后的康复。本文就AMI介入治疗术后的康复运动疗法及现状作简要综述。