急性心肌梗死病人早期口服β受体阻滞剂对住院期间心脏事件的影响

目的探讨急性心肌梗死病人早期口服β受体阻滞剂对住院期间心脏事件的影响.方法急性心肌梗死病人237例,记录病人病史、临床特点、药物治疗情况以及住院期间心脏事件的发生.结果 Logistic回归分析提示,早期使用β受体阻滞剂对于住院期间室性心律失常(OR=0.54,P=0.021)、再发心绞痛(OR=0.54,P=0.027)以及再梗死(OR=0.29,P=0.035)的发生是保护因素,早期应用β受体阻滞剂对于住院期间病死率无明显影响(OR=0.61,P=0.325).结论急性心肌梗死早期口服β受体阻滞剂可减少住院期间室性心律失常、再发心绞痛、再梗死的发生,而对于住院期间病死率无明显的影响.     

Communitywide trends in the use and outcomes associated with beta-blockers in patients with acute myocardial infarction: the Worcester Heart Attack Study

BACKGROUND: Despite the benefits associated with beta-blocker therapy in patients with acute myocardial infarction (AMI), limited recent data are available describing the extent of use of this therapy and the associated hospital and long-term outcomes, particularly from the perspective of a population-based study. Data are also limited about the characteristics of patients with AMI who do not receive beta-blockers. This study examines more than 2 decades of trends in the use of beta-blockers in hospitalized patients with AMI. METHODS: Communitywide study of 10,374 patients hospitalized with confirmed AMI in all metropolitan Worcester hospitals during 12 annual periods between 1975 and 1999. RESULTS: There was a marked increase in the use of beta-blockers in hospitalized patients between 1975 (11%) and 1999 (82%). Older patients, women, and patients with comorbidities were significantly less likely to be treated with beta-blockers. After controlling for other prognostic factors, patients treated with beta-blockers were less likely to develop heart failure (adjusted odds ratio [OR], 0.58; 95% confidence interval [CI], 0.53-0.63), cardiogenic shock (OR, 0.46; 95% CI, 0.39-0.54), and primary ventricular fibrillation (OR, 0.84; 95% CI, 0.65-1.08) and were less likely to die (OR, 0.26; 95% CI, 0.22-0.29) during hospitalization than were patients who did not receive this therapy. Patients who used beta-blockers during hospitalization had significantly lower death rates after hospital discharge. CONCLUSIONS: The results of this observational study demonstrate encouraging trends in the use of beta-blockers in hospitalized patients with AMI and document the benefits to be gained from this treatment.     

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.     

Effect of beta-blockers on the mortality of Japanese patients with myocardial infarction

BACKGROUND: After a myocardial infarction, a higher prevalence of coronary vasospastic response has been reported in the Japanese population than in the Caucasian population. Beta-blockers may exacerbate coronary vasospasm. However, beta-blockers are given to Japanese patients after an acute myocardial infarction, though the mortality benefit is unknown. Thus, we investigated the mortality benefit of beta-blockers given to Japanese patients after an acute myocardial infarction. METHODS: We prospectively studied consecutive patients with a first myocardial infarction admitted to the coronary care unit of Kansai Medical University Hospital, Osaka, Japan from May 1994 through the end of 2001. Patients who died during hospitalization or who were referred for coronary artery bypass graft surgery were excluded. The association of beta-blocker use with mortality after discharge was assessed by a proportional hazards regression analysis. RESULTS: There were 546 patients and 400 (73.3%) patients were treated with beta-blockers at the time of discharge from hospital. During a mean follow-up of 2 years, 46 (8.4%) patients died. Beta-blocker therapy was associated with a reduced mortality after adjustment for age, gender, Q wave myocardial infarction, reperfusion therapy during acute phase, Killip functional class, serum creatinine level, cardiovascular risk factors, and medications (hazard ratio=0.51, 95% confidence interval=0.27 to 0.95). CONCLUSIONS: Contrary to the concern that beta-blocker therapy might induce coronary vasospasm and reduce survival, beta-blocker therapy improved survival after discharge in Japanese patients with a first myocardial infarction.     

Beta-blocker therapy in acute myocardial infarction: evidence for underutilization in the elderly.

PURPOSE: To assess the impact of patient age on the use of beta-blocker therapy in the management of acute myocardial infarction. PATIENTS AND METHODS: The population studied consisted of 4,762 patients hospitalized with validated acute myocardial infarction in 16 hospitals in the Worcester, Massachusetts, Standard Metropolitan Statistical Area during the years 1975, 1978, 1981, 1984, 1986, and 1988. Logistic regression analysis was employed to control for relevant demographic and clinical variables in evaluating the independent effect of patient age as a determinant of receipt of beta-blocker therapy during the hospitalization. RESULTS: A consistent trend toward reduced use of beta-blocker therapy in older patients was demonstrated. After adjustment for demographic and clinical variables (gender; prior history of angina, hypertension, or diabetes mellitus; myocardial infarction characteristics; complications including congestive heart failure and shock; and use of digoxin and diuretics), odds ratios for receipt of beta-blocker therapy relative to patients less than 55 years of age were 0.61 for those 55 to 64; 0.52 for those 65 to 74; 0.36 for those 75 to 84; and 0.26 for those 85 or older. Analyses performed for each study year demonstrated results consistent with those for the overall study population. CONCLUSION: The results of this population-based study suggest that there are substantial opportunities for expanded use of beta-blocker therapy in elderly patients who have sustained an acute myocardial infarction.     

The potential preventability of postoperative myocardial infarction: underuse of perioperative beta-adrenergic blockade

BACKGROUND: Among selected patients undergoing major noncardiac surgery, beta-adrenergic blockade has been shown to reduce the risk for postoperative cardiac complications and mortality. We sought to determine how often postoperative MI might be considered preventable through appropriate use of these medications. METHODS: We reviewed the medical records of patients who developed a postoperative MI between January 1, 1998, and October 31, 2001, at Baystate Medical Center, a 570-bed community-based teaching hospital in Springfield, Mass. We calculated a Revised Cardiac Risk Index score and used criteria from previous randomized trials to determine whether patients would have been candidates for perioperative beta-adrenergic blockade. Postoperative MI was considered potentially preventable if the patient appeared to have been an ideal candidate for beta-blocker therapy but did not receive it before the infarction. We compared the mortality of ideal candidates who did and did not receive beta-blockers before their infarction using multivariable logistic regression. RESULTS: Seventy (97%) of the 72 patients who developed postoperative MI could have been identified as being at increased risk for cardiac complications, and 58 (81%) appeared to be ideal perioperative beta-blocker candidates. Thirty ideal candidates (52%) were treated with beta-blockers before the development of the infarction. Among ideal candidates, treatment with a beta-blocker before infarction was associated with an odds ratio of in-hospital mortality of 0.19 (95% confidence interval, 0.04-0.87). CONCLUSIONS: A large percentage of the postoperative MIs at our institution might have been prevented if a beta-blocker had been administered to all ideal candidates around the time of surgery. Use of beta-blockers before infarction may reduces overall mortality, even among patients who go on to develop this complication.     

Quality of care for acute myocardial infarction in elderly patients with alcohol-related diagnoses

BACKGROUND: Elderly adults with alcohol-related diagnoses represent a vulnerable population that may receive lower quality of treatment during hospitalization for acute myocardial infarction. We sought to determine whether elderly patients with alcohol-related diagnoses are less likely to receive standard indicators of quality care for acute myocardial infarction. METHODS: We conducted a retrospective cohort analysis using administrative and medical record data from the Cooperative Cardiovascular Project. Subjects were Medicare beneficiaries with a confirmed principal discharge diagnosis of acute myocardial infarction from all acute care hospitals in the United States over an 8-month period. Our primary outcome was the receipt of 7 guideline-recommended care measures among all eligible patients and patients who were ideal candidates for a given measure. RESULTS: In all, 1,284 (1%) of the 155,026 eligible patients met criteria for an alcohol-related diagnosis. Among the alcohol-related diagnoses, 1,077/1,284 (84%) were for the diagnoses of alcohol dependence or alcohol abuse. Patients with alcohol-related diagnoses were less likely than those without alcohol-related diagnoses to receive beta-blockers at the time of discharge (55% vs. 60%, p = 0.02). We found no other significant differences in performance of the quality indicators after stratifying by indication and adjustment for baseline characteristics. CONCLUSIONS: Alcohol-related diagnoses are not a barrier to receiving most quality of care measures in elderly patients hospitalized for acute myocardial infarction.     

Lack of physician concordance with guidelines on the perioperative use of beta-blockers

BACKGROUND: The American College of Physicians recommends perioperative use of beta-blockers for certain patients to improve outcomes after surgery. Study of physician behavior with respect to guidelines and recommended practices have shown that beta-blockers have been underutilized after myocardial infarction. We evaluated physician concordance with the perioperative use of beta-blockers along with a specialty-related difference in the frequency of perioperative beta-blocker use. METHODS: To determine perioperative use of beta-blockers, we retrospectively analyzed the medical charts of adult patients who underwent open cholecystectomy at a tertiary care medical center from December 1997 through December 2001. Patients met criteria for perioperative beta-blocker use if they had a history of coronary artery disease or if they had the presence of 2 or more of the following risk factors: 65 years or older; history of hypertension, diabetes mellitus, or hypercholesterolemia; or current smoking. RESULTS: Among the 336 cases of cholecystectomy reviewed, criteria for beta-blocker use were met in 146 patients (43%) who did not have emergency operations and/or contraindications to beta-blocker use. Of these 146 patients, 123 (84%) had a documented preoperative medical evaluation by a physician in the medical chart. There were 44 patients (30%) receiving beta-blockers prior to admission, and 102 patients (70%) were not receiving beta-blockers. Of those 102 patients not receiving beta-blockers at admission but who meet criteria for their use, 94 (92%) were not started on beta-blocker therapy preoperatively. Of the 18 patients evaluated by a cardiologist, 4 (22%) were started on beta-blocker therapy compared with 3 (6%) of 47 patients evaluated by a noncardiologist physician (P =.08). CONCLUSION: Perioperative beta-blocker therapy is underutilized in patients with risk factors for coronary artery disease despite evidence that its use in appropriate individuals may be lifesaving.     

Cardiovascular drug utilization and its determinants in unselected medical patients with ischemic heart disease

Background: In patients with ischemic heart disease (IHD), secondary preventive drug therapy improves overall prognosis. Therefore, this study evaluated cardiovascular drug utilization in patients suffering from IHD, identified factors influencing drug utilization, and determined the prevalence of shortfalls of antithrombotic, beta-blocker, and lipid-lowering drug use. Methods: This study is based on data recorded prospectively between 1996 and 1998 in two Swiss teaching hospitals for the SAS/CHDM pharmacoepidemiologic database project. Drug utilization was evaluated in all 987 monitored medical inpatients with IHD. Results: At discharge, only 64% of patients with IHD received platelet aggregation inhibitors, 42% beta-blockers, and 26% lipid-lowering drugs. Secondary preventive drugs were more frequently administered to patients with acute myocardial infarction and less frequently in the elderly. After including other co-factors, no gender difference could be detected. Shortfalls of antithrombotic therapy occurred in 6.5--8.3% of patients and shortfalls in beta-blocker use in 9.9--23.3%. Only about half of all patients with IHD and elevated cholesterol received lipid-lowering drugs. Conclusions: Drugs for secondary prevention are prescribed to the majority of patients with IHD. However, their use could be further increased, especially in the elderly and in patients with IHD who are admitted to the hospital for reasons other than acute myocardial infarction. Lipid-lowering drugs should also be prescribed more often for patients with hypercholesterolemia.     

Beta-blocker use in decompensated heart failure

Despite the current advances in treatment, acute decompensated heart failure accounts for more than 1 million hospital admissions annually. Many of the patients hospitalized are already receiving long-term treatment with beta-blockers. For patients who receive full dose beta-blocker therapy and suffer acute decompensated heart failure, clinicians face two key questions: what to do, if anything, with the dosage of beta-blocker and what is the best way to integrate inotropic and beta-blocker therapies for patients who require inotropes. This article discusses these issues and reviews the available literature. Because these topics have received little systematic evaluation, we also present our clinical approaches to these problems.     

Hospital outcomes in major teaching, minor teaching, and nonteaching hospitals in New York state

PURPOSE: The possible benefit that hospital teaching status may confer in the care of patients with cardiovascular disease is unknown. Our purpose was to determine the effect of hospital teaching status on in-hospital mortality, use of invasive procedures, length of stay, and charges in patients with myocardial infarction, heart failure, or stroke. SUBJECTS AND METHODS: We analyzed a New York State hospital administrative database containing information on 388 964 consecutive patients who had been admitted with heart failure (n = 173 799), myocardial infarction (n = 121 209), or stroke (n = 93 956) from 1993 to 1995. We classified the 248 participating acute care hospitals by teaching status (major, minor, nonteaching). The primary outcomes were standardized in-hospital mortality ratios, defined as the ratio of observed to predicted mortality. RESULTS: Standardized in-hospital mortality ratios were significantly lower in major teaching hospitals (0.976 for heart failure, 0.945 for myocardial infarction, 0.958 for stroke) than in nonteaching hospitals (1.01 for heart failure, 1.01 for myocardial infarction, 0.995 for stroke). Standardized in-hospital mortality ratios were significantly higher for patients with stroke (1.06) but not heart failure (1.0) or myocardial infarction (1.06) in minor teaching hospitals than in nonteaching hospitals. Compared with nonteaching hospitals, use of invasive cardiac procedures and adjusted hospital charges were significantly greater in major and minor teaching hospitals for all three conditions. The adjusted length of stay was also shorter for myocardial infarction in major teaching hospitals and longer for stroke in minor teaching hospitals. CONCLUSION: Major teaching hospital status was an important determinant of outcomes in patients hospitalized with myocardial infarction, heart failure, or stroke in New York State.     

Impact of intravenous beta-blockade before primary angioplasty on survival in patients undergoing mechanical reperfusion therapy for acute myocardial infarction

OBJECTIVES: We sought to examine the effect of intravenous beta-blockers administered before primary percutaneous coronary intervention (PCI) on survival and myocardial recovery after acute myocardial infarction (AMI). BACKGROUND: Studies of primary PCI but not thrombolysis have suggested that beta-blocker administration before reperfusion may enhance survival. Whether oral beta-blocker use before admission modulates this effect is unknown. METHODS: The Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial randomized 2082 AMI patients to either stenting or balloon angioplasty, each +/- abciximab. In accordance with the protocol, intravenous beta-blockers were administered before PCI in the absence of contraindications. RESULTS: A total of 1136 patients (54.5%, BB+ group) received beta-blockers before PCI, whereas 946 (45.5%, BB- group) did not. The 30-day mortality was significantly lower in the BB+ group than in the BB- group (1.5% vs. 2.8%, p = 0.03), an effect entirely limited to patients who had not been receiving beta-blockers before admission (1.2% vs. 2.9%, p = 0.007). In contrast, no survival benefit with pre-procedural beta-blockers was observed in patients receiving beta-blockers at home (3.3% vs. 1.9%, respectively, p = 0.47). By multivariate analysis, pre-procedural beta-blocker use was an independent predictor of lower 30-day mortality among patients without previous beta-blocker therapy (relative risk = 0.38 [95% confidence interval 0.17 to 0.87], p = 0.02). The improvement in left ventricular ejection fraction from baseline to seven months was also greater after intravenous beta-blockers (3.8% vs. 1.3%, p = 0.01), an effect limited to patients not receiving oral beta-blockers before admission. CONCLUSIONS: In patients with AMI undergoing primary PCI, myocardial recovery is enhanced and 30-day mortality is reduced with pre-procedural intravenous beta-blockade, effects confined to patients untreated with oral beta-blocker medication before admission.     

Rationale, design and organization of the Second Chinese Cardiac Study (CCS-2): a randomized trial of clopidogrel plus aspirin, and of metoprolol, among patients with suspected acute myocardial infarction. Second Chinese Cardiac Study (CCS-2) Collaborative Group

Assessing combined anti-platelet therapy in suspected acute myocardial infarction Aspirin has been shown to be effective in the emergency treatment of acute myocardial infarction. It irreversibly inhibits platelet cyclo-oxygenase and thereby prevents the formation of the platelet aggregating agent thromboxane A2. Clopidogrel is an anti-platelet agent that acts by a different mechanism, inhibiting adenosine diphosphate-induced platelet aggregation. Simultaneous inhibition of both of these pathways might produce significantly greater anti-platelet effects than inhibition of either alone. The Second Chinese Cardiac Study (CCS-2) will reliably determine whether adding oral clopidogrel to aspirin for up to 4 weeks in hospital after suspected acute myocardial infarction can produce a greater reduction in the risk of major vascular events than can be achieved by giving aspirin alone. In order to be able to detect a further reduction of 10-15%, some 20,000-40,000 patients in over 1000 Chinese hospitals will be randomized. Assessing early beta-blocker therapy in suspected acute myocardial infarction Although over 27,000 patients have been studied previously in randomized trials of short-term beta-blocker therapy in acute myocardial infarction, the reduction in early mortality (513 (3.7%) for beta-blocker therapy deaths versus 586 (4.3%) for control deaths) was only just conventionally significant (P = 0.02) and, overall, the absolute benefits were small in the relatively low-risk patients studied. Although there might be worthwhile benefit in higher risk patients, there is currently little routine use of beta-blocker therapy in acute myocardial infarction. Hence, patients in CCS-2 will also be randomly allocated to receive metoprolol (intravenous then oral) or matching placebo for up to 4 weeks in hospital in a 2 x 2 factorial design. Such a design allows all patients to contribute fully to assessment of the separate effects of the anti-platelet regimen and the beta-blocker (without any material effect on study cost or sample size requirements) whilst also providing information about their combined effects. A streamlined trial in a wide range of patients In order to randomize 20,000-40,000 patients, the design of CCS-2 has been streamlined: data collection and other extra work for collaborators is minimal, allowing busy hospitals to take part easily. All patients presenting within 24 h of the onset of suspected acute myocardial infarction are eligible for the study provided they have a definite ECG abnormality and are not persistently hypotensive, and provided the doctor responsible considers there to be no clear indication for or contraindication to either of the trial treatments. Apart from administration of the trial treatments, all other aspects of individual patient management are entirely at the discretion of the doctor responsible. By including many different types of patient from many different types of hospital, with wide variation in ancillary management, the CCS-2 results will be of direct clinical relevance to the heterogeneous realities of future clinical practice. The trial began in July 1999 and is expected to be completed by the year 2003.     

Clinical outcome of acute myocardial infarction in patients on treatment with beta-blockers or calcium antagonists. A study of 7,922 hospitalized first myocardial infarctions.

To assess the effects of current treatments with beta-blockers or calcium antagonists on the clinical outcome of acute myocardial infarction (MI), enzymatically estimated infarct sizes, circulatory arrests from ventricular tachyarrhythmias, ventricular tachycardia (VT)/ventricular fibrillation (VF), and in-hospital mortality were analyzed retrospectively from 7,922 citizens of Malm?, Sweden, hospitalized due to a first MI between 1973 and 1987. Of these patients, 296 were on treatment with calcium antagonists, 393 on treatment with a beta 1-selective beta-blocker, 482 with a nonselective beta-blocker, and 95 on combined treatment with beta-blockers and calcium antagonists at the time of admission to hospital. In a set of multivariate analyses including several clinical characteristics, patients on treatment with a nonselective beta-blocker had a significantly lower peak aspartate aminotransferase (ASAT; difference -0.70 mukat/l, 95% CL: -1.24 to -0.16), whereas no significant relations between peak ASAT and treatment with cardioselective beta-blockers or calcium antagonists were found. Treatment with cardioselective beta-blockers or calcium antagonists, in contrast to treatment with a nonselective beta-blocker, were significant predictors of the occurrence of circulatory arrests from VT/VF. The relative risk of VT/VF in patients on cardioselective beta-blockers was 1.51 (95% CI: 1.12-2.03), and in patients on calcium antagonists 1.44 (95% CI: 1.03-2.02). None of the treatments were significantly associated with in-hospital mortality. In patients on beta-blockers or calcium antagonists when suffering their first MI, nonselective beta-blockade may reduce infarct size. Treatment with beta-blockers or calcium antagonists identified patients with an increased risk of circulatory arrests from VT/VF, but neither of the treatments were significantly associated with in-hospital mortality. We suggest that only minor differences exist between the effects of chronic treatment with beta-blockers and calcium antagonists on the outcome of an acute MI.     

急性心肌梗塞溶栓治疗后早期T波倒置的临床意义

本文回顾性地分析了104例接受溶栓治疗的急性心肌梗塞病人，根据发病24小时有无出现T波倒置，将病人分为A、B两组。A组38例（36．4％），B组66例（63．4％），通过对两组病人住院期间临床过程，超声心动图及冠状动脉造影的比较，得出结论：溶栓治疗后早期T波倒置标志着良好的临床过程，预示着成功而且有效的溶栓治疗。     

Post-myocardial infarction beta-blocker therapy: the bradycardia conundrum. Rationale and design for the Pacemaker & beta-blocker therapy post-MI (PACE-MI) trial

Multiple clinical trials have demonstrated beta-blockers improving survival after myocardial infarction (MI). Patients with "bradycardia-related" contraindications to beta-blockers, such as those with asymptomatic bradycardia or AV conduction abnormalities, have been excluded from clinical trials of beta-blockers and continue to be excluded from post-MI beta-blocker therapy in routine clinical practice. These patients tend to be elderly and have a high 1-year mortality. If beta-blockers provide benefit to the post-MI patient independent of their heart rate-lowering effect, then these patients could benefit substantially from initiation of beta-blocker therapy. However, in this particular group of patients, beta-blockers can be safely initiated only if more severe or significant bradycardia can be prevented by pacemaker implantation. It is unclear whether adverse effects related to pacemaker implantation could also negate some or all of the hypothesized benefit of beta-blocker therapy. Although beta-blockers are particularly effective in the elderly, the benefit of beta-blocker therapy in patients with bradycardia-related contraindications to beta-blockers has not been established. The PACE-MI trial is a randomized controlled trial that will address whether beta-blocker therapy enabled by pacemaker implantation is superior to no beta-blocker and no pacemaker therapy after MI in patients with rhythm contraindications to beta-blockers or in those who have developed symptomatic bradycardia due to beta-blockers. The trial will randomize 1124 patients to standard therapy (not to include beta-blockers as patients must have a contraindication to be enrolled) or standard therapy plus pacemaker implantation and beta-blocker. The primary end point is the composite end point of total mortality plus nonfatal reinfarction.