Beta blockade during and after myocardial infarction: An overview of the randomized trials

Long-term beta blockade for perhaps a year or so following discharge after an MI is now of proven value, and for many such patients mortality reductions of about 25% can be achieved. No important differences are clearly apparent among the benefits of different beta blockers, although some are more convenient than others (or have slightly fewer side effects), and it appears that those with appreciable intrinsic sympathomimetic activity may confer less benefit. If monitored, the side effects of long-term therapy are not a major problem, as when they occur they are easily reversible by changing the beta blocker or by discontinuation of treatment. By contrast, although very early IV short-term beta blockade can definitely limit infarct size, more reliable information about the effects of such treatment on mortality will not be available until a large trial (ISIS) reports later this year, with data on some thousands of patients entered within less than 4 hours of the onset of pain. Our aim has been not only to review the 65-odd randomized beta blocker trials but also to demonstrate that when many randomized trials have all applied one general approach to treatment, it is often not appropriate to base inference on individual trial results. Although there will usually be important differences from one trial to another (in eligibility, treatment, end-point assessment, and so on), physicians who wish to decide whether to adopt a particular treatment policy should try to make their decision in the light of an overview of all these related randomized trials and not just a few particular trial results. Although most trials are too small to be individually reliable, this defect of size may be rectified by an overview of many trials, as long as appropriate statistical methods are used. Fortunately, robust statistical methods exist--based on direct, unweighted summation of one O-E value from each trial--that are simple for physicians to use and understand yet provide full statistical sensitivity. These methods allow combination of information from different trials while avoiding the unjustified direct comparison of patients in one trial with patients in another. (Moreover, they can be extended of such data that there is no real need for the introduction of any more complex statistical methods that might be more difficult for physicians to trust.) Their robustness, sensitivity, and avoidance of unnecessary complexity make these particular methods an important tool in trial overviews.     

Use of exercise cardiac rehabilitation after acute myocardial infarction.

The purpose of this study was to determine the rate of participation of patients after acute myocardial infarction (AMI) in phase II cardiac rehabilitation with exercise training (ie, exercise cardiac rehabilitation, ECR) in Japan. Forty-six hospitals treating patients with AMI were surveyed for their implementation of phase II ECR after AMI in 1996-98. Of the 46 hospitals, 19 were approved and 27 were not approved for health insurance payment for ECR. A total of 13685 patients with AMI were admitted to the 46 hospitals. There were no differences between approved and non-approved hospitals in the annual number of patients with AMI (Approved, 117+61 vs Non-approved, 86+71 patients per hospital, NS), the rate of performance of emergency coronary angioplasty (63+16 vs 65+20%, NS), or the rate of emergency coronary stenting (31+16 vs 34+22%, NS). However, ECR was performed routinely in 84.2% (16/19 hospitals) of the approved hospitals, but in only 22.2% (6/27 hospitals) of the non-approved hospitals (p<0.001). Although the participation rate of AMI patients in ECR was 21.0% (2875/13685 patients) overall, it was markedly lower in the non-approved hospitals (8.0%, 557/6999 patients) than in the approved hospitals (34.7%, 2318/6686 patients, p<0.0001). Based on the present result, the overall rate of participation of AMI patients in ECR in Japan was estimated at 4.8-11.7%. Despite similar patient volumes and acute phase interventional treatment of AMI between the hospitals approved and not approved for health insurance payment for ECR, ECR was markedly underused in the non-approved hospitals in Japan. To promote ECR for all AMI patients in Japan, the number of hospitals approved for ECR should be substantially increased.     

急性心肌梗死早期院内康复结合院外康复的治疗

目的：探讨AMI早期院内康复锻炼与门诊康复结合的安全可行性及对复工的影响。方法：39例AMI患早期康复治疗2－3周后出院，尔后门诊指导继续3－4个月的康复运动治疗。结果：全部病例安全出院，其后3－4个月79％复工。余21％可参与家务、生活自理。结论：AMI早期短程康复治疗结合出院后门诊3－4个月康复运动，是安全、可行的。     

康复运动有助于心肌梗塞患者的恢复

目的:探讨早期康复运动对急性心肌梗塞患者的疗效。方法:将2002年8月到2004年10月在我院循环内科住院并符合入选标准的80例急性心肌梗塞患者,按自愿原则,分成两组,治疗组早期进行常规药物治疗,并早期实行严格合理的运动疗法,对照组绝对卧床,只进行常规药物治疗,不进行康复训练。采用Barthel指数评定患者的日常生活能力,并对比两组的平均住院天数,住院期间的平均花费,心律失常的发生率及生活自理能力,两组患者两年后心肌梗塞的再发率。结果:治疗组平均住院天数、平均花费较对照组减少(P<0.05),日常生活能力较对照组有显著改善(P<0.05),心律失常的发生率两组之间无显著性差异,治疗组的生活自理能力优于对照组(P<0.05)。两年后,治疗组心肌梗塞的再发率均低于对照组(P<0.05)。结论:康复运动有助于心肌梗塞患者的恢复。     

Goal attainment in a randomized controlled trial of rehabilitation after myocardial infarction

PURPOSE: Goal setting is an established strategy in health behavior change programs although its usefulness remains uncertain. The authors investigate the validity of attainment of a patient-identified goal as an outcome measure in cardiac rehabilitation after myocardial infarction. METHODS: On entry into a randomized controlled trial of cardiac rehabilitation after an acute myocardial infarction, patients identified one activity that, if and when attained, would reflect their perception of a successful recovery. Patients reported whether they had attained their goal and the time of goal attainment. This was then related to trial outcomes that included generic and specific health-related quality of life and percent predicted exercise tolerance. RESULTS: Goals identified by 180 of the 201 (89.6%) patients, were attained by 51.5% at 8 weeks and by 86.5% at 12 months. At the end of the 8-week intervention, there was a substantial trend for fewer rehabilitation than usual care patients to have attained their identified goal (P < 0.06), although rehabilitation patients demonstrated greater improvement in specific health-related quality of life and exercise tolerance than usual care patients (P < 0.05). Among patients who identified a recreational physical activity goal (26.7%), significantly fewer (P < 0.007) rehabilitation than usual care patients had attained their goal at the end of the intervention with no differences in improvement in outcomes. CONCLUSIONS: Although improvement in outcomes was greater in rehabilitation patients than usual care patients at 8 weeks, goal attainment, particularly for the recreational physical activity goal, was greater among usual care patients. The validity of self-identified activity goal attainment as a measure of the efficacy of cardiac rehabilitation is unclear and might give misleading results.     

Improved clinical outcomes with abciximab therapy in acute myocardial infarction: a systematic overview of randomized clinical trials

Background

Investigations of glycoprotein (GP) IIb/IIIa inhibition in primary percutaneous coronary intervention (PCI) have suggested the efficacy of abciximab in improving clinical and angiographic outcomes, but sample-size limitations and variability in trial design preclude the ability to generalize these results to a broader patient population.

Methods

Meta-analytic techniques were used to evaluate clinical outcomes from randomized trials comparing GP IIb/IIIa inhibition with placebo or control therapy in primary PCI for acute myocardial infarction (MI).

Results

In 3266 patients, treatment with abciximab significantly reduced the 30-day composite end point of death, reinfarction, or ischemic or urgent target-vessel revascularization (TVR; odds ratio [OR], 0.54; 95% CI, 0.40-0.72), with trends toward reduced 30-day death and death or reinfarction. Abciximab resulted in an increased likelihood of major bleeding (OR, 1.74; 95% CI, 1.11-2.72). By 6 months, abciximab significantly reduced the occurrence of death, reinfarction, or any TVR (OR, 0.80; 95% CI, 0.67-0.97), and there were positive trends favoring a decrease in mortality alone and the composite of death or reinfarction.

Conclusions

Treatment with abciximab significantly reduces early adverse ischemic events, a clinical benefit that is maintained at 6-month follow-up. These findings support the use of adjunctive GP IIb/IIIa inhibition in primary PCI.     

Cardiac rehabilitation after acute myocardial infarction

At the time of evidence-based medicine, while the proofs of the benefits of cardiac rehabilitation to the coronary multiply, a large number of patients are still managed without any form of rehabilitation. In particular, younger patients with myocardial infarction treated by early reperfusion and older subjects. The objective of in-hospital or ambulatory cardiac rehabilitation is a global coverage of the patient and his/her risk factors, that the short duration of hospitalization in the acute phase does not allow. Several randomized studies, metaanalyses, and registers show a decrease from 20 to 30% of the mortality after cardiac rehabilitation. The benefits of physical training on risk factors modification are demonstrated by numerous works: improvement of lipid parameters and arterial pressure, prevention of diabetes, increased smoking cessation, loss of weight, better overall well-being; besides the management of risk factors, physical training improves exercise capacity, a recognised prognostic factor. The efficiency of cardiac rehabilitation may be comparable with that of the key treatments of coronary artery disease, such as beta-blockers or coronary angioplasty. All these proofs give to the cardiac rehabilitation in post-myocardial infarction a high-level recommendation, grade IA.     

急性心肌梗死患者住院期康复运动及出院前的运动负荷试验研究

目的:探讨急性心肌梗死（AMI）患者住院期康复运动及出院前运动负荷试验的安全、有效性。方法:85例AMI无合并症或合并症已控制的患者,于住院期在心电、血压监测下进行三阶段康复运动治疗,并于出院前进行心脏功能评定,评定方法分为标准和非标准运动试验,标准运动试验分为功率自行车和平板运动试验,非标准运动试验选用400m步行试验。结果:所有患者均完成了住院期康复治疗及出院前的运动负荷试验,而且无严重心律失常、再次心肌梗死、心力衰竭等严重心脏病事件发生。38例患者年龄相对较大,左室射血分值较低,康复训练强度低,体能差,选用 400m步行试验作为评定方法,运动贮量为2.86±0.49METs。其余 47例患者选择分级运动试验,29例患者应用自行车运动试验,运动贮旦为4.72±0.90METs,18例患者应用平板运动试验,运动贮量为5.49±1.38METs。结论:在心电及血压监测下进行个体化的康复运动是安全、有效的。出院前运动负荷试验应根据患者具体情况,选择适宜的评定方法,以便安全、准确地评定出患者的运动贮量。     

Early exercise test after myocardial infarction

Exercise tests of coronary function at the tenth day of an uncomplicated myocardial infarction offer objective evaluation of short-term benefits of an early accelerated physical retraining program. They also allow better individual adaptation of exercises prescribed at the start of convalescence at home. Exercise test results show significant correlation with clinical data and bicycle ergometer tests carried out two months after infarction, with respect to physical aptitude, reasons for discontinuation of test and lethality risk two months after infarction. This suggests that exercise tests performed after the acute phase of myocardial infarction are of diagnostic and prognostic value.     

急性心肌梗死患者实施早期运动康复的疗效

目的：探讨急性心肌梗死（AMI）早期运动康复的效果。方法：选择64例生命体征稳定的AMI患者,随机分为早期运动康复组和常规康复组,每组32例。早期运动康复组在发病24h后由床旁康复师给予早期运动康复指导,常规康复组由同水平资质康复师在其绝对卧床1周后给予其运动康复指导。此外两组接受的其他治疗及护理完全相同。观察并统计两组患者的主要不良心血管事件（MACE）（再梗死、死亡、严重心律失常、梗死后心绞痛、心力衰竭）情况、住院天数和生活自理能力情况,并进行比较分析。结果：出院前早期康复组和常规康复组的并发症发生率（40．63％比43．75％）和生活可自理的患者比例（100％比96．88％）无显著差异（P〉0．05）,但早期康复组患者的住院天数明显短于常规康复组[（9．23±1．45）d比（15．03±2．53）d,P〈0．01]。结论：早期运动康复训练对于生命体征稳定的急性心肌梗死患者能缩短患者的住院天数,而且是安全的。     

Secondary prevention trials after acute myocardial infarction

Of those patients who reach the hospital after an acute myocardial infarction, 18% die during their stay and 85% to 90% of the remainder will eventually die of coronary artery disease. Several secondary preventive approaches have been made to prolong life in these patients. Long-term controlled trials involving nonsurgical measures and at least 100 patients will be reviewed. Lipid-lowering regimens have shown no demonstrable effect on survival over a 4- to 6-year period but show some benefit with respect to nonfatal infarction. Survival was not improved essentially by anticoagulants, antiarrhythmic agents or calcium channel blockers, although new trials are underway that might clarify their role. Platelet-active drugs achieved little reduction in mortality but showed benefit in nonfatal infarction (30% reduction with aspirin). Pooled data on physical exercise programs demonstrated a 15% benefit on mortality but larger trials are required to confirm this. The data on beta blockers (particularly those without intrinsic sympathomimetic activity) show that these drugs improve long-term survival after myocardial infarction, reducing all-cause mortality by as much as 25% to 30%. Larger trials are necessary to detect statistically significant reductions in mortality both overall and in selected subgroups of patients.     

Response to upright exercise after myocardial infarction

The left ventricular response to upright bicycle exercise was studied in 39 unselected, non-beta blocked patients (mean(SEM) age 54.2(1.7)yr) (mean(SEM) resting ejection fraction 41.9(2.3)%) 8-10 weeks after myocardial infarction. Nine healthy, age matched, sedentary adult men were studied for comparison (mean(SEM) age 49.8(0.9)yr). The stroke volume and cardiac output were measured by impedance cardiography at rest and after each 3 min workload until symptom limited maximum. The patients were separated into three groups based on stroke volume response to graded exercise. Group 1 (n = 14) had a normal stroke volume response to increasing heart rate. In group 2 (n = 13) stroke volume increased initially then decreased by greater than 15% at a heart rate greater than 100-105 beats.min-1. In group 3 (n = 12) stroke volume failed to increase during exercise. In group 1 cardiac output and mean arterial pressure increased whereas vascular resistance decreased during exercise in a normal fashion. Group 2 had an increased mean arterial pressure and systemic vascular resistance throughout exercise while heart rate increased in a similar fashion to group 1 until work of greater than 70 W was undertaken, at which time heart rate increased in a curvilinear fashion and cardiac output was attenuated. Group 3 had an attenuated cardiac output and a higher heart rate during exercise. In this group of patients systemic vascular resistance failed to decrease normally during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)     

老年急性心肌梗塞早期运动康复的疗效分析

目的 :观察 13例老年急性心肌梗塞 (AMI)患者早期运动康复的疗效。方法 :将 13例老年 AMI分为低危、中危、高危组 ,分别完成 2、 3、 4周康复程序 ,其中 9例患者出院前进行活动平板运动试验。结果 :12例患者如期完成康复程序 ,生活质量及心率变异性明显改善 ,出院前生活均能自理 ,其中 9例运动试验测定的 METS达 5 .17±0 .71。结论 :老年 AMI患者病情平稳后 ,在密切监测、正确药物治疗下进行早期运动康复是可行、安全的 ,可改善患者的预后