Secondary prevention after myocardial infarction: a review of long-term trials

Risk Factors in Patients with Non-ST Segment Elevation Myocardial Infarction

Introduction:

The most common cause of myocardial ischemia is atherosclerotic epicardial coronary artery disease, present in 90% of patients. Risk factors positively correlate with the onset, development and subsequent complications of atherosclerotic disease.

Aim:

Determine the percentage frequency of classic risk factors for coronary disease in patients with non-ST segment elevation myocardial infarction (NSTEMI), with regard to gender.

Methods:

A retrospective study was conducted on 600 respondents, treated for NSTEMI at the Clinic for Internal Medicine of the University Clinical Center (UKC) Tuzla, in the period from June 2016 to December 2019.

Results:

Overall, smoking was the leading risk factor (65%), followed by hypertension (58%), hyperlipoproteinemia (39%), overweight (33%), positive family burden (30%) and diabetes mellitus (19%). In male patients, the leading risk factor was smoking, rating at 74%, while in female patients – it was hypertension at 67%. In younger groups of patients leading risk factors were smoking and a positive family burden.

Conclusion:

With adequate prevention and treatment measures, a significant reduction in the prevalence of the cardiovascular disease can be achieved, since the risk factors for its development have long been known. Quitting smoking is one of the most effective secondary prevention measure since it reduces the reinfarction risk rate by 50%. Knowledge of coronary risks, as well as success in reducing them, can greatly contribute to patients’ overall sense of contentment and significantly raise their self-confidence.

Changing patterns of medical treatment in acute myocardial infarction

TYPE OF STUDY

Descriptive study of trends in the drug therapy for acute myocardial infarction.

SETTING

Population-based register of acute coronary events compiled for the years 1984 to 1990 in the course of the Perth MONICA project.

CASES

5294 cases meeting clinical criteria for acute myocardial infarction.

RESULTS

Striking changes were seen in the use of aspirin before admission to hospital (from 4% to 18%). During the stay in hospital the use of beta-blockers increased steadily from 52% to 76%, while the use of aspirin increased 3.5-fold from 25% to 88% and the use of streptokinase increased 13.5-fold from 2.4% to 32.4%. The proportion of patients prescribed beta-blockers on discharge from hospital increased from 46% to 65% and that for aspirin rose from 16% to 83%. There were also major relative increases in the use of lipid-lowering agents and declines in the use of antiarrhythmic drugs.

CONCLUSION

These trends in the pharmacological management of myocardial infarction mirror the emerging evidence from clinical trials, although the increases in the use of certain types of drugs antedated publication of the results of major randomised studies. The changes in therapy would partly explain observed improvements in case fatality and may have contributed to the decline in coronary mortality observed in the Perth community.

A network analysis of the propagation of evidence regarding the effectiveness of fat-controlled diets in the secondary prevention of coronary heart disease (CHD): Selective citation in reviews

OBJECTIVE

To examine how the first randomised controlled trials (RCTs) evaluating the efficacy of cholesterol-lowering diets in the secondary prevention of coronary heart disease were interpreted in reviews of the literature prior to the National Institutes of Health consensus conference in 1984.

DESIGN

Claim-specific citation network analysis was used to study the network of citations between reviews and RCTs over a defined period (1969-1984). RCTs were identified and classified according to whether their conclusions supported or opposed the use of dietary fat modification/restriction in the secondary prevention of coronary heart disease. Each review published in this period that cited any of the RCTs was classified as supportive, neutral, or unsupportive to the use of dietary fat modification based on a quotation analysis of its evaluation of the findings of these RCTs. Citation bias and underutilisation were detected by applying a comparative density measure, in-degree centrality, and out-degree in a series of sub-graph analyses.

RESULTS

In total, 66 unique publications were identified (four RCTs-one supportive, three unsupportive; 62 reviews-28 supportive, 17 neutral, 17 unsupportive). On average, supportive reviews underutilised the available RCTs to a greater degree than other reviews. Amongst the supportive group, citation bias was common-23 (82%) reviews cited only the one RCT that was supportive.

CONCLUSION

Most reviews that disseminated a supportive evaluation of the results of RCTs in the context of secondary prevention cited only data that supported this position.

Lessons from contemporary trials of cardiovascular prevention and rehabilitation: A systematic review and meta-analysis

BACKGROUND

Meta-analyses of cardiac rehabilitation trials up to 2010 showed a significant reduction in all-cause mortality but many of these trials were conducted before the modern management of acute coronary syndromes.

METHODS

We undertook a meta-analysis of contemporary randomised controlled trials published in the period 2010 to 2015, including patients with other forms of atherosclerotic cardiovascular disease, to investigate the impact of cardiovascular prevention and rehabilitation on hard outcomes including survival.

RESULTS

18 trials randomising 7691 patients to cardiovascular prevention and rehabilitation or usual care were selected. All-cause mortality was not reduced (RR 1.00, 95% CI 0.88 to 1.14), but cardiovascular mortality was by 58% (95% CI 0.21, 0.88). Myocardial infarction was also reduced by 30% (95% CI 0.54, 0.91) and cerebrovascular events by 60% (95% CI 0.22, 0.74). Comprehensive programmes managing six or more risk factors reduced all-cause mortality in a subgroup analysis (RR 0.63, 95% CI 0.43, 0.93) but those managing less did not. In the three programmes that prescribed and monitored cardioprotective medications for blood pressure and lipids all-cause mortality was also reduced (RR 0.35, 95% CI 0.18, 0.70).

CONCLUSIONS

Comprehensive prevention and rehabilitation programmes managing six or more risk factors, and those prescribing and monitoring medications within programmes to lower blood pressure and lipids, continue to reduce all-cause mortality. In addition, these comprehensive programmes not only reduced cardiovascular mortality and myocardial infarction but also, for the first time, cerebrovascular events, and all these outcomes across a broader spectrum of patients with atherosclerotic disease.

The efficacy of a supervised exercise training programme on readmission rates in patients with myocardial ischemia: results from a randomised controlled trial

BACKGROUND

The results of research into the outcomes of physical rehabilitation and its relationship with post-myocardial ischaemia survival and readmissions are inconclusive. Our primary aim was to evaluate the efficacy of a supervised exercise training programme in terms of decreasing hospital cardiac readmission in patients with myocardial ischaemia.

METHODS

We conducted a randomised controlled trial including patients with myocardial ischaemia. Eligible patients were assigned to a control group receiving standard care or to an intervention group that took part in a supervised exercise training programme. The follow-up period was 12 months after hospital discharge.

RESULTS

Of 478 patients assessed for eligibility, 86 were randomised to the control group ( n = 44) or the intervention group ( n = 42). Cardiac readmission rates were 14% versus 5% ( p = 0.268) in the control and intervention groups, respectively, and all-cause readmission rates were 23% versus 15% ( p = 0.34). There were no deaths in either group. More control patients were treated in the emergency services (50% vs. 24%; p = 0.015). In terms of health-related quality of life, patients in the intervention group presented with significant increases in functional capacity and mobility. More intervention patients returned to work (77.3% vs. 36.0%; p = 0.005).

CONCLUSIONS

The supervised physical exercise programme was effective at reducing the number of emergency room visits and at increasing the percentage of patients who returned to work. It also improved patients' exercise capacity and increased their health-related quality of life. Although the results were promising, the programme was not associated with a significant reduction in cardiac and all-cause readmission rates.

Approach to cardiac rehabilitation

Cardiac rehabilitation is now considered an integral part of the management of cardiac disease. However, the approach to objectives has been variable and not well defined. To have a more structured approach towards the goals and objectives of cardiac rehabilitation, this paper discusses the interrelationship of the different factors which determine quality of life, who are the candidates for rehabilitation, the effectiveness of the various modes of intervention, the interface between the rehabilitation process and traditional medical modes of intervention and evaluation of outcome.

Systematic reviews in context: highlighting systematic reviews relevant to Africa in the Pan African Medical Journal

Health research serves to answer questions concerning health and to accumulate facts (evidence) required to guide healthcare policy and practice. However, research designs vary and different types of healthcare questions are best answered by different study designs. For example, qualitative studies are best suited for answering questions about experiences and meaning; cross-sectional studies for questions concerning prevalence; cohort studies for questions regarding incidence and prognosis; and randomised controlled trials for questions on prevention and treatment. In each case, one study would rarely yield sufficient evidence on which to reliably base a healthcare decision. An unbiased and transparent summary of all existing studies on a given question (i.e. a systematic review) tells a better story than any one of the included studies taken separately. A systematic review enables producers and users of research to gauge what a new study has contributed to knowledge by setting the study’s findings in the context of all previous studies investigating the same question. It is therefore inappropriate to initiate a new study without first conducting a systematic review to find out what can be learnt from existing studies. There is nothing new in taking account of earlier studies in either the design or interpretation of new studies. For example, in the 18th century James Lind conducted a clinical trial followed by a systematic review of contemporary treatments for scurvy; which showed fruits to be an effective treatment for the disease. However, surveys of the peer-reviewed literature continue to provide empirical evidence that systematic reviews are seldom used in the design and interpretation of the findings of new studies. Such indifference to systematic reviews as a research function is unethical, unscientific, and uneconomical. Without systematic reviews, limited resources are very likely to be squandered on ill-conceived research and policies. In order to contribute in enhancing the value of research in Africa, the Pan African Medical Journal will start a new regular column that will highlight priority systematic reviews relevant to the continent.

Innovations in medical care and mortality trends from four circulatory diseases between 1970 and 2005

BACKGROUND

Governments have identified innovation in pharmaceuticals and medical technology as a priority for health policy. Although the contribution of medical care to health has been studied extensively in clinical settings, much less is known about its contribution to population health. We examine how innovations in the management of four circulatory disorders have influenced trends in cause-specific mortality at the population level.

METHODS

Based on literature reviews, we selected six medical innovations with proven effectiveness against hypertension, ischaemic heart disease, heart failure and cerebrovascular disease. We combined data on the timing of these innovations and cause-specific mortality trends (1970-2005) from seven European countries. We sought to identify associations between the introduction of innovations and favourable changes in mortality, using Joinpoint-models based on linear spline regression.

RESULTS

For both ischaemic heart disease and cerebrovascular disease, the timing of medical innovations was associated with improved mortality in four out of five countries and five out of seven countries, respectively, depending on the innovation. This suggests that innovation has impacted positively on mortality at the population level. For hypertension and heart failure, such associations could not be identified.

CONCLUSION

Although improvements in cause-specific mortality coincide with the introduction of some innovations, this is not invariably true. This is likely to reflect the incremental effects of many interventions, the time taken for them to be adopted fully and the presence of contemporaneous changes in disease incidence. Research on the impact of medical innovations on population health is limited by unreliable data on their introduction.

Aspirin for the prevention of cognitive decline in the elderly: rationale and design of a neuro-vascular imaging study (ENVIS-ion)

BACKGROUND

This paper describes the rationale and design of the ENVIS-ion Study, which aims to determine whether low-dose aspirin reduces the development of white matter hyper-intense (WMH) lesions and silent brain infarction (SBI). Additional aims include determining whether a) changes in retinal vascular imaging (RVI) parameters parallel changes in brain magnetic resonance imaging (MRI); b) changes in RVI parameters are observed with aspirin therapy; c) baseline cognitive function correlates with MRI and RVI parameters; d) changes in cognitive function correlate with changes in brain MRI and RVI and e) whether factors such as age, gender or blood pressure influence the above associations.

METHODS/DESIGN

Double-blind, placebo-controlled trial of three years duration set in two Australian academic medical centre outpatient clinics. This study will enrol 600 adults aged 70 years and over with normal cognitive function and without overt cardiovascular disease. Subjects will undergo cognitive testing, brain MRI and RVI at baseline and after 3 years of study treatment. All subjects will be recruited from a 19,000-patient clinical outcome trial conducted in Australia and the United States that will evaluate the effects of aspirin in maintaining disability-free longevity over 5 years. The intervention will be aspirin 100 mg daily versus matching placebo, randomized on a 1:1 basis.

DISCUSSION

This study will improve understanding of the mechanisms at the level of brain and vascular structure that underlie the effects of aspirin on cognitive function. Given the limited access and high cost of MRI, RVI may prove useful as a tool for the identification of individuals at high risk for the development of cerebrovascular disease and cognitive decline.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01038583.

Prevention of reinfarction and sudden death

There are many potential approaches to the prevention of reinfarction and sudden death, but the proof of benefit as yet is confined to the use of beta-adrenoceptor blocking drugs and coronary artery bypass surgery. In selected cases, aspirin, anticoagulants and antiarrhythmics drugs may prevent one or other of these complications, but other categories of drugs, including the calcium antagonists, seem at present unsuccessful. Greatest hope for the future lies in the development of strategies that limit infarct size.

The significance of ST and T changes for the development of coronary events in patients with acute coronary chest pain, treated in a coronary care unit without verified acute myocardial infarction

The one-year prognosis for patients with a confirmed diagnosis of acute myocardial infarction (AMI) was compared with that of non-AMI patients treated in the coronary care unit (CCU). The one-year incidence of coronary events (CE) after discharge from CCU was 37% in the 51 AMI patients and 20% in the 81 non-AMI patients. The one-year mortality rates were 27 and 4%, respectively. Among the non-AMI patients, well known risk factors such as hypertension, previous AMI, congestive heart failure, smoking, diabetes and hyperlipaemia were not more common in those who developed a CE. ST segment depression and T wave inversion, each of at least 0.1 mV, in three or more ECG leads were selective criteria for a high-risk group with respect to CE. Preventive measures should be considered in this group of patients without verified AMI.

Preventive use of exercise rehabilitation after myocardial infarction

Randomized controlled clinical trials of exercise after myocardial infarction, although difficult to compare, have not shown a reduction in mortality or morbidity. However, physiological and psychological improvements occur that enable patients to improve their quality of life. The effectiveness of exercise programmes is impaired by poor patient compliance. Some characteristics of poor compliers may be identified, but it is safer to assume all participants are potential non-compliers, and to apply compliance-improving strategies within exercise programmes. The authors' experience has indicated that a number of strategies may be followed at little cost. These include a spouse support programme, a written agreement to participate, self-control techniques including self-monitored exercise testing, and group discussion periods.

The cardiovascular risks of physical activity

The incidence of sudden death, serious arrhythmias, and myocardial infarction in connection with both recreational and rehabilitative physical activity is small. However, the incidence of e.g. sudden death is several times higher in exercise than at other times. This relative risk is highest in middle-aged men, and higher in strenuous than in nonstrenuous exercise. In the vast majority of the cases the underlying cause is advanced coronary heart disease, which in large proportion of the cases has been asymptomatic and has allowed regular strenuous training. Attempts to prevent the complications by special large scale screening programs would be ineffective and individual counselling limited by lack of resources. These measures should, however, be used in selected groups and individuals. Another approach is to inform the exercisers and their families at large by systematic, well-planned and repeated messages of the risks of physical activity, of the symptoms and findings indicating this risk, of the individual and environmental factors increasing the risk, and of the necessary measures to be taken to minimize the risk. Even if all available measures at present were used, the cardiovascular complications of physical activity could not be totally prevented. Fortunately, preliminary evidence suggests that at population level the cardiovascular hazards of physical activity are outweighed by its cardiovascular benefits.

Prognosis and clinical follow-up of patients resuscitated from out-of hospital cardiac arrest

A new organization has been formed in which ambulance personnel have been trained to recognize ventricular tachycardia and ventricular fibrillation (VF) and to defibrillate. Cardiac arrest (CA) occurred in 307 patients and 140 were defibrillated. Twenty-eight patients were resuscitated and admitted for further hospital care. A previous history of ischaemic heart disease was found in 24 patients. Twenty-two of the patients admitted were found to have VF, two asystole and four other rhythms. All 11 survivors regained circulation at the site of the CA. At the time of admission all but one of the patients were unconscious and one long-time survivor remained unconscious until the 5th day following admission. Seventeen patients died while still in hospital. In 16 cases a diagnosis of acute myocardial infarction was established, a further six had VF without evidence of acute myocardial infarction and six had other diagnoses. Ten out of the 11 survivors were still alive six months after discharge. Only one case of recurrent VF was seen during a median follow-up period of 16 months. Prolonged coma, especially in combination with convulsions, was associated with a poor prognosis, while early return of circulation was significantly more common among survivors. Ongoing medication with beta-blockers, a high QRS rate on admission and VF without proof of any acute myocardial infarction were also found to be more common in survivors.

Time-of-day variation in cardiovascular response to maximal exercise testing in coronary heart disease patients taking a beta-blocker

The aim of this study was to investigate the effect of a beta-blocker (atenolol and metoprolol) on exercise heart rate (HR) and rate pressure product (RPP) during a morning and afternoon maximal exercise test (maxET) in patients with coronary heart disease (CHD). Twenty-one CHD patients (59.9 ± 8.9 years of age) treated with either atenolol or metoprolol participated in this study. All subjects underwent a morning and afternoon symptom-limited maximal exercise test (maxET) 2–3 h and 8–10 h after medication intake. No significant differences in exercise capacity (atenolol: 8.3 ± 1.9 vs. 8.3 ± 2.1 metabolic equivalents (METs); metoprolol: 8.8 ± 2.0 vs. 8.7 ± 2.0 METs) or rate of perceived exertion (atenolol: 7.4 ± 1.9 vs. 7.4 ± 1.7 METs; metoprolol: 7.2 ± 1.5 vs. 6.8 ± 0.9 METs) were observed between the 2 maxETs in either group. However, there was a discrepancy in cardiovascular and ischemic responses between morning and afternoon maxET. Subjects treated with atenolol demonstrated better overall control of HR and RPP during the afternoon maxET. The difference between morning and afternoon HRmax (11 ± 8 vs. 19 ± 9 beats·min–1; p = 0.05) was significantly higher in the metoprolol group, but did not attain significance for RPP (31 ± 30 vs. 54 ± 28 mmHg·beats·min–1·10−2; p = 0.09). Also, nearly one quarter of our subjects who had a normal morning maxET demonstrated an abnormal electrocardiogram response and (or) ischemia when exercise testing was done in the late afternoon. These changes were more prevalent in subjects taking metoprolol. The results of this study suggest that there is considerable time-of-day variation in the cardiovascular response to a maxET in CHD patients treated with a beta-blocker.

Depression and medication adherence in outpatients with coronary heart disease: findings from the Heart and Soul Study

BACKGROUND

Depression leads to adverse outcomes in patients with coronary heart disease (CHD). Medication nonadherence is a potential mechanism for the increased risk of CHD events associated with depression, but it is not known whether depression is associated with medication nonadherence in outpatients with stable CHD.

METHODS

We examined the association between current major depression (assessed using the Diagnostic Interview Schedule) and self-reported medication adherence in a cross-sectional study of 940 outpatients with stable CHD.

RESULTS

A total of 204 participants (22%) had major depression. Twenty-eight (14%) of 204 depressed participants reported not taking their medications as prescribed compared with 40 (5%) of 736 nondepressed participants (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.7-4.7; P<.001). Twice as many depressed participants as nondepressed participants (18% vs 9%) reported forgetting to take their medications (OR, 2.4; 95% CI, 1.6-3.8; P<.001). Nine percent of depressed participants and 4% of nondepressed participants reported deciding to skip their medications (OR, 2.2; 95% CI, 1.2-4.2; P = .01). The relationship between depression and nonadherence persisted after adjustment for potential confounding variables, including age, ethnicity, education, social support, and measures of cardiac disease severity (OR, 2.2; 95% CI, 1.2-3.9; P = .009 for not taking medications as prescribed).

CONCLUSIONS

Depression is associated with medication nonadherence in outpatients with CHD. Medication nonadherence may contribute to adverse cardiovascular outcomes in depressed patients.

Exercise-based rehabilitation for coronary heart disease

BACKGROUND

The burden of cardiovascular disease world-wide is one of great concern to patients and health care agencies alike. Cardiac rehabilitation aims to restore patients with heart disease to health through exercise only based rehabilitation or comprehensive cardiac rehabilitation.

OBJECTIVES

To determine the effectiveness of exercise only or exercise as part of a comprehensive cardiac rehabilitation programme on the mortality, morbidity, health-related quality of life (HRQoL) and modifiable cardiac risk factors of patients with coronary heart disease.

SEARCH STRATEGY

Electronic databases were searched for randomised controlled trials, using standardised trial filters, from the earliest date available to December 31st 1998.

SELECTION CRITERIA

Men and women of all ages, in hospital or community settings, who have had myocardial infarction, coronary artery bypass graft or percutaneous transluminal coronary angioplasty, or who have angina pectoris or coronary artery disease defined by angiography.

DATA COLLECTION AND ANALYSIS

Studies were selected independently by two reviewers, and data extracted independently. Authors were contacted where possible to obtain missing information.

MAIN RESULTS

This systematic review has allowed analysis of an increased number of patients from approximately 4500 in earlier meta-analyses to 8440 (7683 contributing to the total mortality outcome). The pooled effect estimate for total mortality for the exercise only intervention shows a 27% reduction in all cause mortality (random effects model OR 0.73 (0.54, 0.98)). Comprehensive cardiac rehabilitation reduced all cause mortality, but to a lesser degree (OR 0.87 (0.71, 1.05)). Total cardiac mortality was reduced by 31% (random effects model OR 0.69 (0.51, 0.94)) and 26% (random effects model OR 0.74 (0.57, 0.96)) in the exercise only and comprehensive cardiac rehabilitation groups respectively. Neither intervention had any effect on the occurrence of non-fatal myocardial infarction. There was a significant net reduction in total cholesterol (pooled WMD random effects model -0.57 mmol/l (-0.83, -0.31)) and LDL (pooled WMD random effects model -0.51 mmol/l (-0.82, -0.19) in the comprehensive cardiac rehabilitation group.

REVIEWER'S CONCLUSIONS

Exercise-based cardiac rehabilitation is effective in reducing cardiac deaths. It is not clear from this review whether exercise only or a comprehensive cardiac rehabilitation intervention is more beneficial. The population studied in this review is still predominantly male, middle aged and low risk. Identification of the ethnic origin of the participants was seldom reported. It is possible that patients who would have benefited most from the intervention were excluded from the trials on the grounds of age, sex or co-morbidity.

beta-blockers reduce the incidence of cardiac events in post-myocardial infarction patients

The capacity of beta-blockers to prevent cardiac events in post-myocardial infarction (MI) patients was investigated. Among 1,483 study participants, a beta-blocker was included in the therapeutic regimens of 833 (beta-blocker group) and was omitted from the regimens of 650 (control group). The incidence of cardiac events (recurrent MI, sudden death and death by congestive heart failure) during a follow up period of 17.4 +/- 20.9 months was retrospectively compared between the two groups. Cardiac events occurred in 27 (3.2%) members of the beta-blocker group and in 44 (6.8%) controls, which represents a significant decline in the incidence of cardiac events among patients administered beta-blockers (p < 0.01, odds ratio 0.46, 95 % confidence intervals 0.28-0.75). Subgroup and multivariate analyses showed beta-blockers to be as efficacious in Japanese post-MI patients as was previously shown in Western patients. While these findings are compelling, it is clear that confirmation in a large, multicenter, placebo - controlled, randomized clinical trial, analogous to those that have been carried out in Western countries, is necessary.

Risk factor modification through nonpharmacological interventions in patients with coronary heart disease

Coronary heart disease (CHD) is still the main cause of death in developed countries. Because of improved treatment, many patients survive the acute phase of a myocardial infarction, which makes secondary prevention of CHD of major importance. Most risk factors responsible for the development and progression of CHD are associated with behavior. Therefore, interventions aimed at behavior change may contribute to risk factor modification and secondary prevention of CHD. The effects of separate risk factor modification efforts by means of randomized, controlled clinical trials of nonpharmacological interventions in patients suffering from CHD are reviewed. Interventions aimed at healthy lifestyles may stimulate smoking cessation rates, reduce elevated serum total and low-density lipoprotein (LDL)-cholesterol concentrations, and favorably modify type A behavior in CHD patients. Moreover, reduction of coronary atherosclerosis has been reported after intensive lifestyle and exercise interventions, whereas exercise and type A interventions may also lead to reduced CHD morbidity and mortality. As for hypertension and obesity, studies aimed at secondary prevention are lacking.

Current concepts in secondary prevention after acute myocardial infarction

Acute myocardial infarction (MI) is the leading cause of death around the globe. Advances in the field of cardiology have identified several effective treatments that have lead to decrease in mortality from this cause over the past 3 decades. The purpose of this article is to review the existing literature in regards to secondary prevention after acute MI. A search of MEDLINE through August of 1999 was carried out to identify any available publications on secondary prevention after MI. Evidence on the use of both pharmacological and nonpharmacological interventions that was shown to be effective in improving morbidity and mortality was sought. Recommendations for the treatment of patients with acute MI are made based on existing evidence. Betablockers, aspirin and lipid-lowering agents for patients with low density lipoprotein-cholesterol > 130 mg% should be used for all patients following a MI. Angiotensin converting enzyme inhibitors are indicated for patients with congestive heart failure and/or reduced left ventricular ejection fraction and are likely protective in most patients. Calcium channel blockers (Verapamil and Diltiazem) are indicated as second-line therapy for patients who have contraindications or are intolerant to betablockers. The routine prophylactic use of antiarrhythmic drugs to suppress ventricular ectopic beats should be avoided. Recommendations regarding diet, smoking cessation and achievement of ideal body weight should be an integral part of patient management. Referral for outpatient rehabilitation should also be strongly encouraged. Finally, adequate control of blood pressure and diabetes cannot be overemphasized. Adherence to these goals in patients with acute MI will lead to better long-term outcomes and reduction in cardiac death, recurrent MI, stroke, and need for coronary revascularization.

Modification of high blood pressure after myocardial infarction

The treatment of high blood pressure (BP) after myocardial infarction is extremely important to decrease reinfarction and mortality. BP should be controlled more strictly in this high-risk hypertensive population. Recently, many clinical trials have demonstrated the benefits of lifestyle modification and antihypertensive agents, particularly beta-blockers and angiotensin-converting-enzyme inhibitors for the treatment of acute myocardial infarction. Treatment with these agents that modify BP may benefit even normotensive patients after a myocardial infarction, although the benefit is greater in hypertensives.

Secondary prevention of myocardial infarction: role of beta-adrenergic blockers and angiotensin-converting enzyme inhibitors

beta-Blockers reduce cardiovascular death and reinfarction in patients with a history of myocardial infarction (MI), and angiotensin-converting enzyme (ACE) inhibitors provide an overall survival benefit in patients with signs or symptoms of left ventricular (LV) dysfunction and a history of acute MI. Despite this, these agents remain underused in clinical practice. Appropriate patient selection in standard clinical practice should be encouraged in order to achieve a mortality rate reduction comparable to that seen in clinical trials. It appears from the findings of recent studies that the greatest benefit from beta-blocker therapy is achieved in patients who are more than 60 years of age and in patients at moderate or high risk for reinfarction and death (eg, patients with LV dysfunction or arrhythmias or both). Patients with class I-IV heart failure treated with ACE inhibitors have fewer recurrent infarctions, a lower incidence of severe congestive heart failure, and a reduced incidence of total cardiovascular death and sudden cardiac death. In addition to the studies completed in patients with MI, there are ongoing studies evaluating whether or not ACE inhibitors can reduce myocardial ischemic events in patients without a prior infarction who have coronary artery disease or hypertension and preserved LV function. There is also growing evidence that concomitant therapy with a beta-blocker and an ACE inhibitor may reduce mortality rates beyond that observed with ACE inhibitors alone in survivors of MI who have LV dysfunction.

[Ambulatory long-term rehabilitation of heart patients]

In Germany cardiac rehabilitation contains a comprehensive 3 to 4 week inpatient program. The aim of our study was to perform an outpatient long-term rehabilitation including intense exercise and behavior therapy. In this setting the health benefits could be increased over the first 6 months. Hundred and twelve patients (94 men and 18 women, age 55 +/- 11 years) after myocardial infarction (52%), bypass-surgery (37%), PTCA (23%), and others (15%) were included in the ongoing study. Cholesterol and LDL-cholesterol diminished significantly. HDL-cholesterol was increased significantly after 6 months. The endurance exercise capacity per rate-pressure-product was increased by 46% during the 6 months period. The intake of cholesterol could significantly be diminished from 307 +/- 25 to 258 +/- 19 mg per day. Five of 16 patients became free from smoking. The first results from the long-term outpatient program show that the time of intervention and also the intensity of the medical, exercise and the behavior therapy are important factors for a successful rehabilitation.

Effect of atenolol on mortality and cardiovascular morbidity after noncardiac surgery. Multicenter Study of Perioperative Ischemia Research Group

BACKGROUND

Perioperative myocardial ischemia is the single most important potentially reversible risk factor for mortality and cardiovascular complications after noncardiac surgery. Although more than 1 million patients have such complications annually, there is no effective preventive therapy.

METHODS

We performed a randomized, double-blind, placebo-controlled trial to compare the effect of atenolol with that of a placebo on overall survival and cardiovascular morbidity in patients with or at risk for coronary artery disease who were undergoing noncardiac surgery. Atenolol was given intravenously before and immediately after surgery and orally thereafter for the duration of hospitalization. Patients were followed over the subsequent two years.

RESULTS

A total of 200 patients were enrolled. Ninety-nine were assigned to the atenolol group, and 101 to the placebo group. One hundred ninety-four patients survived to be discharged from the hospital, and 192 of these were followed for two years. Overall mortality after discharge from the hospital was significantly lower among the atenolol-treated patients than among those who were given placebo over the six months following hospital discharge (0 vs. 8 percent, P<0.001), over the first year (3 percent vs. 14 percent, P=0.005), and over two years (10 percent vs. 21 percent, P=0.019). The principal effect was a reduction in deaths from cardiac causes during the first six to eight months. Combined cardiovascular outcomes were similarly reduced among the atenolol-treated patients; event-free survival throughout the two-year study period was 68 percent in the placebo group and 83 percent in the atenolol group (P=0.008).

CONCLUSIONS

In patients who have or are at risk for coronary artery disease who must undergo noncardiac surgery, treatment with atenolol during hospitalization can reduce mortality and the incidence of cardiovascular complications for as long as two years after surgery.

Obesity as a risk factor for various diseases: necessity of lifestyle changes for healthy aging

Recent research observations indicate that obesity is a significant independent predictor of cardiovascular disease (particularly coronary heart disease and stroke). Aside from the metabolic abnormalities, there are severe social and psychological consequences of obesity. It is clear that obesity is associated, to a large extent, with lifestyle. There is no single best way to treat obesity. In general, the lifestyle therapies include behavioral modification, nutritional adjustments, and exercise conditioning. In treating obesity, the major emphasis is particularly placed upon decreasing energy intake and, to a lesser extent, upon increasing energy expenditure. However, food restriction induces a decline in resting energy expenditure which is related to the decline in body mass. Numerous reports indicate that, although decreasing energy intake is undoutedly the most obvious and effective way to reduce fat, it also induces a significant amount of fat-free tissue loss. Regular exercise is a significant variable to consider in understanding and treating obesity, since it is the principal discretionary component of energy expenditure. In particular, aerobic exercise definitely plays an important role in preventing obesity in most persons. This article reviews the importance of lifestyle behaviors such as regular exercise and proper diet for prevention and maintenance of chronic diseases, along with definitions of some important words and multidimensional information regarding the epidemiology of obesity. Strategies for weight reduction are discussed.

The acute rise in plasma fibrinogen concentration with exercise is influenced by the G-453-A polymorphism of the beta-fibrinogen gene

We have investigated the effects of chronic physical training and acute intensive exercise on plasma fibrinogen levels and the relationship of these responses to beta-fibrinogen G-453-A polymorphism genotype. One hundred fifty-six male British Army recruits were studied at the start of their 10-week basic training, which emphasizes physical fitness. Cohorts were restudied between 0.5 and 5 days after a major 2-day strenuous military exercise (ME) undertaken in their final week of training. Changes in fibrinogen concentration were adjusted for the effects of age, body mass index, and smoking history. Compared with baseline values, fibrinogen concentrations were significantly lower (11.9%, P=.04) at day 5 after ME, consistent with the beneficial effect of training. However, they were higher on days 1 through 3 after ME (suggesting an "acute-phase" response to strenuous exercise) and were maximal on days 1 and 2 (27.2%, P<.001 and 37.1%, P<.001 respectively). Fibrinogen genotype was available in 149 individuals. As expected from previous studies, men with one or more fibrinogen gene A-453 alleles had plasma fibrinogen concentration slightly but significantly higher at baseline (4.5%, P=.11). During the acute-phase response (days 2 and 3), however, the degree of rise was strongly related to the presence of the A allele, being 26.7+/-5.4% (mean+/-SE), 36.5+/-11.0%, and 89.2+/-30.7 for the GG, GA, and AA genotypes, respectively (P=.01). These results confirm that chronic exercise training lowers plasma fibrinogen levels, that intensive exercise generates an acute-phase rise in levels, and that this acute response is strongly influenced by the G/A polymorphism of the beta-fibrinogen gene.

Circadian variation in human ventricular refractoriness

BACKGROUND

The incidence of sudden cardiac death is highest in the morning hours. Although a circadian variation in myocardial ischemia may be responsible in part for this observation, other factors also may be contributory. It is not known whether a circadian variation in ventricular refractoriness exists that may be related to the increased morning incidence of sudden cardiac death.

METHODS AND RESULTS

Nine subjects with primary conduction system disease, no evidence of structural heart disease, and permanent pacemakers were studied. Autonomic nervous system function as assessed by tilt table and baroreflex sensitivity testing was normal in all subjects. Using noninvasive programmed stimulation, ventricular effective refractory periods were measured hourly for 24 hours. Potassium, epinephrine, and norepinephrine levels also were measured hourly. In a subset of five subjects, ventricular refractory periods were again measured hourly over 24 hours during beta-blockade. A significant circadian variation in ventricular refractoriness was noted, with a mean difference between the shortest and longest refractory periods in individual subjects of 23 ms and 21 ms at drive cycle lengths of 600 ms and 400 ms, respectively. In eight subjects, the shortest refractory periods observed over 24 hours occurred within 2 hours of waking (random probability < 10(-8)). Adjustment of refractory period data according to the hour of waking resulted in a better correlation between ventricular refractory periods and time. Although a significant circadian variation was observed in potassium and catecholamine levels, neither was an independent predictor of refractory periods after adjustment for the hour of waking. The adjusted time of day was the only significant (P < .0001) independent predictor of refractory periods. beta-Blockade abolished the circadian variation in ventricular refractory periods.

CONCLUSIONS

A significant circadian variation in ventricular refractory periods exists. Maximal shortening between hourly refractory periods as well as the shortest refractory periods occur in the early morning hours when the incidence of sudden cardiac death is greatest. Fluctuations in beta-adrenergic tone appear to be largely responsible for this phenomenon.

CARDIOVASCULAR RISK FACTOR CLUSTERING AND CORONARY ARTERY DISEASE : A 4-YEAR FOLLOW UP STUDY OF 257 SERVICE PERSONNEL

Two hundred and fifty seven service personnel with established diagnosis of (a) silent ischaemia (40.47%) (b) Q-infarction (25.68%) and (c) non-Q-infarction (33.85%) along with 50 age-matched controls were subjected to stress tests before and after identification and control of risk factors. Lack of exercise (63.0%), dietetic indiscretion (47.4%) and cigarette smoking (40.4%) were the main risk factors. Hypercholesterolaemia (22.1%), alcohol over-indulgence (17.1%), positive family history (16.3%), diabetes mellitus (9.7%) and hypertension (6.2%) were other contributing factors. Clustering or multiplicity of risk factors was seen in 61.1% cases. All patients were advised for control of risk factors along with necessary specific therapy wherever indicated. Initial stress test was positive in 83.3% of the total and on repetition, after 4 years, the positivity dropped to 45.9% with a rate of improvement of 44.9%. Patients with silent ischaemia showed the maximum improvement (57.8%) following the risk factor intervention. Only 4 cases (1.56%) showed deterioration with reinfarction during the 4-year follow up.

Long-term functioning and well-being outcomes associated with physical activity and exercise in patients with chronic conditions in the Medical Outcomes Study

This study was carried out to determine whether levels of physical activity of patients with various chronic diseases are associated with subsequent functioning and well-being. It was an observational 2-year longitudinal design. The setting was offices of medical and mental health practices within health maintenance organizations, large multispecialty groups, and solo practices or small single-specialty group practices in three U.S. cities. Included in the study were 1758 adult patients with one or more of the following: diabetes, hypertension, congestive heart failure, recent myocardial infarction, depressive symptoms, or current depressive disorder. Outcome measures included physical, role, and functioning; energy/fatigue; pain intensity; sleep problems; depressed affect, anxiety, positive affect, and overall psychological distress/well-being; health distress; and current health perceptions. Cross-sectional (base-line), 2-year endpoint, and change score relationships were evaluated between baseline levels of physical activity and each outcome, controlling for chronic conditions, comorbidity, smoking, alcohol use, overweight, self-reported adherence, and other patient and study characteristics. Higher baseline levels of exercise were uniquely associated with better functioning and well-being at baseline and 2 years later for some measures. The magnitude of the differences varied by disease group, but tended to be between 0.17 and 0.39 of the baseline SD. Greater levels of exercise are associated with feeling and functioning better for patients with chronic conditions over a 2-year period, suggesting that this is a fruitful area for further study using controlled interventions.

Design of the training levels comparison trial

The Training Levels Comparison (TLC) trial was a grant-supported, multicenter, randomized, controlled clinical trial designed to determine whether cardiac rehabilitation patients would benefit from supervised exercise for a prolonged period (2 years) and whether subjecting patients to a more vigorous exercise program than currently recommended would provide additional cardiac benefit. If high-intensity exercise does not enhance the cardiac benefit, then physical activity should be limited to low-intensity levels that are safer, easier to implement and more adaptable to a greater number of patients. Patients were randomly assigned to either a low-intensity or high-intensity training program. All patients were to attend three 1-hour supervised exercise sessions per week for a period of 2 years. Attendance at exercise sessions and adherence to assigned treatments were monitored throughout the study. Patients were evaluated for outcome measures at 3, 6, 12, and 24 months. This paper reports the study design and methodology for the TLC trial, and should be useful in providing methodologies to facilitate comparison of data from other studies with different levels of exercise as an intervention.

Post infarct heart failure: what to do in addition to ACE inhibition

ACE (angiotensin converting enzyme) inhibitors are revolutionizing the management of heart failure and are now earning themselves a place in the early treatment of post myocardial infarction (MI) patients who have evidence of left ventricular (LV) dysfunction or, more modestly, evidence of infarct expansion. The aims of ACE inhibitor therapy are to control symptoms, if any, and to improve prognosis. For these indications, they are impressive. Nonetheless, they are not a panacea. Post MI patients face a variety of threats, not least from progression of their underlying ischemic disease, and they should not be denied prognostically advantageous interventions, such as beta-blockers and aspirin. Moreover, ACE inhibitor monotherapy may not be the best management for heart failure itself. The role of other additive agents should not be dismissed.

Physical activity of public housing residents in Birmingham, Alabama

OBJECTIVES

Because few data are available concerning physical activity among minority and low-income persons, we characterized physical activity patterns among public housing residents.

METHODS

Two separate cross-sectional surveys were conducted 1 year apart of randomly selected residents of eight rental communities administered by the housing authority of Birmingham, Ala. Indigenous interviewers completed 687 interviews in survey 1 and 599 in survey 2.

RESULTS

In both surveys, respondents were most frequently young adult African-American women, reflecting the predominance of women in these communities. Participants were generally poorly educated and either unemployed or working in service occupations. Thirty percent of the respondents in both surveys reported no participation in any of 13 physical activities in the previous year; approximately half reported activity levels equivalent to or less than walking 4 hours per week for 8 months of the year. Respondents who were younger and male were significantly more likely to have higher activity levels.

CONCLUSIONS

A sedentary life-style is common among this low-income minority group, and, thus, interventions to promote exercise in these communities are needed.