Prevalence of left-ventricular systolic dysfunction and heart failure in the Echocardiographic Heart of England Screening study: a population based study.

BACKGROUND: Accurate data for prevalence rates for heart failure due to various causes, and for left-ventricular systolic dysfunction in all adults are unavailable. Our aim was to assess prevalence of left-ventricular systolic dysfunction and heart failure in a large representative adult population in England. METHODS: Of 6286 randomly selected patients aged 45 years and older, 3960 (63%) participated in the study. They came from 16 randomly selected general practices. We assessed patients by history and examination, electrocardiography, and echocardiography. Prevalence of left-ventricular systolic dysfunction (defined as ejection fraction <40%) and heart failure was calculated for the overall population on the basis of strict criteria and, when necessary, adjudication by a panel. FINDINGS: Left-ventricular systolic dysfunction was diagnosed in 72 (1.8% [95% CI 1.4-2.3]) participants, half of whom had no symptoms. Borderline left-ventricular function (ejection fraction 40-50%) was seen in 139 patients (3.5% [3.0-4.1]). Definite heart failure was seen in 92 (2.3%, [1.9-2.8]) and was associated with an ejection fraction of less than 40% in 38 (41%) patients, atrial fibrillation in 30 (33%), and valve disease in 24 (26%). Probable heart failure was seen in a further 32 (0.8% [0.6-1.1]) patients. In total, 124 (3.1% [2.6-3.7]) patients aged 45 years or older had definite or probable heart failure. INTERPRETATION: Heart failure is often misdiagnosed or underdiagnosed in primary care. Our results suggest that assessment of left-ventricular function in patients with suspected heart failure could lead to more effective diagnosis and treatment of this disorder.

A comparison of the effects of strength and aerobic exercise training on exercise capacity and lipids after coronary artery bypass surgery.

BACKGROUND: Coronary artery surgery improves symptoms and prognosis in patients with angina. Aerobic exercise rehabilitation improves exercise capacity and prognosis in cardiac patients. Strength exercise training has not been extensively studied. DESIGN: We studied the effects of 6 months aerobic and strength exercise training after coronary artery surgery in 81 men, mean age 57 years. RESULTS: Treadmill time(s) increased by 130.3 (95% confidence interval 46.4 to 214.2) in the aerobic group; by 83.1 (0.9 to 165.3) in the strength group, and by 34.3 (-1 to 69.6) in the control group (P = 0.04, control versus aerobic) after 3 months; and by 196.4 (112.2 to 280.7) in the aerobic group, by 122.7 (37.7 to 207.6) in the strength group and by 27 (-40.4 to 94.4) in the control group (P = 0.002, control versus aerobic, and P = 0.03 control versus strength) after 6 months. The level of fitness improved more in the strength-trained group, and there was a minor reduction in body weight and degree of fatness. There were no changes in lipoprotein levels. Aerobic exercise training causes early and sustained benefit in treadmill exercise capacity, while the effects of strength exercise training are later in onset. Exercise training alone did not influence lipid levels. CONCLUSION: Cardiac rehabilitation programmes should be comprehensive, including advice on diet and other risk factor modifications in addition to exercise sessions involving aerobic and strength training elements.

Does thrombolysis affect the prognostic value of the post-infarct exercise test?

There has been some debate on usefulness of the exercise test in risk stratification after myocardial infarction in the thrombolytic era. This was assessed in 295 patients of whom 184 were treated with thrombolysis. Each had an exercise test using a modified Naughton protocol within 14 days of acute myocardial infarction. The tests were graded as high risk positive (112), low risk positive (83), or negative (100). These gradings predicted use of multiple drug therapy (p = 0.05), severity of coronary artery disease (p < 0.01), and coronary artery bypass grafting (p < 0.01). There was no influence on heart failure, recurrent myocardial infarction or death. This was independent of the use of thrombolytic therapy. The whole group had a good prognosis with a mortality of 2.4% after 56 weeks' follow-up. The exercise test is still a useful screening test after myocardial infarction. In this study, there was a high negative predictive accuracy of 91% for any event. Its use is not altered by thrombolysis. The finding of a lack of influence of the exercise test on major events may be a reflection of the current good prognosis after myocardial infarction and the prompt use of revascularisation.

Effects of ciprofibrate on LDL metabolism in man.

This study examined the effects of ciprofibrate therapy (100 mg/day) on plasma lipids, lipoproteins and low density lipoprotein (LDL) kinetic heterogeneity in moderately hypercholesterolaemic subjects. The drug lowered plasma triglyceride and cholesterol by 41% and 17%, respectively. Very low density lipoprotein (VLDL) cholesterol fell by 38%, LDL cholesterol fell by 22%, while the content of the lipid in high density lipoprotein (HDL) increased by 11%. LDL structural and metabolic heterogeneity were assessed before and during therapy in eight subjects. Density gradient centrifugation was used to fractionate LDL into three species. LDL-I, the least dense, was not affected by therapy whereas LDL-II and LDL-III were decreased by 28% (P < 0.01) and 31% (N.S.). Baseline turnover studies revealed that LDL catabolism was subnormal and this was the cause of the raised cholesterol in these subjects. Ciprofibrate therapy increased the apoLDL fractional catabolic rate (FCR) by 19%, principally by inducing a 38% enhancement (P < 0.03) in apoLDL removal by the receptor pathway. ApoLDL kinetics exhibited metabolic heterogeneity both before and during drug therapy. Analysis of plasma decay curves for the LDL tracer and urinary excretion data indicated that the lipoprotein comprised two metabolically distinct species, one with an FCR of about 0.50 pools/day (Pool A), the other with an FCR of about 0.18 pools/day (Pool B). Drug therapy decreased synthesis of and hence reduced the plasma mass of apoLDL in the slow metabolised pool B. This perturbation in synthesis was linked to the change in plasma triglyceride concentration. The resultant reduced proportion of pool B vs. pool A material accounted for the observed promotion of LDL receptor-mediated clearance. Ciprofibrate, therefore, produced beneficial changes in the plasma levels of VLDL, LDL and HDL and in the metabolism of LDL.

Early diagnosis of acute myocardial infarction: CK-MB and myoglobin compared.

We have measured changes in plasma concentration of creatine kinase MB (CK-MB) and myoglobin in 50 patients admitted to the Coronary Care Unit with chest pain of presumed cardiac origin. Eight serial blood samples were obtained in the 6 h period following admission and both CK-MB and myoglobin concentrations were measured. We compared the performance of single values of both tests. Myoglobin concentration, in the coronary care population studied, proved to be as specific as CK-MB concentration (92.6% in both cases) but with sensitivity of 100% being achieved 1.5 h post admission rather than 4 h post admission in the case of CK-MB. On this evidence, measurement of plasma myoglobin could prove useful in the rapid diagnosis of myocardial infarction with consequent effects on optimal Coronary Care utilisation and selection of patients for thrombolytic therapy.

Cardiac rehabilitation following myocardial infarction. A practical approach.

The concept of cardiac rehabilitation following myocardial infarction is not a new one but is now at last gaining acceptance as an essential part of the service to the coronary patient. Its aim is to restore the effectiveness of post-infarct patients by ensuring that they are well adjusted, well educated and fit and thereby best able to cope with the long term consequences of their ischaemic heart disease. The first essential factor for good rehabilitation is patient education. Studies have shown high levels of distress and anxiety after infarction and to a large extent this is related to lack of information. Where patients have been given adequate information concerning their condition and treatment there is a high level of patient satisfaction and greater compliance. It must be appreciated that stress and anxiety impair the patient's ability to assimilate information and therefore repeated reinforcement is necessary. During the in-hospital period, the staff who are caring for the patient are constantly changing and while there is a role for all to educate the patient, the use of a cardiac liaison sister provides a continuity throughout the early recovery period to ensure that the education process is adequate. The use of written material and both audio and video tapes is also helpful. It is also important for the liaison sister to extend her role to the patient's immediate family, who also require information, and finally the liaison sister can provide a link into the post discharge phase, to answer the many questions that arise at this time, and to provide encouragement to the patient who is attempting to modify his lifestyle by stopping smoking, changing his diet and taking regular exercise. The use of exercise training is the second vital ingredient for adequate rehabilitation. This begins in earnest after the 6-week assessment, which can provide information on which to base an exercise prescription. The majority of patients enrolled within exercise programmes are medically stable and relatively symptom-free. There is increasing evidence that those with extensive myocardial damage, left ventricular dysfunction or failure, and ongoing myocardial ischaemia may also benefit. Traditional training programmes have been hospital based and have used mainly aerobic exercise. However, home based programmes should not be discounted where they may be more economical, more convenient, and improve patient compliance. Similarly, circuit training with weights has been shown to improve aerobic endurance and muscle strength and to have additional benefits in improved treadmill time compared with traditional aerobic programmes.(ABSTRACT TRUNCATED AT 400 WORDS)

Influence of power and aerobic exercise training on haemostatic factors after coronary artery surgery.

OBJECTIVES: To determine the effects of aerobic and power exercise training on haemostatic factors after coronary artery surgery and to compare the effect of the two exercise programmes. DESIGN: A prospective randomised controlled study of six months aerobic and power exercise training in men after coronary artery surgery. SETTING: Exercise rehabilitation classes in a teaching hospital in Glasgow. PATIENTS: 55 men within 12 months of coronary artery surgery recruited from surgical centres and medical clinics and asked to participate in the study. INTERVENTIONS: Assessments, including a treadmill test, measurements of haemoglobin, platelet, fibrinogen, factor VIIc, and fibrinopeptide A concentrations, and packed cell volume, done at baseline, three months, and six months. Patients in the two exercise groups attended training sessions three times weekly for six months. Control patients had no formal exercise training but continued with their leisure time activities. MAIN OUTCOME MEASURES: Exercise performance on a treadmill, haematology, and haemostatic factor assays at baseline, three months, and six months. RESULTS: In the aerobic trained group exercise performance increased significantly over baseline at three months (interval change 146.7, 95% confidence interval (95% CI) 52.5 to 240.9 s, p = 0.003) and was maintained at six months (interval change 172.1, 95% CI 63.3 to 280.9 s, p = 0.002). In the power trained groups significant improvement in exercise performance was delayed until six months (interval change 99.9 s, 95% CI 20.3 to 170.5 s, p = 0.01). Exercise performance in the control did not change significantly. Haemoglobin, concentration, packed cell volume, and platelet counts did not change significantly at any time. Fibrinogen concentration was significantly lower in the aerobic group than the other two groups at three months (2.96 g/dl compared with 3.3 g/dl and 3.87 g/dl in the power and control groups, p = 0.01). The power group had a lower fibrinogen concentration than the control group (p = 0.04). The lower fibrinogen concentration in the aerobic group was maintained at six months. There was a gradual rise in factor VIIc concentrations in the aerobic and control groups compared with a small fall in the power group. Fibrinopeptide A concentrations showed no consistent changes. CONCLUSIONS: Aerobic exercise training after coronary artery surgery causes an early favourable change in treadmill performance and in fibrinogen concentrations, that is maintained with further training. Power exercise training causes delayed benefit in treadmill performance. It also causes a small fall in fibrinogen concentrations. These changes may be relevant in reducing cardiovascular morbidity from graft failure and occurrence of myocardial infarction after coronary artery surgery.

An outbreak of isoniazid resistant tuberculosis in Glasgow 1981-1988.

An increase in the number of patients attending the Victoria Infirmary, Glasgow with isoniazid resistant tuberculosis, prompted a survey of the incidence of the condition in Glasgow. There was a clustering of cases among the homeless and/or alcoholic population of the city, particularly between the years 1982 and 1986. This suggests an outbreak of isoniazid resistance among that population, probably spread from a single, but unidentified source.