Clinical articles

This article looks at the results of four studies which examined the delivery of early thrombolysis by general practitioners and ambulance paramedics to patients suffering an acute myocardial infarction. The studies found that they could provide early thrombolysis safely.
One study in an isolated rural area in Scotland found general practitioners would have very limited experience of thrombolysis – one case per general practitioner per year – and that use of thrombolysis by local general practitioners fell off sharply after the study. A second study carried out in 15 European countries and Canada, found that there was no significant improvement in mortality and morbidity in the pre-hospital group given thrombolysis at home. This was also found by a Dutch study. An American study using computer-assisted diagnostic ECGs relayed to a physician at the base hospital, found little difference in the pre-hospital and hospital treatment arms but a dramatic improvement in the speed of treatment of both groups. Pre-hospital thrombolysis was also reduced. Two studies found ambulances became ‘tied up’ when thrombolysis was delivered at home.
These studies were used as part of a submission on behalf of the Primary Care Cardiovascular Society to the National Institute for Clinical Excellence. The rest of the submission is discussed in part two of this article next month.

The authors describe a case of a Wolff-Parkinson-White syndrome patient experiencing atrial fibrillation, which was difficult to distinguish from ventricular tachycardia.

Thrombolytic therapy has revolutionised the management of acute myocardial infarction (MI) and saved many thousands of lives. Since these agents first became available nearly 20 years ago, many new pharmacological therapies have been developed to try and improve both short-term and long-term outcome following MI. Surgical interventions too are being considered as a serious option during the immediate post-MI period to avoid the adverse effects of thrombolysis and improve long-term outcome. At the same time, research is focusing on what therapy should follow acute MI treatment to improve the long-term outlook for patients. Both old and new therapeutic options need to be considered to offer patients the best chance of a full recovery and long-term survival after MI.

These images are from a 65-year-old woman referred for stress echocardiography following a history of exercise-induced dizziness and shortness of breath. A dobutamine stress echocardiogram was performed. The resting heart rate was 90 beats per minute and resting blood pressure was 210/90 mmHg. The resting images showed severe concentric left ventricular hypertrophy with normal systolic function.

In the last few years our ideas about the physiological and pathological roles of aldosterone have changed enormously. It is now widely recognised that this hormone not only plays a crucial role in normal salt and water regulation, and its abnormalities in congestive heart failure and some types of hypertension, but also has other effects. These may include the promotion of cardiac and vascular inflammation and fibrosis and increased likelihood of arrhythmias. These perspectives coincide with a revived interest in aldosterone antagonists, particularly since the RALES trial showing the benefits of spironolactone in patients with congestive heart failure. This long-established drug does unfortunately have serious adverse effects, notably gynaecomastia and menstrual abnormalities. New drugs, such as eplerenone, are being developed which are more selective for the aldosterone receptor and have less interaction with receptors for other steroid hormones. Early studies indicate that this drug may have comparable efficacy to spironolactone in patients with hypertension and heart failure, while adverse effects appear to be less frequent and severe. The development of such compounds will encourage greater emphasis on aldosterone antagonism in cardiovascular drug therapy.

The major objective for the diagnosis and treatment of hypertension should be the detection of those at increased risk of coronary heart disease (CHD) and stroke, and the reduction of this risk.

We examined the workload implications of the National Service Framework for Coronary Heart Disease and the 1999 British Hypertension Society guidelines for the management of hypertension in clinical practice. The 1998 Health Survey for England was used to estimate the proportion of the English population aged 35 to 74 years that may require antihypertensive therapy. Of 8,154 subjects with blood pressure measurements, 400 (4.9%; 95% CI 4.4 to 5.4%) with cardiovascular disease were taking antihypertensive drugs and a further 100 (1.2%; 1.0 to 1.5%) were at treatment thresholds for secondary prevention of cardiovascular disease. There were 848 (10.4%; 9.7 to 11.1%) subjects free of cardiovascular disease on antihypertensive therapy and an additional 1,083 (13.3%; 12.5 to 14.0%) were identified for treatment. We estimate that 29.8% (28.8 to 30.8%) of the English population aged 35 to 74 years were candidates for antihypertensive therapy, of which 15.3% (14.5 to 16.1%) were already being treated but only 5.4% (4.9 to 5.9%) had their blood pressure controlled. An additional 14.5% of the English population will need antihypertensive therapy and an extra 9.9 % will need to have their treatment intensified to attain the blood pressure targets set by the British Hypertension Society guidelines.

Heart transplantation is an accepted therapeutic option in selected patients with end-stage heart failure. Up to 10% of patients develop renal failure while on the waiting list for heart transplantation. Renal dysfunction is a relative contraindication to heart transplantation. In order to establish current practice in UK heart transplant centres and overall surgical outcomes for combined heart and kidney transplantation, we surveyed the eight units currently responsible for heart transplantation, all but one of which had carried out at least one combined heart and kidney transplant. We obtained outcome data from the United Kingdom Transplant organisation. We found a wide variability in the level of renal function considered a contraindication to heart transplantation, and no consensus on the criteria for combined heart and kidney transplantation. The 30-day mortality was 14% (4/28) and survival at one, three, five and 10 years was 66.5 (95% confidence interval 57.3–75.7), 50.2 (40.3–60.1), 45.6 (35.6–55.7), and 30.8 (19.2–42.4) respectively, with significant variability between centres.
A prospective, controlled trial is needed to address these issues, but such a study remains extremely unlikely in the context of the increasing scarcity of organ donors.

This study looks at how well cardiovascular risk factors were being controlled in a high-risk group of patients awaiting coronary artery bypass surgery. It shows significant short falls in the implementation of currently advocated strategies.

This article explains how general practitioners can diagnose and treat heart failure in primary care. Diagnosis is difficult and four diagnostic tests – the electrocardiogram, chest x-ray, blood test for natriuretic peptides and echocardiography – are recommended as being of particular value in confirming the diagnosis in primary care.
A six-step treatment strategy is then given advising i) confirming the diagnosis, ii) excluding other treatable causes of heart failure, iii) giving general advice to the patient, iv) starting treatment with a diuretic, v) then adding an angiotensin-converting enzyme inhibitor, and, vi) finally adding a beta blocker. A 10-point plan explaining in detail how to start beta blockers in primary care concludes the article.