Clinical articles

With an ageing population in the United Kingdom, atrial fibrillation has become an increasing cause of morbidity and mortality, and a burden on health resources. Drug therapies for the management of atrial fibrillation have a number of roles, including the restoration and maintenance of sinus rhythm and the prevention of thrombo-embolic complications. New anti-arrhythmic drugs are under development and alternatives to warfarin are being investigated. This article examines the current knowledge on the effectiveness of drug therapy in atrial fibrillation and discusses some aspects of the future of drug therapy for atrial fibrillation.

With an ageing population in the United Kingdom, atrial fibrillation has become an increasing cause of morbidity and mortality, and a burden on health resources. Drug therapies for the management of atrial fibrillation have a number of roles, including the restoration and maintenance of sinus rhythm and the prevention of thrombo-embolic complications. New anti-arrhythmic drugs are under development and alternatives to warfarin are being investigated. This article examines the current knowledge on the effectiveness of drug therapy in atrial fibrillation and discusses some aspects of the future of drug therapy for atrial fibrillation.

In addition to identifying those patients with coronary heart disease, the National Service Frame-work also requires general practitioners to identify all people with a diagnosis of occlusive arterial disease, including stroke and peripheral vascular disease, and offer appropriate interventions. Asymptomatic peripheral vascular disease is common; it is estimated almost one in five patients between the ages of 55 and 74 would be identified as at risk. Patients with asymptomatic disease have the same increased risk of cardiovascular events and death as in patients with symptomatic disease. The author discusses how to diagnose asymptomatic disease, the merits of a screening programme in primary care, and which patients general practitioners should target.

The current focus of our efforts in treating hypertension is to ‘treat to target’ using combination therapy. However, 24-hour control of blood pressure (BP) is of crucial importance in reducing cardiovascular risk. There is a circadian rhythm for such risk, with morning peaks in sudden cardiac death, myocardial infarction, unstable angina and ischaemic stroke. There is also a natural circadian rhythm in BP. Lack of a significant nocturnal dip worsens prognosis: patients tend to have increased left ventricular hypertrophy, cardiovascular mortality and cerebrovascular disease. Risk is related to the patient’s total BP load.
The implications are that truly long-acting once-daily antihypertensives are needed, with a trough/peak ratio > 50%. Patient compliance is very important. Ambulatory BP monitoring should be used in selected patients. Patients should be advised to take their antihypertensive medication on waking rather than waiting until after breakfast.

We describe a case of infective endocarditis, which presented with digoxin toxicity. This case is of interest since the patient only became pyrexial six days after admission when blood cultures grew Streptococcus viridans. We believe this is the first case of infective endocarditis presenting with digoxin toxicity.

Erectile dysfunction (ED) is reported to coexist with cardiovascular disease. It may be the first clinical manifestation of cardiovascular disease making it a helpful, early marker. Psychogenic causes are also an important component of ED. Around half of all men over the age of 40 years are affected by ED but treatment is often not requested by the patient. ED can be successfully treated pharmacologically. PDE-5 inhibitors are currently the treatment of choice. Physicians should initiate discussion about sexual health and ED in the diagnosed cardiovascular patient.

Multiple lines of evidence show that high-density lipoproteins (HDL) protect against coronary heart disease (CHD), and that low blood levels of HDL cholesterol (HDLc) indicate high risk of a coronary event. Major epidemiological studies show that a low HDLc is a strong predictor of CHD, and this relationship occurs at any level of low-density lipoprotein cholesterol (LDLc) or triglycerides, demonstrating independence. When the HDLc level is raised by drug therapy, coronary atherosclerosis is decreased and CHD events are lessened. Increases in HDLc are in fact independently correlated with coronary angiographic and clinical benefit. HDL stimulates the removal of cholesterol from cells in the vascular wall. The cholesterol is taken up by HDL and shuttled in part to the liver for excretion in the bile.
Experiments in transgenic mice provide proof that increased HDL secretion protects against atherosclerosis caused by an atherogenic diet or genetic hyperlipidaemia. In humans, HDL has direct beneficial effects on coronary arterial vasodilation. This compelling scientific evidence thus justifies HDLc as a target to reduce risk of CHD. An international group of experts in epidemiology, clinical and basic science formed a consensus that an HDLc concentration of 1.0 mmol/L (40 mg/dL) is a realistic clinical guideline for patients at high risk of a coronary event. Specific diet and drug therapies were recommended.

Older patients represent the majority of those considered for coronary intervention but they are under-represented in most clinical trials in this area. Reviewing registry data and pooled data from clinical trials, this article discusses the effect of age on procedural mortality and morbidity. It also reviews the effect of age on interventional procedures in unstable patients, and on pharmacological intervention. Despite the higher initial risks in older patients, the authors argue that several risk factors are responsible for predicting poor outcome following interventional procedures. Percutaneous coronary intervention can be very successful in the elderly and its risks must be balanced against the many important benefits older patients stand to gain from the procedure.

Non-steroidal anti-inflammatory drugs (NSAIDs) have potentially dangerous side effects, which has led to intense interest in the development of the cyclo-oxygenase (COX) inhibitors. This article reviews the science, safety and clinical evidence to date with these drugs.
They appear to have fewer gastrointestinal and equivalent renal risks to NSAIDs. Reviewing the clinical evidence, particularly the complex cardiovascular effects of the COX inhibitors, the article discusses the clinical relevance of their thrombogenic and anti-atherosclerotic potential. Since many of the studies are retrospective analyses, randomised clinical trials are needed to ascertain whether these cardiovascular effects constitute a problem or an unexpected benefit, and whether there are differences between the different COX-2 inhibitors.

Epidemiological studies in the Netherlands first demonstrated an inverse relationship between ordinary (technically known as black) tea drinking and cardiovascular disease (CVD) mortality. Subsequent population-based studies have variously agreed with, been opposite to (notably in the UK) or produced null results. Currently, UK epidemiological studies look out of step with the rest of the world. This review highlights that, in the UK, tea drinking is more pronounced in the lower socio-economic (SE) groups, whilst tea drinking is associated with higher SE groups in the other countries that have linked tea to CVD. It is this key difference that may account for the apparent positive relationship between tea drinking and CVD mortality in the UK; low SE status (and high tea drinking) is also strongly associated with a high prevalence of the major CVD risk factors.
Any positive benefits from tea drinking are likely to be due to a high content of antioxidant flavonoids, particularly the catechins. In vitro and intervention studies support mechanisms, such as improved endothelial function, whereby tea flavonoids may be cardioprotective.
Whilst there is no evidence from population studies of positive cardiovascular benefit from tea drinking in the UK, tea is still contributing flavonoids to individual diets and these may well be beneficial. Tea drinking can safely be encouraged as part of a healthy diet. Further studies are required to clarify the situation.