Clinical articles

There is extensive evidence of an increased risk of coronary heart disease (CHD) amongst South Asians (Indo-Asians) compared with Caucasians. This increased risk is not explained by conventional risk factors for CHD, such as smoking, hypertension and elevated total cholesterol levels. Studies have consistently demonstrated an increased prevalence of metabolic abnormalities including insulin resistance, diabetes, impaired glucose tolerance and dyslipidaemia, characterised by low plasma levels of high-density lipoprotein cholesterol (HDL-C) and high levels of triglycerides and lipoprotein a (Lp[a]), amongst South Asians. Together these factors predispose to accelerated atherosclerosis, and this is accentuated by adoption of a Western lifestyle. Nicotinic acid is the most potent lipid-modifying therapy for increasing HDL-C (by up to 30%), and is also effective in reducing triglycerides and Lp(a). Clinical studies in Caucasian patients have shown that nicotinic acid can also be safely used in patients with controlled type 2 diabetes. Long-term intervention studies have demonstrated the clinical benefits of nicotinic acid treatment, reducing cardiovascular morbidity and mortality in Caucasian patients with CHD. Nicotinic acid could potentially offer important therapeutic benefits in South Asians. Further clinical studies in this patient group are needed to substantiate this potentially useful treatment strategy and identify specific groups that would derive most benefit.

Amiodarone is used to prevent atrial and ventricular arrhythmias
in high-risk patients, such as after a myocardial infarction (MI)
and in congestive cardiac failure. Its use has increased since the mid-1990s
and, in 2001, around one million prescriptions were dispensed in primary care in England.

Many large studies have confirmed the importance of controlling hypertension in reducing cardiovascular morbidity and mortality. Prescribers are now faced with a wide choice of antihypertensives and a growing body of evidence about their effects.
This article reviews recent evidence about angiotensin II receptor blockers (ARBs). It concludes that they are effective in reducing blood pressure and cardiovascular disease. ARBs also have a renoprotective effect in diabetes. They are generally better tolerated than ACE inhibitors or beta blockers. Newer members of the class may be more effective than older ones at controlling hypertension, and combinations of ARBs with ACE inhibitors may be more effective than either drug alone. Many patients will require combinations of different classes of antihypertensive agents, and ARBs have an important place in providing therapy tailored to the needs of the individual patient.

We report a case of very early onset of
amiodarone-induced pulmonary toxicity,
which appeared 12 days after starting treatment.

Antiplatelet therapy plays a major role in the secondary prevention of ischaemic stroke. The antiplatelet agents that are most used in the clinic include aspirin, dipyridamole and clopidogrel. These agents inhibit platelet activation through different mechanisms of action. Aspirin is the first-line drug in the secondary prevention of stroke; a combination of aspirin with dipyridamole produces a synergistic antithrombotic effect. Clopidogrel is slightly more effective than aspirin at reducing the risk of ischaemic events. Trials comparing the combination of aspirin and clopidogrel versus aspirin are underway. Intravenous antiplatelet therapy with glycoprotein IIb/IIIa receptor inhibitors for acute stroke and as an adjunct to carotid artery stenting appears promising. However, oral GPIIb/IIIa receptor inhibitors appear hazardous.

Five case histories are described to illustrate the importance of patent foramen ovale and atrial septal aneurysm as risk factors in stroke aetiology. Diagnostic methods, and the current and future management of these atrial septal defects, are briefly discussed.

The Framingham Heart Study investigators have recently developed new coronary risk appraisal functions which relate risk factors to the short-term probability of experiencing cardiovascular disease events. We populated the risk appraisal functions with UK data and estimated that approximately 256,000 new coronary artery disease (CAD) events occur annually in the UK. Approximately half of the estimated CAD events were acute myocardial infarctions (AMI) and almost three quarters occurred in men. Our estimates fit well with hospital in-patient data but less well with British Heart Foundation estimates of AMI and angina. Differences between US and UK relative risks, clinical practice and populations may account for these discrepancies. Our estimates may be considered as a lower limit of the annual number of UK CAD events.

Assisting smokers to stop smoking is often seen as a difficult task but is crucial for health improvement, especially for those with established cardiovascular disease. Healthcare professionals are now, more than ever, in a position to help smokers who want to stop. For the greatest chance of success smokers should be referred to stop smoking services that provide multi-session treatment combining intensive behavioural support with nicotine replacement therapy or bupropion. Promising new medications are being developed that will add to the current treatment strategies and may give smokers a greater chance of stopping for good.

The renin-angiotensin system (RAS) plays a fundamental role in cardiovascular pathophysiology. In particular, angiotensin II (AII) has been identified as a culprit in endothelial and vascular damage, elevated blood pressure, and cardiac failure. Pharmacological inhibition of this system is available through two mechanisms; the reduction of AII formation by inhibition of angiotensin-converting enzyme (ACE), and by direct blockade of the type 1 angiotensin II receptor by angiotensin II receptor blockers (ARBs).
Angiotensin-converting enzyme (ACE) inhibitors have a proven role in the management of elevated blood pressure and diabetes and may confer specific vascular benefit. In patients with chronic heart failure (CHF) secondary to left ventricular systolic dysfunction (LVSD), there is extensive evidence that, when compared to placebo, ACE inhibitors reduce morbidity and mortality. Randomised placebo controlled trials have also shown ACE inhibitors reduce all-cause mortality and major cardiovascular events after myocardial infarction.
Given the unequivocal benefit of ACE inhibitors, initial studies with ARBs in patients with LV dysfunction (in CHF and following myocardial infarction) have focused on two areas: the role of ARBs when compared with ACE inhibitors, and when combined with ACE inhibitors.
Only recently, with the results of the CHARM study, have the role of ARBs when compared to placebo in a population with CHF been clarified. This study also addressed the benefit of ARBs in patients with heart failure and preserved LV systolic function.