Clinical articles

Stroke, cognitive impairment and dementia are well-established complications of long-standing hypertension. There is a considerable time lag, usually several decades, between the onset of hypertension and the occurrence of these complications. Although antihypertensive treatment has been shown to decrease the risk of a first stroke, little evidence is available on the effects of antihypertensive treatment on the incidence of recurrent cerebrovascular events, cognitive impairment and dementia. The results of recent studies addressing this issue are discussed, along with directions for future research.

Vascular dementia (VaD) and Alzheimer”s disease (AD) are often described as distinct entities. Recent literature suggests that they may be part of a continuum, where pure VaD is quite rare, Alzheimer”s disease is only 40% of the total and AD with cerebrovascular disease makes up the majority of cases that present to memory clinics. This relationship between VaD and AD is highlighted by their common risk factors – especially cardiovascular. Pure VaD is a heterogeneous entity, now separated clinically and radiologically into cortical, subcortical and strategic infarct subtypes. The treatment of VaD includes the primary and secondary prevention of cardiovascular and cerebrovascular disease; and early signs of a dementia may not always involve memory loss. This can lead to late presentations of patients when the more obvious signs and symptoms occur. Consequently, dementia services should work more closely with cardiology and stroke services in order to detect early cases of VaD. This will be increasingly important as new treatments become available.

Achieving good glycaemic control is an important part of the treatment strategy to minimise vascular complications in diabetes. An expanding range of differently acting oral antidiabetic agents provides new choices for type 2 patients. This review considers the attributes and limitations of these agents, and their positioning in the treatment process.

My approach to assessing CHD risk

There are now well-recognised guidelines which state that when reducing someone’s risk of cardiovascular disease the decision to start medication depends on the patient’s absolute risk of coronary heart disease, as opposed to their relative risk, which should be determined using multiple risk factors.
More than 29 cardiovascular risk tools are available to calculate a patient’s absolute risk of cardiovascular disease. Choosing which risk tool to use can be difficult. This article gives a description of the differences between cardiovascular risk tools. It also discusses some of the problems and benefits of risk tools in general and examines the differences between absolute and relative risk.

Scotland has one of the highest mortality rates for ischaemic heart disease (IHD) in the world, accounting for one quarter of all deaths. Much evidence demonstrates aggressive management of risk factors can make a significant difference to this high morbidity and mortality. Current evidence suggests that secondary prevention of IHD is currently not carried out well in primary care in the UK. Our practice set out to see if this could be improved by using computer records. Over the course of four years more than 80% of IHD patients are now on aspirin, almost 90% have blood pressure recorded annually (average 130/74 mmHg), 82% are non-smokers, 84% have an annual cholesterol check, 65% have a cholesterol < 5 mmol/L, 56% are on a cholesterol-lowering drug (average cholesterol is 4.76 mmol/L), 61% are on cardioprotective drugs, and there was one acute infarct. We suggest that secondary prevention can be improved at a practice level with a good recording system, and a motivated primary care team.

Angina pectoris occurs in 30–40% of patients with aortic stenosis, despite a normal coronary circulation. This along with syncope, classically occurs during exercise. There are a number of suggested pathophysiological mechanisms for these symptoms, all of which lead to an imbalance between myocardial oxygen supply and demand. We report an 81-year-old patient who had several episodes of chest pain occurring at rest, leading to syncope resulting in electro-mechanical disassociation (EMD) cardiac arrest. The electrocardiogram (ECG) during these episodes showed profound ST depression, leading to the hypothesis that the underlying pathophysiology was due to myocardial ischaemia caused by the aortic stenosis alone.

Sibutramine is one of two anti-obesity agents approved by the National Institute of Clinical Excellence. It inhibits the re-uptake of noradrenaline and serotonin in the brain. By enhancing the sensation of satiety after a meal and reducing the fall in basal metabolic rate which usually occurs during weight loss, sibutramine is a useful aid to achieving weight loss and weight maintenance. Randomised controlled trials have shown that sibutramine 10 mg/day, in combination with diet and exercise, produces and maintains a dose-related weight loss of 5–10% in the majority of obese patients studied. This is accompanied by a range of important health benefits, including improvements in cholesterol and triglyceride levels.
Adverse publicity led to the European Commission’s Committee for Proprietary Medicinal Products recently carrying out an in-depth investigation into the use of sibutramine in over 12,000 patients across Europe. Its findings support the use of sibutramine in obesity management, with no causal link found between the use of the drug and mortality. No change has been made to the Summary Product of Characteristics regarding the cardiovascular safety of sibutramine and the drug has been re-instated for use in Italy.
Prescribers should be aware of the cautions surrounding sibutramine use. While it is not advisable for those with a history of coronary heart disease or cardiac arrhythmias, published data reveal that most patients on sibutramine experience a drop in blood pressure and it may be used safely in patients with controlled hypertension. A small number of patients treated may show increases in blood pressure, particularly those who appear to be non-responders. Regular blood pressure monitoring is therefore advised.

Almost a half of all myocardial infarctions occur in those over 70 years of age and this is projected to rise further as the number of older patients in the total population increases. Following myocardial infarction, complications are more common in the older patient and the mortality outlook is much worse in those aged over 75 years. Guidelines generally favour the administration of thrombolysis post-myocardial infarction to older patients, although there is a lack of randomised clinical trials with thrombolysis in this group. Observational data, however, suggest that there is a significantly increased risk of mortality in patients aged over 75 years and this means the elderly are less likely to receive thrombolytic therapy, even when no contraindications are present. Randomised trials have shown that percutaneous coronary intervention is associated with a better outcome in the older patient. With the advances in antiplatelet therapy and the advent of intracoronary stents, this outcome is expected to improve further. The article also discusses therapeutic options in secondary prevention.

Clinical and epidemiological studies suggest elevated levels of total plasma homocysteine (> 15 µmol/L) are associated with an increased risk of cardiovascular disease, independent of other known risk factors. This review outlines the causes of hyperhomocysteinaemia, current evidence of a positive association with cardiovascular disease, and how such findings may have important implications for future assessments of risk and nutritional recommendations, particularly for those with a previous or family history of cardiovascular disease.