Clinical articles

Patients with mechanical prosthetic heart valves require oral anticoagulation to reduce the risk of thromboembolic events, but this can be complicated by anticoagulant-associated intracerebral haemorrhage (ICH). In order to make appropriate decisions about the resumption of anticoagulation in patients with mechanical heart valves and ICH, the risks of further bleeding must be weighed against those of thromboembolic events. There is limited evidence available to guide clinical decision-making in this situation and each case must be assessed individually, ideally with a multi-disciplinary team approach.

The British Society of Echocardiography (BSE) Education Committee has published a minimum dataset of 24 views for acquiring a standard adult transthoracic echocardiogram. To establish adherence to the minimum dataset, and secondly to establish the indication for echocardiography, we performed a retrospective review of 961 patients’ echocardiogram images and a prospective review (re-audit) of 832 patients’ echocardiograms, following a programme of echocardiographer education. Images were obtained from a computerised database over three months. Subjects were adult patients referred to the cardiology department of a large tertiary hospital in Oxfordshire. Results showed 17 views were consistently obtained in over 78% of patients, irrespective of audit period. Seven views were obtained in less than 50% of patients; of these, five views were performed significantly more frequently during re-audit. Apical four chamber continuous wave Doppler across the tricuspid valve, and subcostal views were performed in less than 45% of patients; this did not increase during re-audit. The main indication for performing an echocardiogram was assessment of left ventricular function, followed by assessment of valve function and investigation of arrhythmia. In conclusion, all echocardiographers need to be made aware of, and adhere closely to the requirements of the minimum dataset.

In a retrospective longitudinal cohort study of 111 consecutive patients with suspected left ventricular systolic dysfunction (LVSD) referred for open-access echocardiography, patient’s views at one-year follow-up in terms of satisfaction with the service, ongoing symptoms and personal health beliefs were assessed. Eighty-five (76%) patients completed a one-year follow-up questionnaire. LVSD was identified in only 18 (16%) patients. While 93% of all patients found the echocardiogram useful, 27% of patients could not recall being informed of the result. Many patients remained undiagnosed and symptomatic at one year. The detection rate for LVSD by open-access echocardiography remains low despite the use of a structured referral letter and screening electrocardiogram and chest X-ray.

The incidence of statin intolerance due to non-severe side effects is estimated to be 5–10%. As an increasing number of patients become eligible for lipid-lowering treatment, this is becoming a more prevalent issue. Very limited, if any, data exist so far in the management of this subgroup of patients. Clinic letters from 1,100 patients who attended the Lipid Clinic at Hull Royal Infirmary from January 2000 until December 2004 were searched for ‘statin intolerance’. Forty patients (19 male, 21 female, median age 62 years) were identified with intolerance to at least one statin drug but with an absolute indication to be on treatment. Out of the 40 patients, 26 (65%, 11 male, 15 female) were eventually able to tolerate a statin for at least six months without their initial side effect, the most commonly successful statins being rosuvastatin (n=9) and pravastatin (n=8). Overall, this required a median of two switches (range one to four) in statin treatment. Fourteen (35%) were unable to continue treatment after a median of 1.5 switches (range one to three), either because of continued intolerance or a decision not to proceed with more alternatives. In conclusion, nearly two thirds of patients with initial problems with a particular statin are able to take an alternative statin without side effects. This supports the trial of different statins in intolerant patients.

Risk stratification is important in the assessment of cardiac patients enrolled in physical training programmes but is often based on inadequate information. Measuring blood B-type natriuretic peptide (BNP) level, a marker of left ventricular dysfunction, might improve risk assessment. In an observational study blood BNP levels were measured in 100 consecutive patients joining a cardiac rehabilitation programme following acute myocardial infarction. The results were compared with the clinical risk assessment – high, moderate or low. There was a significant correlation between risk category (high, moderate or low) and BNP level (r=0.41, p=0.001). A BNP level of 100 pg/L or more gave a sensitivity of 89% (95% confidence interval [CI] 0.69, 0.97) and a specificity of 61% (95% CI 0.57, 0.63) for predicting high-risk patients with a positive predictive value of 33% (95% CI 0.26, 0.36) and a negative predictive value of 96% (95% CI 0.89, 0.99). A BNP level of less than 100 pg/ml gave a sensitivity of 78% (95% CI 0.55, 0.91) and a specificity of 54% (95% CI 0.43, 0.64) for predicting low-risk patients with a positive predictive value of 27% (95% CI 0.17, 0.40) and a negative predictive value of 92% (95% CI 0.80, 0.97). In conclusion, BNP levels provide information that may improve the accuracy of risk assessment of cardiac rehabilitation patients particularly when other information is limited.

Correction of thyroid hormone levels using thyroxine can have important cardiac implications. We report a case of myocardial infarction following rapid up-titration of thyroxine.

Familial hypercholesterolaemia is a common genetic disorder that remains under-recognised. At present a simple genetic test is not available, although targeted genetic screening is being piloted in the UK. Recognition and treatment of this condition could help prevent many incidences of coronary heart disease. This article provides an overview of the pathophysiology, epidemiology, diagnosis and treatment of familial hypercholestrolaemia.

Low-density lipoprotein (LDL)-apheresis is the treatment of choice in homozygous familial hypercholesterolaemia as well as various other severe dyslipidaemic conditions. However, it appears to be under utilised in the UK. This article reviews the recent advances in (LDL)-apheresis techniques, as well as the beneficial effects and clinical outcomes of this therapeutic modality.

Anticoagulant therapy plays a key role in pharmacological reperfusion therapy for acute ST segment elevation myocardial infarction (STEMI). Until recently, the established role of unfractionated heparin (UFH) was unquestioned, but large trials with new agents including factor Xa inhibitors, direct thrombin inhibitors, and in particular, low molecular weight heparins (LMWHs), have shown potential advantages compared with UFH. This paper reviews the evidence base for the newer anticoagulants, with a focus on LMWH including the Enoxaparin and Thrombolysis Reperfusion for Acute Myocardial Infarction Treatment – Thrombolysis in Myocardial Infarction (ExTRACT TIMI)-25 study, which found that enoxaparin when appropriately adjusted for weight, age and renal function, provided superior net clinical benefit (balancing efficacy and safety) compared with UFH. In addition, new data from higher risk subgroups (the elderly, those with renal dysfunction or undergoing early coronary intervention) and the efficacy and safety of using concurrent clopidogrel are discussed to illustrate how these data may be integrated into contemporary practice.

Data from 101 practices that had completed a survey of cholesterol target achievement using rosuvastatin in routine general practice were pooled to assess effectiveness at a national level. A total of 10,396 patients, who had total cholesterol (TC) measured prior to, and on, rosuvastatin 10 mg daily, were included in the analysis. Of these, 6,375 patients had not received a statin prior to rosuvastatin. The remainder had been switched from another statin.

Significant reductions were observed in TC (28%) and low-density lipoprotein cholesterol (40%) when comparing prior to and on rosuvastatin 10 mg (p<0.001). A significantly greater proportion of patients achieved the General Medical Services (GMS) Quality and Outcomes Framework (QOF) target of TC ≤5 mmol/L with rosuvastatin 10 mg compared with prior to rosuvastatin (81% vs. 19%; p<0.0001). Of the 580 patients who had failed to reach target on atorvastatin 10 mg daily, 70% reached target on rosuvastatin 10 mg. Similarly, 68% of 246 patients who had failed to reach target on simvastatin 40 mg daily reached target on rosuvastatin 10 mg.

General practitioners across the UK also substantially achieved other national and international cholesterol targets in patients treated with rosuvastatin 10 mg, including second line to simvastatin 40 mg and where higher doses of other statins had failed to reach target.