The British Medical Journal has published the results of a meta-analysis into the efficacy of different classes of blood pressure lowering drugs in preventing coronary heart disease (CHD) and stroke. Additionally, this study aimed to determine who should be treated.
The analysis included data from 147 randomised controlled trials and 464,000 individual participants. The data were analysed by categorising patient data into one of three groups: no history of vascular disease, a history of CHD, or a history of stroke.
It was found that a blood pressure reduction of 10mmHg for systolic blood pressure and 5mmHg for diastolic blood pressure resulted in a 22% reduction in CHD events (95% confidence interval: 17% - 27%) and a 41% reduction in stroke (33% - 48%). The five main classes of drugs (thiazides, beta-blockers, ACE inhibitors, angiotensin receptor blockers and calcium channel blockers) were all equally effective in reducing CHD events while calcium channel blockers were slightly more effective in reducing strokes. Reductions in CHD and stroke appear to persist with reductions as low as blood pressures of 110/70mmHg; below this level there are insufficient data to draw conclusions.
The authors conclude that, "consideration should be given to replacing current policies that focus on routinely measuring blood pressure with policies that focus on routinely lowering blood pressure". This assertion has been reported in the general media (BBC).
Action: Clinicians should be aware of this meta-analysis. Any changes in national policy need to be made after consideration of the economic impact and any potential safety issues that may arise from greater usage of antihypertensives. As such, clinicians should continue to implement current guidelines.
The Food Standards Agency has published revised salt reduction targets for 2012 including 80 categories of food. It has been suggested that additional salt reductions could save 20,000 lives a year.
Since 2000-2001, average salt intake has dropped by 0.9g per day to 8.6g but this is still some way above the 6g recommended level. It is proposed that this reduction is already saving 6,000 lives a year through blood pressure reductions.
About 75% of daily salt we consume is already added to the food we buy during manufacturing. The new targets focus upon foods that make the greatest contribution to daily intake such as bread, meat products and cereals, as well as convenience foods such as pizza, ready meals and savoury snacks.
Action: Clinicians should encourage patients to reduce their salt intake and particularly advise patients about foods with a high salt content.
The World Health Organisation (WHO) report that there have now been 8480 confirmed cases of influenza A(H1N1) infection in 39 countries with 72 fatalities. The pandemic alert remains at Stage 5.
The Health Protection Agency (HPA) report 101 confirmed cases in the UK up to 17th May with the majority of cases occurring in London.
The Medicines and Healthcare products Regulatory Agency (MHRA) has also launched an online area with the aim of ensuring continued access to medicines and medical devices during the pandemic period.
Finally, the health minister and chief medical officer have warned the public not to become complacent about the threat still posed by this virus.
Action: Clinicians should be aware of the latest information. Although the situation appears to be under control at the moment this could easily change.
The Archives of Internal Medicine has published an article that reviews the results of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) in the context of meta-analyses, other trials and more recent analyses of the ALLHAT data.
This review considers the results of ALLHAT in conjunction with several other large hypertension trials including ASCOT, ACCOMPLISH, INSIGHT and CONVINCE. Differences in study design, treatment and outcome blinding and blood pressure lowering effect in different treatment arms are discussed.
The authors conclude that, "neither the alpha-blocker, ACE inhibitor, nor the CCB surpasses the thiazide-type diuretic as initial therapy for control of BP or reduction of cardiovascular or renal clinical outcomes". This is despite concerns that thiazide-type diuretics have unfavourable effects on glucose and lipid levels.
Action: The current NICE hypertension guideline presents clinicians with a choice of a diuretic or calcium channel blocker for black patients or those aged 55 year and older. This review would support first-line therapy with thiazide-type diuretics.
The Scottish Medicines Consortium (SMC) has issued its monthly advice on new medicines.
Pregabalin (Lyrica®) has been accepted for restricted use for the treatment of
peripheral neuropathic pain in adults. The review notes that evidence of efficacy is limited being based upon open-label, uncontrolled, non-randomised studies with small numbers of patients. As such pregabalin is only recommended in patients who have not benefited from or failed to tolerate conventional first and second line treatments.
[Update] This review also recommended that treatment is stopped if the patient has not shown sufficient benefit within 8 weeks of reaching the maximally tolerated therapeutic dose.
Thanks to Rita Shah for reminding me of this point.
Action: Clinicians should be aware of the recommendations of the SMC. Routine use of rejected and restricted medicines should be avoided.