Listening to repeated choruses of Disco Science can improve the rate of chest compressions in subjects carrying out cardiopulmonary resuscitation (CPR) but does not help to achieve the correct depth of compressions, a study has found. Dr Peter Savill reviewed the paper: 'Significantly more delegates maintained compressions within the optimal range of 100 to 120 compressions a minute when listening to Disco Science than when listening to Achy Breaky Heart (82% vs 64%, p=0.07). Achy Breaky was no better than no music (64% vs 65%). However, compressions were still too shallow irrespective of the background music; 39% at the correct depth with Disco Science, 43% with Achy Breaky and 42% with no music. Furthermore, incorrect hand positioning was rife and seen in up to two thirds of delegates. The authors were therefore unconvinced that music provides any benefit in improving the quality of CPR compared with a metronome or audible feedback. Time to abandon iPod augmented CPR then!'

Warfarin consistently lowers the risk of thromboembolism in high-risk patients with atrial fibrillation compared with aspirin and no treatment, a meta-analysis has found.

Overweight and obese patients who were referred to Weight Watchers lost twice as much weight as those who received standard care in general practice, a study in The Lancet has shown. A total of 772 adults, with a BMI 27-35 kg/m² and at least one additional risk factor for obesity-related disease, were recruited from primary care practices in the UK, Australia and Germany. The study was a parallel group, non-blinded, randomised controlled trial. The authors concluded that a commercial weight loss programme that provides regular weighing, advice about diet and physical activity, motivation, and group support could offer a clinically useful early intervention for weight management in overweight and obese people.

Effort-related pain and two or more episodes of pain in 24 hours are associated with poor outcomes in patients presenting with chest pain of uncertain origin, according to a study, from Spain, in the BMJ. Dr Peter Savill comments:'Patients presenting with chest pain can be a real challenge. Furthermore, an ECG is rarely helpful although often advocated in guidelines. Although this research comes from an acute settingI think the message carries some relevance for primary care physicians as they try to navigate a path through the potential minefield of chest pain.'

Exercising at a moderate intensity for 300 minutes a week is associated with a 20% reduction in CHD risk. Halving this amount of physical activity reduced CHD risk by 14% and a significant risk reduction was also achieved with lower levels of exercise. A meta-analysis was carried out on 33 prospective cohort studies looking at physical activity and primary prevention of CHD, published since 1995. Nine of the studies allowed quantitative estimates of leisure-time physical activity.The researchers found that people who reported the equivalent of 150 minutes per week of moderate-intensity activity had a 14% lower CHD risk, relative risk (RR)=0.86 (95% CI: 0.77-0.96) compared with those reporting no exercise. Those who undertook 300 minutes per week of moderate-intensity activity had a 20% lower risk, RR=0.80 (95% CI: 0.74-0.88). Increasing exercise above 300 minutes per week only produced a modest increase in benefit.

A recent meta-analysis, published in JAMA, has suggested an increase in the risk of developing diabetes with high-dose statin therapy compared with moderate-dose therapy. However, the cardiovascular benefits appear to outweigh the risk of diabetes.The researchers analysed large, randomised controlled, hard end point studies that compared intensive with moderate-dose statin therapy and included more than 1,000 patients followed up for longer than a year. The trials studied in the meta-analysis were PROVE IT-TIMI 22, A to Z, TNT, IDEAL, and SEARCH. These five trials included 32,752 patients without diabetes mellitus at baseline.

A large systematic review has found no evidence that angiotensin receptor blockers (ARBs) increase the risk of MI. Compared with patients on other active treatment or placebo, those on ARBs also had a lower risk of stroke, heart failure and diabetes. The researchers analysed a total of 37 randomised controlled trials (39 comparator arms) with 147,020 patients. Dr Peter Savill comments: 'This is a large and comprehensive analysis and has produced firm evidence to refute the hypothesis that ARBs increase the risk of MI. The authors comment that they were able to rule out as low as a 0.3% absolute increase. Furthermore, compared with controls, ARBs reduced the risk of stroke, heart failure, and new onset diabetes. The concern that ARBs may increase the risk of MI has mainly arisen from under-powered observations and secondary endpoint analysis of several ARB trials but such observations can cause clinicians some concern. I am not certain to what degree this has influenced the prescribing of this class of drugs but this recent meta-analysis should now lay this concern to rest. From a practical perspective, I would still stick with ACEIs as the first-line renin angiotensin system drug for the indications discussed above but when ACEIs are genuinely not tolerated, and cardioprotection is not the sole aim of treatment, then ARBs would appear to be a safe and effective alternative.'

Guidance from NICE on stopping antibiotic prophylaxis before invasive procedures in patients at risk has not resulted in an increase in cases of infective endocarditis. In March 2008, NICE released new guidance on the role of antibiotic prophylaxis in the prevention of infective endocarditis. This caused quite a stir as it proposed a radical shift in clinical practice by suggesting that such prophylaxis, before dental and other invasive procedures, should be stopped. Furthermore, it was not based on any new evidence. It had been accepted practice to recommend antibiotic prophylaxis before potentially bacteraemic procedures for patients with underlying cardiac conditions which could result in turbulent blood flow such as valve disease and congenital defects. Despite the initial furore this guidance has generally been adopted and a recent study in the BMJ set out to investigate its impact. The authors stated aim was to quantify the change in prescribing of antibiotic prophylaxis before invasive dental procedures for those at risk of infective endocarditis, and any concurrent change in the incidence of infective endocarditis following the introduction of the NICE guidance. The results showed that following the introduction of the NICE guidance there was a highly significant 78.6% reduction (p<0.001) in the prescribing of antibiotic prophylaxis, from a mean of 10,277 prescriptions per month to 2,292. They also found that despite a general upward trend in the number of cases of infective endocarditis before the guidance that there was no significant change in this trend after the guidance was introduced (p=0.61). Dr Peter Savill writes: 'This would seem to support NICE and silence the critics, of which I was one, but it should be remembered that we must continue to monitor the situation as trends may appear over time.'

Tai chi can improve mood, quality of life and exercise self-efficacy in patients with heart failure although it does not appear to increase functional capacity, a study from the US has found. A single-blind, parallel-group, randomised controlled trial evaluated 100 outpatients with systolic heart failure (New York Heart Association class I-III, left ventricular ejection fraction <40%). The mean age of patients enrolled was 67 and the mean ejection fraction 29% (SD 8%). ' The authors conclude that tai chi, as an adjunct to standard medical care, may improve the quality of life, mood, and exercise self-efficacy of patients with heart failure. However, they acknowledge the limitations of this study such as the small sample size and single blind nature of the randomisation. Furthermore, the lack of impact on functional measures may be seen as a lack of meaningful benefit. However, we must not underestimate the value of even a small improvement in the quality of life to such patients. This should certainly lead to further consideration of the role of mind-body interventions in cardiac rehabilitation programmes.'

A 30-minute office-based automated blood pressure measurement is as effective at identifying white coat hypertension and sustained hypertension as conventional daytime ambulatory blood pressure measurement (ABPM), according to a Dutch study. 'The authors support the use of ABPM and home blood pressure monitoring but point out that these methods are not without problems. Patient compliance can affect home blood pressure monitoring and ABPM is laborious, costly and not tolerated by all patients. They accept that any clinic-based method will be unable to identify diurnal blood pressure patterns, blood pressure variability, and mean nocturnal blood pressure but conclude that their protocol is as accurate as daytime ABPM and will be more cost effective and tolerable. You may wonder how a busy practice could set aside a room for such monitoring on a regular basis but given the trend towards ABPM as a first-line investigation in hypertension this could be a more cost-effective solution.'

Arrhythmia-free survival rates after a single catheter ablation procedure for atrial fibrillation (AF) were 40% after a year but dropped to below 30% after five years' follow-up, a study from France has found.

The CHA₂DS₂-VASc score appears to be better than the CHADS₂ score at predicting patients with atrial fibrillation (AF) who will have a stroke over the next 10 years. It is also more accurate in identifying those at very low risk who do not need anticoagulation, a registry-based study has found. 'Estimating the risk of thrombo-embolism in AF is one of the most important aspects of the management of this common arrhythmia. To avoid a stroke at all costs using CHA₂DS₂-VASc thresholds for anticoagulation is preferable, but applying this at a population level may lead to an appreciable and significant increase in anticoagulant-related adverse events in patients who may still have a low risk of stroke. I think ultimately CHADS₂ is the easiest to apply in everyday practice as a first-line tool with the more detailed scoring system applied to those scoring 1 with CHADS₂ and who clinically appear to be at higher risk.'

Statins have no effect on survival rates in high-risk patients who do not have established cardiovascular disease, a comprehensive meta-analysis has demonstrated. The huge meta-analysis published in Archives of Internal Medicine included eleven randomised, controlled trials involving 65,229 patients. 'This was the largest analysis of statin therapy in a purely primary prevention setting and probably includes the totality of evidence available for primary prevention. However, it is important to consider that mortality rates are low in primary prevention trials and it is therefore difficult to show a mortality benefit. It must also be remembered that the analysis looked at the short term, <4 years, benefit of statin therapy and it is possible that longer-term trials may reveal important benefits. Statin use in these populations can significantly reduce the incidence of non-fatal cardiovascular events. Therefore, from a practical perspective I would not necessarily look to statins to help people without established cardiovascular disease live longer but they might reduce the incidence of other, not necessarily fatal, outcomes such as MI and stroke and this may be just as important to our patients.'

Green but not black tea may lower the risk of coronary artery disease (CAD), the limited evidence suggests. The researchers performed a meta-analysis of 18 observational studies identified from a search of PubMed and EMBASE databases from 1966 through November 2009. Thirteen studies were on black tea and five on green. 'The authors do recognise several limitations to this analysis such as a small number of included studies, observational study designs prone to confounding and differing methods for measuring tea consumption. They therefore conclude that additional studies are needed before firm conclusions can be drawn. So no need to switch teas just yet then. '

Uninterrupted chest compressions can improve the likelihood of a good outcome after cardiac arrest compared with standard CPR, a meta-analysis has shown. The delivery of rescue breaths during CPR is time-consuming particularly for lay bystanders and prevents the maintenance of a continuous uninterrupted coronary perfusion pressure. The notion that rescue breaths may be detrimental to the success of adult CPR is not a new one and a recent meta-analysis published in The Lancet explored the current evidence. The authors reviewed studies published over the past 25 years comparing chest compression only bystander CPR with standard CPR with ventilations for adults with prehospital cardiac arrest. 'The takehome message is that emergency medical services dispatchers should instruct bystanders to focus on chest compression only CPR in adults with prehospital cardiac arrest. However, the situation for unassisted lay bystander CPR is unclear. I was also interested to read that the American Heart Association is telling the public to remember CAB (Compressions Airway Breathing) rather than ABC.'

Around three-quarters of patients are still taking all their prescribed medications three months after hospitalisation for stroke, a study from the US has found. Researchers used the Adherence Evaluation After Ischemic Stroke-Longitudinal (AVAIL) Registry, which included 3,068 adult stroke patients at 106 hospitals participating in the American Heart Association/American Stroke Association ‘Get with the Guidelines'-Stroke program. Overall, 2,598 patients were contacted three months after hospital discharge and asked about adherence to prescribed antiplatelet drugs, warfarin, antihypertensives, lipid-lowering drugs, and diabetes treatments.

The relative risk of eating a high-fat, fast food meal may be able to be neutralised by taking a statin, according to researchers from Imperial College, London. The investigators compared the increase in relative risk of cardiovascular disease (CVD) associated with the total and trans fat content of a fast food meal with the reduction in relative risk observed from a recent meta-analysis of seven primary prevention statin trials covering 42, 848 patients. The authors suggest that fast food restaurants could offer customers a statin to go with their meal. They hypothesise that the statin could be sprinkled onto quarter pounders, into milkshakes, or onto supersized French fries to offset the fat found in these fast food delights.

Adding ivabradine to standard treatment significantly reduced hospitalisation and deaths from heart failure, in a randomised, placebo-controlled trial. Ivabradine is a new rate-limiting drug which acts as a selective inhibitor of a sodium-potassium channel highly expressed in the sinoatrial node. A total of 6,558 patients with NYHA class ll-lV heart failure, an LVEF ≤ 35%, a resting heart rate ≥ 70 bpm, and a hospital admission for heart failure within the previous year were enrolled in the SHIFT study. 'Critics of the trial have cited an atypical patient population and suboptimal beta-blocker dosing (only 56% of patients were on ≥ 50% of beta-blocker target dosage and only 26% were on the target dosage). However, I think the study population represents a fairly typical real-world situation and would take the result of this trial as encouraging.'

Transcatheter aortic valve implantation (TAVI) improves one-year mortality and hospitalisation rates in patients with aortic stenosis who are unfit for surgery. The PARTNER study is the first trial to assess the impact of this new procedure. The non-surgical study cohort comprised 358 patients from 21 centres, mainly in North America, randomised to either TAVI or standard (non-surgical) care. There were two primary endpoints: one-year all cause mortality and a composite endpoint of one-year all cause mortality or repeat hospitalisation. 'Severe aortic stenosis is becoming increasingly prevalent with an aging population. The only effective treatment has been valve replacement and no drug intervention has been shown to reduce progression. Significant comorbidities greatly increase the risk of surgery in this population. The recent development of a transcatheter aortic valve prosthesis has provided a real alternative to surgery in patients with severe aortic stenosis felt to be too great a risk for open surgery. Overall these are very impressive results with only five patients needing to be treated to prevent one death.'

A recent meta-analysis has shown that calcium supplementation without co-administration of vitamin D may increase the risk of MI by nearly a third. Studies included in the meta-analysis were randomised, placebo controlled trials of calcium supplements (500 mg/day), with 100 or more participants. The mean age of trial participants had to be >40 years (actual mean age was 75 years) and the trial duration > 1 year. 'While remaining alert to the limitations of meta-analysis this data suggest that we should perhaps reassess our current approach to calcium supplements especially in patients at high risk or with established cardiovascular disease. Calcium supplements are routinely prescribed for, and taken by, patients either at risk of, or with, established osteoporosis and many of these are elderly women who may also be at high risk of cardiovascular disease.'

Another study has cast doubt on the role of aspirin in primary prevention. The Aspirin for Asymptomatic Atherosclerosis trial showed no reduction in vascular events with aspirin in asymptomatic subjects with a low ankle brachial index (ABI). Men and women aged 50-75 years living in central Scotland were invited for ABI screening for asymptomatic atherosclerosis over a ten-year period from 1998 to 2008. A total of 28,980 patients were screened of which 3,350 had a low ABI and were randomised to aspirin 100mg or placebo. Patients were followed up for a mean of 8.2 years.'There is little doubt that aspirin is beneficial in patients with symptomatic cardiovascular disease or with a history of stroke but this trial adds further weight to the reluctance to use aspirin for primary prevention in asymptomatic patients even in those considered at high risk with little evidence of benefit and some evidence of harm.'

This study further reinforces the message that age should not be a barrier to warfarin use and that older patients have the most to gain from anticoagulation. It also shows that the CHADS2 scoring system is not only simple to apply but an accurate predictor of stroke risk. However, not all elderly patients will be candidates for warfarin and it is still important to make a clinical judgment as to the risks and benefits in each individual patient.