Changing tides: moving away from warfarin use, a headache or nothing that an aspirin cannot solve?
The results of a recently published study demonstrated that neither aspirin, nor warfarin was superior for the prevention of the combined risk of death, stroke and cerebral hemorrhage in patients with heart failure and a normal heart rhythm.
The 10-year WARCEF trial is the largest double-blind comparison study of these two medications for the treatment of heart failure, and has followed a total of 2305 patients from over 168 sites in 11 countries. The randomized trial was double-blinded, in order that both the patient and clinician were both unaware of which drug the patient was taking. The patent was instructed to take tablets from two bottles, labeled aspirin and warfarin, one contained the active medication and the other contained a placebo. All patients underwent regular blood tests and the process undertaken provides confidence in that the trial was conducted in an unbiased way.
In the head-to-head comparison, the combined risk of death, stroke and cerebral hemorrhage was found not to be statistically significant – 7.47% per year for patients receiving warfarin (Coumadin®, Bristol-Myers Squibb, NJ, USA) and 7.93% per year for those taking aspirin. In patients taking warfarin, stroke risk was half that of those taking aspirin (0.72 vs 1.36% per year). However, patients taking warfarin had more than double the risk of major bleeding (1.8 vs 0.87% per year). The investigators, led by Clinical Principal Investigator Schinichi Homma, Columbia University Medical Center and New York-Presbyterian Hospital (NY, USA) have suggested that these results cancel each other out, however, in patients followed for 4 years or longer, warfarin could be more effective in preventing the combined outcome of death, stroke and intracerebral hemorrhage. Further follow-up analyses will evaluate the evidence, in order to identify patients for whom one of the medications is preferred.
Patients with heart failure generally have a weakened heart, which puts the individual patient at a greater risk for blood clots, which may lead to a stroke. Aspirin prevents clotting and warfarin acts to thin the blood and therefore act to reduce the risk of a stroke due to a clot or blockage in the cerebral artery. Unlike aspirin, warfarin requires a prescription and regular blood work to monitor clotting levels and adjust drug doses.
Homma commented, “Since the overall risks and benefits are similar for aspirin and warfarin, the patient and his or her doctor are free to choose the treatment that best meets their particular medical needs. However, given the convenience and low cost of aspirin, many may go down this route.”
However, Andrew Clark, from the British Society for Heart Failure and the University of Hull (Hull, UK), argued that the risks from warfarin were less serious, “The study shown here demonstrates that warfarin quite markedly reduces the risk of stroke associated with heart failure compared with aspirin, but at a cost of an increase in major hemorrhage. How to interpret that for individual patients means weighing the risk of stroke against the risk of hemorrhage, but also weighting that by importance. I would regard a gastrointestinal hemorrhage requiring transfusion as being of less importance than a stroke, so would tend to be in favor of warfarin. I would be more inclined to prescribe warfarin than previously, but the evidence is not overwhelming.”
The British Heart Foundation said both warfarin and aspirin had risks and benefits, but this study showed that “neither has an advantage over the other overall in preventing stroke or death in the long term.”
Commenting on the study, Walter Koroshetz, NINDS Deputy Director said “With at least 6 million Americans – and many more around the world – suffering from heart failure, the results of the WARCEF study will have a large public health impact. Patients and their physicians now have critical information to help select the optimum treatment approach. The key decision will be whether to accept the increased risk of stroke with aspirin, or the increased risk of primarily gastrointestinal hemorrhage with warfarin.”
Previous studies had established warfarin as a superior medication to aspirin for preventing stroke in heart failure patients with atrial fibrillation. WARCEF is the first study to authoritatively answer the question for the majority of heart failure patients with normal heart rhythm.
– Written by Michael Dowdall
Sources: Columbia University Newsroom: www.cumc.columbia.edu/news-room/2012/05/aspirin-and-warfarin-equally-effective-for-most-heart-failure-patients; BBC Health News: www.bbc.co.uk/news/health-17925581
New expert consensuses update catheterization laboratory standards and appropriate use criteria
Two influential new documents have been released by the American College of Cardiology Foundation (ACCF) and the Society for Cardiovascular Angiography and Interventions (SCAI) to update when and how cardiology procedures should be used in catheterization laboratories.
The first, an updated 80-page consensus for detailing recommendations, quality control and training in the catheterization laboratory aims to bring the current 11-year-old guidelines into modern times and agree on a new standard of practice for the rapidly expanding numbers of catheterization clinics.
Taking over 3 years to complete and involving an international writing committee of experts, the consensus was released by the ACCF and the SCAI, in collaboration with the Society of Thoracic Surgeons (STS) and Society for Vascular Medicine (SVM).
“There have been a lot of changes since 2001, some of them dramatic,” said Thomas M Bashore, chair of the writing committee and Professor at Duke University (NC, USA) in a statement. “This document sets the stage for what‘s really happening in catheterization laboratories today.”
One of the biggest changes to the guidelines was to lift the previous restriction on catheterization laboratories working on patients without on-site surgical backup, something that was previously not recommended in those with conditions such as heart failure, severe stress test abnormalities and valvular disease. Primary percutaneous coronary intervention for acute coronary syndrome is now allowed in stand-alone clinics; however the document did recommend that laboratories working on therapeutic procedures on children or adults with congenital heart disease should have access to on-site surgical backup due to potential risks. In line with this, the report recommended that “both training and practice activity associated with structural heart disease intervention be concentrated among a limited number of laboratories and operators with a particular interest in these procedures.”
Other consensus agreements in the document focused on quality assurance initiatives, detailing requirements and suggestions to ensure that patients get the best care.
The second release, issued by the ACCF and the SCAI, provides new criteria for when it is and when it is not appropriate to use catheter-based interventions. Identifying 166 possible clinical scenarios, the authors hoped that the situational-based recommendations will assist those making immediate clinical decisions about which procedure would be most appropriate.
“Invasive coronary catheterization is a cornerstone for how we diagnose and care for people with heart disease,” reported Manesh Patel, from Duke University and co-chair of the writing group for the appropriate use committee. “We want to encourage the appropriate and judicious use of all of our techniques and procedures. With this document, we aim to help all clinicians, not just cardiologists, determine when it would be reasonable to perform diagnostic cardiac catheterization.”
Overall, the group determined cardiac catheterization to be “appropriate” in about half of the clinical situations, including for definite or suspected acute coronary syndrome, and typical symptoms and higher-risk diagnostic findings. Almost 30% of the scenarios were listed as “uncertain,” where the procedure may be considered reasonable, depending on the clinical situation. Immediate referral for catheterization was deemed not justified or “inappropriate” for 25% of the indications. Patel noted that extenuating clinical circumstances may justify their use on occasion and that decisions should always be individualized to patients and clinics. However, he went on to note that, “In our ongoing effort to provide efficient, quality cardiovascular care, we hope these criteria will support real-time clinical decisions.”
– Written by Louise Rishton
Sources: Bashore TM, Balter S, Barac A; American College of Cardiology Foundation Task Force on Expert Consensus Documents; Society of Thoracic Surgeons; Society for Vascular Medicine et al. 2012 American College of Cardiology Foundation/Society for Cardiovascular Angiography and Interventions Expert Consensus Document on Cardiac Catheterization Laboratory Standards Update. J. Am. Coll. Cardiol. doi:10.1016/j.jacc.2012.02.010 (2012) (Epub ahead of print); Patel MR, Bailey SR, Bonow RO et al. ACCF/SCAI/AATS/AHA/ASE/ASNC/HFSA/HRS/SCCM/SCCT/SCMR/STS 2012 appropriate use criteria for diagnostic catheterization: a report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, Society for Cardiovascular Angiography and Interventions, American Association for Thoracic Surgery, American Heart Association, American Society of Echocardiography, American Society of Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, Society of Critical Care Medicine, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, and Society of Thoracic Surgeons. J. Am. Coll. Cardiol. 59(22), 1995–2027 (2012); SCAI Press release: www.scai.org/Press/detail.aspx?cid=0ecbea7a-fa37–4842–8d45-b1e54b4248c8; SCAI Press release: www.scai.org/Press/detail.aspx?cid=2a6e4faa-36f7–4487-ac5f-24db55fa2856
Are heart palpitations a warning sign for future atrial fibrillation?
A large European cohort study involving over 20,000 patients has found that palpitations may be linked with the occurrence of later atrial fibrillation (AF). The study, which aimed to determine risk factors for the arrhythmia, found that both hypertension and reports of palpitations were significantly linked to AF in both sexes after 11 years of follow-up, adding to the picture of which patients are at risk of developing the deadly arrhythmia.
AF is the most common cardiac arrhythmia and is known to be a major risk factor for stroke, heart failure and overall mortality. Aiming to determine which patient characteristics can raise the risk of AF, the Troms⊘ study followed a cohort of 22,815 patients for an average of 11 years.
The defined outcome measure was first-ever AF on ECG, which was found to have an incidence rate of 2.71 per 1000 patient-years for women and 3.87 per 1000 patients-years for men. Palpitations and hypertension were associated with a significantly increased risk of AF in both sexes. Although hypertension has been confirmed to be linked to AF in patients, the researchers were surprised by the correlation between the occurrence of palpitations and AF risk; 62% increase in women and men by 91%.
To try to determine whether the relationship was causal, the researchers instigated analysis to determine whether there were any overlapping risk factors for AF and palpitations. Although some risk factors were shared( e.g., height, hypertension and coronary heart disease) the most prominent risk factors for AF were biological and the most prominent for palpitations were lifestyle-based, implying they may be distinct.
First author Audhild Nyrnes from the Department of Community Medicine, University of Troms⊘ (Troms⊘, Norway) commented on this finding, cautioning that “we cannot conclude with certainty that the association is causal. However, in this case it is not unreasonable to propose a causal relationship. ‘Palpitations‘ are used subjectively to describe irregular heart beats or accelerated heart rate, and it is likely that a proportion of palpitations also represent cases of irregular heart rhythm, which is a main characteristic of AF.”
The authors went on to discuss whether subjects with palpitations could have paroxysms of AF, and should be investigated further, with prolonged ECG monitoring recommended for some. Nyrnes stated that “palpitations per se are not harmful. They are in fact mostly harmless; the challenge is to detect those which might signify an underlying condition and future AF.”
As well as palpations, the study also confirmed that hypertension significantly raised the risk of AF, with raised blood pressures above 140/90 mmHg, nearly doubling the risk of AF. This led the authors to emphasize how important lowering blood pressure to normal levels can be in order to reduce AF and the accompanying mortality risk.
– Written by Louise Rishton
Sources: Nyrnes A, Mathiesen EB, Njolstad E, Wilsgaard T, Lochen ML. Palpitations are predictive of future atrial fibrillation. An 11-year follow-up of 22,815 men and women: the Tromso Study. Eur. J. Prev. Cardiol. doi: 10.1177/2047487312446562 (2012) (Epub ahead of print); ESC Press Release: www.escardio.org/about/press/press-releases/pr-12/Pages/palpitations-predict-future-atrial-fibrillation.aspx
Consensus released for the care of patients with Wolff–Parkinson–White ECG
The Pediatric and Congenital Electrophysiology Society (PACES) and the Heart Rhythm Society (HRS) have issued a statement on how clinicians should monitor and treat young patients with the Wolff–Parkinson–White ECG patterns, 65% of whom are asymptomatic.
The recommendations, published in Heart Rhythm, are intended to guide clinicians treating patients aged 8–21 years in who, according to Mitchell Cohen, (Phoenix Children‘s Hospital, Phoenix, AZ, USA), “Essentially one of three things can happen: they may remain asymptomatic; they may develop an arrhythmia that can be managed with medication or ablation; or, more concerning, they may have a life-threatening event and die suddenly. The incidence of sudden death is quite rare, but it‘s not zero.”
Although modern treatment for the condition using catheter-based radiofrequency ablation is effective, it is not always necessary.
The consensus makes a number of recommendations, including recommending testing and monitoring to calculate patient risk and when ablation is necessary in patients. The guidelines also recommend that it is safe for asymptomatic patients to take medications for attention-deficit/hyperactivity disorder with a Wolff–Parkinson–White ECG after cardiac evaluation as long as they are monitored by a cardiologist.
– Written by Louise Rishton
Sources: Cohen MI, Triedman JK, Cannon BC et al. PACES/HRS Expert Consensus Statement on the Management of the Asymptomatic Young Patient with a Wolff–Parkinson–White (WPW, Ventricular Preexcitation) Electrocardiographic Pattern: Developed in partnership between the Pediatric and Congenital Electrophysiology Society (PACES) and the Heart Rhythm Society (HRS). Endorsed by the governing bodies of PACES, HRS, the American College of Cardiology Foundation (ACCF), the American Heart Association (AHA), the American Academy of Pediatrics (AAP), and the Canadian Heart Rhythm Society (CHRS). Heart Rhythm 9(6),1006–1024 (2012); HeartWire Press Release: www.theheart.org/article/1397783.do