Commentary By: Joshua Olstein, MD Associate Editor, Clinical Correlations
Let’s begin this week by congratulating the Superbowl XLII champion New York Giants on an excellent victory. As Americans wakes up the day after and begin to recover from our collective binge on nachos, wings, guacamole and all other things trans-fat, let us review some of the recent literature in a vascular disease-themed edition of shortcuts.
Perhaps the most concerning study in light of Sunday’s nail-bitter are the results from a study published in this week’s New England Journal of Medicine examining cardiovascular event rates among Germans during the 2006 World Cup soccer matches. If the results are generalizable to American football fans though, my biggest post-game concern is the potential flood of admissions to the busy Bellevue Medical service for acute coronary syndromes. The authors assessed the number of cardiovascular events during days when the German team played a match and compared the incidence to two previous control periods. The overall incidence of events, defined as STEMIs, NSTEMIs, unstable angina, symptomatic arrhythmia, or AICD discharge were 2.66 times the incidence during the control period. Risk was increased even further in men and among those with known coronary artery disease. These differences were significant for all pre-specified comparisons. Maybe we should put a bowl of aspirin and metoprolol next to the chips and dip next year.
Moving past the coronaries we encounter the carotids and updated guidelines from the US Preventative Services Task Force for screening for asymptomatic carotid artery stenosis (CAS). The last version of these guidelines were released in 1996 and stated that evidence was insufficient to recommend for or against screening of asymptomatic persons for CAS by using physical examination or carotid ultrasonography. This current update now gives a Grade D recommendation for screening, meaning the practice of screening asymptomatic patients for CAS is not recommended and should be discouraged. This is based on the fact that a small proportion of disabling strokes are related to CAS, duplex ultrasonography, the screening test of choice is associated with a high false-positive rate, and the benefit of intervention in an asymptomatic general population would be small. These guidelines are similar to those published by the American Heart Association but differ slightly from the Society of Vascular Surgery guidelines which recommend screening those with cardiovascular risk factors or known disease.
While USPTF recommends against screening for CAS, most of us are aware of last year’s updated guidelines recommending screening anytime male smokers for abdominal aortic aneurysms. In part, the rationale for this selective screening approach is related to the risk of operative repair of “triple As”. A large observational study published in last weeks NEJM compared perioperative mortality rates for patients undergoing endovascular versus open repairs of their AAA’s. Over 45,000 patients were compared in the analysis which showed 30 day mortality for endovascular repair was only 1.2% compared to 4.8% (p<0.001) for open repairs. The mortality difference was larger with increasing age however the survival curves converged by 3 years. It will be interesting to see if screening recommendations are adjusted based on these results.
We finish by reviewing a meta-analyses published in last month’s Annals of Internal Medicine which focus on the most common of vascular diseases, hypertension. The review analyzed studies comparing patients taking angiotensin converting enzyme inhibitors (ACE-I) versus those taking angiotensin receptor blockers (ARB) for essential hypertension. Sixty-one studies of all design were included and the results showed equal effects on blood pressure control between ACE-Is and ARBs. There was increased cough associated with the ACE-I group which may have caused increased withdrawal of treatment. Data regarding the incidence of cardiovascular events was absent from the majority of studies included however and so no conclusions can be drawn with regard to additional cardiovascular endpoints.
