This week’s Annals of Internal Medicine focused on angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB). Two studies addressed questions such as: Which class (ACE/ARB or both) is more effective as an anti-hypertensive? Which class is more effective for proteinuria? What are the adverse events of the combination? What are long term outcomes?
The first article was a systematic review that compares these drugs as anti-hypertensive agents. 61 studies were identified, the majority of which (47/61) were randomized controlled trials. The outcomes confirm that monotherapy with ACE or ARBs is similar both in terms of effectiveness as anti-hypertensive agents and in terms of adverse effects, with the exception of cough, which, as already known, is more common with use of ACE inhibitors. In fact, the absolute difference in the rate of cough between the two is 6.7%. Unfortunately, information on long-term effects of treatment is severely limited as the vast majority of trials reported results of patients on medications for <6 months.
The second article was a meta-analysis focusing on the anti-proteinuric effects of these medications. 49 randomized controlled trials were examined encompassing 6000 patients. While all trials examined monotherapy of ACE or ARB, of the 49 trials, 23 included an arm which examined the combination of ACE/ARB. The results reveal that ARB’s have similar protein lowering effects to ACE inhibitors. Importantly though, the question of the efficacy of the combination is not fully answered. The results suggest that the combination reduces protein excretion more effectively than monotherapy, but results are tempered by limited reporting of side effects and an overall short duration of therapy(6 months). Thus, in clinical practice, there does not seem to be sufficient evidence to treat patients wtih proteinuria with the combination of ACE/ARB until better information is available.
Defibrillators have been a hot topic lately and there has been a general movement toward promoting the availability of automatic external defibrillators (AED’s) on soccer fields, in schools, airports, etc. If one is going to have a cardiac arrest, one might guess that the safest place for this to occur is in the hospital. The January 2nd issue of NEJM published an article that made it to the front page of the NYT. The study identified 6789 patient who had incurred in-hospital cardiac arrest secondary to either ventricular fibrillation or ventricular tachycardia. The investigators studied the time to defibrillation and sought to determine reasons for the delay (delay being defined as >2 minutes in this study). Overall, the findings were:
• Median time to defibrillation was 1 minute
• Delay (>2 minutes) occurred in 30% of patients
• Delay was associated with a decreased likelihood of survival to discharge (39% without delay vs 22% with delay)
• Characteristics associated with delay include: black race, non-cardiac admitting diagnosis, a small hospital, being in an unmonitored unit and after hours cardiac arrest
Importantly, the reason behind black race being associated with delay in defibrillation is unclear. The question of disparity in health care looms, but is not answered in this study. The editorial accompanying the article suggests a novel approach. The technology exists to place electrodes on the skin of all hospitalized patients; vfib or vtach could then be detected via an automatic detection algorithm. This is the same technology used in ICDs and AEDs. Once detected, a signal could be transmitted wirelessly to an alarm station triggering a team response. Whether this is practical or economical is still unknown.
And finally a couple of quick interesting pearls-this month’s JGIM surveyed 231 internists from Chicago and found that 45% actively used a placebo in their daily clinical practice. (If we were all being perfectly honest, I suspect that number might be quite a bit higher -editor). The FDA this week approved a rapid blood test that determines if a given bacterium is MRSA in less than 2 hours. Current testing takes approximately 48 hours.
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