September 30th, 2013
Selections from Richard Lehman’s Literature Review: September 30th
CardioExchange is pleased to reprint this selection from Dr. Richard Lehman’s weekly journal review blog at BMJ.com. Selected summaries are relevant to our audience, but we encourage members to engage with the entire blog.
NEJM 26 Sep 2013 Vol 369
Dabigatran vs. Warfarin in Patients with Mechanical Heart Valves (pg. 1206): One of the few genuinely promising advances I’ve been able to track in the journals over fifteen years has been the arrival of fixed dose oral anticoagulants. My, how the drug companies have scrambled to conquer this immense market! Boehringer-Ingelheim managed to score with dabigatran for atrial fibrillation in the RE-LY trial, though doubts remain, and the cost is prohibitive for routine use. The authors of this paper describe how this success then spurred them to set up the phase 2 trial RE-ALIGN trial in 39 centres across 10 countries to see if they could find a new market in people with mechanical heart valves. In the chosen settings, patients in the comparator group receiving warfarin were in the target INR range just 50% of the time. But despite this obvious source of gross bias, dabigatran failed to show any added benefit, and showed an excess of bleeding. Goodbye dabigatran for mechanical valve patients.
JAMA Intern Med 23 Sep 2013 Vol 173
Echocardiographic Screening of the General Population and Long-term Survival (pg. 1592): I was once interested in population echographic screening for systolic dysfunction and valvular disease (I was a naïve 45-year old back then), but I gradually realised the error of my ways. My interest moved to BNP screening in high risk groups—but that is another story, and another error. Here are the long-term results from 6861 middle-aged participants from the population-based Tromsø Study in Norway who were randomised 15 years ago to have echocardiography or not. “During 15 follow-up years, 880 persons (26.9%) in the screening group and 989 persons (27.6%) in the control group died (hazard ratio, 0.97; 95% CI, 0.89-1.06). No significant differences between the groups were observed in the secondary outcome measures (sudden death, mortality from any heart disease, or incidence of fatal and nonfatal myocardial infarction and stroke).”
Use of Antihypertensive Medications and Breast Cancer Risk Among Women Ages 55 to 74 (pg. 1629): Drugs to lower blood pressure in middle-aged people typically have numbers-needed-to-treat of several hundred to prevent an adverse cardiovascular event within 10 years. So any drug you use to lower blood pressure must (a) be proved to reduce CV events and (b) be proved to be free of long-term harms. Millions of women across the world use calcium channel blockers to reduce blood pressure, and this case-control study from the Seattle–Puget Sound metropolitan area raises the unwelcome possibility that this doubles their chance of getting breast cancer over a 10 year period, regardless of the odipine, adipine or edipine used. Someone urgently needs to do a massive data trawl of the UK CPRD, to settle the matter within weeks.