A good year for big data
A selection of important data from the past few years were presented by John Camm (St George’s University of London, UK) on Thursday in a lecture summarizing the best clinical scientific papers for the year 2012. As well as outlining some of the best clinical trials that are currently in play, Professor Camm noted various studies that have achieved great results in terms of characterizing best treatment options for certain patient groups, from antiarrhythmia drugs to ablation, surgery to electrophysiology.
Noting the growing burden of AF around the world that parallels the proliferation of scientific studies whose goal it is to understand and treat the disease, Professor Camm said: “Let me start with what really was an exhortation to clinical scientists, not only in North America but in the world in general, to address major issues in AF. This specifically refers to the Institute of Medicine’s comparative effectiveness research program in which AF was top of the list or led the list. Just tapping ‘atrial fibrillation’ into PubMed reveals staggering results. You can see that between 1992 and 2012, just two decades, the number of publications per year has increased several fold. We now have, last year, 3,580 publications in AF. If you look at the breakdown of these articles you can see the tremendous surge of interest in everything related to stroke. But also clinical trials, ablation, anticoagulation and mechanisms of AF is very high. Interestingly, publications about antiarrhythmic drugs are very few.”
Describing the first of his selected antiarrhythmia studies, Professor Camm said: “Little has been published, but one publication that hit The Lancet was the Flec-SL study.1 This came from the German AF Network (AFNET). In this particular trial, patients who were being cardioverted were randomized to take either a short course of antiarrhythmic drugs, in this instance flecainide for four weeks were compared with placebo. The following the cardioversion, versus important finding was that 80 percent patients who were placed on therapy of the antiarrhythmic effect achieved in the long term. Both of these groups by the antiarrhythmic drug was achieved by just a simple four week course of therapy, and not a great deal was achieved by continuing therapy – giving some authority and evidence base to many physicians’ practice of using only short courses of flecainide or other antiarrhythmic drug.”
Professor Camm continued. “I’d like to turn now to HESTIA. 2 This is in the tradition of Greek gods and goddesses, and the study is done with dronedarone. In this particular case, it was exploring AF burden defined as the percentage of time the patient was in AF, using patients of course that were fitted with cardiac pacemakers. The results were cheerful in the sense that dronedarone certainly reduced the burden of AF by some 60 percent compared with placebo, but draws into question the value of burden and how it relates to both, for example, AF-related stroke and to other indicators and parameters of antiarrhythmic effect, like the time to first event.”
One of Professor Camm’s choices for 2012 was a registry of data following patients who had undergone ablation that is sure to produce enlightening results in the future. “This is part of a large European endeavor organized by the European society of cardiology, called the ESC EURObservational Research Programme. And the first of these is an ablation registry for patients with AF. In this pilot study, some 1,300 patients followed for one year, there were four deaths and 19 patients whose status was unknown. 73 percent of patients had no recurrence of AF and 26 percent did. Of those that had no recurrence, almost half were also taking antiarrhythmic drugs. The complication rate was relatively low, both in hospital and during the 12 months of further follow-up. This registry continues, and will be very large in the future.”
1) Kirchhof P et al. Short-term versus long-term antiarrhythmic drug treatment after cardioversion of atrial fibrillation (Flec-SL): a prospective, randomised, open-label, blinded endpoint assessment trial. Lancet (2012); 380(9838):238-46
2) HESTIA (The Effects of Dronedarone on Atrial Fibrillation Burden in Subjects with Permanent Pacemakers).
3) EURObservational Research Programme. http:// www.escardio.org/guidelines-surveys/eorp/ Pages/welcome.aspx