NEW ORLEANS-Arrhythmia therapy for high-risk patients is marching to different drummers.
Implantable defibrillators have been on a roll, but a new study suggests that all high-risk patients aren’t helped automatically. In the CABG Patch trial, defibrillators equaled no treatment for CABG patients defined as high risk by an LV ejection fraction under 36% and abnormal signal-averaged ECG.
In the trial, 446 of 900 patients were randomized to the devices, Columbia’s Dr. J. Thomas Bigger told the North American Society of Pacing and Electrophysiology meeting here. Not all had symptomatic arrhythmias.
CABG Patch did not require electrophysiology studies proving inducible arrhythmias, and Mass General’s Dr. Jeremy Ruskin pointed out that as a result many patients might not have been expected to benefit from devices.
The Multicenter Automatic Defibrillator Implantation Trial (MADIT) found improved survival for patients with inducible VT. In the Antiarrhythmics vs. Implantable Defibrillators trial, the devices had a 38% one-year survival advantage over amiodarone (Cordarone, Wyeth-Ayerst) or sotalol (Betapace, Berlex) for documented VF and VT.
In a meta-analysis of 13 amiodarone trials including 6,553 patients, Dr. Stuart Connolly of McMaster in Hamilton, Ont., reported that amiodarone therapy cut total mortality 13%, primarily because of a 29% reduction in arrhythmia deaths. But at two years 41% of patients stopped taking amiodarone, vs. 27% in the placebo group.
Substudies of the Canadian and European trials of amiodarone post-MI (CAMIAT and EMIAT) found that it dramatically reduced the risk of arrhythmic death or VF if patients were also taking beta blockers, but not if they weren’t. The studies found amiodarone worked better in patients with elevated heart rates. -Larry Husten
NEW ORLEANS-Arrhythmia therapy for high-risk patients is marching to different drummers.
