DANPACE: No AAIR pacemakers for sick sinus syndrome patients
MedWire News: Sick sinus syndrome patients should not receive rate-adaptive single chamber atrial pacing (AAIR) because of a raised risk for reoperation and atrial fibrillation when compared with rate-adaptive dual chamber pacing (DDDR), conclude DANPACE investigators.
More than 1400 patients referred for a first pacemaker implantation were randomized to either AAIR or DDDR and followed up for a mean period of 5.5 years, resulting in over 7000 operational years of evidence. There were no significant differences between AAIR and DDDR patients in terms of survival, stroke, and the incidence of heart failure. However, patients assigned to AAIR had a significantly increased rate of reoperation and paroxysmal atrial fibrillation compared with DDDR patients.
"In prior trials, ventricular stimulation has been found to increase the incidences of atrial fibrillation and heart failure," said Jens Nielsen (Aarhus University Hospital, Skejby, Denmark), reporting the results at the European Society of Cardiology Annual Congress, in Stockholm, Sweden.
"However, we demonstrated for the first time that dual-chamber pacing actually decreases atrial fibrillation and has no influence on the incidence of heart failure when compared with single-lead atrial pacing without ventricular stimulation. Simply, AAIR pacing should no longer be used."
DANPACE (Danish Multicenter Randomised Study on AAI Versus DDD Pacing in Sick Sinus Syndrome) was a randomized controlled trial in which 1415 patients with symptomatic bradycardia and documented sinus-pause >2 s or sinus bradycardia <40 bpm for >1 minute whilst awake, a PR-interval of ≤0.22 s (aged 18-70 years) or a PR-interval of ≤0.26 s (aged ≥70 years), and QRS width <0.12 s were randomized to either AAIR or DDDR.
The primary endpoint was death from any cause, while the secondary endpoints were paroxysmal atrial fibrillation at planned follow-up, chronic atrial fibrillation, stroke, heart failure, and pacemaker reoperation.
The baseline characteristics were well matched between the AAIR and DDDR groups, although the AAIR patients were slightly, but borderline significantly, older, at 73.5 years versus 72.4 years (p=0.054), and were significantly more likely to use diuretics, at 43.0% versus 37.2% (p=0.03). Full data were available for 83% of AAIR patients and 90% of DDDR patients.
There were no significant differences at follow-up between the two patient groups for all-cause mortality, at 29.6% versus 27.3% for AAIR versus DDDR, respectively (p=0.53); similarly, no significant differences were seen for stroke (p=0.56), New York Heart Association class at last follow-up (p=0.43), use of diuretics at last follow-up (p=0.89), and hospitalization for heart failure (p=0.90). However, AAIR patients were significantly more likely to undergo reoperation, at a hazard ratio of 2.00 (p<0.001), and experience paroxysmal atrial fibrillation, at a hazard ratio of 1.24 (p=0.042).
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010
By Liam Davenport