AHA: Reprogramming Defibrillators Improves Therapy
(HealthDay News) – Reprogramming the firing settings for an implantable cardioverter-defibrillator (ICD) in patients with heart disease reduces inappropriate firings and reduces death.
Arthur J. Moss, MD, from the University of Rochester Medical Center in New York, and colleagues randomly assigned 1,500 patients with heart disease who were scheduled to receive an ICD to programming configurations set to fire with high-rate therapy (a 2.5-second delay before initiation of therapy at a heart rate of ≥200 beats per minute [bpm]), delayed therapy (a 60-second delay at 170–199bpm, a 12-second delay at 200–249bpm, and a 2.5-second delay at ≥250bpm), or conventional therapy (a 2.5-second delay at 170–199bpm and a 1-second delay at ≥200bpm).
During an average follow-up of 1.4 years, the researchers found that high-rate and delayed therapy were both superior to conventional therapy in reducing a first occurrence of inappropriate therapy (hazard ratios, 0.21 and 0.24, respectively). Compared with conventional therapy, high-rate and delayed therapy reduced all-cause mortality (hazard ratios, 0.45 and 0.56; 95% confidence intervals, 0.24–0.85 and 0.30–1.02, respectively). The three groups were similar in terms of procedure-related adverse events.
"Programming of ICD therapies for tachyarrhythmias of >200bpm or with a prolonged delay in therapy at >170bpm, as compared with conventional programming, was associated with reductions in inappropriate therapy and all-cause mortality during long-term follow-up," Moss and colleagues conclude.
The study was funded by Boston Scientific; several authors disclosed financial ties to pharmaceutical companies, including Boston Scientific.