In patients affected by permanent atrial fibrillation (AF), cardiac resynchronisation therapy (CRT) proved superior to conventional right ventricle apical pacing in reducing the clinical manifestations of heart failure, a new study presented at Heart Rhythm 2011 has shown.
The results were obtained “on top” of rate regularisation achieved by means of atrioventricular junction ablation, Michele Brignole, Ospedali del Tigullio, Lavagna, Italy, told delegates.
Data of the prospective, randomised APAF (Ablate and pace in atrial fibrillation) trial were presented as a late-breaking clinical trial in San Francisco in May.
The hypothesis of the study, Brignole said, was that CRT is superior to normal right ventricle pacing in reducing clinical events in patients undergoing atrioventricular junction ablation (‘ablate and pace’ therapy) for permanent AF.
“Current guidelines recommend CRT only for patients with left ventricle ejection fraction ≤35%, NYHA ≥III and QRS width ≥120ms or ≥130ms (or pacing dependence),” Brignole stated. “On the basis of the current knowledge, CRT cannot be recommended as a first treatment for all patients with symptomatic permanent AF undergoing atriventricular ablation or pacing.”
The multicentre study included 186 patients who had successfully undergone atrioventricular junction ablation and received a biventricular pacemaker, and who were randomised to receive echo-guided CRT (97 patients) or right ventricle apical pacing (89 patients). During a median follow-up of 20 months, the CRT group had fewer worsening heart failure symptoms and heart failure hospitalisations; total mortality was similar in both groups. Additionally, only the CRT mode remained an independent predictor of absence of clinical failure (defined as death due to heart failure, hospitalisation due to heart failure or worsening heart failure) during the follow-up.
Patients receiving CRT had a 63% relative reduction in the primary composite endpoint of death from heart failure, hospitalisation from heart failure, or worsening heart failure when compared to patients undergoing right ventricle pacing (absolute reducation from 26% to 11%).
“These findings suggest CRT should be considered as the preferred treatment approach for patients that require the ‘ablate and pace’ procedure,” said Michele Brignole, lead investigator and electrophysiologist, Ospedali del Tigullio, Lavagna, Italy. “While these results provide evidence supporting the potential expansion of indications regarding the use of CRT as a first-line treatment for all permanent AF patients who must undergo atrioventricular junction ablation, we look forward to conducting additional studies to provide further confirmation that will ultimately result in the modification of treatment guidelines.”
Brignole added “Only 25% to 32% of the study population met the criteria of the most recent guidelines; the majority did not. The beneficial effect of CRT was consistent both in patients who met the current recommendations for CRT and those who did not.
“Our results provide experimental evidence to the indications for CRT of the current guidelines which were mainly based on expert consensus and, if confirmed by others, will support an extension of indications for CRT in permanent AF patients,” he concluded.
The S-ICD system is currently under review by FDA for use in the United States.