Long-term effects of cardiac resynchronisation therapy in patients with atrial fibrillation

Objective: To compare the effects of cardiac resynchronisation therapy (CRT) in patients with heart failure (HF) in either atrial fibrillation (AF) or sinus rhythm (SR). Design: Prospective observational study. Patients: 295 consecutive patients with HF (permanent AF in 66, paroxysmal AF in 20, SR in 209; New York Heart Association (NYHA) class III or IV; left ventricular ejection fraction (LVEF) <= 35%, QRS >= 120 ms). Interventions: All patients underwent CRT without atrioventricular junction ablation. Main outcome measures: The primary end point was the composite of cardiovascular death or unplanned hospitalisation for major cardiovascular events. Secondary end points included the composite of cardiovascular death or hospitalisation for worsening HF. Cardiovascular mortality, total mortality and changes in NYHA class, 6-minute walking distance, quality of life (Minnesota Living with Heart Failure questionnaire) and echocardiographic variables were also considered. Results: Over a follow-up period of up to 6.8 years, no differences emerged between patients in AF or SR in any of the mortality or morbidity end points. The AF and SR groups derived similar improvements in mean NYHA class (-1.3 vs -1.2), 6-minute walking distance (92.3 vs 78.4 m) and quality of life scores (-25.2 vs -18.7) (all p<0.001). In both the AF and the SR groups, reductions were seen in left ventricular end-systolic (-25.9 vs -34.5 ml, both p<0.001) and end-diastolic (-20.2 ml, p = 0.001 vs 26.2 ml, p<0.001) volumes and improvements in LVEF (4.69% vs 7.86%, both p<0.001). Conclusions: Cardiac resynchronisation therapy leads to similar prognostic and symptomatic benefits in patients in AF and SR, even without atrioventricular junction ablation. Echocardiographic improvements are also comparable.