Management of Atrial Fibrillation Suppression in AF-HF Comorbidity Therapy (MASCOT) Trial

Abstract

Inter- [1,2], intra- [3,4], and atrioventricular [51(AV) dyssynchrony are not new concepts, but only recently have attempts been made to correct these disorders in an effort to treat heart failure (HF). A series of trials [6] has addressed partial or comprehensive cardiac resynchronization in patients with severe HF and evidence of cardiac dyssynchrony. Cardiac resynchronization should improve left ventricular (LV) performance; several trials [7-10] have demonstrated improvement in many hemodynamic parameters (LV and aortic pressure, shortening of mitral diastolic regurgitation, synchronized LV and atrial systole, LV volume, reduced myocardial oxygen consumption) and clinical end-points (quality of life, peak oxygen uptake, functional capacity, reduced number of hospitalizations). The incidence of atrial fibrillation (AF) double every 10 years in adults: there are 2-3 new cases/1000 annually in the age group of 55-64 years and 35 new cases/1000 annually between the age of 85 and 94 years [11-13]. The Framingham study demonstrated that AF is an independent risk factor for mortality with a relative risk of 1.5 for men and 1.9 for women. In patients with HF, the prevalence of AF is directly related to NYHA class: AF is present in 10% of patients in NYHA class II and 40% of patients in NYHA classes III-IV. However, HF morbidity is highly influenced by the coexistence of AF, independently of functional class. Moreover, the presence of symptomatic or asymptomatic AF in patients with LV dysfunction is linked to a poor prognosis and is independently associated with a higher risk of death from all causes and from progressive pump failure [14,15]. The prevalence of AF in most trials [16-22] on HF is shown in Fig. 1.