The C of CHADS: Historical perspective and clinical applications for anticoagulation in patients with non valvular atrial fibrillation and congestive heart failure

The risk stratification of patients with coexisting non valvular atrial fibrillation and congestive heart failure, is often a clinical challenge, as the definitions of congestive heart failure in the popular CHADS2 and CHA2DS2VASc scoring systems, and amongst major clinical trials on Warfarin and Novel Oral Anticoagulants (NOAC) have heterogeneity. Available evidence reveals that any heart failure and/or left ventricular systolic dysfunction is associated with higher rates of stroke/systemic embolism and bleeding in patients with non valvular atrial fibrillation compared to patients without heart failure and normal left ventricular function. Most standard dose NOAC regimens have a better safety and efficacy profile over warfarin in most heart failure sub-group types with a few exceptions including patients with NYHA III/IV on Dabigatran 150 mg BID from the RE-LY trial, who had higher major bleeding events, and patients with asymptomatic left ventricular dysfunction (ejection fraction ≤ 40%) and heart failure with reduced ejection fraction on 20 mg of Rivaroxaban in the ROCKET-AF trial, when compared to patients on Warfarin in the corresponding groups. With the gaining popularity and use of NOACs, understanding their safety profile in such situations is paramount.