Heart Failure and Afib: A Circular Process

Heart failure and atrial fibrillation often coexist.

Both conditions have similar risk factors including aging, hypertension, diabetes, smoking, obesity, renal insufficiency, sleep apnea, and coronary artery disease.

Heart failure causes cardiac hypertrophy through increased filling pressure, renin-angiotensin aldosterone system (RAAS) activation, and myocyte calcium misuse.

These factors lead to and maintain cardiac arrhythmias. Atrial fibrillation decreases stroke volume and increases valvular regurgitation, thereby causing heart failure separately.

Many clinicians consider heart failure and atrial fibrillation a circular process.

Whether atrial fibrillation independently predicts adverse outcomes in patients with heart failure is still controversial.

However, an article published online ahead-of-print in Circulation Journal explored new-onset atrial fibrillation’s role as a prognostic factor in heart failure patients.

One of every 3 patients in the CHART-2 cohort had atrial fibrillation currently or in the past, and 1.2% developed atrial fibrillation annually.

Atrial fibrillation development increased the risk of death (especially in the first year), but the adjusted risk of death was not significant because patients with comorbid atrial fibrillation typically had more severe heart failure.

The similar JCARECARD study showed comparable risk of all-cause death, cardiac death, re-hospitalization for heart failure, and all-cause hospitalization independent of atrial fibrillation comorbidity.

Atrial fibrillation has a larger impact on patients with heart failure with preserved ejection fraction due to impaired left ventricular filling.

The study authors noted that 2 things increase risk in new-onset atrial fibrillation patients with preexisting heart failure:

· Starting antiarrhythmics or anticoagulants often causes adverse effects.

· Development of new-onset atrial fibrillation may tax myocardial tissue metabolically until compensatory metabolic pathways upregulate.

The study authors suggested focusing on atrial fibrillation prevention in heart failure patients with RAAS agents and statins. Many heart failure patients are already on these medications due to a history of myocardial infarction or hypertension and hypercholesterolemia.

The researchers also recommended paying particularly close attention in the first year after atrial fibrillation diagnosis in heart failure patients, as mortality risk is significantly elevated.