Atrial Fibrillation as a Risk Marker in Patients with Decompensated Heart Failure

Background:

Atrial Fibrillation (AF) and Heart Failure (HF) most commonly coexist, and each condition can exacerbate and complicate the course of treatment of the other. The relationship between these two conditions is not entirely understood. Loss of atrial systole is an important contributing factor in decreasing cardiac output and can increase the risk of blood stasis, thromboembolism, inflammation, and cardiac myocyte dysfunction.

Objective:

This study aimed to assess the relationship between AF and cardiovascular mortality and high-risk clinical, laboratory, and echocardiographic variables in patients with acute decompensated HF.

Methods:

This historical cohort study was conducted on 298 consecutive patients admitted with acute decompensated HF. The patients were divided into sinus rhythm (198 patients, 66.44%) and AF (100 patients, 33.56%) groups. The two groups were compared regarding demographic, laboratory, and echocardiographic variables and cardiovascular mortality within six months after index hospitalization using independent t-test, chi-square, and Fisher’s exact tests. In addition, independent echocardiographic risk factors for development of AF were determined by a logistic regression model. Variables with P < 0.05 were considered to be significant. All statistical analyses were done by SPSS/PASW software.

Results:

The results showed that the patients with AF were older and had female predominance, a lower prevalence of diabetes mellitus, a lower rate of glomerular filtration, and a higher six-month cardiovascular mortality compared to those with sinus rhythm (P = 0.011, 0.05, 0.005, 0.043, and 0.041, respectively). These patients also had a larger left atrial diameter (P < 0.001) and a higher prevalence of right ventricular enlargement, systolic dysfunction, and moderate or severe functional mitral regurgitation compared to those with sinus rhythm (P = 0.02, 0.016, and 0.011, respectively). The results of logistic regression analysis indicated that left atrial diameter was the only independent predictor of AF (odds ratio = 2.27, 95% confidence interval [1.38 – 3.75]).

Conclusion:

The results showed that AF was associated with increased cardiovascular mortality and high-risk clinical, laboratory, and echocardiographic markers in patients with decompensated HF.