Comparison of clinical features and conventional echocardiographic characteristics of patients with heart failure with mid-range ejection fraction with and without interatrial block

OBJECTIVE
Heart failure with mid-range ejection fraction (HFmrEF) has been proposed as a distinct heart failure (HF) phenotype. Interatrial block (IAB) is a conduction delay between the atria and is associated with cardiovascular disease. Although there are several studies examining the effect of IAB in patients with HF with reduced ejection fraction and HF with preserved ejection fraction, a literature review did not reveal any study investigating the clinical importance of the presence of IAB in patients with HFmrEF. Thus, the aim of this research was to evaluate clinical characteristics of HFmrEF with and without IAB.

METHODS
A total of 520 consecutive patients with HFmrEF in sinus rhythm who were examined at outpatient clinics were enrolled in the study (244 patients with IAB and 276 patients without IAB). Surface 12-lead standard electrocardiograms (ECGs) were recorded. Clinical characteristics, echocardiographic examination results, and laboratory values of the patients were recorded.

RESULTS
The mean age of the patients was 67.4±11.1 years, and 76.1% were male. The patients with IAB had more comorbidities, including hypertension, diabetes mellitus, and stroke/transient ischemic attack. A statistically significant, strong, positive linear correlation was observed between P-wave duration and age, systolic blood pressure, and left atrial volume index (r=0.718, p<0.001; r=0.704, p<0.001; and r=0.725, p<0.001, respectively).

CONCLUSION
To the best of our knowledge, the present study is the first to evaluate the clinical relevance of IAB in HFmrEF. Adding this simple ECG marker to the clinical evaluation could add significantly to the management of HFmrEF. IAB can be used to identify high-risk HFmrEF patients, as well as to guide follow-up and appropriate treatment.