Clinical relationship between anemia and atrial fibrillation recurrence after catheter ablation without genetic background.

BACKGROUND

Anemia is a known adverse prognostic factor among patients with cardiovascular diseases. We investigated whether the hemoglobin level was associated with the rhythm outcome after atrial fibrillation (AF) catheter ablation (AFCA).

METHODS

We included 2627 patients who underwent AFCA and a guidelines-based rhythm follow-up (age 58 ± 10.9 years, 73% men, 30.6% with persistent AF), and evaluated the association of pre-AFCA anemia (haemoglobin <13 g/dL in men and <12 g/dL in women) and rhythm outcomes. We studied the mechanistic relationship between anemia and AF recurrence using a Mendelian randomization analysis (1775 subjects with genome-wide association study) after reviewing already proven 12 hemoglobin-associated genetic polymorphisms.

RESULTS

The body mass index, paroxysmal AF, warfarin use, and baseline red cell distribution width were independently associated with anemia in patients with AF. During a 23-month follow-up (interval OR 9-48 months), the clinical AF recurrence rate was significantly higher in patients with than without anemia (log-rank p = 0.001; propensity score-matched log-rank p = 0.004). This pattern was more significant in male patients (Log-rank p < 0.001) or patients with paroxysmal AF (Log-rank p < 0.001). Anemia (hazard ratio [HR] 1.45 [1.17-1.80], p = 0.001), left atrial diameter (HR 1.03 [1.01-1.04], p < 0.001), a female sex (HR 1.17 [1.00-1.36], p = 0.047), and persistent AF (HR 1.58 [1.36-1.84], p < 0.001) were independently associated with post-AFCA clinical recurrence. In the Mendelian randomization, we could not find a significant direct causal relationship between anemia and AF recurrence at the genetic level.

CONCLUSIONS

Pre-AFCA anemia is an independent predictor of post-AFCA clinical recurrence, especially in male patients, without a genetically direct causal relationship.