Anemia is a marker for the recurrence of atrial fibrillation (AFib) following catheter ablation, according to a new observational study.
“Anemia is a known adverse prognostic factor among patients with cardiovascular diseases,” the authors wrote in their study. “We investigated whether the hemoglobin level was associated with the rhythm outcome after atrial fibrillation (AF) catheter ablation (AFCA).”
The researchers included 2,627 patients who underwent AFCA and guideline-based follow-up. They also determined the association between pre-AFCA anemia (hemoglobin <13 g/dL in men and <12 g/dL in women) and rhythm outcomes. Using Mendelian randomization analysis, the authors studied the mechanistic relationship between anemia and AFib recurrence after reviewing 12 hemoglobin-associated genetic polymorphic. Patients were followed up for more than three months after AFCA.
Anemia Independently Associated
According to the study results, 252 (9.6%) of patients had anemia at baseline prior to the procedure. Patients with anemia and AFib tended to be older, were more likely to be women, more likely to have paroxysmal AFib, had lower body mass index, were non-drinkers, were non-smokers, and were more likely to use warfarin. During 23 months of follow-up, the authors reported that the rate of clinical recurrence of AFib was significantly higher in patients with anemia than those without, an association that persisted even after propensity-score matching for age, BMI, sex, AFib type, anticoagulation, smoking history, alcohol history, hypertension, diabetes, and prior stroke/transient ischemic attack, and other factors. The pattern was more significant in males, in patients with paroxysmal AFib, and in patients over the age of 60.
The authors also reported that after using Mendelian randomization at the genetic level, they did not observe a direct causal relationship.
“Pre-AFCA anemia was independently associated with a clinical recurrence of AF, especially in male patients and patients with paroxysmal AF,” the researchers wrote in their conclusion. “However, we did not find a direct causal relationship between anemia and post-AFCA recurrence at the genetic level using the Mendelian randomization.”
The team cited the observational design of the study and the single-center experience as limitations. The paper was published in IJC Heart and Vasculature.