Impact of global longitudinal strain and anemia for predicting cardiovascular mortality in patients hospitalized for acute heart failure with atrial fibrillation

Abstract Background Iron deficiency is a prognostic factor in heart failure (HF) with reduced ejection fraction (EF). In patients with atrial fibrillation (AF) and HF, left ventricular EF (LVEF) measurements are imprecise due to irregular tachycardia, but it is unclear whether global longitudinal strain (GLS) and anemia assessment are prognostic. Purpose We examined whether GLS and anemia predict cardiovascular death (CD) in patients with acute HF complicated by AF. Methods We retrospectively enrolled patients aged 18 years or older with acute HF complicated by AF who were consecutively admitted to our hospital from January 2014 to December 2018. Exclusion criteria were acute coronary syndromes, no transthoracic echocardiogram performed within 30 days before or after admission, and missing data. All patients were followed up from admission to CD (due to myocardial infarction, HF, stroke or sudden death), or were censored at the date of last contact or 3 years. Anemia was defined as hemoglobin < 12 g/dL in females and hemoglobin < 13 g/dL in males. Patients were divided into four groups according to median GLS and anemia status. Results A total of 320 patients (mean age 79 ± 12 years, 163 females) were included in the analysis. The median duration of AF was 1.2 years; 11% (36/320) had paroxysmal AF. The median brain natriuretic peptide value was 623 pg/ml, and 52% of the patients (165/320) were in New York Heart Association functional class 4. During a median follow-up of 528 days, 24% (77/320) patients were observed with CDs: 2 myocardial infarctions, 51 HF-related deaths, 6 strokes, and 18 sudden cardiac deaths. At the 3-year follow-up, the survival rate by the Kaplan-Meier curve was 89% (95% confidence interval (CI) 76%-95%) in the no anemia group with high GLS (< -10%) and 40% (95% CI 25%-54%) in the anemia group with low GLS (≥ -10%) (p < 0.001, log-rank test). In multivariate Cox regression analysis, GLS (adjusted hazard ratio (aHR) 1.06, 95% CI 1.01-1.14, p = 0.017) and hemoglobin (aHR 0.85, 95% CI 0.76-0.96, p = 0.009) were independent factors for CD, with a significantly increased risk in the anemia group with low GLS compared to the no anemia group with high GLS (aHR 4.11, 95% CI 1.59-10.6, p = 0.004). The results were consistent with no interaction by gender or LVEF 50%. Conclusions Anemic patients with low GLS with AF and HF may have poor prognosis. Prospective studies are needed to determine whether iron supplementation improves prognosis in such patients.