Growth differentiation factor-15 in Assessment of Prognosis of patients with Atrial Fibrillation (GAP-AF Study)

Introduction: Differentiating growth factor-15 (GDF-15) is a marker of oxidative stress and inflammation and is increased in a number of cardiovascular disorders. Objectives: To evaluate the distribution of GDF-15 values ??and associations with severity parameters in hospitalized patients with atrial fibrillation or flutter (AF). Methods: Fifty patients hospitalized with a primary or secondary diagnosis of AF or flutter in two private hospitals (49 with atrial fibrillation and one with atrial flutter) were included. Prospective, observational, longitudinal study with a 1-year follow-up to assess outcomes. GDF-15 was measured, as well as cardiac and inflammatory biomarkers. We performed baseline analyzes comparing baseline characteristics in groups with high (above median) and low (below median) GDF-15. Correlations of the GDF-15 with other variables were made using the Pearson or Spearman methods, according to whether or not the variables were normal. Results: 29 (58%) patients were male and the mean age was 68.5±17.3 years. Twenty-eight (56%) had permanent AF and 18 (36%) had HF with reduced ejection fraction. The median GDF-15 was 2724 pg/mL (interquartile range 1116-5139). Patients with high GDF-15 values ??were older (77.5±9.7 vs 59±18.5 years, p=0.0001) and with higher rates of arterial hypertension (92.3% vs 70%, p=0.018) and permanent AF (69.2% vs 37.5%, p=0.016). They also had higher values ??of NT-proBNP (4006 pg/mL [2156-7023] vs 816 [174-3814], p=0.0015), creatinine (1.2 [0.95-1.7] vs 1. 0 [0.75-1.15], p=0.017) and C-reactive protein (3.1 [1.55-7.32] vs 1.25 [0.55-2.45], p=0.008) . All risk scores were higher in patients with elevated GDF-15, namely CHA2DS2-VASC (4.5±1.6 vs 2.9±2.3, p=0.008), HAS-BLED (2.4 ±1.3 vs 1.3±1.1, p=0.0029), ORBIT (3.5±1.5 vs 1.7±1.5, p=0.0003) and MAGGIC (20.8 ±12.3 vs 11±11.2, p=0.006). There was a direct correlation between GDF-15 and NT-proBNP (r=0.5, p=0.002), D-dimer (r=0.52, p=0.002) and age (r=0.43, p=0.002) . Conclusions: GDF-15 values ??were associated with parameters of greater severity in AF. GDF-15 can be useful as a prognostic factor and possibly in guiding the indication of anticoagulation in AF. We hope that the results from the 1-year follow-up reinforce these initial impressions.