Interactions Between Atrial Fibrillation and Natriuretic Peptide in Predicting Heart Failure Hospitalization or Cardiovascular Death

Background Natriuretic peptides are routinely quantified to diagnose heart failure (HF). Their concentrations are also elevated in atrial fibrillation (AF). To clarify their value in predicting future cardiovascular events, we measured natriuretic peptides in unselected patients with cardiovascular conditions and related their concentrations to AF and HF status and outcomes. Methods and Results Consecutive patients with cardiovascular conditions presenting to a large teaching hospital underwent clinical assessment, 7‐day ECG monitoring, and echocardiography to diagnose AF and HF. NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide) was centrally quantified. Based on a literature review, four NT‐proBNP groups were defined (<300, 300–999, 1000–1999, and ≥2000 pg/mL). Clinical characteristics and NT‐proBNP concentrations were related to HF hospitalization or cardiovascular death. Follow‐up data were available in 1616 of 1621 patients (99.7%) and analysis performed at 2.5 years (median age, 70 [interquartile range, 60–78] years; 40% women). HF hospitalization or cardiovascular death increased from 36 of 488 (3.2/100 person‐years) in patients with neither AF nor HF, to 55 of 354 (7.1/100 person‐years) in patients with AF only, 92 of 369 (12.1/100 person‐years) in patients with HF only, and 128 of 405 (17.7/100 person‐years) in patients with AF plus HF (P<0.001). Higher NT‐proBNP concentrations predicted the outcome in patients with AF only (C‐statistic, 0.82; 95% CI, 0.77–0.86; P <0.001) and in other phenotype groups (C‐statistic in AF plus HF, 0.66; [95% CI, 0.61–0.70]; P