AGXT2 and atrial fibrillation: When excluding the patients with structural heart disease from the analysis, a highly significant association for AGXT2 rs16899974 was observed with any AF (P = 3.9 × 10−8), and with paroxysmal AF (P = 3.0 × 10−5) and chronic AF (P = 7.0 × 10−4) separately.