FGF23 and atrial fibrillation: HFpEF patients with FGF23 above the median plasma concentration experienced lower systolic BP, more frequent prior HF hospitalization, more prevalent AF, greater prescription of loop diuretics, worse renal function (urea, creatinine, and eGFR), worse exercise capacity (greater proportion of NYHA III/IV and reduced 6MWT distance), higher LV filling pressures (E/e′), and lower LAEF.