Abstract 14245: Fibroblast Growth Factor 23 and Long-term Cardiac Function: The Multi- Ethnic Study of Atherosclerosis

Abstract

Background: While fibroblast growth factor 23 (FGF23) is associated with incident heart failure (HF) and atrial fibrillation (AF), the mechanisms driving these associations are unclear. FGF23 elevation leads to cardiomyocyte calcium handling abnormalities, suggesting that FGF23 may directly reduce myocardial function. Methods: In the Multi-Ethnic Study of Atherosclerosis, a cohort free of cardiovascular disease at recruitment, we evaluated the associations of serum FGF23 (2000-2002) with measures of left ventricular (LV) and left atrial (LA) mechanical function on cardiac magnetic resonance (CMR) at 10-year follow up (2010-2012). Results: Of 2,276 participants with baseline FGF23 and CMR at 10-year follow up, participants with higher FGF23 levels were more likely white race, taking anti-hypertensive medications, and had lower baseline glomerular filtration rate (GFR). After covariate adjustment, baseline FGF23 levels were independently associated with worse LV global circumferential strain, worse LV mid-wall circumferential strain, and lower LA total emptying fraction in later life ( Table ). The association of FGF23 and LV global circumferential strain was consistent across the spectrum of GFR ( Figure ). While higher FGF23 was associated with higher LV mass (β coefficient per SD higher: 1.14, 95% CI: 0.16, 2.12, P= 0.02), it was not associated with the presence of macroscopic myocardial scar (OR per SD higher: 1.12, 95% CI: 0.86-1.45, P= 0.42). Conclusions: Baseline FGF23 is independently associated with lower LV and LA systolic function in later life. These findings provide mechanistic insight driving the associations of FGF23 with development of both HF and AF.