Abstract 13464: Association of Left Atrial Hemodynamics by Magnetic Resonance Imaging With Long Term Outcomes in Patients With Cardiac Amyloidosis

Abstract

Introduction: We investigated left atrial (LA) function and strain by MRI in patients with cardiac amyloidosis (CA) and their associations with clinical outcomes. Methods: We conducted a retrospective case control study of 51 CA patients (24 transthyretin [ATTR] and 27 systemic [AL]) and 51 age, gender, and race matched controls without cardiovascular disease who underwent MRI in sinus rhythm. We measured LA function and strain parameters including indexed volumes (LAVi), ejection fraction, expansion index, reservoir (εR), contractile (εCT), and conduit (εCD) strain. A multivariate regression model was adjusted for age, hypertension, NYHA class, modified staging system (using Troponin-I, BNP, and GFR) and left ventricular ejection fraction (LVEF). We used endpoints of all-cause mortality and a composite endpoint of heart failure hospitalization (HFH) or death. Results: Mean age was 65.3 for AL vs 76.2 for ATTR. ATTR patients had higher LAV, indexed LV and RV end systolic volumes and lower LVEF than AL patients. CA patients had significantly lower LA strain (11.5, 4.7, 6.8 vs 38.2, 14.2, 24 for εR, εCT, εCD respectively) and higher LAVs than controls. Median follow up was 12.6 months. εCT (OR 0.6, CI: 0.41-0.89), minimum LAVi (OR 1.06, CI: 1.02-1.13) and maximum LAVi (OR 1.08, CI: 1.01-1.15) were associated with the composite outcome of death or HFH. Cox Hazard regression models showed a difference in the composite outcome as LAVi increases and ↋CT is reduced. χ2 statistic were 23.1 for ↋CT versus 18.4 for LAVi (P=0.04, 0.01). Conclusion: In our retrospective study of CA patients, εCT, minimum and maximum LAVi were significantly associated with the composite outcome of death or HFH.