Association of Left Atrial Hemodynamics by Magnetic Resonance Imaging With Long-Term Outcomes in Patients With Cardiac Amyloidosis.

Background: Left atrial (LA) function and strain patterns by magnetic resonance imaging (MRI) have been investigated as markers of several cardiovascular pathologies, including cardiac amyloidosis (CA). However, associations with clinical outcomes have not been investigated.

Purpose: To compare LA function and strain by MRI in CA patients to a matched cohort of patients without cardiovascular disease (CVD) and evaluate the association with long-term clinical outcomes in CA patients.

Study Type: Retrospective case control.

Population: A total of 51 patients with CA and 51 age-, gender-, and race-matched controls without CVD who underwent MRI in sinus rhythm.

Field Strength/sequence: ECG-gated balanced steady-state free precession sequence at 1.5 T.

Assessment: All measurements were completed by one investigator (M.M.B.). LA function and strain parameters were measured including LA indexed minimum and maximum volumes, LA reservoir (R), contractile (CT), and conduit (CD) strain. We compared groups after adjusting for age, hypertension, New York Heart Association class, modified staging system (troponin-I, BNP, estimated GFR) and left ventricular ejection fraction (LVEF) for an endpoint of all-cause mortality and a composite endpoint of heart failure hospitalization (HFH) or death.

Statistical Tests: Differences between groups were evaluated with t tests for continuous variables or χ tests for categorical variables. A multivariable regression model was used to assess the associations of the P values-two-sided tests-<0.05 were considered statistically significant.

Results: CA patients with median follow up of 4.9 (8.5) months had significantly lower LA strain and higher LA volumes in comparison to the matched cohort. In the multivariable analysis, only LVEF was significantly associated with death while ƐCT (OR 0.6, CI: 0.41-0.89), indexed minimum LA volume (OR 1.06, CI: 1.02-1.13) and indexed maximum LA volume (OR 1.08, CI: 1.01-1.15) were significantly associated with the composite outcome of death or HFH.

Conclusion: In this retrospective study of CA patients, ƐCT and indexed minimum and maximum LA volumes were significantly associated with the composite outcome of death or HFH.

Evidence Level: 3 TECHNICAL EFFICACY: Stage 3.