Predictive Value of Assessing Diastolic Strain Rate on Survival in Cardiac Amyloidosis Patients with Preserved Ejection Fraction

OBJECTIVES: Since diastolic abnormalities are typical findings of cardiac amyloidosis (CA), we hypothesized that speckle-tracking-imaging (STI) derived longitudinal early diastolic strain rate (LSRdias) could predict outcome in CA patients with preserved left ventricular ejection fraction (LVEF >50%). BACKGROUND: Diastolic abnormalities including altered early filling are typical findings and are related to outcome in CA patients. Reduced longitudinal systolic strain (LSsys) assessed by STI predicts increased mortality in CA patients. It remains unknown if LSRdias also related to outcome in these patients. METHODS: Conventional echocardiography and STI were performed in 41 CA patients with preserved LVEF (25 male; mean age 65±9 years). Global and segmental LSsys and LSRdias were obtained in six LV segments from apical 4-chamber views. RESULTS: Nineteen (46%) out of 41 CA patients died during a median of 16 months (quartiles 5-35 months) follow-up. Baseline mitral annular plane systolic excursion (MAPSE, 6 ± 2 vs. 8 ± 3 mm), global LSRdias and basal-septal LSRdias were significantly lower in non-survivors than in survivors (all p < 0.05). NYHA class, number of non-cardiac organs involved, MAPSE, mid-septal LSsys, global LSRdias, basal-septal LSRdias and E/LSRdias were the univariable predictors of all-cause death. Multivariable analysis showed that number of non-cardiac organs involved (hazard ratio [HR] = 1.96, 95% confidence interval [CI] 1.17-3.26, P = 0.010), global LSRdias (HR = 7.30, 95% CI 2.08-25.65, P = 0.002), and E/LSRdias (HR = 2.98, 95% CI 1.54-5.79, P = 0.001) remained independently predictive of increased mortality risk. The prognostic performance of global LSRdias was optimal at a cutoff value of 0.85 S-1 (sensitivity 68%, specificity 67%). Global LSRdias < 0.85 S-1 predicted a 4-fold increased mortality in CA patients with preserved LVEF. CONCLUSIONS: STI-derived early diastolic strain rate is a powerful independent predictor of survival in CA patients with preserved LVEF.