Prognostic significance of strain Doppler imaging in light-chain amyloidosis
1Boston University Amyloidosis Treatment and Research Program, Brigham and Women's Hospital, Boston Massachusetts, USA. jkoyama@shinshu-u.ac.jp
Objectives:
To clarify the prognostic value of strain and strain rate imaging in light-chain (AL) amyloidosis.
Background:
Myocardial strain and strain rate Doppler imaging are objective measurements that may detect regional subtle myocardial functional abnormalities in patients with amyloidosis.
Methods:
We prospectively examined 119 consecutive, untreated patients with biopsy-proven AL amyloidosis. The mean values of tissue velocity, strain, and strain rate were calculated from the basal, mid, and apical left ventricular (LV) multiple walls in apical 2- and 4-chamber views. The prognostic value of these parameters was compared with standard 2-dimensional echocardiographic and Doppler measurements of transmitral and pulmonary venous flow.
Results:
Seventy patients had cardiac involvement defined as the mean value of LV wall thickness greater than 12 mm. Thirty-two patients (27%) (including 22 proven cardiac deaths) died during a mean follow-up period of 285 +/- 136 days. No echocardiographic or Doppler features differentiated patients with cardiac involvement without congestive heart failure (CHF) from noncardiac amyloid group other than the pre-defined wall thickness and LV end-diastolic and end-systolic diameters. On the other hand, strain rate and strain imaging clearly detected differences of longitudinal LV myocardial deformation among 3 groups (noncardiac involvement group, cardiac amyloidosis without CHF group, and cardiac amyloidosis with CHF group). Univariate analysis showed that strain rate, strain, and tissue velocity values were statistically significant predictors of outcome at most of the sites. Multivariate analysis showed that the mean LV basal strain was the only independent predictor of both cardiac and overall deaths.
Conclusions:
Among patients with AL amyloidosis, the mean basal strain, a measure of longitudinal LV function, was a powerful predictor of clinical outcome and was superior to standard 2-dimensional echocardiographic, Doppler flow measurements, and simple tissue velocity indexes.
