Incremental value of global longitudinal strain in prediction of all-cause mortality in predialysis and dialysis chronic kidney disease patients.

BACKGROUND: The aim of this prospective study was to investigate the prediction of all-cause mortality from global longitudinal strain (GLS) in two groups of chronic kidney disease patients (CKD): predialysis and dialysis. METHODS: In 89 patients undergoing echocardiography, 37.2 % predialysis (16/43) and 58.6 % dialysis patients (27/46) died during the mean follow-up 70.2 ± 35 months. In addition to conventional echocardiographic measurements, GLS was assessed by velocity vector imaging from three standard apical views. RESULTS: Cox proportional hazards regression enter model showed the following variables to predict survival: the only significant predictor of survival in predialysis patients, among the set of conventional echocardiographic parameters was GLS (HR, 0.58; 95 % CI, 0.39-0.87; p = 0.01). In the group of dialysis patients GLS with E/Em ratio remained as significant predictors of survival (HR, 0.72; 95 % CI, 0.56-0.92; p = 0.01, and HR, 1.02; 95 % CI, 1.004-1.04; p = 0.01, respectively). GLS ≥ - 13.2 % had 58.3 % sensitivity and 91.7 % specificity for prediction of mortality in predialysis patients, and GLS ≥ - 12.02 % had 73.3 % sensitivity and 78.9 % specificity for prediction of mortality in dialysis patients. In dialysis group E/Em ratio ˃ 17.02 had 71.4 % sensitivity and 84.2 % specificity for prediction of mortality. CONCLUSIONS: Our study demonstrates the incremental value of GLS in prediction of all-cause mortality during a long follow-up period in CKD patients. GLS together with E/Em ratio may be used for the assessment of left ventricular systolic and diastolic function and risk stratification of CKD patients in different stages of renal failure.

Diagnostic accuracy of global myocardial deformation indexes in coronary artery disease: a velocity vector imaging study.

The aim of our study was to assess the diagnostic accuracy of a global longitudinal strain and strain rate (GLS, GLSR) and mean radial strain and strain rate (MRS, MRSR) of the left ventricle to predict multivessel disease. In 113 patients, who underwent coronary angiography, left ventricular deformation was analysed by speckle-tracking based velocity vector imaging. In three standard apical views strain and strain rate curves were generated corresponding with two opposite basal, mid, and apical segments. The negative peaks of systolic strain and strain rate from 18 curves were averaged as GLS and GLSR. Similarly, in short axis view 6 negative systolic peaks were averaged and considered as MRS and MRSR. Four subgroups were defined: (1) without significant coronary stenosis, 0-vessel disease (0VD), (2) single-vessel disease (1VD), (3) double-vessel disease (2VD), and (4) triple-vessel disease (3VD). In comparison with patients without significant coronary artery disease, all deformation indexes were significantly decreased in patients with 3VD. The left ventricular ejection fraction (LVEF) and wall motion score index (WMSI) showed lower significance level as deformation parameters. MRSR was the strongest predictor of multivessel disease. Receiver-operating characteristic curves (ROC) showed that MRSR had the highest diagnostic accuracy. Comparing ROC areas, MRSR had significantly higher diagnostic accuracy than LVEF and WMSI. The results of our study show that global deformation indexes have a good diagnostic accuracy in differentiating multivessel disease. MRSR tended to be better in identification of 3VD than traditional indexes of global and regional left ventricular function.

Velocity vector imaging to quantify left atrial function.

The aim of our study was to assess the feasibility of a new image analysis, velocity vector imaging (VVI), in the assessment of left atrial volumes (LAV) and left atrial ejection fraction (LAEF). We retrospectively analysed 100 transthoracic echocardiographic findings in 71 men, and 29 women (mean age 57 +/- 19.8 years). Two subgroups of patients were defined: (1) with left ventricular (LV) EF > 50%, and (2) LV EF < 50%. For the VVI method of indexed LAV assessment we used the apical four-chamber view. From the displacement of LA endocardial pixels time-volume curves were extracted which provided automatically data regarding indexed maximum LAV (LAVImax), indexed minimum LAV (LAVImin), and LAEF. LAVs and LAEF by 2-dimensional echocardiograhy (2DE) were measured by Simpson's biplane disc summation method. Comparing LAVImax, LAVImin, and LAEF by VVI versus 2DE in the total study population, we found significant correlations: r = 0.94, P < 0.0001, r = 0.94, P < 0.0001, r = 0.79, P < 0.0001, respectively. In addition, LAVImax >or= 40 ml/m(2) was 94% sensitive and 72% specific, LAVImin >or= 27 ml/m(2) was 90% sensitive and 86% specific, and LAEF < 30% was 80% sensitive and 96% specific for the detection of LV systolic dysfunction. There were highly significant inverse associations of LAVImax and LAVImin to LVEF. LAEF was also significantly related to LV systolic function. When comparing the time required for VVI and 2DE measurements, VVI led to 62% reduction in the measurement time. In conclusion, VVI is a feasible method for the assessment of LAVs and LAEF. It provides close agreement with that measured by conventional 2DE Simpson's biplane method with significant time saved.