Prognostic significance of incorporating exercise tissue doppler mitral annular early diastolic velocity in exercise diastolic dysfunction assessment.

BACKGROUND: The existing algorithm for defining exercise-induced diastolic dysfunction incorporates resting e' velocity as a surrogate of myocardial relaxation. The additive prognostic value of incorporating post-exercise e' velocity in definition of exercise-induced diastolic dysfunction is poorly studied. AIM: To define the additive prognostic value of post-exercise e' septal velocity in the assessment of exercise-induced diastolic dysfunction compared to the traditional approach. METHODS: This retrospective study included 1409 patients undergoing exercise treadmill echocardiography with available full set of diastolic variables. Doppler measures of diastolic function included resting septal e' velocity, post-exercise septal e' velocity, post-exercise E/e' ratio, and post-exercise tricuspid regurgitant jet velocity. Approaches incorporating resting septal e' velocity and post-exercise septal e' velocity were compared in defining exercise-induced diastolic dysfunction, and for association with adverse cardiovascular outcomes. RESULTS: The mean age of study subjects was 56.3 ± 16.5 years and 791 (56%) patients were women. A total of 524 patients had disagreement between resting and post exercise septal e' velocities, and these values showed only weak agreement (kappa statistics: .28, P = .02). All categories of the traditional exercise-induced DD approach incorporating resting septal e' velocity witnessed reclassification when exercise septal e' velocity was used. When both approaches were compared, increased event rates were only evident when both approaches agreed on exercise-induced diastolic dysfunction (HR: 1.92, P < .001, 95% CI: 1.37-2.69). This association persisted after multivariable adjustment and propensity score matching for covariates. CONCLUSION: Incorporation of post-exercise e' velocity into the set of variables defining exercise-induced diastolic dysfunction can improve the prognostic utility of diastolic function assessment.

Precision Phenotyping in Heart Failure and Pattern Clustering of Ultrasound Data for the Assessment of Diastolic Dysfunction.

OBJECTIVES: The aim of this study was to investigate whether cluster analysis of left atrial and left ventricular (LV) mechanical deformation parameters provide sufficient information for Doppler-independent assessment of LV diastolic function. BACKGROUND: Medical imaging produces substantial phenotyping data, and superior computational analyses could allow automated classification of repetitive patterns into patient groups with similar behavior. METHODS: The authors performed a cluster analysis and developed a model of LV diastolic function from an initial exploratory cohort of 130 patients that was subsequently tested in a prospective cohort of 44 patients undergoing cardiac catheterization. Patients in both study groups had standard echocardiographic examination with Doppler-derived assessment of diastolic function. Both the left ventricle and the left atrium were tracked simultaneously using speckle-tracking echocardiography (STE) for measuring simultaneous changes in left atrial and ventricular volumes, volume rates, longitudinal strains, and strain rates. Patients in the validation group also underwent invasive measurements of pulmonary capillary wedge pressure and LV end diastolic pressure immediately after echocardiography. The similarity between STE and conventional 2-dimensional and Doppler methods of diastolic function was investigated in both the exploratory and validation cohorts. RESULTS: STE demonstrated strong correlations with the conventional indices and independently clustered the patients into 3 groups with conventional measurements verifying increasing severity of diastolic dysfunction and LV filling pressures. A multivariable linear regression model also allowed estimation of E/e' and pulmonary capillary wedge pressure by STE in the validation cohort. CONCLUSIONS: Tracking deformation of the left-sided cardiac chambers from routine cardiac ultrasound images provides accurate information for Doppler-independent phenotypic characterization of LV diastolic function and noninvasive assessment of LV filling pressures.

Radius of proximal isovelocity surface area in the assessment of rheumatic mitral stenosis: Connecting flow to anatomy and hemodynamics.

BACKGROUND: Echocardiographic assessment of left atrial pressure (LAP) in mitral stenosis (MS) is controversial. We sought to examine the role of the radius of the proximal isovelocity surface area (PISA-r) in the assessment of the hemodynamic status of MS after fixing the aliasing velocity (Val). METHODS AND RESULTS: We studied 42 candidates of balloon mitral valvuloplasty (BMV), for whom pre-BMV echocardiography was done and LAP invasively measured before dilatation. PISA-r was calculated after fixing aliasing velocity to 33 cm/s. In addition, the ratio IVRT/Te'-E was also measured, where IVRT was isovolumic relaxation time, and Te'-E was the time difference between the onset of mitral flow E-wave and mitral annular early diastolic velocity. IVRT/Te'-E and PISA-r showed a strong correlation with LAP (r = -0.715 and -0.637, all p < 0.001) and with right-sided pressures. In addition, PISA-r correlated with mitral valve area by planimetry method (MVA) and with left ventricular outflow tract stroke volume (r = 0.66 and 0.71, all p < 0.001). Receiver operator characteristic curve (ROC-curve) showed that PISA-r was not inferior to IVRT/Te'-E in differentiating LAP ⩾25 from <25 mmHg. CONCLUSION: Provided that Val is set to a constant of 33 cm/s, PISA-r can assess the hemodynamic status of MS, and seems a simple alternative to the tedious IVRT/Te'-E for estimation of LAP.

Utility of comprehensive assessment of strain dyssynchrony index by speckle tracking imaging for predicting response to cardiac resynchronization therapy.

The strain delay index is reportedly a marker of dyssynchrony and residual myocardial contractility. The aim of this study was to test the hypothesis that a relatively simple version of the strain dyssynchrony index (SDI) can predict response to cardiac resynchronization therapy (CRT) and that combining assessment of radial, circumferential, and longitudinal SDI can further improve the prediction of responders. A total of 52 patients who underwent CRT were studied. The SDI was calculated as the average difference between peak and end-systolic strain from 6 segments for radial and circumferential SDI and 18 segments for longitudinal SDI. Conventional dyssynchrony measures were assessed by interventricular mechanical delay, the Yu index, and radial dyssynchrony by speckle tracking strain. Response was defined as a ≥15% decrease in end-systolic volume after 3 months. Of the individual parameters, radial SDI ≥6.5% was the best predictor of response to CRT, with sensitivity of 81%, specificity of 81%, and an area under the curve of 0.87 (p <0.001). Circumferential SDI ≥3.2% and longitudinal SDI ≥3.6% were also found to be predictive of response to CRT, with areas under the curve of 0.81 and 0.80, respectively (p <0.001). Moreover, radial, circumferential, and longitudinal SDI at baseline were correlated with reduction of end-systolic volume with CRT. In addition, the response rate in patients with 3 positive SDIs was 100%. In contrast, rates in patients with either 1 or no positive SDIs were 42% and 22%, respectively (p <0.005 and p <0.001 vs 3 positive SDIs). In conclusion, the SDI can successfully predict response to CRT, and the combined approach leads to more accurate prediction than using individual parameters.