Nathalie De Michelis

Automated quantification of mitral inflow and aortic outflow stroke volumes by three-dimensional real-time volume color-flow Doppler transthoracic echocardiography: comparison with pulsed-wave Doppler and cardiac magnetic resonance imaging.

BACKGROUND The aim of this study was to compare the feasibility, accuracy, and reproducibility of automated quantification of mitral inflow and aortic stroke volumes (SVs) using real-time three-dimensional volume color-flow Doppler transthoracic echocardiography (RT-VCFD), with cardiac magnetic resonance (CMR) imaging as the reference method. METHODS In 44 patients (86% of the screened patients) without valvular disease, RT-VCFD, CMR left ventricular short-axis cines and aortic phase-contrast flow measurement and two-dimensional (2D) transthoracic echocardiography (TTE) were performed. Dedicated software was used to automatically measure mitral inflow and aortic SVs with RT-VCFD. CMR total SV was calculated using planimetry of short-axis slices and aortic SV by phase-contrast imaging. SVs by 2D TTE were computed in the conventional manner. RESULTS The mean age of the included patients was 40 ± 16 years, and the mean left ventricular ejection fraction was 61 ± 9%. Automated flow measurements were feasible in all study patients. Mitral inflow SV by 2D TTE and RT-VCFD were 85.0 ± 21.5 and 94.5 ± 22.0 mL, respectively, while total SV by CMR was 95.6 ± 22.7 mL (P < .001, analysis of variance). On post hoc analysis, mitral inflow SV by RT-VCFD was not different from the CMR value (P = .99), while SV on 2D TTE was underestimated (P = .001). The respective aortic SVs were 82.8 ± 22.3, 94.2 ± 22.3, and 93.4 ± 24.6 mL (P < .001). On post hoc analysis, aortic SV by RT-VCFD was not different from the CMR value (P = .99), while SV on 2D TTE was underestimated (P = .006). The interobserver variability for SV measurements was significantly worse for 2D TTE compared with RT-VCFD. CONCLUSIONS RT-VCFD imaging with an automated quantification algorithm is feasible, accurate, and reproducible for the measurement of mitral inflow and aortic SVs and is superior to manual 2D TTE-based measurements. The rapid and automated measurements make this technique practical in the clinical setting to measure and report SVs routinely where the acoustic window will allow it, which was 86% in our study.

Feasibility, accuracy, and reproducibility of real-time full-volume 3D transthoracic echocardiography to measure LV volumes and systolic function: a fully automated endocardial contouring algorithm in sinus rhythm and atrial fibrillation.

OBJECTIVES To assess the feasibility, accuracy, and reproducibility of real-time full-volume 3-dimensional transthoracic echocardiography (3D RT-VTTE) to measure left ventricular (LV) volumes and ejection fraction (EF) using a fully automated endocardial contouring algorithm and to identify and automatically correct the contours to obtain accurate LV volumes in sinus rhythm and atrial fibrillation (AF). BACKGROUND 3D transthoracic echocardiography is not used routinely to quantify LV volumes and EF. A fully automated workflow using RT-VTTE may improve clinical adoption. METHODS RT-VTTE was performed and 3D EF and volumes obtained using an automated trabecular endocardial contouring algorithm; an automated correction was applied to track the compacted myocardium. Cardiac magnetic resonance (CMR) and 2-dimensional biplane Simpson method were the reference standard. RESULTS Ninety-one patients (67 in normal sinus rhythm [NSR], 24 in AF) were included. Among all NSR patients, there was excellent correlation between RT-VTTE and CMR for end-diastolic volume (EDV), end-systolic volume (ESV), and EF (r = 0.90, 0.96, and 0.98, respectively; p < 0.001). In patients with EF ≥50% (n = 36), EDV and ESV were underestimated by 10.7 ± 17.5 ml (p = 0.001) and by 4.1 ± 6.1 ml (p < 0.001), respectively. In those with EF <50% (n = 31), EDV and ESV were underestimated by 25.7 ± 32.7 ml (p < 0.001) and by 16.2 ± 24.0 ml (p = 0.001). Automated contour correction to track the compacted myocardium eliminated mean volume differences between RT-VTTE and CMR. In patients with AF, LV volumes and EF were accurate by RT-VTTE (r = 0.94, 0.94, and 0.91 for EDV, ESV, and EF, respectively; p < 0.001). Automated 3D LV volumes and EF were highly reproducible. CONCLUSIONS Rapid, accurate, and reproducible EF can be obtained by RT-VTTE in NSR and AF patients by using an automated trabecular edge contouring algorithm. Furthermore, automated contour correction to detect the compacted myocardium yields accurate and reproducible 3D LV volumes.

Quantification of chronic functional mitral regurgitation by automated 3-dimensional peak and integrated proximal isovelocity surface area and stroke volume techniques using real-time 3-dimensional volume color doppler echocardiography: In vitro and clinical validation

Background—The aim of this study was to test the accuracy of an automated 3-dimensional (3D) proximal isovelocity surface area (PISA) (in vitro and patients) and stroke volume technique (patients) to assess mitral regurgitation (MR) severity using real-time volume color flow Doppler transthoracic echocardiography. Methods and Results—Using an in vitro model of MR, the effective regurgitant orifice area and regurgitant volume (RVol) were measured by the PISA technique using 2-dimensional (2D) and 3D (automated true 3D PISA) transthoracic echocardiography. The mean anatomic regurgitant orifice area (0.35±0.10 cm2) was underestimated to a greater degree by the 2D (0.12±0.05 cm2) than the 3D method (0.25±0.10 cm2; P<0.001 for both). Compared with the flowmeter (40±14 mL), the RVol by 2D PISA (20±19 mL) was underestimated (P<0.001), but the 3D peak (43±16 mL) and integrated PISA-based (38±14 mL) RVol were comparable (P>0.05 for both). In patients (n=30, functional MR), 3D effective regurgitant orifice area correlated well with cardiac magnetic resonance imaging RVol r=0.84 and regurgitant fraction r=0.80. Compared with cardiac magnetic resonance imaging RVol (33±22 mL), the integrated PISA RVol (34±26 mL; P=0.42) was not significantly different; however, the peak PISA RVol was higher (48±27 mL; P<0.001). In addition, RVol calculated as the difference in automated mitral and aortic stroke volumes by real-time 3D volume color flow Doppler echocardiography was not significantly different from cardiac magnetic resonance imaging (34±21 versus 33±22 mL; P=0.33). Conclusions—Automated real-time 3D volume color flow Doppler based 3D PISA is more accurate than the 2D PISA method to quantify MR. In patients with functional MR, the 3D RVol by integrated PISA is more accurate than a peak PISA technique. Automated 3D stroke volume measurement can also be used as an adjunctive method to quantify MR severity.

On-going palliative care enhances perceived control and patient activation and reduces symptom distress in patients with symptomatic heart failure: A pilot study

Introduction: There is a paucity of research about the impact of palliative care (PC) on perceived control (i.e. one’s perceived influence over outcomes or events in the environment) and activation (i.e. ability to self-manage) in patients with symptomatic heart failure (HF). Likewise, little is known about the association between perceived control, activation, and symptom distress in this patient population. We hypothesized that patients with advanced HF who received ongoing PC services (i.e. ≥2 PC consultations) vs no access or a single PC consultation would have greater improvements in perceived control and activation and greater reductions in symptom distress three months post-discharge for HF exacerbation. Methods: Forty-two patients (average age 53.9±8.0 years; predominantly male (72%), White (61%) and married (69%)) participated in the study. However, only 36 (85.7%) patients completed an outpatient PC consultation of which 29 (69%) patients returned for additional follow-up visits with the PC team. Data on perceived control, activation, and symptom distress were collected at baseline and three months. Parametric statistical models were applied to draw conclusions. Results: Findings showed that the patients who received ≥2 PC consultations had greater improvements in perceived control and activation than their counterparts; these increases were associated with greater reductions in symptom distress. Conclusion: Our findings suggest that on-going PC interventions enhance perceived control and activation in patients with advanced HF and open up the possibility of planning larger studies to assess the effect of PC on these variables as possible mediators to improvements in self-management and clinical outcomes.

An academic medical centre's programme to develop clinical pathways to manage health care: focus on acute decompensated heart failure

Heart failure (HF) is a major public health issue and acute decompensated heart failure (ADHF) is a leading cause of hospitalization in the USA. The United States health care delivery system is bound by regulatory agencies requiring strict compliance to key clinical indicators, which are publicly reported. Clinical pathway development is a systematic approach to managing health care that involves a high degree of collaboration between patients, physicians, nurses and various health-care team professionals. The University of California, Irvine Medical Center (UCIMC) developed an evidence-based multidisciplinary pathway for patients with ADHF. This clinical pathway incorporates universally proven assessment and treatment measures in ADHF. Adjunctive to this process are patient and nursing guides to the ADHF pathway. Utilization of this pathway has been shown to significantly impact clinical performance by early identification of potential negative clinical outcomes. Clinical pathways, such as the ADHF pathway, promote clinical excellence in caring for acute and chronic diseases states.

AUTOMATED CONTOUR CORRECTION WITH INSTANTANEOUS REAL-TIME 3D-VOLUME TRANSTHORACIC ECHOCARDIOGRAPHY IMPROVES ACCURACY OF LEFT VENTRICULAR VOLUME MEASUREMENTS IN PATIENTS WITH SYSTOLIC DYSFUNCTION: COMPARISON TO CARDIAC MRI

Results: In 14 patients with EF>50% the r values between VTTE and MRI for EDV, ESV and EF were 0.95, 0.89, and 0.64 respectively, p < 0.01. The EDV and ESV were underestimated by 8.7 and 1.8ml, while the EF was underestimated by 0.02%. Contour corrections did not change the correlations for volumes or EF. In 12 patients with EF <50%, the respective r values were 0.96, 0.97, 0.97, p<0.01. However, the EDV, ESV, and EF were underestimated by 32.9ml, 24.8ml, and 0.01%. With contour correction the EDV and ESV underestimation was decreased to 14.6 and 9.3ml (within 6% of MRI volumes); EF did not change. C