Vendor-Neutral Right Ventricular Strain Measurement

Validation of Echocardiographic Measurements in Patients with Pulmonary Embolism in the RIETE Registry

Background  In acute pulmonary embolism (PE), echocardiographic identification of right ventricular (RV) dysfunction will inform prognostication and clinical decision-making. Registro Informatizado Enfermedad TromboEmbolica (RIETE) is the world's largest registry of patients with objectively confirmed PE. The reliability of site-reported RV echocardiographic measurements is unknown. We aimed to validate site-reported key RV echocardiographic measurements in the RIETE registry. Methods  Fifty-one randomly chosen patients in RIETE who had transthoracic echocardiogram (TTE) performed for acute PE were included. TTEs were de-identified and analyzed by a core laboratory of two independent observers blinded to site-reported data. To investigate reliability, intraclass correlation coefficients (ICCs) and Bland-Altman plots between the two observers, and between an average of the two observers and the RIETE site-reported data were obtained. Results  Core laboratory interobserver variations were very limited with correlation coefficients >0.8 for all TTE parameters. Agreement was substantial between core laboratory observers and site-reported data for key parameters including tricuspid annular plane systolic excursion (ICC 0.728; 95% confidence interval [CI], 0.594-0.862) and pulmonary arterial systolic pressure (ICC 0.726; 95% CI, 0.601-0.852). Agreement on right-to-left ventricular diameter ratio (ICC 0.739; 95% CI, 0.443-1.000) was validated, although missing data limited the precision of the estimates. Bland-Altman plots showed differences close to zero. Conclusion  We showed substantial reliability of key RV site-reported measurements in the RIETE registry. Ascertaining the validity of such data adds confidence and reliability for subsequent investigations.

Comparison of echocardiographic parameters with cardiac magnetic resonance imaging in the assessment of right ventricular function

INTRODUCTION

The right ventricle (RV) strain measured by speckle tracking (RVS) is an echocardiographic parameter used to assess RV function. We compared RVS to RV fractional area change (FAC%), tricuspid annular plane systolic excursion (TAPSE) and Doppler tissue imaging-derived peak systolic velocity (S') in the assessment of right ventricular (RV) systolic function measured using cardiac magnetic resonance imaging (MRI).

METHODS

We enrolled consecutive patients who underwent cardiac MRI between Jan 2012 and Dec 2017 and a transthoracic echocardiogram (TTE) within 1 month of the MRI with no interval event. Baseline clinical characteristics and MRI parameters were extracted from chart review. Echocardiographic parameters were measured prospectively. TTE parameters including RVS, TAPSE, S', and FAC% were tested for accuracy to identify impaired RV EF (EF < 45% & <30%) using receiver operator curves.

RESULTS

The study cohort included 500 patients with mean age 55 years ± 18 and peak tricuspid regurgitation velocity 2.7 ± 1.4 m/s. The area under ROC for RVS was 0.69 (95% CI 0.63-0.75) and 0.78 (95% CI 0.70-0.88) to predict RVEF < 45% & RVEF < 30%, respectively. The RV FAC% had second highest accuracy of predicting RVEF among all the TTE parameters tested in study.

CONCLUSION

Right ventricular strain is the most accurate echocardiographic method to detect impaired right ventricular systolic function when using MRI as the gold standard.

Transthoracic echocardiographic assessment of the right ventricle before and after caesarean delivery: A preliminary investigation

Transthoracic echocardiographic evaluation of the right ventricle is more difficult than the left ventricle and has not been well characterised in the parturient during delivery. As a preliminary investigation, our goal was to use bedside transthoracic echocardiography to evaluate right ventricular myocardial function before and after caesarean delivery. Term parturients undergoing caesarean delivery under spinal anaesthesia were enrolled. Echocardiography was performed pre- and postoperatively. Assessment of myocardial function included longitudinal myocardial strain using 2D-speckle tracking for both ventricles, and fractional area change for the right ventricle. Troponin-T, creatine kinase-muscle/brain and brain natriuretic peptide were measured pre- and postoperatively. One hundred patients were enrolled; 98 completed the study. Adequate images from both timepoints (pre- and postoperatively) were obtained in 85 patients for left ventricle assessment, and 66 for the right ventricle. Right ventricular fractional area change (mean (standard deviation)) (24.9% (8.9%) to 24.9% (9.2%); P = 0.99) and strain (-19.7% (6.8%) to -18.1% (6.5%); P = 0.08) measurements suggested mild baseline dysfunction and did not change after delivery. Left ventricular strain values were normal and unchanged after delivery (-23.8% (7.4%) to -24.3% (6.7%); P = 0.51). One patient had elevated troponin-T and demonstrated worse biventricular function. Elevation of brain natriuretic peptide (n=7) was associated with mildly decreased left ventricular strain, but creatine kinase-muscle/brain (n=4) was not associated with consistent changes in cardiac function. Further investigations into peripartum right ventricular function are required to validate the findings in this preliminary study. Findings of baseline mild right ventricular dysfunction and functional changes associated with troponin-T and brain natriuretic peptide warrant rigorous investigation.

The Year in Perioperative Echocardiography: Selected Highlights from 2018

This article is the third of an annual series reviewing the research highlights of the year pertaining to the subspecialty of perioperative echocardiography for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor-in-chief, Dr. Kaplan, and the editorial board for the opportunity to continue this series. In most cases, these will be research articles targeted at the perioperative echocardiography diagnosis and treatment of patients after cardiothoracic surgery; but in some cases, these articles will target the use of perioperative echocardiography in general.

A Comparison of Left- and Right-Sided Strain Software for the Assessment of Intraoperative Right Ventricular Function

OBJECTIVE

To compare intraoperative right ventricular (RV) strain measurements made with left ventricular (LV) strain software commonly found on the echocardiography machine (Philips QLAB chamber motion quantification, version 10.7, Philips, Amsterdam, The Netherlands), with offline analysis using the dedicated RV strain software (EchoInsight, version 2.2.6.2230, Epsilon Imaging, Ann Arbor, MI).

DESIGN

Prospective, nonrandomized, observational study.

SETTING

Single tertiary level, university-affiliated hospital.

PARTICIPANTS

The study comprised 48 patients undergoing transesophageal echocardiography for cardiac or noncardiac surgery.

INTERVENTIONS

Two-dimensional (2D) and 3-dimensional (3D) images of the right ventricle were obtained. Intraoperative 2D images were analyzed in real time for RV free wall strain (FWS) and global longitudinal strain (GLS) using QLAB chamber motion quantification (CMQ) LV strain software on the echocardiography machine. Two dimensional images were then analyzed offline to determine the RV FWS and GLS using EchoInsight RV-specific strain software. Three-dimensional images were then analyzed offline to detemine the 3D RV ejection fraction (3D RV EF) using TomTec 4D RV function (Unterschleissheim, Germany). Spearman's correlation and Bland-Altman analyses were used to characterize the relationship between RV strain measurements. Both types of strain measurements were compared to a reference standard of 3D RV EF.

MEASUREMENTS AND MAIN RESULTS

Intraoperative RV strain measurements using LV-specific strain software correlated with offline RV strain measurements using the RV-specific strain software (FWS rho = 0.85; GLS rho = 0.81). The bias and limits of agreement were 0.75% (- 6.66 to 8.17) for FWS and -4.53% (-11.55 to 2.50) for GLS. The sensitivity and specificity for RV dysfunction for the intraoperative LV-specific software were 94% (95% confidence interval [CI] 73-100) and 70% (95% CI 51-85), respectively, for RV FWS and 94% (95% CI 73-100) and 67% (95% CI 47-83), respectively, for RV GLS. The sensitivity and specificity for RV dysfunction for the offline RV-specific software were 89% (95% CI 65-99) and 73% (95% CI 54-88), respectively, for RV FWS and 94% (95% CI 73-100) and 30% (95% CI 15-49), respectively, for RV GLS.

CONCLUSION

Intraoperative RV strain measurements using LV-specific strain software commonly available on the echocardiography machine (QLAB CMQ) correlate with offline RV strain measurements using RV-specific strain software (EchoInsight). The bias and limits of agreement for these left- and right-sided strain software suggest that these 2 measures of RV function cannot be used interchangeably. Both, however, were sensitive measures of RV dysfunction and therefore are likely clinically relevant.