Differentiation between acute and chronic cor pulmonales with midventricular systolic strain of the right ventricle in the emergency department

Right Ventricular Longitudinal Strain-Related Indices in Acute Pulmonary Embolism

Pulmonary embolism (PE) is correlated with serious morbidity and mortality. Efforts have been made to establish and validate mortality predictive scores based mainly on clinical parameters. Patients with PE and traditional indices of echocardiographic right ventricular (RV) dysfunction or pressure overload have a higher probability of a worse outcome. During the last two decades, studies regarding the use of two-dimensional speckle-tracking echocardiography (2DSTE) and its derived indices in the setting of acute PE have been conducted. In this comprehensive review of the literature, we aimed to summarize these studies. Safe conclusions and comparisons among the reviewed studies are prone to statistical errors, mainly because the studies published were heterogenous in design, different 2DSTE-derived parameters were tested, and different clinical outcomes were used as endpoints. Nonetheless, RV strain indices and, more commonly, regional longitudinal strain of the RV free wall have shown a promising correlation with mortality, assisting in the differential diagnosis between PE and other acute or chronic disorders.

Indexing of Speckle Tracking Longitudinal Strain of Right Ventricle to Body Surface Area Does Not Improve Its Efficiency in Diagnosis and Mortality Risk Stratification in Patients with Acute Pulmonary Embolism

BACKGROUND

Acute pulmonary embolism (PE) is associated with a serious mortality rate. Thus, the rapid diagnosis and identification of patients at high risk of death is pivotal. The search for echocardiographic parameters for this purpose continues. Recent publications reveal correlations between myocardial longitudinal strain (LS) and body surface area (BSA). The aim of the study was to evaluate the usefulness of indexing the right ventricular (RV) speckle tracking LS to BSA in detecting PE and stratifying the risk of 30-day all-cause mortality.

METHODS

the prospective cross-sectional observational study group consisted of 167 consecutive patients (76 men, 45.5%) aged 69.5 ± 15.3 years, and they were referred for computed tomography pulmonary angiography. Patients underwent a transthoracic echocardiographic examination within 24 h of admission to the hospital ward. RVLS and their derivatives indexed to BSA were included in the analysis.

RESULTS

PE was confirmed in 88 patients, while 79 patients had no radiological features of PE. The only echocardiographic parameters that differed between subgroups were pulmonary flow acceleration (Act), McConnell's sign, LS of the middle segment of the RV free wall, and its derivative indexed to BSA. During the 30-day follow-up of a subgroup of subjects with PE, 12 patients died. The mortality predictors with increasing prediction value included a RV free wall mid-segment LS (cut-off value: -21%, Area Under the Curve-AUC 0.6, p = 0.02) and its derivative indexed to BSA (-14 %/m², AUC 0.62, p = 0.003), body mass index (24.7 kg/m², AUC 0.63, p = 0.002), D-dimer serum concentration (3559 pg/mL, AUC 0.66, p < 0.001), Act (67 ms, AUC 0.67, p < 0.001), septal basal LS (-15%, AUC 0.68, p = 0.02), RV free wall basal segment LS (-14%, AUC 0.7, p = 0.015), age (66 years, AUC 0.74, p = 0.004), NT-proBNP (1120 pg/mL, AUC 0.75, p = 0.01), troponin T (66 ng/mL, AUC 0.78, p = 0.005), and the complex score of the Pulmonary Embolism Severity Index (AUC 0.88, p < 0.001).

CONCLUSIONS

indexing of RVLS to BSA does not improve its prognostic value in patients with acute PE.

Strain Analysis of the Right Ventricle Using Two-dimensional Echocardiography

Right ventricular (RV) systolic dysfunction has been identified as an independent prognostic marker of many cardiovascular diseases. However, there are problems in measuring RV systolic function objectively and identification of RV dysfunction using conventional echocardiography. Strain echocardiography is a new imaging modality to measure myocardial deformation. It can measure intrinsic myocardial function and has been used to measure regional and global left ventricular (LV) function. Although the RV has different morphologic characteristics than the LV, strain analysis of the RV is feasible. After strain echocardiography was introduced to measure RV systolic function, it became more popular and was incorporated into recent echocardiographic guidelines. Recent studies showed that RV global longitudinal strain (RVGLS) can be used as an objective index of RV systolic function with prognostic significance. In this review, we discuss RVGLS measurement, normal reference values, and the clinical importance of RVGLS.

The use of echocardiographic indices in defining and assessing right ventricular systolic function in critical care research

PURPOSE

Many echocardiographic indices (or methods) for assessing right ventricular (RV) function are available, but each has its strengths and limitations. In some cases, there might be discordance between the indices. We conducted a systematic review to audit the echocardiographic RV assessments in critical care research to see if a consistent pattern existed. We specifically looked into the kind and number of RV indices used, and how RV dysfunction was defined in each study.

METHODS

Studies conducted in critical care settings and reported echocardiographic RV function indices from 1997 to 2017 were searched systematically from three databases. Non-adult studies, case reports, reviews and secondary studies were excluded. These studies' characteristics and RV indices reported were summarized.

RESULTS

Out of 495 non-duplicated publications found, 81 studies were included in our systematic review. There has been an increasing trend of studying RV function by echocardiography since 2001, and most were conducted in ICU. Thirty-one studies use a single index, mostly TAPSE, to define RV dysfunction; 33 used composite indices and the combinations varied between studies. Seventeen studies did not define RV dysfunction. For those using composite indices, many did not explain their choices.

CONCLUSIONS

TAPSE seemed to be the most popular index in the last 2-3 years. Many studies used combinations of indices but, apart from cor pulmonale, we could not find a consistent pattern of RV assessment and definition of RV dysfunction amongst these studies.

Heart rate in pulmonary embolism

Heart rate is a rapidly available risk stratification parameter in acute pulmonary embolism (PE). We aimed to investigate the effectiveness of heart rate in predicting the outcome in acute PE. Data of 182 patients with acute PE were analysed retrospectively. Logistic regression models were calculated to investigate the associations between heart rate and in-hospital death, myocardial necrosis, PE status and presence of right ventricular dysfunction (RVD), respectively. ROC curve and cut-off values for heart rate predicting RVD as well as intermediate risk PE status in normotensive PE patients and for heart rate predicting in-hospital death and myocardial necrosis in all PE patients were calculated. ROC analysis for heart rate predicting RVD and intermediate risk PE were 0.706 and 0.718, respectively, with cut-off value of 86 beats/min. Regression models showed associations between heart rate >85 beats/min and both RVD (OR 4.871, 95 % CI 2.256-10.515, P = 0.000055) and intermediate risk PE (OR 5.244, 95 % CI 2.418-11.377, P = 0.000027). In hemodynamically stable and unstable PE patients, logistic regression models showed a borderline significant association between tachycardia and in-hospital death (OR 7.066, 95 % CI 0.764-65.292, P = 0.0849) and a significant association between heart rate and myocardial necrosis (OR 0.975, 95 % CI 0.959-0.991, P = 0.00203). ROC analysis for heart rate predicting in-hospital death and myocardial necrosis revealed AUC of 0.655 and 0.703 with heart rate cut-off values of 99.5 beats/min and 92.5 beats/min, respectively. An elevated heart rate in acute PE is connected with a worse outcome. Effectiveness in the prediction of RVD, intermediate PE status, cardiac injury and in-hospital death is acceptable. The cut-off value for the prediction of RVD and intermediate risk PE status in normotensive PE is 86 beats/min, while tachycardia predicts in-hospital death.

A comparison of different techniques of two-dimensional speckle-tracking strain measurements of right ventricular systolic function in patients with acute pulmonary embolism

BACKGROUND

Speckle-tracking echocardiography has been applied to measure right ventricular (RV) systolic function in various diseases. However, variations in strain measurement by different vendors have limited the application of these techniques for assessment of RV function. We sought to compare two methods for the assessment of RV systolic function in patients with acute pulmonary embolism (PE).

METHODS

From August 2007 to May 2011, all consecutive PE patients were prospectively included in this cohort study. Global longitudinal strains of RV measured with EchoPAC PC software (GLSRV-EchoPAC; GE Medical Systems) and velocity vector imaging (GLSRV-VVI; Siemens Medical Systems) were recorded on the same set of echocardiographic images.

RESULTS

We analyzed a total of 50 patients (12 males, 68 ± 14 years) with acute PE in this study. GLSRV-EchoPAC and GLSRV-VVI were correlated (r = 0.793, p < 0.001) and they showed significant correlations with conventional echocardiographic parameters of RV systolic function and Log B-type natriuretic peptide (BNP) level. However, GLSRV-VVI only showed significant correlations with cardiac biomarkers as serum creatinine kinase-MB (r = 0.367, p = 0.010) and tropoinin-I concentrations (r = 0.294, p = 0.040).

CONCLUSION

GLSRV-VVI and GLSRV-EchoPAC showed significant correlations with conventional echocardiographic parameters of RV systolic function and LogBNP value in patients with PE.