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

Abstract

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.

Echocardiographic parameters as adjuncts to the Pulmonary Embolism Severity Index in predicting 30-day mortality in acute pulmonary embolism patients

“…In our study AUC of TTE parameters with prognostic value (TAPSE, RVFWLS, RVGLS and AcT) only in case of AcT AUC exceeded 0.7 and showed only acceptable discrimination. Similar conclusions come from previous studies which included these echocardiographic markers [14,16,[24][25][26].…”

“…Analogically, the prediction value of TTE and its quality might vary among PE patients of different features and can be affected by the studies' design [27]. Noteworthy, TTE assessment should be based on simple reproducible ultrasound modalities as more advanced ones like speckle-tracking longitudinal strain measurement is highly operator and equipment dependent [16,34,35].…”

“…A standard diagnostic protocol comprised determination in all patients on the day of admission to the ward the laboratory parameters including serum concentrations of troponin T, N-terminal pro B-type natriuretic peptide (NT-proBNP) and D-dimer with laboratory methods summarized formerly [14]. TTE was performed within 24 hours after admission to the ward by an experienced sonographer cardiologist (JW) using echocardiographic systems of Vivid S60N or Vivid S6 (General Electric Company, Boston, MA, US) according to the unified protocol [14][15][16]. The measurements were made based on the current guidelines of European Association of Cardiovascular Imaging with real-time electrocardiographic recording executed in order to accurately define the heart cycle phases [17].…”

“…The measurements were made based on the current guidelines of European Association of Cardiovascular Imaging with real-time electrocardiographic recording executed in order to accurately define the heart cycle phases [17]. The measurements of RV longitudinal strain by two-dimensional speckle-tracking echocardiography were performed within 6 segments of RV at the same time in the apical four-chamber view as described before [16,18]. with tissue Doppler imaging <9.5 cm/s and paradoxical septal motion [1,13,[18][19][20][21][22].…”