ABSTRACT
Few data exist regarding the effect of image quality on measurements of two-dimensional longitudinal strain (2DLS). In the 2DLS for Diagnosing Chest Pain in the Emergency Room (2DSPER) multicenter study, 2DLS was not useful for ruling out acute coronary syndromes (ACS) in the emergency department (ED). The aim of this substudy was to determine the effect of 2D image quality on the diagnostic accuracy of 2DLS for ACS. We reviewed apical views used for 2DLS analysis in all 605 patients included in the 2DSPER study. Studies with the best image quality (HighQ, n = 177), were compared to the lower quality group (LowQ, n = 428). Abnormal 2DLS was defined as PSS20% > - 17% (PSS20% being the peak left ventricular systolic strain value identifying the 20% worst strain values). Global longitudinal strain (GLS) and PSS20% were significantly worse in LowQ compared to HighQ patients. LowQ independently predicted abnormal 2DLS (OR 1.9, 95% CI 1.3-2.9, P = 0.003). The sensitivity of PSS20% > - 17% for ACS was 85% for LowQ vs. 73% for HighQ (P = 0.2), specificity 22% vs. 38% (P < 0.0001) and overall accuracy 29% vs. 44% (P = 0.0004). Despite better overall accuracy in the HighQ group there was no significant difference between the receiver operating characteristic curves of either GLS or PSS20% in the two groups and abnormal 2DLS did not predict ACS even in HighQ patients (OR 1.7, 95% CI 0.7-4.3, P = 0.3). LowQ echo is associated with worse 2DLS. Abnormal 2DLS was not clinically useful for excluding ACS in the ED even in patients with optimal 2D image quality.Clinical Trial Registration URL: http://www.clinicaltrials.gov . Unique identifier: NCT01163019.
Subject(s)
Acute Coronary Syndrome/diagnostic imaging , Angina Pectoris/diagnostic imaging , Echocardiography/methods , Myocardial Contraction , Ventricular Function, Left , Acute Coronary Syndrome/physiopathology , Aged , Angina Pectoris/physiopathology , Biomechanical Phenomena , Emergency Service, Hospital , Female , Humans , Israel , Male , Middle Aged , Predictive Value of Tests , Prospective Studies , Reproducibility of ResultsABSTRACT
AIMS: Left ventricular (LV) two-dimensional longitudinal strain (2DLS) analysis by echocardiography has been suggested as a useful tool for the detection of acute coronary syndromes (ACS). Our aim was to determine whether 2DLS analysis could assist in triage of patients with chest pain (CP) in the emergency department (ED). METHODS AND RESULTS: We prospectively enrolled patients presenting to the ED with CP and suspected ACS but without a diagnostic ECG or elevated troponin. An echocardiogram was performed within 24 h of CP. For each patient, a histogram of LV myocardial peak systolic strain (PSS) was generated and the value identifying the 20% worst strain values (PSS20%) was determined. A predefined value of greater than -17% was considered abnormal. 2DLS analysis was available for 605 patients (mean age 58 ± 9 years, 70% males), of which 74 (12.2%) had ACS. During a 6-month follow-up, MACE occurred in 4 (5.8%) patients with and in 3 (0.6%) without ACS. An abnormal PSS20% was present in 60/74 patients with ACS (sensitivity 81%, negative predictive value 91%), but also in 391/531 patients without ACS (specificity 26%, positive predictive value 13%). Similar results were found for global longitudinal strain (GLS). Receiver-operating characteristic curves showed an area under curve of 0.59 for PSS20% and 0.6 for GLS (P= 0.3). Independent predictors of abnormal 2DLS were male gender, body mass index, heart rate, and mean tissue Doppler e', but not ACS. CONCLUSION: In this large multicentre prospective study, 2DLS was not a useful tool to rule out ACS in the ED. CLINICAL TRIAL REGISTRATION: http://clinicaltrials.gov. UNIQUE IDENTIFIER: NCT01163019.
