부산대학교 도서관

Introduction: Dobutamine stress echocardiography (DSE) is widely used in clinical practice although it remains subjective. Strain imaging by speckle-tracking echocardiography provides an automated and objective method of detecting inducible ischaemia by DSE. However its accuracy has never been evaluated against a true gold standard. In this study we aim to determine the diagnostic performance of strain imaging for the detection of ischaemia in coronary artery disease (CAD).Methods: Consecutive patients undergoing DSE were assessed using strain analysis and expert visual assessment. Regional and global peak-systolic longitudinal strain were recorded at baseline and peak stress and displayed as a Bull’s-Eye graphic. All patients had invasive measurement of fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) to assess ischaemia. Clinicians were blinded to patient information and investigation results.Results: We analysed 128 patients (mean age 68±9 years, 96 (75%) men) with stable angina and angiographic single-vessel CAD. Ischaemia was diagnosed by strain in 73 (57.0%) patients and by conventional visual DSE in 60 (46.9%). Using standard clinical thresholds (FFR≤0.80, iFR≤0.89), invasive physiology was positive in 79 patients (61.7%) and negative in 33 (25.8%). The sensitivity, specificity and accuracy of strain was 60.8%, 51.5% and 58.0% respectively (Figure 1). Expert visual assessment was not superior (sensitivity 53.2%, specificity 63.6%, accuracy 56.3%). The agreement with FFR was poor for both strain and expert visual DSE (Kappa 0.028 and 0.061, p>0.05).Conclusions: Strain imaging may improve sensitivity and accuracy for ischaemia detection compared to visual interpretation. Neither method achieved published levels of performance when compared to invasive coronary physiology. Future diagnostic techniques for patients with stable angina must be evaluated against the current gold standard.