Doppler Tissue Imaging Is an Independent Predictor of Outcome in Patients with ST-Segment Elevation Myocardial Infarction Treated with Primary Percutaneous Coronary Intervention

Abstract

Doppler tissue imaging (DTI) detects early signs of left ventricular (LV) dysfunction; however, the prognostic significance of DTI after ST-segment elevation myocardial infarction (STEMI) is unknown. The aim of this study was to evaluate the prognostic value of DTI after STEMI in patients treated with primary percutaneous coronary intervention. In total, 391 patients who were admitted with STEMIs and treated with primary percutaneous coronary intervention were prospectively included. All participants were examined by echocardiography 2 days (interquartile range, 1-3 days) after STEMI. Longitudinal systolic (s'), early diastolic (e'), and late diastolic (a') myocardial velocities were measured using color DTI at six mitral annular sites and averaged to provide global estimates. The median follow-up period was 25 months (interquartile range, 19-32 months). The primary end point was a composite of death, heart failure, or a new myocardial infarction. Patients with low global systolic function (s') or low global diastolic function (e') had >2 times greater risk for the combined end point compared with patients with high global s' (hazard ratio, 2.60; 95% confidence interval, 1.64-4.13; P < .001) or e' (hazard ratio, 2.26; 95% confidence interval, 1.44-3.55; P < .001), respectively. After adjustment for age, gender, peak troponin I, previous myocardial infarction, LV ejection fraction, LV mass index, and LV dimension in a multivariate Cox model, patients with low values of both global s' and e' remained at significantly higher risk than patients with high s' and/or e' (hazard ratio, 1.69; 95% confidence interval, 1.02-2.81; P = .043). A pattern of low systolic and diastolic performance as assessed by DTI is a paramount marker of adverse prognosis for patients with STEMIs independent of conventional echocardiographic parameters. DTI velocities should be evaluated together as they interact with the prognosis.