Prognostic Value of Follow-up Measures of Left Ventricular Global Longitudinal Strain in Patients With ST-Segment Elevation Myocardial Infarction.

INTRODUCTION

After ST-segment elevation myocardial infarction (STEMI), follow-up imaging is currently recommended only in patients with left ventricular ejection fraction (LVEF) <40%. Left ventricular global longitudinal strain (LVGLS) was shown to improve risk stratification over LVEF in these patients but has not been thoroughly studied during follow-up. The aim of this study was to explore the changes in LVGLS after STEMI and their potential prognostic value.

MATERIALS AND METHODS

Data were analyzed from an ongoing STEMI registry. Echocardiography was performed during the index hospitalization and 1 year after STEMI; LVGLS was expressed as an absolute value and the relative LVGLS change (ΔGLS) was calculated. The study end point was all-cause mortality.

RESULTS

A total of 1,409 STEMI patients (age 60 ± 11 years; 75% men) who survived at least 1 year after STEMI and underwent echocardiography at follow-up were included. At 1-year follow-up, LVEF improved from 50% ± 8% to 53% ± 8% (P < .001) and LVGLS from 14% ± 4% to 16% ± 3% (P < .001). Median ΔGLS was 14% (interquartile range, 0.5%-32%) relative improvement. Starting 1 year after STEMI, a total of 87 patients died after a median follow-up of 69 (interquartile range, 38-103) months. The optimal ΔGLS threshold associated with the end point (derived by spline curve analysis) was a relative decrease >7%. Cumulative 10-year survival was 91% in patients with ΔGLS improvement or a nonsignificant decrease, versus 85% in patients with ΔGLS decrease of >7% (P = .001). On multivariate Cox regression analysis, ΔGLS decrease >7% remained independently associated with the end point (hazard ratio, 2.5 [95% CI, 1.5-4.1]; P < .001) after adjustment for clinical and echocardiographic parameters.

CONCLUSIONS

A significant decrease in LVGLS 1 year after STEMI was independently associated with long-term all-cause mortality and might help further risk stratification and management of these patients during follow-up.