Prediction of ischemic events by anatomic M-mode strain rate stress echocardiography.
OBJECTIVE
We assessed the prognostic value of anatomic M-mode strain rate stress echocardiography (SRSE) in patients with known or suspected coronary artery disease. Previous studies showing that M-mode SRSE may be an accurate method for detection of coronary artery disease suggest that this technique may be useful for risk stratification.


METHODS
M-mode SRSE, using a color-coded display of strain rate (SR), was performed in 358 patients (48, dobutamine; 68, bicycle; 242, treadmill). SR was graded by visual assessment of the color-coded display in 12 apical segments. Abnormal rest SR was defined as SR more positive than -1/s (green-yellow). Ischemia was defined by the development of post-systolic shortening or lack of improvement of SR to more negative than -2/s (brown hue) with stress. Patients were followed for cardiac events.


RESULTS
Twelve patients with early intervention for an abnormal two-dimensional stress echocardiogram or stress electrocardiogram were excluded. Follow-up (mean 10.7 months) was completed in 98% (338/346) of the remaining patients. Events occurred in 1.7% (4/230) of patients with normal SRSE compared with 10% (11/108) with abnormal SRSE (P = .002). The annualized hard event (infarction, death) rate in those with normal SRSE was 0.5% versus 7.2% in those with abnormal SRSE (P = .001). Smoking (P = .048, relative risk 2.91), nitrate use (P = .001, relative risk 7.81), and the severity of the abnormality on SRSE (P = .009, relative risk 1.75) independently predicted events. Wall motion assessment was not predictive. Patients with normal SRSE had better event-free survival compared with those with abnormal SRSE (P < .001).


CONCLUSIONS
SRSE is an independent predictor of outcome. A normal SRSE predicts a low risk of infarction or death in short-term follow-up.
Mastouri
Ronald
R
Department of Medicine, Indiana University Medical Center and the Krannert Institute of Cardiology, Indianapolis, Indiana, USA.
Mahenthiran
Jothiharan
J
Kamalesh
Masoor
M
Gradus-Pizlo
Irmina
I
Feigenbaum
Harvey
H
Sawada
Stephen G
SG
D004280:Dobutamine; D018618:Echocardiography, Doppler, Color / Q000379:methods*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D016247:Information Storage and Retrieval / Q000379:methods*; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications / Q000000981:diagnostic imaging*; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology
D004280:Dobutamine