Relationship between strain rate imaging and coronary flow reserve in assessing myocardial viability after acute myocardial infarction.
OBJECTIVE
To evaluate the relationship between strain rate (SR) imaging and coronary flow reserve (CFR) in assessing viability of akinetic myocardium after acute myocardial infarction (MI).


METHODS
Forty patients with acute first ST-elevation MI were analyzed. SR imaging and CFR by intracoronary flow measurement were obtained on the same day, 3~5 days after primary percutaneous coronary intervention. Viability of the akinetic myocardium was determined on 6-week echocardiography.


RESULTS
Systolic SR (SRs, -0.42 ± 0.10 vs. -0.35 ± 0.11 per second, P = 0.03), early diastolic SR (SRe, 0.68 ± 0.31 vs. 0.41 ± 0.22 per second, P = 0.003), and systolic strain (Ss, -5.9 ± 3.4 vs. -2.5 ± 4.0%, P = 0.04) were greater in akinetic, but viable myocardium of 21 patients than in akinetic and nonviable myocardium of 19 patients. CFR was also higher in patients with akinetic, but viable myocardium (2.0 ± 0.5 vs. 1.5 ± 0.5, P < 0.001). SRs, SRe, and Ss were significantly related to CFR (r =-0.50, r = 0.58, r =-0.56, respectively, all P ≤ 0.001) and SRe was most related to CFR (P < 0.001). The sensitivity and specificity to predict myocardial viability were 85.7% and 68.4% for CFR (cutoff = 1.75), and 90.5% and 57.9% for SRe (cutoff = 0.37 per second), respectively.


CONCLUSIONS
The degree of myocardial deformation determined by SR imaging was related to the degree of microvascular integrity determined by CFR, and can be used as a noninvasive method to predict myocardial viability after acute MI.
Park
Seong-Mi
SM
Division of Cardiology, Korea University College of Medicine, Seoul, Republic of Korea.
Hong
Soon-Jun
SJ
Park
Jae-Suk
JS
Lim
Sang-Yup
SY
Ahn
Chul-Min
CM
Lim
Do-Sun
DS
Shim
Wan-Joo
WJ
D000465:Algorithms; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000000981:diagnostic imaging*; D017682:Myocardial Stunning / Q000000981:diagnostic imaging* / Q000209:etiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014022:Tissue Survival