The extent of microvascular damage during myocardial contrast echocardiography is superior to other known indexes of post-infarct reperfusion in predicting left ventricular remodeling: results of the multicenter AMICI study.
OBJECTIVE
We sought to evaluate the value of the extent of microvascular damage as assessed with myocardial contrast echocardiography (MCE) in the prediction of left ventricular (LV) remodeling after ST-segment elevation myocardial infarction (STEMI) as compared with established clinical and angiographic parameters of reperfusion.


BACKGROUND
Early identification of post-percutaneous coronary intervention microvascular dysfunction may help in tailoring appropriate pharmacological interventions in high-risk patients. The ideal method to establish effective microvascular reperfusion after percutaneous coronary intervention remains to be determined.


METHODS
A total of 110 patients with first successfully reperfused STEMI were enrolled in the AMICI (Acute Myocardial Infarction Contrast Imaging) multicenter study. After reperfusion, peak creatine kinase, ST-segment reduction, and Thrombolysis In Myocardial Infarction (TIMI) and myocardial blush grade were calculated. We evaluated perfusion defects with MCE by using continuous infusion of Sonovue (Bracco, Milan, Italy) in real-time imaging. The endocardial length of contrast defect (CD) on day 1 after reperfusion was calculated. Wall motion score index, the extent of wall motion abnormalities, LV end-diastolic volume, and ejection fraction after reperfusion and at follow-up also were calculated.


RESULTS
Of 110 patients, 25% evolved in LV remodeling and 75% did not. Although peak creatine kinase, ST-segment reduction >70%, and myocardial blush grade were not different between groups, in patients exhibiting LV remodeling, TIMI flow grade 3 was less frequent (p < 0.001), wall motion score index was greater (p < 0.001), and CD was greater (p < 0.001). At multivariate analysis, only TIMI flow grade <3 and CD with a cutoff of >25% were independently associated with LV remodeling. Among patients with TIMI flow grade 3, CD was the only independent variable associated with LV remodeling.


CONCLUSIONS
Among patients with TIMI flow grade 3, the extent of microvascular damage, detected and quantitated by MCE, is the most powerful independent predictor of LV remodeling after STEMI as compared with persistent ST-segment elevation and myocardial blush grade.
Galiuto
Leonarda
L
Institute of Cardiology, Catholic University of the Sacred Heart, Rome, Italy. lgaliuto@rm.unicatt.it
Garramone
Barbara
B
Scarà
Antonio
A
Rebuzzi
Antonio G
AG
Crea
Filippo
F
La Torre
Giuseppe
G
Funaro
Stefania
S
Madonna
Mariapina
M
Fedele
Francesco
F
Agati
Luciano
L
D000368:Aged; D000704:Analysis of Variance; D015906:Angioplasty, Balloon, Coronary; D003326:Coronary Circulation; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008833:Microcirculation / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy; D015425:Myocardial Reperfusion; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D020257:Ventricular Remodeling