Reversible microvascular dysfunction coupled with persistent myocardial dysfunction: implications for post-infarct left ventricular remodelling.
BACKGROUND
Recent studies have shown that microvascular dysfunction after myocardial infarction is a dynamic phenomenon.


OBJECTIVE
To evaluate the implications of dynamic changes in microvascular dysfunction on contractile recovery and left ventricular remodelling, and to identify the ideal timing of assessment of such microvascular dysfunction.


RESULTS
In 39 patients with a first myocardial infarction who underwent successful percutaneous coronary intervention, microvascular dysfunction was studied by myocardial contrast echocardiography (MCE) at 24 h, 1 week and 3 months after the procedure. Real-time MCE was performed by contrast pulse sequencing and intravenous Sonovue. 14 patients exhibited left ventricular remodelling at 3 months (>20% increase in left ventricular end-diastolic volume, group B), whereas 25 did not (group A). Microvascular dysfunction was similar in the two groups at 24 h and improved in group A only, being significantly better than that of group B at 1 week (p<0.05) and 3 months (p<0.005). Improvement in microvascular dysfunction was not associated with improvement in wall motion in the same segments. With multivariate analysis including all echocardiographic variables, microvascular dysfunction at 1 week was found to be the only independent predictor of left ventricular remodelling (p<0.01). With a cut-off value of 1.4, 1-week microvascular dysfunction predicts left ventricular remodelling with sensitivity and specificity of 73%.


CONCLUSIONS
Improvement in microvascular dysfunction occurs early after myocardial infarction, although it is not associated with a parallel improvement in wall motion but is beneficial in preventing left ventricular remodelling. Accordingly, 1-week microvascular dysfunction is a powerful and independent predictor of left ventricular remodelling.
Galiuto
Leonarda
L
Institute of Cardiology, Catholic University of the Sacred Heart, Rome, Italy. lgaliuto@rm.unicatt.it
Gabrielli
Francesca A
FA
Lombardo
Antonella
A
La Torre
Giuseppe
G
Scarà
Antonio
A
Rebuzzi
Antonio G
AG
Crea
Filippo
F
D003287:Contrast Media; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology*; D009204:Myocardial Revascularization / Q000379:methods; D010743:Phospholipids; D013318:Stroke Volume / Q000502:physiology; D013459:Sulfur Hexafluoride; D020257:Ventricular Remodeling / Q000502:physiology*
D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride