Duration of ischemia is a major determinant of transmurality and severe microvascular obstruction after primary angioplasty: a study performed with contrast-enhanced magnetic resonance.
OBJECTIVE
This study sought to assess the relationship between duration of ischemia and both myocardial transmural necrosis (TN) and severe microvascular obstruction (SMO), by contrast-enhanced magnetic resonance (CE-MR), in patients with acute myocardial infarction (AMI) treated with angioplasty (PCI), and to estimate the risk of TN and SMO with the duration of ischemia.


BACKGROUND
The impact of ischemic time on myocardial and microvascular injury is not well characterized in people.


METHODS
We performed CE-MR in 77 patients with first AMI, 5 +/- 3 days after successful PCI. The AMI was labeled as transmural if hyperenhancement at CE-MR was extended to > or =75% of the thickness in two or more ventricular segments. The SMO was identified as areas of late hypoenhancement surrounded by hyperenhanced tissue. The relationship between ischemic time and CE-MR evidence of SMO or TN was evaluated by logistic regression.


RESULTS
Thirteen patients were excluded because of preprocedural Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 of the infarct-related artery. For the remaining 64 patients, the mean time to treatment was 190 +/- 110 min, 45 (65%) patients had TN and 23 (39%) had SMO. Mean pain to balloon time was 90 +/- 40 min, 110 +/- 107 min, and 137 +/- 97 min in patients without TN and SMO, with TN but without SMO, or with both TN and SMO, respectively (p = 0.001). Multivariate analysis showed that time delay was significantly associated both with TN (odds ratio per 30 min, 1.37, p = 0.032), and SMO (odds ratio per 30 min, 1.21; p = 0.021).


CONCLUSIONS
In AMI patients with impaired coronary perfusion undergoing PCI, the risk of TN and SMO increases with the duration of the ischemic time.
Tarantini
Giuseppe
G
Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova Medical School, Padua, Italy. giuseppe.tarantini.1@unipd.it
Cacciavillani
Luisa
L
Corbetti
Francesco
F
Ramondo
Angelo
A
Marra
Martina Perazzolo
MP
Bacchiega
Enrico
E
Napodano
Massimo
M
Bilato
Claudio
C
Razzolini
Renato
R
Iliceto
Sabino
S
D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects*; D003287:Contrast Media; D023921:Coronary Stenosis / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000628:therapy*; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000209:etiology; D009336:Necrosis; D012720:Severity of Illness Index; D013997:Time Factors
D003287:Contrast Media