[The predictive value of microvascular obstruction for adverse left ventricular remodeling after primary percutaneous coronary intervention in patients with acute ST-elevation myocardial infarction: a prospective study].

Objectives: Microvascular obstruction (MVO) is a specific cardiac magnetic resonance (CMR) imaging feature in patients with acute myocardial infarction. The purpose of this study was to elucidate the predictive value of MVO in left ventricular adverse remodeling after primary percutaneous coronary intervention (PCI) in patients with acute ST-elevation myocardial infarction (STEMI). Methods: A total of 167 patients with STEMI undergoing primary PCI in the Chinese PLA General Hospital from 2016 to 2020 were enrolled in this prospective cohort study, the average age of study patients was 57±10 years old, with 151 males (90.4%) and 16 females (9.6%). The patients were divided into the MVO group (n=81) and non-MVO group (n=86) according to the presence or absence of MVO on CMR imaging, respectively. The primary endpoint of the study was the occurrence of left ventricular adverse remodeling, which was defined as an increase in left ventricular end diastolic volume (LVEDV) by >20% at 6 months after primary PCI compared with the baseline. Patients who completed follow-up were diagnosed as left ventricular adverse remodeling or no left ventricular adverse remodeling according to CMR. The baseline data, perioperative data, and related data of end points were compared between the MVO group and non-MVO group. Finally, the predictive value of MVO in left ventricular adverse remodeling was calculated by receiver operating characteristic curve analysis. Results: In the baseline data, preoperative thrombolysis in myocardial infarction (TIMI) flow (χ2=13.74, P=0.003) and postoperative TIMI flow (χ2=14.87, P=0.001) were both obviously decreased in the MVO group. After 6 months of follow-up, the incidence of left ventricular adverse remodeling in the MVO group was significantly higher than that in the non-MVO group [37.0%(27/73) vs. 18.9%(14/74), χ2=5.96, P=0.015]. The left ventricular end systolic volume at 6 months post infarction in the MVO group was significantly larger than that in the non-MVO group [(94±32) vs. (68±20) ml, t=-5.98, P<0.001], as well as the LVEDV [(169±38) vs. (143±29) ml, t=-4.74, P<0.001]. Receiver operating characteristic curve showed that the area under the curve of MVO size for predicting left ventricular adverse remodeling was 0.637. Conclusion: The risk of left ventricular adverse remodeling is significantly increased in patients with MVO after primary PCI for acute STEMI.