Abstract 20119: Impact of Microvascular Resistance Index on Left Ventricular Remodeling after Primary Coronary Intervention for ST-elevation Acute Myocardial Infarction
Background: Previous studies have shown that microvascular dysfunction in recanalized infarct-related coronary arteries may predict progressive LV dilatation. A dual-sensor (pressure and Doppler velocity) guidewire has an ability to evaluate microvascular dysfunction quantitatively. The aim of this study was to investigate the relationship between microvascular dysfunction assessed by a dual-sensor guidewire and LV remodeling after primary percutaneous coronary intervention (PCI) in AMI patients.
Methods and results: Twenty-two patients who underwent primary PCI for a first anterior AMI were enrolled in the study. Immediately after primary PCI, using a dual-sensor guidewire, microvascular resistance index (MVRI) was calculated as the ratio of mean distal pressure to average peak flow velocity during maximal hyperemia. The degree of microvascular dysfunction was evaluated on the basis of MVRI. According to MVRI, patients were divided into two groups (MVRI < median and ≥ median). Cardiovascular magnetic resonance (CMR) was performed 2 weeks after the onset to determine microvascular obstruction (MVO) on late gadolinium-enhanced imaging, infarct size, and transmural extent of infarction. Cine imaging was also used to determine LV volumes and global function at baseline and 8-month follow-up. MVRI was strongly correlated with infarct size by CMR (r = 0.785, p < 0.0001). In patients with a MVRI greater than the median value of 3.03 mmHg•cm−1•s, the incidence of MVO (64% vs. 18%, p=0.08) and transmural necrosis (64% vs. 27%, p=0.20) tended to be higher. LV volume profiles at 8-month follow-up were significantly greater in the group with a MVRI ≥ 3.03 mmHg•cm−1•s compared with < 3.03 mmHg•cm−1•s (Table).
Conclusion: MVRI immediately after primary PCI predicts LV remodeling in patients with anterior AMI.
- © 2010 by American Heart Association, Inc.