Abstract 2805: Quantification of Microvascular Damage after Primary Coronary Angioplasty to Estimate Long Term Left Ventricular Volumes
Background: Extent of microvascular dysfunction after acute myocardial infarction (AMI) was known to be an important and independent contributor to subsequent changes in left ventricular (LV) geometry and performance. In this study we interrogated microvascular integrity by using various methods 48 hours after primary angioplasty (PA) and investigated their relations with long term left ventricular volumes.
Methods and results: Forty-one patients with AMI treated with PA were included. ST segment resolution (STR) was calculated. At 48 hours patients were recatheterized to evaluate microvascular integrity. Myocardial blush grades (MBG), corrected TIMI frame counts (cTFC), coronary flow reserve (CFR), pressure derived collateral flow index (CFIp), coronary wedge pressure (CWP), diastolic deceleration time (DDT) and index of microvascular resistance (IMR) were determined. Control angiographies were performed at 6 months. Nine patients with significant restenosis in the stented vessel were excluded from the analysis. Ventricular volumes [end-systolic (ESV) and end-diastolic (EDV)] were measured at 6 months. ESV at six months strongly correlated with CWP (r = 0.79, p <0.001), CFIp (r = 0.70, p <0.001), IMR (r = 0.66, p <0.001), DDT (r = −0.58, p = 0.002) and CFR (r = −0.51, p = 0.003,), and weakly correlated with MBG (r = −0.40, p = 0.02) and cTFC (r = 0.38, p = 0.03) and STR (r = − 0.36, p = 0.034). Similarly, EDV at six months strongly associated with CWP (r = 0.69, p <0.001), IMR (r = 0.56, p <0.001), CFIp (r = 0.54, p <0.001) DDT (r = −0.48, p = 0.006) and CFR (r = −0.43, p= 0.003) and weakly with MBG (r = −0.38, p = 0.035). Correlations of TFC (r = 0.34, p = 0.06) and STR (r = −0.31, p = 0.1) with EDV were not significant.
Conclusion: Degree of microvascular dysfunction after acute myocardial infarction was related with LV volumes at long term follow-up. These relations were found to be stronger when microvascular function was assessed with invasive, independent and quantitative indices compared to conventional, semi quantitative and non-invasive indices.