Abstract 17083: Assessment of Both Coronary Microvascular Damage and Left Ventricular Chamber Stiffness after Successful Percutaneous Coronary Intervention Predicts In-Hospital Cardiac Complications and Left Ventricular Remodeling in ST-Segment Elevation Myocardial Infarction

Background: In ST-segment elevation myocardial infarction (STEMI), the short deceleration time of left ventricular (LV) early filling by Doppler is a powerful independent predictor of clinical cardiac events. It has also been reported that the coronary flow velocity pattern in patients with microvascular obstruction is characterized by the presence of early systolic retrograde flow and a rapid diastolic deceleration time (DDT). The purpose of this study was to examine the effects of both microvascular damage and LV chamber stiffness on cardiac complications and LV remodeling after successful percutaneous coronary intervention (PCI) in STEMI patients. Methods: Two hundred and one consecutive patients with first anterior STEMI were studied following successful PCI. Microvascular damage was evaluated on the basis of coronary flow velocity patterns using Doppler guidewires. We defined the presence of microvascular obstruction as DDT ≤600 ms and the presence of systolic flow reversal. LV filling patterns were determined by LV inflow pulsed-wave Doppler examination on day 3 after STEMI. Deceleration time ≤130 ms was defined as restrictive. We classified patients into three categories: without restrictive and microvascular obstruction (group 1, n=116), with restrictive or microvascular obstruction (group 2, n= 38), and with restrictive and microvascular obstruction (group 3, n=47). Left ventriculograms were obtained immediately and 6 months after PCI. LV remodeling was defined as an increase in end-diastolic volume index ≥20%. The clinical event rate was compared among the 3 groups. Results: The in-hospital event rates for LV thrombus (2/116 [2%], 5/38 [13%] and 14/47 [30%], respectively; P < 0.01) and congestive heart failure (5/116 [4%], 10/38 [26%], and 22/47 [47%]; P < 0.01) were highest in group 3 and lowest in group 1. Group 3 was at the highest risk of LV remodeling, while group 1 was at the lowest (7/116 [6%], 14/38 [37%], and 39/47 [83%]; P < 0.01). Conclusions: Assessment of both microvascular damage and LV chamber stiffness can accurately predict in-hospital complications and LV remodeling in STEMI patients who underwent successful reperfusion of the infarct-related coronary artery, identifying a subset of high risk patients.