Abstract 8826: Association of TIMI-3 Epicardial Blood Flow Before and After Percutaneous Coronary Intervention with Microvascular Obstruction in Patients with ST-Segment Elevation Myocardial Infarction
Background: The beneficial effects of full restoration of the epicardial coronary flow (TIMI flow grade 3) and spontaneous reperfusion before percutaneous coronary intervention (PCI) are well known. However, previous studies evaluating the influence of pre-PCI and post-PCI TIMI flow grade on cardiac mortality reported conflicting results. The impact of epicardial flow before and after PCI on microvascular damage in patients with ST-segment elevation myocardial infarction (STEMI) has been insufficiently studied. The purpose of this study was to examine the interaction of TIMI-3 antegrade flow before and after PCI on degree of microvascular damage in patients with STEMI.
Methods: Two hundred and eleven consecutive patients with first anterior STEMI who underwent successful PCI (post-TIMI 2,3 flow) were subjected to coronary flow measurement with a Doppler guidewire. The coronary flow velocity spectrum provided the following parameters: systolic peak velocity (SPV) and diastolic deceleration time (DDT). We defined the presence of microvascular obstruction as DDT of ≤ 600 ms and the presence of systolic flow reversal. We classified the patients into three categories according to the post-TIMI 2 flow (group 1), the pre-TIMI 0-2 and post-TIMI 3 flow (group 2), the pre- and post-TIMI 3 flow (group 3).
Results: As for the relationship between the epicardial blood flow before and after PCI and the severity of microvascular damage, group 1 was at the highest risk of microvascular obstruction, while group 3 was at the lowest: 32/40 (80%) for group 1, 55/142 (39%) for group 2, and 0/29 (0%) for group 3 (p<0.05). The DDT were shortest in group 1 and longest in group 3 (358±226 vs. 596±227 vs. 784±133 ms; p<0.05) and the SPV were lowest in group 1 and highest in group 3 (-23±22 vs. -1±24 vs. 14±16 cm/s; p<0.05).
Conclusions: In patients with STEMI, epicardial blood flow both before and after PCI may have significant impacts on ischemic microvascular damage. In particular, all patients who achieved reperfusion with TIMI-3 epicardial blood flow before and after PCI were successfully salvaged from microvascular obstruction. Of critical importance, the effect of pre-procedural TIMI-3 flow on microvascular integrity persisted even when corrected for post-procedural TIMI-3 flow.
- Intravascular ultrasound/Doppler
- Myocardial infarction, STEMI
- Coronary microcirculation
- Interventional cardiology
- © 2011 by American Heart Association, Inc.