Abstract 16868: Impact of Primary Coronary Angioplasty Delay on Microvascular Obstruction as Assessed by Coronary Flow Velocity Measurements and Long-Term Cardiac Events in ST-Segment Elevation Myocardial Infarction
Background: The impact of total ischemic time on microvascular obstruction as assessed by coronary flow velocity measurements (MVO-CFV) and clinical outcome has been insufficiently studied. This study investigated the relationship between long-term cardiac events and the incidence of MVO-CFV worsened by primary coronary angioplasty delay in patients with ST-segment elevation myocardial infarction (STEMI).
Methods: Because of the low incidence of microvascular obstruction in the presence of normal blood flow before reperfusion as previously reported, 34 patients with pre-procedural TIMI 3 flow were excluded. A total of 193 consecutive patients with first anterior STEMI who underwent angioplasty were subjected to CFV measurement with a Doppler guidewire. The CFV spectrum provided the systolic peak velocity and diastolic deceleration time (DDT). We defined the presence of MVO-CFV as a DDT of ≤600 ms and the appearance of systolic flow reversal.
Results: All patients who achieved reperfusion within 120 min after symptom onset were successfully salvaged from MVO-CFV. There was a significant correlation between duration of ischemia and incidence of MVO-CFV (P < 0.01). There were no changes in the incidence of MVO-CFV beyond 240 min after symptom onset. We classified the patients into three categories according to duration of ischemia: ≤120 min, >120 to 240 min, and >240 min. The major adverse cardiovascular events (MACE) rate was compared among the three groups. Earlier reperfusion was associated with a significantly lower risk of MVO-CFV (0/18 [0%], 29/73 [40%], and 63/102 [62%], respectively; P < 0.01). Long-term follow-up was performed at a mean of 5.5 ± 3.5 years. The long-term incidence of MACE was lowest in the ≤120 min group and highest in the >240 min group.
Conclusions: Very early recanalization preserves coronary microvascular integrity associated with clinical outcome in patients with anterior STEMI undergoing primary angioplasty.
- Myocardial infarction, STEMI
- Cardiovascular imaging
- Coronary microcirculation
- Reperfusion injury
- © 2013 by American Heart Association, Inc.