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Updated: Jul 15, 2026
Myocardial Infarction and Functional Outcome Assessment in Pigs
Published on: April 25, 2014
Excimer laser in myocardial infarction: a comparison between STEMI patients with established Q-wave versus patients
Insights
Excimer laser angioplasty effectively treats acute myocardial infarction (AMI) in both Q-wave (QWMI) and non-Q-wave (NQMI) patients, achieving similar procedural success. QWMI patients with heavy thrombus burden showed maximal laser gain, while NQMI patients trended towards fewer adverse events.
Area of Science:
- Cardiology
- Interventional Cardiology
- Vascular Medicine
Background:
- Acute myocardial infarction (AMI) necessitates urgent revascularization within 24 hours due to ongoing ischemia and hemodynamic instability.
- Distinguishing between Q-wave myocardial infarction (QWMI) and non-STEMI (NQMI) is crucial, yet data on device outcomes in these groups are limited.
- Excimer laser angioplasty is a key modality for debulking atherosclerotic plaque and thrombus in AMI patients.
Purpose of the Study:
- To compare the acute outcomes of excimer laser angioplasty in patients with QWMI versus NQMI undergoing urgent revascularization.
- To evaluate the effectiveness of laser angioplasty in relation to thrombus burden in different AMI presentations.
Main Methods:
- A retrospective analysis of 151 AMI patients undergoing urgent revascularization within 24 hours of symptom onset.
- Patients were divided into two groups: established Q-wave myocardial infarction (QWMI) and non-ST-elevation myocardial infarction (NQMI).
- Excimer laser angioplasty and stenting were performed, with outcomes assessed by quantitative coronary arteriography.
Main Results:
- QWMI patients exhibited higher rates of failed thrombolysis, cardiogenic shock, left anterior descending artery involvement, TIMI 0 flow, and greater thrombus burden compared to NQMI patients.
- Laser angioplasty demonstrated similar improvements in minimal luminal diameter and percent diameter stenosis in both groups.
- QWMI patients with heavy thrombus burden showed significantly greater acute laser gain; NQMI patients trended towards reduced major adverse coronary events.
Conclusions:
- Despite baseline differences in clinical characteristics and infarct severity, excimer laser angioplasty achieves comparable procedural success and low complication rates in both QWMI and NQMI patients.
- The study highlights the benefit of laser treatment in heavily thrombosed lesions within the QWMI group.
- NQMI patients may experience a more favorable short-term outcome regarding major adverse coronary events.
Abstract:
Patients sustaining acute myocardial infarction (AMI) often require urgent percutaneous revascularization within the first 24 h from onset of the infarction due to continuous ischemia and hemodynamic instability. Upon arrival to the cardiac catheterization, the electrocardiogram of AMI patients may exhibit acute ST-elevation (STEMI) with or without accompanying Q-wave or depression of the ST segment (non-STEMI or non-Q-wave infarction). Data comparing acute outcome of device application in patients presenting for urgent revascularization with established Q-wave myocardial infarction (QWMI) versus those with non-STEMI (NQMI) are sparse. Excimer laser is a revascularization modality applied for debulking of atherosclerotic plaque and vaporization of associated thrombus in the setting of AMI. One hundred fifty-one AMI patients with continuous chest pain and ischemia who enrolled into a multicenter study and underwent urgent revascularization were divided for the purpose of a retrospective analysis into two groups. One group presented with established electrocardiographic Q-wave, whereas the other had ST-depression (NQMI). In comparison with the NQMI group, the QWMI patients had a higher incidence of failed thrombolytic therapy (17% vs 3, p = 0.006), cardiogenic shock (20 vs 6%, p = 0.01), left anterior descending as a culprit infarct-related vessel (46 vs 14%, p < 0.0001), a higher incidence of TIMI 0 flow (48 vs 24%, p = 0.04), a heavier thrombus burden (grade 4 TIMI thrombus, 58 vs 23%; p = 0.0001), and higher CPK (1272 +/- 2180 vs 404 +/- 577, p = 0.001) and troponin levels (62 +/- 95 vs 14 +/- 48, p = 0.0003). Both groups underwent laser angioplasty and stenting for relief of continuous chest pain and ischemia within 24 h of infarction onset. Quantitative coronary arteriography in an independent core laboratory measured similar improvement in baseline minimal luminal diameter and percent diameter stenosis by application of laser energy in both groups. Among the QWMI patients, a significantly higher acute gain was recorded with the laser treatment in lesions containing a large/extensive thrombus burden as compared with lesions containing only a small clot burden (1.2 +/- 0.7 vs 0.8 +/- 0.5, p = 0.01). Such a phenomenon was not detected among the NQMI patients (1.0 +/- 0.5 vs 0.8 +/- 0.6, p=ns). Baseline TIMI flow grade (0.9 +/- 1.0 for QWMI vs 1.5 +/- 1.2 for NQMI, p = 0.0001) increased with laser emission to 2.8 +/- 0.5 and subsequently reached a final level of TIMI 3 in both groups. In comparison with the QWMI patients, there was a trend toward a reduced rate of major adverse coronary events among the NQMI patients (12% QWMI vs 4% NQMI, p = 0.09). Significant differences in baseline clinical characteristics, extent of myocardial damage, location of infarct related vessel, thrombus burden, and TIMI flow exist between QWMI and NQMI patients who require urgent intervention. However, application of excimer laser results in similar high procedural success and low complication rates in both groups. Maximal acute laser gain is achieved among QWMI patients whose lesions are laden with a heavy thrombus burden.
