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Delayed recovery of coronary resistive vessel function after coronary angioplasty
N G Uren1, T Crake, D C Lefroy
1Department of Medicine, Hammersmith Hospital, London, England.
Insights
Coronary vasodilator response is impaired for at least 7 days after successful angioplasty, indicating persistent abnormal resistive vessel function. This impairment affects maximal myocardial blood flow following dipyridamole administration.
Area of Science:
- Cardiovascular Medicine
- Interventional Cardiology
- Physiology
Background:
- Coronary vasodilator response can be impaired immediately post-angioplasty despite successful stenosis dilation.
- Understanding this impairment is crucial for optimizing post-procedural cardiac care.
Purpose of the Study:
- To investigate the role and time course of abnormal coronary resistive vessel function.
- To assess the impairment of coronary vasodilator response after successful coronary angioplasty using Doppler catheterization and positron emission tomography (PET).
Main Methods:
- Studied 12 men with single-vessel coronary artery disease.
- Measured coronary vasodilator response using intracoronary Doppler before and after angioplasty.
- Determined basal and maximal myocardial blood flow with H2(15)O PET at 1 day, 7 days, and 3 months post-angioplasty.
Main Results:
- Coronary vasodilator response by Doppler was similar pre- and immediately post-angioplasty.
- Basal myocardial blood flow in the angioplasty region was elevated for at least 7 days post-angioplasty.
- Dipyridamole-induced increase in maximal myocardial blood flow was reduced for at least 24 hours post-angioplasty.
Conclusions:
- Successful angioplasty leads to increased basal myocardial blood flow in the treated region for over 7 days.
- The coronary vasodilator response remains impaired for at least 7 days post-angioplasty.
- Abnormal resistive vessel function distal to the stenosis persists for 7 days to 3 months.
Objectives:
The aim of this study was to use Doppler catheterization and sequential dynamic positron emission tomography (PET) to investigate the role and time course of abnormal coronary resistive vessel function in the impairment of the coronary vasodilator response (maximal/basal coronary blood flow) after successful coronary angioplasty.
Background:
The coronary vasodilator response may be impaired immediately after coronary angioplasty, despite successful dilation of a flow-limiting stenosis.
Methods:
Twelve men (mean age 52 +/- 10 years) with single-vessel coronary artery disease and normal left ventricular function were studied. The coronary vasodilator response to intravenous dipyridamole (0.5 mg.kg-1 over 4 min) was determined from intracoronary Doppler measurement of coronary flow velocity, before and after successful angioplasty. Basal and maximal myocardial blood flow in the angioplasty region and a normal region were determined in nine patients wtih positron emission tomography with H2(15)0 at 1 day (PET1), 7 days (PET2) and 3 months (PET3) after angioplasty.
Results:
The coronary vasodilator response, measured by Doppler catheterization, was similar before and immediately after angioplasty, 1.63 +/- 0.41 and 1.62 +/- 0.55, respectively (p = NS). After angioplasty, in seven of nine patients without restenosis, basal myocardial blood flow at PET1, PET2 and PET3 was 0.98 +/- 0.16, 0.94 +/- 0.09 and 0.99 +/- 0.13 ml.min-1 x g-1, respectively, in the remote region and 1.19 +/- 0.23 (p < 0.01 vs. remote region), 1.17 +/- 0.19 (p < 0.01 vs. remote region) and 1.10 +/- 0.08 ml.min-1 x g-1 (p = NS vs. remote region), respectively, in the angioplasty region. Myocardial blood flow after dipyridamole at PET1, PET2 and PET3 was 3.04 +/- 0.68, 3.00 +/- 0.71 and 3.00 +/- 0.60 ml.min-1 x g-1, respectively, in the remote region and 2.11 +/- 0.80 (p < 0.01 vs. remote region), 2.28 +/- 0.73 (p = NS vs. remote region) and 3.06 +/- 0.86 ml.min-1 x g-1 (p = NS vs. remote region), respectively, in the angioplasty region. The coronary vasodilator response at PET1, PET2 and PET3 was 3.15 +/- 0.85, 3.18 +/- 0.68 and 3.08 +/- 0.75, respectively, in the remote region and 1.80 +/- 0.68 (p < 0.01 vs. remote region), 1.94 +/- 0.49 (p < 0.01 vs. remote region) and 2.77 +/- 0.74 (p = NS vs. remote region), respectively, in the angioplasty region.
Conclusions:
After successful angioplasty, basal myocardial blood flow is increased for > or = 7 days in the angioplasty region, with a reduction in the dipyridamole-induced increase in maximal myocardial blood flow for > or = 24 h after the procedure. Thus, the coronary vasodilator response is impaired for > or = 7 days after angioplasty, indicating that there is abnormal resistive vessel function in the coronary vascular bed distal to a coronary artery stenosis that persists for 7 days to 3 months.