Related Experiment Videos
Coronary vasoconstriction after angioplasty of total occlusions: relation to change in coronary perfusion pressure
1Department of Medicine, University of Hong Kong, Queen Mary Hospital.
Insights
Distal coronary vasoconstriction is common after chronic total occlusion angioplasty. This response is linked to changes in coronary perfusion pressure, suggesting autoregulation reset.
Area of Science:
- Cardiovascular medicine
- Interventional cardiology
- Vascular physiology
Background:
- Distal coronary vasoconstriction is a known phenomenon post-angioplasty.
- Its occurrence and mechanisms after chronic total occlusion (CTO) angioplasty are less understood.
Purpose of the Study:
- To evaluate coronary vasomotor response after successful CTO angioplasty.
- To test if distal vasoconstriction depends on altered perfusion pressure.
Main Methods:
- Studied 30 patients with successful left coronary CTO angioplasty.
- Performed quantitative coronary measurements pre- and post-angioplasty, and after nitroglycerin.
- Assessed vasoconstriction in distal and control segments relative to perfusion pressure changes.
Main Results:
- Distal segments showed significant vasoconstriction at 15 and 30 min post-angioplasty compared to baseline and control segments.
- The degree of vasoconstriction at 30 min strongly correlated with the change in distal perfusion pressure (r=0.73, p<0.001).
Conclusions:
- Coronary distal vasoconstriction is frequent after successful CTO angioplasty.
- This vasoconstriction is closely related to changes in coronary perfusion pressure.
- Findings support a hypothesis of reset epicardial coronary autoregulation in chronic hypoperfusion states.
Objectives:
This study evaluated the coronary vasomotor response after successful angioplasty of chronic total coronary occlusions and tested the hypothesis that the degree of distal vasoconstriction is dependent on the change in perfusion pressure.
Background:
Although distal coronary vasoconstriction has been observed to occur frequently after successful percutaneous transluminal coronary angioplasty, little is known about this vasomotor response after angioplasty of chronic total occlusions.
Methods:
Thirty patients with successful angioplasty of chronic total occlusions of the left coronary artery were studied. Quantitative coronary measurements were made at 0, 15 and 30 min after angioplasty and again after intracoronary nitroglycerin administration in coronary artery segments distal to the dilated lesion and in a control vessel. The change in distal perfusion pressure was defined as mean systemic arterial pressure minus residual mean trans-stenotic pressure gradient minus mean coronary wedge pressure.
Results:
The distal segments showed greater vasoconstriction (vs. nitroglycerin) at 15 and 30 min compared with that at 0 min after angioplasty (32.3 +/- 2.2% and 35.2 +/- 2.5% vs. 12.5 +/- 1.8%, respectively, p < 0.005) and compared with control segments (32.3 +/- 2.2% vs. 12.1 +/- 2.0%, p < 0.005, and 35.2 +/- 2.5% vs. 12.5 +/- 2.0%, p < 0.005, respectively). The degree of vasoconstriction at 30 min in the distal segments was found to correlate closely with the change in distal perfusion pressure (r = 0.73, p < 0.001).
Conclusions:
Coronary distal vasoconstriction occurs frequently after successful angioplasty of chronic total occlusions and correlates closely with the change in coronary perfusion pressure. These findings support the hypothesis of reset epicardial coronary autoregulation in chronic hypoperfusion such that restoration of normal perfusion pressure after successful angioplasty may provoke reflex vasoconstriction.