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Applications of coronary flow velocity during angioplasty and other coronary interventional procedures
1Cardiology Division, George Washington University, Washington, D.C.
Insights
Measuring distal coronary artery blood flow post-intervention reveals significant velocity improvements after balloon angioplasty and laser angioplasty, aiding clinical decisions.
Area of Science:
- Cardiovascular Medicine
- Interventional Cardiology
- Hemodynamics
Background:
- Previous Doppler catheter studies showed limited improvement in proximal coronary artery velocities post-intervention.
- Assessing distal coronary artery hemodynamics offers a more sensitive measure of intervention success.
Purpose of the Study:
- To evaluate the utility of measuring distal coronary artery blood flow velocity parameters after various interventional procedures.
- To determine if distal flow velocity measurements can effectively assess the hemodynamic outcome of coronary interventions.
Main Methods:
- Utilized a low-profile Doppler angioplasty guidewire to measure distal coronary artery velocities, flow reserve, and diastolic/systolic velocity ratios.
- Analyzed data from patients undergoing balloon angioplasty, excimer laser angioplasty, and directional coronary atherectomy.
Main Results:
- Balloon angioplasty significantly increased distal peak velocity (19 to 35 cm/sec) and improved the diastolic/systolic ratio (1.3 to 1.8).
- Excimer laser angioplasty showed marked increases in distal peak velocity and diastolic/systolic ratio, further enhanced by adjunctive balloon angioplasty.
- Directional coronary atherectomy yielded only modest improvements in distal peak velocity and no significant change in the diastolic/systolic ratio.
Conclusions:
- Distal coronary artery flow velocity measurements provide valuable insights into the immediate hemodynamic results of interventions.
- These distal measurements may aid in clinical decision-making following coronary artery interventions.
Abstract:
Previous studies utilizing Doppler catheters to assess blood flow immediately following coronary artery interventions have failed to demonstrate significant improvement in proximal coronary artery velocities or vasodilator reserve. Measurement of blood flow velocity, flow reserve, and the phasic diastolic/systolic velocity ratio in the distal coronary artery has been performed following various interventional procedures utilizing a low profile (.018 in) Doppler angioplasty guidewire. Following balloon angioplasty in 38 patients, average peak velocity increased significantly from 19 +/- 12 to 35 +/- 16 cm/sec in the distal coronary artery. The diastolic/systolic flow ratio improved from 1.3 +/- 0.5 to 1.8 +/- 0.5 and coronary flow reserve remained unchanged. Similar improvement in distal mean velocities (200%) versus proximal mean velocities (90% increase), and improvement in phasic velocity patterns, total velocity integral, and peak diastolic velocity were also noted in a separate study of 29 patients, before and after balloon angioplasty. Following excimer laser angioplasty in 10 patients, average peak velocity in the distal coronary artery was noted to increase from 6.3 to 13.0 cm/sec following laser alone, with a further increase to 20.6 cm/sec following adjunctive balloon angioplasty. The diastolic/systolic flow ratio increased from a mean value of 1.1 to 2.0 following laser recanalization, with a further increase to 2.9 following adjunctive balloon angioplasty. Following directional coronary atherectomy only modest improvement in distal average peak velocity was noted (24.7 to 31.2 cm/sec), with no significant change in diastolic/systolic velocity ratio (1.78 vs 2.04) immediately following the procedure. Measurement of distal flow velocity parameters performed immediately following coronary interventions may prove useful in assessing the hemodynamic result of these interventions and may prove useful in clinical decision making.