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Effect of Elective Percutaneous Coronary Intervention on Hyperemic Absolute Coronary Blood Flow Volume and
Yoshihisa Kanaji1, Tadashi Murai1, Taishi Yonetsu1
1From the Department of Cardiovascular Medicine, Tsuchiura Kyodo General Hospital, Japan (Y.K., T.M., T.Y., E.U., M.A., J.M., M.H., M.Y., T.N., M.H., S.I., R.H., Y.K., T.K.) and Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Japan (M.I.).
Insights
Percutaneous coronary intervention (PCI) increases absolute coronary blood flow (ABF) but does not significantly change myocardial resistance (MR). Pre-PCI MR correlates with ABF increase post-PCI, offering insights into coronary hemodynamics.
Area of Science:
- Cardiovascular Physiology
- Interventional Cardiology
- Medical Imaging and Diagnostics
Background:
- Coronary hemodynamics, particularly the interplay between absolute coronary blood flow (ABF) and myocardial resistance (MR), are complex.
- The precise impact of percutaneous coronary intervention (PCI) on these hemodynamic parameters remains incompletely understood.
Purpose of the Study:
- To investigate the changes in hyperemic ABF and MR before and after elective PCI.
- To elucidate the relationship between ABF, MR, and fractional flow reserve (FFR) following PCI.
Main Methods:
- Utilized a thermodilution method with a pressure-temperature sensor-equipped wire to measure ABF.
- Continuous saline infusion through a microcatheter facilitated the thermodilution measurements.
- Calculated myocardial resistance (MR) as the ratio of distal coronary perfusion pressure to ABF during maximal hyperemia.
- Assessed fractional flow reserve (FFR) pre- and post-PCI.
Main Results:
- Fractional flow reserve (FFR) significantly increased post-PCI (0.70 to 0.88).
- Absolute coronary blood flow (ABF) also significantly increased post-PCI (137.8 to 173.3 mL/min).
- Myocardial resistance (MR) showed variable changes (decreased in 11 vessels, increased in 17), with no significant overall change observed between pre- and post-PCI (P=0.37).
- A significant correlation was found between pre-PCI MR and the increase in ABF (r=0.44; P=0.02).
Conclusions:
- Direct measurement of ABF and MR using thermodilution is a feasible method for assessing coronary hemodynamics.
- This approach provides valuable insights into the complex hemodynamic changes occurring after PCI.
- Understanding the pre-PCI MR's influence on post-PCI ABF is crucial for interpreting hemodynamic responses.
Background:
The hemodynamics involved in the relationship between absolute coronary blood flow (ABF) volume and myocardial resistance (MR) are complex, and the effect of percutaneous coronary intervention (PCI) on their changes remains unclear. The aim of this study was to investigate the differences in hyperemic ABF and MR before and after elective PCI using a thermodilution method.
Methods And Results:
We investigated 28 vessels (right coronary artery, 9; left anterior descending coronary artery, 18; left circumflex coronary artery, 1) from 28 patients with stable angina pectoris undergoing elective PCI. ABF was measured pre- and post-PCI using a pressure-temperature sensor-equipped wire, based on a thermodilution method with a continuous saline infusion of 20 mL/min through a proximally located microcatheter with an end-hole in the target vessel. MR equals distal coronary perfusion pressure divided by ABF at maximal hyperemia. Conventional fractional flow reserve was also measured pre- and post-PCI. Fractional flow reserve increased significantly after PCI (from 0.70 [0.65-0.75] to 0.88 [0.85-0.95]) in all examined territories. ABF also increased significantly (from 137.8 mL/min [86.3-180.8 mL/min] to 173.3 mL/min [137.9-234.3 mL/min] ; increase: 52.8 mL/min [9.7-80.8 mL/min]) while MR decreased in 11 vessels and increased in 17. No significant relationship was detected between these increases in fractional flow reserve and ABF. Both pre- and post-PCI MR distributed in a wide range, and there was a significant relationship between pre-PCI MR and the increase in ABF (r=0.44; P=0.02) although no significant change in MR was observed between pre- and post-PCI (P=0.37).
Conclusions:
Direct measurement of ABF and MR using thermodilution method offers a feasible approach that could shed a light on previously unclear aspects of coronary hemodynamics.