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Significant correlation of recruitable coronary collateral blood flow determined by coronary wedge pressure with
Shigeshi Kamikawa1, Kohichiro Iwasaki, Keizo Yamamoto
1Department of Medicine and Medical Science, Okayama University Graduates School of Medicine and Dentistry, Japan.
Insights
Fractional collateral flow (Qc/Q(N)) effectively predicts sufficient coronary collateral blood flow during percutaneous coronary intervention (PCI). This measurement helps prevent myocardial ischemia by assessing blood flow adequacy before obstruction.
Area of Science:
- Cardiology
- Interventional Cardiology
- Physiology
Background:
- Quantitative assessment of coronary collateral blood flow is crucial for managing coronary artery stenosis.
- Percutaneous coronary intervention (PCI) involves temporary coronary artery occlusion, necessitating evaluation of collateral circulation.
- Electrocardiographic changes during PCI can indicate myocardial ischemia due to insufficient collateral blood flow.
Purpose of the Study:
- To investigate the relationship between recruitable coronary collateral blood flow and electrocardiographic changes during PCI.
- To determine if quantitative measurements of coronary pressure can predict the adequacy of collateral blood flow.
- To assess the utility of fractional collateral flow (Qc/Q(N)) in preventing ischemia during coronary obstruction.
Main Methods:
- Coronary pressure and electrocardiograms were measured in 119 patients undergoing PCI for left anterior descending coronary artery stenosis.
- Fractional collateral flow (Qc/Q(N)) was calculated by dividing coronary wedge pressure by mean aortic pressure during balloon inflation.
- Myocardial ischemia was defined by ST-segment shifts, and correlations between Qc/Q(N) and ST-segment changes (MaxST, sumST) were analyzed.
Main Results:
- A significant inverse correlation was found between Qc/Q(N) and both MaxST (r=-0.455) and sumST (r=-0.477), indicating higher collateral flow reduces ischemic changes.
- A Qc/Q(N) cut-off value of 0.27 demonstrated 71.4% sensitivity and 76.2% specificity for predicting sufficient collateral blood flow.
- No significant increase in collateral blood flow was observed with repeated transient coronary occlusions during PCI.
Conclusions:
- Fractional collateral flow (Qc/Q(N)) is a clinically valuable parameter for assessing sufficient recruitable coronary collateral blood flow during PCI.
- Qc/Q(N) can help prevent myocardial ischemia by identifying patients with inadequate collateral circulation before obstruction.
- The study suggests that repeat occlusions do not enhance collateral blood flow during a single PCI procedure.
Objectives:
Quantitative assessment of coronary collateral blood flow can be archived by measuring coronary pressure. We studied the relationships between recruitable coronary collateral blood flow and electrocardiographic changes during percutaneous coronary intervention (PCI).
Methods:
We measured coronary pressure during coronary occlusion with PCI in 119 patients with left anterior descending coronary artery stenosis. During balloon inflation, the electrocardiogram was continuously recorded. The ST-segment elevation in the most elevated lead was defined as MaxST and the sum of the maximal ST elevation in leads V2-V4 was defined as sumST. Fractional collateral flow (Qc/Q(N)) was calculated as the coronary wedge pressure divided by the mean aortic pressure. Myocardial ischemia was defined as an ST-segment shift >0.1 mV in any of the V2, V3 or V4 leads.
Results:
A significant relationship between Qc/Q(N) and MaxST was observed (r=-0.455, P<0.0001). Similarly, Qc/Q(N) was significantly correlated with sumST (r=-0.477, P<0.0001). The receiver operating characteristic curve showed that a cut-off value of 0.27 for Qc/Q(N), with sensitivity of 71.4% and specificity of 76.2%, was an indicator of electrophysiologically sufficient recruitable coronary collateral blood flow for prevention of ischemia during coronary obstruction. Qc/Q(N) values during the first, second, third and fourth inflation were not significantly different.
Conclusions:
Qc/Q(N) could be clinically useful for determining whether there is electrophysiologically sufficient recruitable coronary collateral blood flow for prevention of ischemia during coronary obstruction. Repeat transient coronary occlusion during PCI did not lead to increased collateral blood flow.
