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Quantitative coronary angiography in predicting functional significance of stenoses in an unselected patient cohort
J Bartúnek1, S U Sys, G R Heyndrickx
1Cardiovascular Center, Aalst, Belgium.
Insights
Quantitative coronary angiography (QCA) correlates with coronary flow reserve but is imprecise for individual patients. However, QCA accurately predicts fractional flow reserve, aiding clinical decisions in coronary artery disease.
Area of Science:
- Cardiovascular Imaging and Physiology
- Interventional Cardiology
- Diagnostic Accuracy Studies
Background:
- Quantitative coronary angiography (QCA) has shown limitations in correlating with functional assessments of coronary stenoses in patients with extensive coronary artery disease.
- Advancements in pressure-monitoring wire technology have enabled the validation of myocardial fractional flow reserve (FFR) derived from coronary pressure measurements.
Purpose of the Study:
- To evaluate the predictive value of quantitative coronary angiography for coronary flow reserve, determined by transstenotic pressure gradients.
- To assess the diagnostic accuracy of QCA in an unselected patient cohort undergoing coronary angioplasty.
Main Methods:
- One hundred ten patients with normal left ventricular function were studied.
- Quantitative coronary angiography (QCA) was performed using the ACA system.
- Myocardial fractional flow reserve (FFR) was calculated from aortic and distal coronary pressures during maximal hyperemia.
Main Results:
- A curvilinear relationship was observed between FFR and diameter stenosis (r=0.79) and minimal lumen diameter (r=0.82).
- A linear relationship was found between FFR and angiographic stenosis flow reserve (r=0.78).
- Despite significant correlations, a large dispersion in FFR values for similar stenosis degrees was noted. However, a minimal lumen diameter <1.5 mm showed 96% sensitivity and 89% specificity for predicting FFR <0.72. Diameter stenosis >50% demonstrated 93% sensitivity and 85% specificity.
Conclusions:
- Geometric indices from QCA correlate significantly with physiological variables but lack precision for individual patient assessment.
- Quantitative coronary angiography demonstrates high diagnostic accuracy in predicting low fractional flow reserve (<0.72), supporting its clinical utility for decision-making during procedures.
Objectives:
This study investigated the value of quantitative coronary angiography for predicting coronary flow reserve, as calculated from the transstenotic pressure gradient in a large, unselected patient cohort.
Background:
In patients with extensive coronary artery disease, quantitative coronary angiographic findings fail to correlate with functional variables of coronary stenoses. New developments in pressure-monitoring wire technology permitted validation in humans of the concept of myocardial fractional flow reserve as assessed from coronary pressure measurements.
Methods:
One hundred ten patients with normal left ventricular function were studied in the setting of coronary angioplasty. Quantitative coronary angiography was performed on-line using the ACA system. Myocardial and coronary fractional flow reserve were calculated from aortic and distal coronary pressures during maximal coronary hyperemia.
Results:
When data before and after angioplasty were pooled, a curvilinear relation was found between myocardial fractional flow reserve and both diameter stenosis (r = 0.79) and minimal lumen diameter (r = 0.82), and a linear relation was found between myocardial fractional flow reserve and angiographic stenosis flow reserve (r = 0.78). Correlations between quantitative angiographic and pressure-derived indexes, although significant, were characterized by a large dispersion of the values of myocardial fractional flow reserve for a similar angiographic degree of stenosis. Nevertheless, the sensitivity and specificity of a minimal lumen diameter < 1.5 mm to predict myocardial fractional flow reserve < 0.72 were 96% and 89%, respectively. The corresponding values for a diameter stenosis > 50% were 93% and 85%, respectively.
Conclusions:
1) In an unselected patient cohort, geometric indexes of stenosis severity derived from quantitative coronary angiography correlate significantly with physiologic variables, although these relations are imprecise in individual patients. 2) Nevertheless, the diagnostic accuracy of quantitative coronary angiography in predicting myocardial fractional flow reserve < 0.72 is high and allows its use for clinical decision making in the individual patient during diagnostic or interventional procedures.