Quantification of collateral flow in humans: a comparison of angiographic, electrocardiographic and hemodynamic variables.

OBJECTIVES: Evaluation of collateral vascular circulation according to hemodynamic variables and its relation to myocardial ischemia.
BACKGROUND: There is limited information regarding the hemodynamic quantification of recruitable collateral vessels.
METHODS: Angiography of the donor coronary artery was performed before and during balloon coronary occlusion in 63 patients with one vessel disease. Patients were divided into groups of those with an absence of collateral vessels (group 1, n = 10), those with recruitable collateral vessels (group 2, n = 23) and those with spontaneously visible collateral vessels (group 3, n = 30). During balloon inflation the coronary wedge/aortic pressure ratio (Pw/Pao) was determined as were collateral blood flow velocity variables, using a 0.014" Doppler guide wire. Myocardial ischemia was defined as > or =0.1 mV ST-shift on a 12 lead electrocardiogram at 1 min coronary occlusion.
RESULTS: Myocardial ischemia was present in all patients of group 1, in 14 patients of group 2 and in 3 patients of group 3. Recruitable collateral flow without ischemia showed similar hemodynamic values as in group 3 while these values were similar to group 1 in regard to the presence of recruitable collateral vessels showing ischemia. Logistic regression analysis revealed both Pw/Pao and Vi(col) as independent predictors for the function of collateral vessels.
CONCLUSIONS: Hemodynamic variables of collateral vascular circulation are better markers of the functional significance of collateral vessels than is coronary angiography. The total collateral blood flow velocity integral and coronary wedge/aortic pressure ratio are good and independent predictors of the function of collateral vessels producing complementary information.