CLINICAL INVESTIGATION Coronary wedge pressure in relation to spontaneously visible and recruitable collaterals

Coronary angiography demonstrates only collateral arteries that are already in use (spontaneously visible collaterals). Percutaneous transluminal coronary angioplasty (PTCA) provides an opportunity to uncover collaterals ready to become functional in case of occlusion of the recipient artery (recruitable collaterals). The incidence of recruitable collaterals and their relation to the distal pressure in the occluded artery (coronary wedge pressure) during a 30 sec or longer balloon occlusion was assesed in 57 coronary arteries of 49 patients undergoing PTCA for a proximal coronary stenosis or occlusion. Collaterals to 75% of the arteries were present. Spontaneously visible collaterals were four times as frequent as recruitable collaterals. Coronary wedge pressure was significantly higher in arteries with spontaneously visible and recruitable collaterals (41 + 12 and 36 ± 12 mm Hg, respectively) than in arteries without collaterals (18 ± 4 mm Hg). A coronary wedge pressure of 30 mm Hg or higher was found exclusively in the presence of collaterals. Electrocardiographic changes during balloon occlusion were found more frequently with arteries without collaterals than with arteries with spontaneously visible or recruitable collaterals. Chest pain was more frequent in patients without collaterals or with recruitable collaterals than in those with spontaneously visible collaterals. Major inhospital events occurred in three patients with collaterals, with a salutary influence of the collaterals in two. The coronary wedge pressure allows prediction of recruitable collaterals. Their clinical impact remains to be investigated in long-term studies on large patient populations. Circulation 75, No. 5, 906-913, 1987. COLLATERAL CORONARY ARTERIES are important in coronary artery disease. A totally obstructed coronary artery perfused by well-developed collaterals has been shown to be hemodynamically comparable to an artery with a 91% to 99% diameter stenosis.l Typically, it causes exertional angina pectoris but no pain at