Reappraisal of functional importance of coronary collateral circulation.

Coronary collateral circulation (CCC) is defined as an alternative blood-conveying circuit to the ischemic myocardium supplied by a jeopardized coronary artery. Accumulating evidence on CCC and its functional role has been derived from basic and clinical studies over several decades. Progress in molecular biology and genetic engineering has enabled us to elucidate the mechanisms of collateral growth on the basis of the development of new experimental models and methods for accurate assessment of CCC. These achievements in basic research have been promptly translated into the clinical setting. Interaction between basic and clinical sciences in the fascinating field of CCC will contribute to the establishment of innovative collateral-promoting therapy for severe coronary artery disease.