Total coronary artery occlusion.

: Although once believed to be unsuitable for coronary angioplasty, patients with subacute and chronic total occlusions have now emerged as important candidates for this procedure. They account for between 10% and 15% of current angioplasties. With careful attention to patient selection factors (occlusion duration, length, morphology, associated thrombus) and technique (initial use of soft guidewires and low-profile dilatation catheters, confirmation of correct wire position, examination for unsuspected distal disease, prolonged heparinization post-procedure), primary success can be achieved in more than 75% of patients. New equipment and techniques--such as thermal or specialized mechanical angioplasty--may facilitate successful crossing of the remaining 25% of total occlusions. The presence of collateral blood flow to the distal vessel provides an important "safety net" and explains the low incidence of emergency surgery following PTCA in this patient group. Patients undergoing successful PTCA of total occlusions should be watched carefully, given the somewhat higher incidence of abrupt reclosure and late restenosis compared with dilatation of conventional stenoses.