Intracoronary administration of dipyridamole prior to percutaneous transluminal coronary angioplasty provides a protective effect exceeding that of ischemic preconditioning

Background Ischemic preconditioning renders hearts more resistant to the de leterious consequences of ischemia, Adenosine is an important mediator in t he induction and maintenance of ischemic preconditioning, Percutaneous tran sluminal coronary angioplasty (PTCA) allows the investigation of the conseq uences of ischemia in humans. The severity of myocardial ischemia decreases with subsequent balloon inflations during the course of PTCA, Objective To compare the effect of intracoronary administration of dipyrida mole with the effect of consecutive balloon inflations, Methods We investigated 30 patients undergoing PTCA of the left anterior de scending coronary artery in the setting of stable angina pectoris. Patients were randomly allocated to be administered either 0.5 mg/kg body weight di pyridamole intracoronarily or an equal amount of saline, Patients administe red saline served as a control group, All patients were subjected to three consecutive balloon inflations. Severity of myocardial ischemia was assesse d in terms of severity of chest pain, electrocardiographic signs of ischemi a, and duration of balloon inflation tolerated, Results Patients administered dipyridamole intracoronarily tolerated signif icantly longer durations of balloon inflation than did patients in the cont rol group. Severity of anginal pain and extent of electrocardiographic sign s of ischemia were significantly lower after intracoronary administration o f dipyridamole. The reductions in anginal pain and ST-segment shift caused by intracoronary administration of dipyridamole during the first balloon in flation were even more pronounced than the protection that was afforded by the third balloon inflation for patients in the control group. Conclusions Intracoronary administration of dipyridamole prior to PTCA is a ssociated with a significant gain in tolerance of ischemia, The protection afforded by intracoronary administration of dipyridamole is even more prono unced than the effect of ischemic preconditioning, Coron Artery Dis 11:607- 613 (C) 2000 Lippincott Williams & Wilkins.