OBJECTIVES To investigate the effect of intracoronary dipyridamole on the incidence of abrupt vessel closure, myocardial infarction, necessity for bypass grafting, and death following percutaneous transluminal coronary angioplasty (PTCA).

PATIENTS Patients were randomly allocated to receive either conventional pretreatment (heparin 15 000 IU and aspirin 500 mg intravenously) or additional intracoronary dipyridamole (0.5 mg/kg bodyweight). Dipyridamole was administered in 550 PTCA procedures (455 interventions in men, mean (SD) age 59.2 (8.4) years; 74 acute coronary syndromes), while conventional pretreatment was administered in 544 interventions (444 interventions in men 58.3 (7.9) years old; 81 acute coronary syndromes). In 53 interventions bail out stenting was performed for threatened abrupt vessel closure.

RESULTS Intracoronary dipyridamole significantly reduced the incidence of abrupt vessel closure (odds ratio 0.42. 95% confidence interval (CI) 0.22 to 0.79). While abrupt vessel closure occurred in 6.1% of interventions following conventional pretreatment, dipyridamole reduced the incidence to 2.5%. Restricting the analysis to balloon angioplasty, this reduction was observed in patients with stable angina (odds ratio 0.49, 95% CI 0.23 to 0.96) as well as in those with acute coronary syndromes (odds ratio 0.29, 95% CI 0.09 to 0.87). Reduction of secondary end points in the dipyridamole treated patients failed to reach significance in the PTCA group.

CONCLUSIONS Intracoronary dipyridamole before PTCA reduces the incidence of abrupt vessel closure following PTCA for stable angina and acute coronary syndromes.