Left main or proximal left anterior descending coronary artery disease location identifies high-risk patients deriving potentially greater benefit from prolonged dual antiplatelet therapy duration

Aims: It is currently unclear if the location of coronary artery disease affects decision making with regard to dual antiplatelet therapy (DAPT). We investigated if the presence of at least 30% luminal narrowing in the left main (LM) and/or proximal left anterior descending (pLAD) coronary arteries on angiography is an outcome modifier with respect to DAPT duration. Methods and results: In the Prolonging Dual Antiplatelet Treatment After Grading Stent-Induced Intimal Hyperplasia (PRODIGY) study, 953 (54.3%) patients with and 801 (45.7%) without LM/pLAD lumen narrowing at the qualifying coronary intervention were randomised to six or 24 months of DAPT. Twentyfour month as compared to six-month DAPT reduced the occurrence of definite, probable or possible stent thrombosis by 50% in patients with (2.8% vs. 5.6%; HR 0.45, 95% CI: 0.23-0.89; p=0.02) but not in those without LM/pLAD lumen narrowing, with a highly significant interaction testing (P_INT = 0.002). This result remained consistent irrespective of whether stenting was (P: 0.01) or was not (P_INT: 0.02) performed in the LM/pLAD. Conclusions: Left main and/or proximal LAD lumen narrowing may be a treatment modifier with respect to the duration of DAPT. Patients fulfilling these angiographic characteristics seem to benefit from a prolonged dual antiplatelet treatment. Trial registration: ClinicalTrials.gov Identifier: NCT00611286