Coronary artery restenosis and target lesion revascularisation in women by pregnancy history.

BACKGROUND: Women's pregnancy history is associated with incident risk of coronary artery disease with some evidence also suggesting a relevance for prognosis following treatment. OBJECTIVES: To study the associations between maternal history of preterm delivery, a history of small for gestational age infant, parity and age at first delivery with clinical restenosis after percutaneous coronary intervention (PCI). METHODS: In this prospective cohort study, we included 6027 women <65 years undergoing their first PCI 2006-2017, merging clinical register data on PCI procedures in Sweden with comprehensive registry data on deliveries since 1973. We used proportional hazards regression to study the association between aspects of pregnancy history and clinical restenosis in per-segment analyses, and with target lesion revascularisation (TLR) in per-patient analyses. We adjusted models for procedural-related and patient-related predictors of restenosis. RESULTS: During 15 981 segment-years of follow-up, 343 (3.7%) events of clinical restenosis occurred. We found no strong evidence of associations between the studied aspects of pregnancy history and clinical restenosis following PCI. For example, the restenosis HR for a history of preterm delivery in the fully adjusted model was 1.09 (95% CI 0.77 to 1.55) and the TLR HR was 1.18 (95% CI 0.91 to 1.52). CONCLUSION: Risk of restenosis following treatment with PCI did not differ by the studied aspects of pregnancy history, including preterm delivery, in young and middle-aged women. Larger studies are needed to obtain more precise estimates.