Impact of chronic total occlusions, arterial access site, and pretreatment with antiplatelet drugs on mortality in patients with ischemic heart disease: A report from the SWEDEHEART registry

Abstract: Impact of chronic total occlusions, arterial access site and pretreatment with antiplatelet drugs on mortality in patients with ischemic heart disease: A report from the SWEDEHEART registry Background Treatment of ischemic heart disease has advanced substantially in the past half-century. However, despite these achievements the survival rates in high-income countries such as Sweden have reached a plateau in the last decade. Strategies to further reduce mortality are needed. Aims To evaluate the impact of chronic total occlusions, choice of arterial access site and pretreatment with P2Y12 inhibitors on mortality in patients with coronary artery disease. Methods This thesis is based on observational studies. We have used data from the SWEDEHEART registry and the Swedish National Cause of Death Register. All coronary procedures in Sweden, angiography and PCI, are registered in the SWEDEHEART registry. We used multiple imputation to impute missing data (papers I-IV), propensity score matching to adjust for known confounders (papers II, IV), multilevel models to account for a hierarchical database (paper II; III, IV) and instrumental variable analysis to adjust for known and unknown confounders (paper III) Results In paper I, we found an adjusted HR 1,29 for death in patients with a CTO, as compared to patients with coronary artery disease without CTO. In paper 2, pretreatment was not associated with better 30-day survival or differences in bleeding in STEMI-patients. In paper 3, pretreatment was in NSTE-ACS patients not associated with better 30-day survival but associated with a higher risk of in-hospital bleeding. In paper IV we could show that radial access in patients undergoing primary PCI for STEMI was associated with a lower risk of death (adjusted OR 0,70) within 30 days, as compared to femoral access. Conclusion Chronic total occlusions of a coronary artery are associated with increased mortality. Pretreatment with P2Y12 receptor antagonists is not associated with reduced mortality in patients with acute coronary syndrome but is associated with increased in-hospital bleeding in NSTE-ACS patients. Our findings in paper II and III add external validity to findings in randomized trials on lack of benefit and potential harm of pretreatment. Use of radial artery access for primary PCI in STEMI is associated with reduced mortality in comparison to using femoral access. The findings in paper IV support the ESC guideline recommendation for the use of radial access in STEMI.