Balancing the Risks of Recurrent Ischaemic and Bleeding Events in a Stable Post ACS Population

To better guide decisions regarding antithrombotic treatment in individual patients surviving 6 months following an acute coronary syndrome (ACS) by balancing between subsequent recurrent ischaemic and bleeding risk.

Patients surviving 6 months following an ACS were followed in an Australian registry. Ischaemic (composite of cardiovascular death, myocardial infarction or stroke) and bleeding (≥BARC 2) events were collected. A dual binary outcome modelling strategy was used arriving at a common set of variables from which bleeding and ischaemic risk could be independently determined in individual patients. Patients in whom bleeding rates exceeded composite ischaemic event rates during the follow-up period were identified.

The cohort comprised 5,905 patients in whom 215 experienced an ischaemic event and 49 a bleeding event. The single set of variables included in both ischaemic and bleeding models (C-statistics 0.71 and 0.72 respectively) included modified TIGRIS¹ ischaemic score, mode of revascularisation, history of heart failure, anaemia, multivessel disease, readmission within 6 months of index ACS and age >75. In the majority, ischaemic events were more frequent than bleeding events. In higher risk patients post coronary artery bypass grafting (CABG), bleeding events were more frequent than recurrent ischaemic events.

The risk of recurrent ischaemic events exceeds bleeding in most patients followed 6 to 24 months following an ACS. Post CABG patients with comorbidities have a higher risk of bleeding over this period during which time attention should be directed towards modifiable bleeding risk factors including requirement for dual antiplatelet therapy.