PB0013 - Elevated Activated Partial Thromboplastin Time-based Clot Waveform Analysis Parameters are Associated with Acute Myocardial Infarction and its Adverse Outcomes

Background: Activated partial thromboplastin time (aPTT)-based clot waveform analysis (CWA) is a plasma-based global haemostatic assay that has potential utility in various thrombotic and bleeding conditions. Elevated CWA parameters have previously been shown to be associated with hypercoagulability in venous thromboembolism, but its role in arterial thrombosis has not been studied.

Aims: We aimed to explore the relationship between aPTT-based CWA and arterial thrombotic disease, by focusing on acute myocardial infarction (AMI). We hypothesised that CWA parameters will be positively associated with AMI.

Methods: In this retrospective case-control study, CWA data was retrieved from pre-procedure aPTT tests of AMI patients who underwent emergency cardiac catheterisation from April to December 2018, and control patients who underwent elective orthopaedic or urological procedures. Patients who were on anticoagulant or fibrinolytic treatment, had fever on presentation, active cancer, or ongoing chemotherapy or hormonal therapy were excluded. aPTT and its CWA parameters min1, min2 and max2 (representing the maximum velocity, maximum acceleration and maximum deceleration of clot formation kinetics respectively) were analysed for their association with the occurrence of AMI and adverse outcomes in AMI patients.

Results: 214 AMI patients and 109 control patients were included in this study (Table 1). Shortened aPTT below the reference range, and raised CWA parameters (min1, min2 and max2) above their respective reference ranges, was each significantly associated with the occurrence of AMI (Table 2). However, only elevated min1 and min2 demonstrated significant association with the presence of at least one adverse outcome (Table 2).

Conclusion(s): Elevated aPTT-based CWA parameters are significantly associated with the occurrence of AMI and its adverse outcomes. Raised CWA may be a potential risk factor and prognostic marker for AMI. Future work is warranted to validate our findings.