Analysis of Prothrombin Time (PT) and Activated Partial Thromboplastin Time (aPTT) in Patients with Acute Myocardial Infarction on Anticoagulation Therapy to Assess the Thrombogenic Potential

Abstract

Background: Activated partial thromboplastin time and prothrombin time measures the action of the
intrinsic and extrinsic pathways of coagulation needed to maintain homeostasis in the body. We studied
aPTT and PT levels in acute myocardial infarction (AMI) patients on anticoagulation therapies and normal
subjects. The aim of the study is to assess aPTT and PT in patients of acute MI on anticoagulation.
Materials And Method: This study was conducted on 42 patients with chest pain and 84 AMI patients,
admitted to Dhiraj hospital, Vadodara. The AMI patients were classified into STEMI (n=28) and NSTEMI
(n=56). PT and aPTT were assayed on a fully automatic Stago-coagulometer instrument (STA Compact
Max).
Conclusion: Patients with STEMI had mean aPTT of 40.79 ± 1.83 s, NSTEMI had 41.33 ± 2.06 s, aPTT in
control subjects was 31.35 ± 0.48 s. Patients with acute coronary syndrome had significantly higher levels
of aPTT. Patients with STEMI has PT of 17.42 ± 5 s, NSTEMI had 18.56 ± 5 s. Patients on anticoagulation
therapy had higher aPTT and PT values.Both PT and aPTT are high in acute MI patients on anticoagulants.
The elevations in PT values were more than 3 fold greater than aPTT suggesting that PT has a higher
sensitivity for predicting blood clotting capacity in patients already on anticoagulations.