PT and INR as predictors of Factor VII coagulation activity: a single center study

Abstract

Factor VII deficiency is characterized by normal PTT and prolonged PT values. It is diagnosed by determining protein level and coagulation activity (FVII:C). Our work aimed to study the correlation between PT, INR and FVII:C in pediatric patients prior to E.N.T surgery. FVII:C data was collected from 100 cases found to have normal PTT and prolonged PT values during preoperative E.N.T surgery coagulation workup between 2016 - 2019. We utilized Pearson correlation coefficient test and Binary Logistic regression for our statistical analysis. The mean values of PT, INR and FVII:C ​ were found to be 14.2, 1.16 and 62 IU/ml respectively. 56% of participants displayed normal FVII:C compared to 44% with decreased FVII:C. A statistically significant negative correlation between FVII:C to PT values and between FVII:C to INR was observed. PT values were better predictors of FVII:C compared to INR. PT and INR values could successfully predict 85% of expected normal FVII:C levels but to a lesser extent predict decreased FVII:C levels (45%). Coagulation screening (PTT, PT/INR) should continue to be part of routine preoperative workup. Determining FVII protein level and coagulation activity remain crucial for diagnosing and initiating surgical prophylactic treatment in patients with Factor VII deficiency.