Prevalence and Predictors of VTE in Patients with a Diagnosis of Idiopathic Pulmonary Fibrosis; a Population-Based Study

Rationale: Idiopathic pulmonary fibrosis (IPF) is characterized by progressive fibrous tissue deposition in the lungs; it is known that IPF is associated with higher risk of VTE, we are aiming to investigate the predictors of VTE in those patients and the effect of Pirfenidone of that risk. Methods: Using a commercial database (Explorys Inc, Cleveland, Ohio), which includes electronic health record data from 26 major integrated US health care systems, all patients diagnosed with IPF for five years were identified based on Systematized Nomenclature Of Medicine-Clinical Terms. We determined the prevalence of VTE and the potential associated factors using univariate analysis. Results: Out of 37,64,8170 patients in the database, 22250 were found to have IPF in the period between 2015 and 2020. A total of 2.69% patients with IPF vs. 1.79 % [0.9% difference, 95% CI (0.69%-1.12%), P < 0.0001] without IPF were diagnosed with VTE. Individuals with IPF and VTE compared with IPF without VTE, were more likely to be Caucasian [OR: 1.13; 95% CI (1.02 to 1.25), P = 0.0166], female [OR: 1.83; 95% CI (1.46 to 2.29), P < 0.0001], smoker [OR: 1.35; 95% CI (1.23-1.49), P < 0.0001], diabetic [OR: 1.69; 95% CI (1.57-1.82), P < 0.0001], have hypertension [OR: 2.16; 95% CI (1.94-2.40), P < 0.0001], solid malignancy [OR: 1.64; 95% CI (1.52-1.77), P < 0.0001], chronic liver disease [OR: 1.61; 95% CI (1.42-1.83), P < 0.0001], Coronary artery disease [OR: 1.59; 95% CI (1.48-1.72), P < 0.0001], and chronic kidney disease [OR: 2.02; 95% CI (1.8803 to 2.1868), P < 0.0001]. The prevalence of VTE was similar in both groups of IPF with and without Pirfenidone [OR: 0.9; 95% CI (0.7900 to 1.0404), P < 0.16].Conclusion: IPF is associated with a higher prevalence of VTE compared to those without IPF. This could be due to a higher prevalence of VTE risk factors among those with IPF or due to the IPF itself, females with IPF are more likely to have VTE compared to males, also Pirfenidone was not associated with lower risk of VTE. VTE should be considered in the differential diagnosis of a patient with IPF who presents with worsening respiratory symptoms. Further prospective studies are warranted to assess the association of VTE in IPF, and to assess the effect of IPD-targeted therapy on that risk.