PURPOSE: Venous thromboembolism (VTE) is a common disorder among hospitalized patients. A thorough review of the literature revealed limited data about the association of Usual Interstitial Pneumonitis (UIP) with VTE.
METHODS: We retrospectively collected data of patients with UIP diagnosed by either open surgical biopsy or autopsy. Variables examined included demographics, smoking history, body mass index (BMI), diagnosis of VTE, pulmonary function tests, and D-dimer levels. Patients with a history of malignancy were excluded. Logistic regression analysis identified the risk factors for VTE. Prevalence of VTE in patients with UIP was calculated. We also calculated the prevalence of VTE in patients with Idiopathic Pulmonary Fibrosis (IPF), a subset of UIP.
RESULTS: 221 charts were reviewed over a period of 10 years (1997-2006). 51 with biopsy-proven UIP were analyzed for the purpose of this abstract. 29 (56.86%) had IPF, while 22 (43.14%) had other forms of UIP (NonIPF). Prevalence of VTE was 25.49% among all patients, and it was not statistically different between the two groups (IPF 24.14%, NonIPF 27.27%; P=0.79). Logistic regression analysis of VTE predictors revealed only two significant factors: BMI [OR: 1.023 (1.005-1.04) P=0.015] and a negative smoking history [OR: 0.75 (0.58-0.97) P=0.042]. It is interesting to note that smoking was associated with lower probability of VTE, but the magnitude was minimal.
CONCLUSION: Prevalence of VTE is relatively high in a cohort of patients with biopsy-proven UIP. Prevalence is not statistically different according to type of UIP. We found that a higher BMI and no smoking history are risk factors for VTE. Small sample size limits our analysis; nevertheless, this is the first study that reported prevalence of VTE in UIP.
CLINICAL IMPLICATIONS: Clinicians need to be aware of the association between VTE and UIP; however, the impact of this association on outcome is yet to be explained. Lack of a prospective, systematic study for VTE may have underestimated the true prevalence. A larger, prospective study is required to further clarify our findings.
DISCLOSURE: Steven Schuster, No Financial Disclosure Information; No Product/Research Disclosure Information