Upper Extremity Deep Vein Thrombosis in Medical Inpatients and Association with Central Venous Catheters: Results From the Medical Inpatients and Thrombosis (MITH) Study.
Authors: Winters John P. , Cushman Mary , Callas Peter W , Repp Allen B , Zakai Neil A 
Published: October 2019

Abstract
Abstract 2251

Introduction:
Upper extremity deep vein thrombosis (UEDVT) is an increasingly recognized complication in medical inpatients, contributing to morbidity and increased cost of hospitalizations. Despite the rising use of central venous catheters (CVCS), there is little data available on incidence and risk factors for UEDVT in medical inpatients.

Methods:
All cases of hospital-acquired VTE (Venous Thromboembolism) were identified using ICD-9 codes and confirmed by medical record review at a 500-bed teaching hospital in the United States between January 2002 and June 2009. Hospital-acquired VTE was defined as imaging confirmed deep venous thrombosis (DVT) of the limbs or pulmonary emboli (PE) occurring during the hospitalization and not present on admission. Controls without VTE ICD-9 codes were matched 2:1 to cases by admission year and service. A standard form was used to collect information on both cases and controls including use of CVCs. CVC use in the controls was used to estimate CVC use in medical inpatients based on the sampling frequency. Weighted logistic regression was used to calculate odds ratios (OR) for VTE for CVCs after adjusting for VTE risk factors from a previously developed VTE risk assessment model.

Results:
299 cases of VTE complicated 64,034 admissions (4.6 per 1000 admissions). A total of 51% (91/180) of DVTs were UEDVT, for an overall incidence of 1.4 (95% CI 0.8–1.4) per 1000 admissions. There were 247 (95% CI 203, 292) CVCs placed per 1000 admissions. PICC lines were placed in 87 (95% CI 62, 113) per 1000 admission, non-PICC upper extremity CVCs in 127 (95% CI 99, 156) per 1000 admissions and lower extremity CVCs in 17 (95% CI 9, 25) per 1000 admissions. VTE incidence was 10.0 (95% CI 7.4, 12.5) per 1000 admissions in patients with a CVCs vs. 3.0 (95% CI 2.4, 3.6) per 1000 in patients without a CVC. The incidence of UEDVT was 4.9 (95% CI 3.3 – 6.2) per 1000 admissions in patients with CVCs versus 0.3 (95% CI 0.2 – 0.5) per 1000 admissions in patients without CVCs. The adjusted ORs for VTE are presented in the table. Risk of upper extremity DVTs was strongly associated with use of CVCs (OR 14.0; CI 5.9–33.2), with the highest risk associated with PICCs (13.0 (6.1–27.6), followed by lower extremity CVCs, and non-PICC upper extremity CVCs. Placement of lower extremity CVCs was associated with the highest odds of PE and lower extremity DVT. Most (72%) patients with lower extremity CVCs also had an upper extremity line placed prior to their VTE. The odds of PE were increased in non-PICC upper extremity CVC and lower extremity CVCs but not PICCs (Table). CVCs placed prior to the hospitalization were not associated with an increased risk of VTE.

Conclusion:
For the first time we demonstrate the impact CVCs have on hospital-acquired VTE in medical inpatients. Quality organizations and clinical trials of VTE prevention have not addressed UEDVTs, however they are frequent in medical inpatients and contribute to morbidity and medical costs. Increased awareness of UEDVTs associated with CVCs and inclusion of these events in clinical trials of VTE prophylaxis are needed to develop appropriate preventive strategies.

Disclosures:
Cushman: Beckman: Honoraria.