Longer Admissions for IBD Flares Linked to VTE Risk

ORLANDO — Longer hospitalization for flares of inflammatory bowel disease (IBD) was linked to greater risk of subsequent venous thromboembolism (VTE) independent of other risk factors, according to a small retrospective study.

A longer hospital stay doubled the odds of VTE in the 6 months after discharge (OR 2.0, 95% CI 1.3-4.2, P=0.02), Alice Xu, MD, of the University of Iowa Healthcare in Iowa City, reported in a research poster at the Advances in Inflammatory Bowel Disease annual meeting.

A higher albumin nadir decreased the odds of a VTE by 89%, but this association had marginal significance (OR 0.11, 95% CI 0.01-0.70, P=0.05).

“Given the low incidence of post-hospitalization VTE in our cohort, no recommendation can be made at this time for extended VTE prophylaxis following hospitalization for an IBD flare,” the authors concluded. “However, patients with these risk factors should be monitored closely for about a month after discharge for the development of VTE even without a history of surgery or other thrombotic risk factors.”

The study was limited by the small number of patients — seven total — out of an overall cohort of 519 who experienced a VTE without some other major risk factor.

“It is encouraging to see that the risk of VTE, a potentially devastating complication of IBD, is low,” Alexander Levy, MD, director of the IBD fellowship program at Yale School of Medicine in New Haven, Connecticut, told MedPage Today. “Unfortunately, the study is too small to make practice-altering conclusions, and there are no current recommendations for post-discharge VTE prophylaxis.”

Established risk factors for VTE in patients with IBD include active disease, the severity of the disease, use of steroids, surgery, and any hospitalization. Risk of VTE is estimated at 2% in all patients with IBD and as high as 8% during active IBD, which is about two to three times higher than in the general population, as Xu’s group noted. But it’s less clear how many of these VTEs are attributable to confounding factors.

The researchers therefore used an IBD database of data prospectively collected from EPIC medical records at University of Iowa Hospitals and Clinics from 2010 to 2023 to examine cases of VTE after hospitalization in patients with IBD. They were looking for potential risk factors beyond known ones that could help identify which patients need VTE prophylaxis.

Among 519 patients with an IBD flare and hospital admission who experienced a VTE within 6 months of discharge, 487 were excluded from the study because of a history of VTE, presence of a hypercoagulable comorbidity, or surgery, which would have increased risk of VTE.

After individual case review led to additional exclusions for lack of hospitalization or lack of VTE, the researchers had a cohort of just seven patients. The average time to the VTE was 20 days, ranging from 9 to 25. The type of VTE was pulmonary embolism in 14% of patients and deep vein thrombosis in an extremity in 86%.

The authors noted that the rate of VTE in their cohort was low for “IBD hospitalization specifically identified for medically treated flares without other confounding risk factors for VTE,” although that low rate was supported by a previous study that estimated the rate at 0.5%.

They matched each of these cases to two no-VTE control patients in terms of disease phenotype, age within 10 years, body mass index (BMI), treatment class, smoking history, extent and duration of disease, and Charlson Comorbidity Index.

After matching, the average age of the patients with VTE was 55 years compared with 32 for the control cohort. Average age of diagnosis was 31 in the VTE cohort and 22 in the controls, with an average duration of disease of 4 and 6 years, respectively. Three VTE patients and four control participants had a prior history of surgery. With small numbers of patients, none of these differences reached statistical significance.

The cohorts each comprised 43% patients with ulcerative colitis and 57% with Crohn’s disease.

Just over half the patients in the VTE group got VTE prophylaxis — 43% receiving enoxaparin and 14% receiving heparin, while 43% received none — compared with 29% of control patients receiving enoxaparin and 71% not receiving any prophylaxis.

The researchers identified two risk factors that differentiated risk of VTE between the two groups. Average length of stay was 10 days in the VTE patients, compared with 4 days in the control group (P=0.001). The albumin nadir was 2.7 in the VTE cohort, compared with 3.4 in the cohort of control patients (P=0.04). Previous research has also identified hypoalbuminemia as a potential risk factor for VTE.

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