Oral (15W133)

Identification of predictive factors for positive capsule endoscopy findings in obscure gastrointestinal bleeding and anaemia

Author(s)

Grainne Holleran, Mary Hussey, Deirdre McNamara

Department(s)/Institutions

Department of Gastroenterology, Tallaght Hospital and Trinity Academic Gastroenterology Group

Introduction

Capsule endoscopy(CE) is the recommended first second-line investigation in obscure gastrointestinal bleeding(OGIB) and iron deficiency anaemia(IDA). Currently, there are no known predictive factors to identify high risk patients or guidelines on prioritising patients.

Aims/Background

To evaluate the diagnostic yield(DY) of CE in IDA and OGIB, and to identify predictive factors which may be useful in prioritising requests for CE.

Method

A retrospective review of the CE database at Tallaght Hospital was performed identifying patients who underwent a CE for IDA or OGIB;either occult or overt. Data was collected by reviewing clinic and referral letters, discharge summaries and laboratory results. Information including:demographics, CE indication, lowest haemoglobin(Hb)level, interval from referral, comorbidities and medication usage, was recorded. Results were compared between groups based on CE positivity and clinical factors using a student’s t test or relative risk(RR) ratio.

Results

From our database of 1379CEs, we identified 455patients whose indication was IDA or OGIB. Of these, 51%(n=232) were female and the mean age was 64years(13-99). Indications were IDA:62%(n=281), occult bleeding:26%(n=117) and overt bleeding:12%(n=57). The overall DY was 57%(n=258), with a significantly lower DY-49%(n=137)(p=0.01) in IDA, compared to occult(63(n=74) and overt(77%(n=44) OGIB. Between the negative and positive CE groups, there was a significant difference in age 61vs67years(p<0.001,95%CI -8.91- -2.93) and lowest Hb10.3g/dL vs9.3g/dL(p<0.003,95%CI 0.33-1.55), but there was no difference in gender. The presence of overt bleeding increased the DY from 53%to77%, with a RR of 1.46(p<0.0001). Clinical data was available in 39%(n=178) of patients, of which 56%(n=99) had positive findings. In the 56(31%) patients who underwent CE within 4days of presentation, the DY was significantly higher than beyond 4days with DYs of 68%vs49%(p=0.02, 95%CI 0.03-0.34) respectively. The use of warfarin and antiplatelet agents had RRs of 1.36(p=0.03) and 1.31(p=0.04) respectively, however no medical conditions or other medications were found to be predictive. When Hb levels were assessed, a cut-off<10g/dL was associated with a positive CE, with a RR of 1.43(p<0.03), and a DY of 61%vs44% with a Hb>10g/dL.

Conclusions

The DY of CE in OGIB is increased in patients with overt bleeding and when performed within 4days of presentation. Older age, Hb<10g/dL, anticoagulation and antiplatelets all increase the risk of positive findings and should be assessed when prioritising patients for CE.