P1529 - Clinical Predictors of a Positive CT Angiogram Study Used for the Evaluation of Acute Gastrointestinal Hemorrhage

Monday, October 25, 2021

10:30 AM – 4:15 PM PT

Location: Shoreline Exhibit Hall

Has Audio

Presenting Author(s)

Anthony J. Horton, MD

Duke University Medical Center
DURHAM, NC, United States

Anthony J. Horton, MD¹, Daniel Wild, MD¹, Zachary Spiritos, MD, MDH², Donna Niedzwiecki, PhD³, Alice Parish, MSPH⁴, Geargin Wilson, MD¹
¹Duke University Medical Center, Durham, NC; ²Duke Unversity Hospital, Apex, NC; ³Duke University School of Medicine, Durham, NC; ⁴Duke University, Durham, NC

Introduction: Acute gastrointestinal (GI) bleeding is one of the leading causes of emergency department visits and hospital admissions. CT angiography (CTA) has had an expanding role in the evaluation of acute GI bleeding because it is rapidly performed, widely available, reasonably sensitive and provides precise localization when positive. We attempted to identify patient and clinical characteristics that predict CTA results in order to help guide the utilization of this modality in patients with acute GI bleeding.

Methods: In this retrospective study, we analyzed all CTAs performed for the evaluation of GI bleeding in the Duke University healthcare system between October 2019 and March 2020. We captured patient characteristics including age, sex, vital signs, hemoglobin, platelets, PT/INR and anticoagulation status. We grouped study indication into three categories: upper GI bleeding (hematemesis or coffee ground emesis); small bowel bleeding (melena or dark stool); and lower GI bleeding (hematochezia or bright red blood per rectum) as indicated by the ordering provider. Chi-square, Wilcoxon, t-test, and multivariate logistic regression were used to describe and assess the relationship between patient characteristics and study outcomes (Table 1).

Results: A total of 317 studies were performed between October 2019 and March 2020. Forty-three patients (13.6%) had a CTA positive for active bleeding. Multivariable logistic regression showed that after controlling for age, MAP and indication, only a hemoglobin drop from baseline was significantly associated with a positive CTA. For each 1 unit increase in hemoglobin drop, the odds of a positive CT increased by 1.17 (OR 1.17 95% CI 1.00 – 1.36, p = 0.04). Age (OR 1.02 95% CI 0.99 – 1.04, p = 0.06) and lower GI bleeding (OR 2.09 95% CI 0.94 - 4.64, p = 0.07) approached statistical significance.

Discussion: In patients who present to the hospital with GI bleeding, those with a drop in hemoglobin from baseline are most likely to have active bleeding found on CTA. Older age and suspected lower GI bleeding are also likely to be valuable predictors of a positive CTA. In the absence of these factors, CTA is less likely to be clinically useful.

Patient Characteristics by Positive CT for GI Bleed
	No (N=274)	Yes (N=43)	Total (N=317)	p value
Gender				0.451¹
Female	138 (50.4%)	19 (44.2%)	157 (49.5%)
Male	136 (49.6%)	24 (55.8%)	160 (50.5%)

Age, median (Q1, Q3)	65 (51, 75)	70 (62, 80)	66 (52, 76)	0.009²

Heart rate, median (Q1, Q3)	86 (74, 100)	89 (72, 98)	86 (74, 99)	0.783²

MAP, mean (SD)	87.32 (15.52)	81.72 (16.53)	86.56 (15.75)	0.030³

Shock index, median (Q1, Q3)	0.70 (0.58, 0.85)	0.78 (0.55, 1.00)	0.71 (0.58, 0.85)	0.348²

Hemoglobin				0.331²
N	273	43	316
Median (Q1, Q3)	8.50 (6.90, 11.00)	7.70 (6.50, 11.30)	8.45 (6.90, 11.00)

Baseline hemoglobin				0.196²
N	258	39	297
Median (Q1, Q3)	11.20 (9.40, 13.00)	12.00 (9.40, 14.00)	11.20 (9.40, 13.00)

Hemoglobin drop from baseline				0.065²
N	258	39	297
Median (Q1, Q3)	2.10 (0.60, 3.70)	2.70 (1.20, 4.80)	2.20 (0.70, 3.80)

Platelets, median (Q1, Q3)	219.5 (141, 301)	183 (139, 246)	217 (139, 282)	0.105²

INR				0.265²
N	263	42	305
Median (Q1, Q3)	1.10 (1.00, 1.30)	1.20 (1.00, 1.30)	1.10 (1.00, 1.30)

Anticoagulation				0.129¹
No	155 (56.6%)	19 (44.2%)	174 (54.9%)
Yes	119 (43.4%)	24 (55.8%)	143 (45.1%)

Upper GI bleeding				0.397¹
No	251 (91.6%)	41 (95.3%)	292 (92.1%)
Yes	23 (8.4%)	2 (4.7%)	25 (7.9%)

Small Bowel bleeding				0.757¹
No	216 (78.8%)	33 (76.7%)	249 (78.5%)
Yes	58 (21.2%)	10 (23.3%)	68 (21.5%)

Lower GI bleeding				0.087¹
No	134 (48.9%)	15 (34.9%)	149 (47.0%)
Yes	140 (51.1%)	28 (65.1%)	168 (53.0%)

¹Chi-Square ²Wilcoxon ³Equal Variance T-Test

Table: Clinical predictors of a positive CT angiogram study used for the evaluation of acute gastrointestinal hemorrhage

Disclosures:
Anthony Horton indicated no relevant financial relationships.
Daniel Wild indicated no relevant financial relationships.
Zachary Spiritos indicated no relevant financial relationships.
Donna Niedzwiecki indicated no relevant financial relationships.
Alice Parish indicated no relevant financial relationships.
Geargin Wilson indicated no relevant financial relationships.

Anthony J. Horton, MD¹, Daniel Wild, MD¹, Zachary Spiritos, MD, MDH², Donna Niedzwiecki, PhD³, Alice Parish, MSPH⁴, Geargin Wilson, MD¹. P1529 - Clinical Predictors of a Positive CT Angiogram Study Used for the Evaluation of Acute Gastrointestinal Hemorrhage, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.