Screening for anemia in patients on warfarin facilitates diagnosis of gastrointestinal malignancies and pre-malignant lesions

Role of prescribed medication in the development of iron deficiency anaemia in adults-a case-control study

OBJECTIVE

To estimate the strength of association between exposure to selected classes of prescribed medications and the risk of developing iron deficiency anaemia (IDA), specifically considering oral anticoagulants (OACs), antidepressants, antiplatelet agents, proton pump inhibitors (PPIs) and non-steroidal anti-inflammatories.

DESIGN

A case-control study involving the analysis of community repeat prescriptions among subjects referred with IDA, and unmatched controls referred as gastroenterology fast-tracks for other indications. Multivariable logistic regression modelling was used to calculate ORs for the association between IDA presentation and each medication class, adjusted for age, sex and coprescribing. For those classes showing significance, it was also used to calculate risk differences between those in the IDA group with or without haemorrhagic lesions on investigation.

RESULTS

A total of 1210 cases were analysed-409 in the IDA group, and 801 in the control group. Significant associations were identified between presentation with IDA and long-term exposure to PPIs (OR 3.29, 95% CI: 2.47 to 4.41, p<0.001) and to OACs (OR 2.04, 95% CI: 1.29 to 3.24, p=0.002). IDA was not associated with long-term exposure to any of the other three drug classes. In contrast to the relationship with PPIs, the association with OACs was primarily in the IDA sub-group with haemorrhagic lesions.

CONCLUSION

Long-term exposure to PPIs and OACs are independently associated with the risk of developing IDA. There are grounds for considering that these associations may be causal, though the underlying mechanisms probably differ.

Associations of anaemia with bleeding and thrombotic complications in patients with atrial fibrillation treated with warfarin: a registry-based nested case-control study

OBJECTIVES

We studied association of laboratory testing beyond the international normalised ratio (INR) with bleeding and stroke/transient ischaemic attack (TIA) outcomes in patients with atrial fibrillation treated with warfarin.

DESIGN

This was a retrospective nested case-control study from the Finnish Warfarin in Atrial Fibrillation (FinWAF) registry (n=54 568), reporting the management and outcome in warfarin-anticoagulated patients. Associations of blood count test frequency and results were assessed together with risk of bleeding or stroke/TIA during 5-year follow-up.

SETTING

National FinWAF registry, with data from all six hospital districts. Follow-up period for complications was 1 January 2007-31 December 2011.

PARTICIPANTS

A total of 54 568 warfarin-anticoagulated patients.

RESULTS

The number of patients with bleeding was 4681 (9%) and stroke/TIA episodes, 4692 (9%). In patients with bleeds, lower haemoglobin (within 3 months) preceded the event compared with the controls (median 126 vs 135 g/L; IQR 111-141 g/L vs 123-147 g/L, p<0.001), while patients with stroke/TIA had only modestly lower INR (median 2.2 vs 2.3; 1.8-2.6 vs 2.1-2.7, p<0.001). When the last measured haemoglobin was below the reference value (130 g/L for men, 120 g/L for women), the OR for a bleeding complication was 2.9 and stroke/TIA, 1.5. If the haemoglobin level was below 100 g/L, the complication risk increased further by 10-fold. If haemoglobin values were repeatedly (more than five times) low during the preceding 3 months, future OR was for bleeds 2.3 and for stroke/TIA 2.4.

CONCLUSIONS

The deeper the anaemia, the higher the risk of bleeding and stroke/TIA. However, INR remained mainly at its target and only occasionally deviated, failing to detect the complication risk. Repeated low haemoglobin results, compatible with persistent anaemia, refer to suboptimal management and increased the complication risk in anticoagulated patients.

A new model (Alfalfa-Warfarin-GIB) for predicting the risk of major gastrointestinal bleeding in warfarin patients

BACKGROUND

This study aimed to analyze the factors influencing warfarin-related major gastrointestinal bleeding (GIB) and to develop a score that would provide a reference for assessing the risk of major GIB associated with warfarin treatment.

METHODS

This was a retrospective analysis of clinical and follow-up data from warfarin-treated patients. Scores were analyzed using logistic regression. The area under the subject working characteristic curve (AUC), sensitivity, specificity, and Hosmer-Lemeshow test were used to evaluate the scoring performance.

RESULTS

A total of 1591 patients who met the requirements for warfarin use were included in this study, and 46 developed major GIB. After univariate analysis as well as multivariate logistic regression analysis, nine factors were found to be associated with increased risk of major GIB, namely age ≥ 65 years, history of peptic ulcer, history of major bleeding, abnormal liver function, abnormal renal function, cancer, anemia, labile international normalized ratio, and combination of antiplatelet agents/non-steroidal anti-inflammatory drugs. The Alfalfa-Warfarin-GIB score was constructed using these nine factors. The AUC and Bootstrap method-corrected AUC of the Alfalfa-Warfarin-GIB score were 0.916 (95% CI: 0.862-0.970, P < 0.001) and 0.919 (95% CI: 0.860-0.967, P < 0.001), respectively, which were higher than those of the HAS-BLED score (AUC = 0.868, 95% CI: 0.812-0.924, P < 0.001).

CONCLUSION

Based on nine risk factors, the Alfalfa-Warfarin-GIB score was constructed to predict the risk of warfarin-related major GIB. The newly developed Alfalfa-Warfarin-GIB score has a better predictive value than the HAS-BLED score and may be an effective tool to help reduce the occurrence of major GIB in patients on warfarin.

Gastrointestinal Bleeding on Oral Anticoagulation: What is Currently Known

Gastrointestinal bleeding (GIB) is the most common type of bleeding occurring in patients on oral anticoagulation. A meta-analysis of the landmark randomized controlled trials (RCTs) for patients with atrial fibrillation demonstrated that direct oral anticoagulants (DOACs) were associated with higher GIB rates compared to warfarin. However, significant heterogeneity existed between studies. While rivaroxaban, high-dose dabigatran, and high-dose edoxaban were associated with higher GIB rates than warfarin, GIB rates were similar between warfarin users and both apixaban and low-dose dabigatran users. Additionally, previous observational studies have yielded conflicting reports on whether GIB rates differ between warfarin and DOACs. Meta-analyses of observational studies demonstrated that warfarin is associated with lower rates of GIB compared to rivaroxaban, similar or lower rates compared to dabigatran, and higher rates compared to apixaban. Importantly, no RCT has compared individual DOACs directly and due to the different selection criteria of the initial RCTs, indirect comparisons between DOACs using these studies are unreliable. The best available information of comparisons between individual DOACs is therefore limited to observational studies. There is mounting evidence that suggests that rivaroxaban is associated with a higher risk of GIB compared to other DOACs. Finally, GIB induced by oral anticoagulation may have some positive aspects. Interestingly, there are studies that indicate oral anticoagulation facilitates colorectal cancer detection. Furthermore, results from RCTs and observational studies suggest that warfarin may even decrease the incidence of cancer.

Gastrointestinal bleeding and the risk of colorectal cancer in anticoagulated patients with atrial fibrillation

AIMS

Gastrointestinal bleeding (GI-bleeding) is frequent in patients with atrial fibrillation (AF) treated with oral anticoagulation (OAC) therapy. We sought to investigate to what extent lower GI-bleeding represents the unmasking of an occult colorectal cancer.

METHODS AND RESULTS

A total of 125 418 Danish AF patients initiating OAC therapy were identified using Danish administrative registers. Non-parametric estimation and semi-parametric absolute risk regression were used to estimate the absolute risks of colorectal cancer in patients with and without lower GI-bleeding. During a maximum of 3 years of follow-up, we identified 2576 patients with lower GI-bleeding of whom 140 patients were subsequently diagnosed with colorectal cancer within the first year of lower GI-bleeding. In all age groups, we observed high risks of colorectal cancer after lower GI-bleeding. The absolute 1-year risk ranged from 3.7% [95% confidence interval (CI) 2.2-6.2] to 8.1% (95% CI 6.1-10.6) in the age groups ≤65 and 76-80 years of age, respectively. When comparing patients with and without lower GI-bleeding, we found increased risk ratios of colorectal cancer across all age groups with a risk ratio of 24.2 (95% CI 14.5-40.4) and 12.3 (95% CI 7.9-19.0) for the youngest and oldest age group of ≤65 and >85 years, respectively.

CONCLUSION

In anticoagulated AF patients, lower GI-bleeding conferred high absolute risks of incident colorectal cancer. Lower GI-bleeding should not be dismissed as a benign consequence of OAC therapy but always examined for a potential underlying malignant cause.

New horizons in iron deficiency anaemia in older adults

Iron deficiency anaemia (IDA) is common in older adults and associated with a range of adverse outcomes. Differentiating iron deficiency from other causes of anaemia is important to ensure appropriate investigations and treatment. It is possible to make the diagnosis reliably using simple blood tests. Clinical evaluation and assessment are required to help determine the underlying cause and to initiate appropriate investigations. IDA in men and post-menopausal females is most commonly due to occult gastrointestinal blood loss until proven otherwise, although there is a spectrum of underlying causative pathologies. Investigation decisions should take account of the wishes of the patient and their competing comorbidities, individualising the approach. Management involves supplementation using oral or intravenous (IV) iron then consideration of treatment of the underlying cause of deficiency. Future research areas are outlined including the role of Hepcidin and serum soluble transferrin receptor measurement, quantitative faecal immunochemical testing, alternative dosing regimens and the potential role of IV iron preparations.

Practical gastrointestinal investigation of iron deficiency anaemia

About 10% of oesophagogastroduodenoscopies (OGDs) and colonoscopies are done for investigation of iron deficiency anemia (IDA) . Much of the existing guidance on investigation of IDA predates CRC screening, which has driven significant improvements in colonoscopy quality and completion rates, as well as a reduction in Helicobacter pylori prevalence and increase in PPI usage, and therefore probably needs re-consideration. New investigations, e.g. CT colonography, enteroscopy and capsule endoscopy have also been introduced. Areas covered: This review updates the approach to practical investigation of IDA. Medline was searched using the terms iron deficiency AND anemia AND/OR gastroscopy, colonoscopy, capsule and enteroscopy, together with review of recent relevant published abstracts on the topic. Expert commentary: Gastrointestinal pathology is now a more common cause of IDA than upper GI causes, reflecting better colonoscopy accuracy and completion rates as well as changing disease patterns, and carcinomas are more likely cause IDA than benign adenomas. Increasing use of antiplatelet and anticoagulants is driving greater presentation of IDA. Capsule endoscopy, enteroscopy and CT colonography are increasingly used. Fecal occult blood testing may be a useful simple screening method in the frail, as a negative test can avoid the need for invasive tests.

Does antiaggregant administration lead to early diagnosis in proximal colon cancer?

OBJECTIVE:

Cancers of the proximal colon are often diagnosed in advanced stages with iron deficiency anemia and nonspecific symptoms. Aspirin and clopidogrel are commonly used antiaggregant agents for various clinical conditions. The aim of this study was to investigate the effects of antiaggregant medication on the early diagnosis of proximal colon cancer.

METHODS:

Cases of colon cancer patients who had received curative surgical procedures between January 1, 2013 and July 31, 2016 were retrospectively reviewed. The clinical and pathological results of patients who had used antiaggregant drugs were compared to those who had not.

RESULTS:

During the studied period, 246 colorectal cancer patients underwent curative surgical procedures. Of the 67 patients with proximal colon cancer who were included in the study, 27 (40.3%) had taken antiaggregant medication. The mean age of the antiaggregant group was 67.1 years (range: 34–88 years), while it was 58.3 years (range: 34–83 years) for the non-antiaggregant group; the difference between the 2 groups was statistically significant (p=0.03). A pathological evaluation revealed that 74.1% of the antiaggregant group was in the early stages (Stage I/II: 7/13), while 42.5% of the non-antiaggregant group was in the early stages (Stage I/II: 2/15); the difference was statistically significant (p=0.011).

CONCLUSION:

Antiaggregant medication has a positive effect on diagnosing proximal colon cancer at early stages. Patients using aspirin or clopidogrel should undergo a complete colonoscopic evaluation in the presence of gastrointestinal tract bleeding or newly developed anemia.

Risk of gastrointestinal bleeding during anticoagulant treatment

INTRODUCTION

Gastrointestinal bleeding (GIB) is a major problem in patients on oral anticoagulation therapy. This issue has become even more pressing since the introduction of direct oral anticoagulants (DOACs) in 2009. Areas covered: Here we review current evidence related to GIB associated with oral anticoagulants, focusing on randomized controlled trials, meta-analyses, and post-marketing observational studies. Dabigatran 150 mg twice daily and rivaroxaban 20 mg once daily increase the risk of GIB compared to warfarin. The risk increase with edoxaban is dose-dependent, while apixaban shows apparently, no increased risk. We summarize what is known about GIB risk factors for individual anticoagulants, the location of GIB in patients taking these compounds, and prevention strategies that lower the risk of GIB. Expert opinion: Recently there has been an important shift in the clinical presentation of GIB. Specifically, upper GIB has decreased with the decreased incidence of peptic ulcers due to the broad use of proton pump inhibitors and the decreased prevalence of H. pylori infections. In contrast, the incidence of lower GIB has increased, due in part to colonic diverticular bleeding and angiodysplasia in the elderly. In this population, the addition of oral anticoagulation therapy, especially DOACs, seems to increase the risk of lower GIB.

Major Gastrointestinal Bleeding Often Is Caused by Occult Malignancy in Patients Receiving Warfarin or Dabigatran to Prevent Stroke and Systemic Embolism From Atrial Fibrillation

BACKGROUND & AIMS

Gastrointestinal (GI) bleeding in patients receiving anticoagulation agents can be caused by occult malignancies. We investigated the proportions and features of major GI bleeding (MGIB) events related to occult GI cancers in patients receiving anticoagulation therapy.

METHODS

We analyzed data from the Randomized Evaluation of Long Term Anticoagulant Therapy study (conducted between December 2005 and March 2009 in 951 clinical centers in 44 countries worldwide), which compared the abilities of dabigatran vs warfarin to prevent stroke and systemic embolism in 18,113 patients with atrial fibrillation. Two blinded gastroenterologists independently reviewed source documents of MGIB events (n = 595) that occurred during the study period. We collected data on MGIB events caused by previously unidentified GI malignancies, and compared characteristics of MGIB events in patients who received dabigatran vs warfarin (primary end point), and in patients with bleeding from cancer, vs patients bleeding from a nonmalignant or unidentified source.

RESULTS

Of 546 unique MGIB events, 44 (8.1%) were found to be from GI cancers (34 of 398 MGIB events in dabigatran users and 10 of 148 MGIB events in warfarin users; P = .60). Colorectal cancer accounted for 35 of 44 of all cancers identified. There were more colorectal cancer-associated MGIB events in the dabigatran group (30 of 34) than in the warfarin group (5 of 10) (P = .02), but more gastric cancer-associated MGIB events in the warfarin group (5 of 10) than in the dabigatran group (1 of 34) (P = .001). There were no differences in the short-term outcomes of cancer-related MGIB events in the dabigatran vs the warfarin group, but 75% of all cancer-related MGIB events required at least 1 blood transfusion and the mean hospital stay was 10.1 days. Compared with MGIB events from a nonmalignant or unidentified source, MGIB from cancer occurred sooner (343.0 vs 223.1 d; P = .003), but the bleeding was more likely to be chronic (for >7 d) (27.3% vs 63.6%; P < .001).

CONCLUSIONS

In evaluating data from a study of the effects of anticoagulation therapy, we found approximately 1 of every 12 MGIB events to be related to an occult cancer. Approximately two thirds of cancer-related MGIB presents with chronic bleeding, and morbidity, and resource utilization is high.

The Association of Drugs With Severity and Specific Causes of Acute Lower Gastrointestinal Bleeding: A Prospective Study

OBJECTIVES

Studies on the association of acute lower gastrointestinal bleeding (ALGIB) and drugs are scarce. We aimed to investigate the association of drugs and ALGIB, especially regarding specific causes of ALGIB, and their role in the severity of ALGIB.

MATERIALS AND METHODS

The study was prospective and included all patients undergoing colonoscopy in 2010 and 2013 at the National University Hospital of Iceland. Use of nonsteroidal anti-inflammatory drugs (NSAIDs), low-dose aspirin (LDA), and warfarin before ALGIB was registered. Clinically significant bleeding was defined as: hemoglobin <100 g/L, hemodynamic instability, blood transfusion, surgery, or death.

RESULTS

Overall, 2392 patients underwent 2751 colonoscopies, of those, 325 (14%) had ALGIB, mean age 64 years (±20). The commonest diagnoses were diverticulosis (22%) and ischemic colitis (14%). In multivariate analysis, NSAIDs, LDA, and warfarin use was associated with ALGIB, odds ratio (OR) 3.3 [95% confidence interval (95% CI), 1.99-5.82], OR 1.5 (95% CI, 1.01-2.13), and OR 2.7 (95% CI, 1.61-4.57), respectively. Clinically significant bleeders were more likely than nonclinically significant bleeders to use NSAIDs or LDA+warfarin, OR 2.3 (95% CI, 1.26-3.76) and OR 33.0 (95% CI, 6.74-595), respectively. Patients with diverticular bleeding had greater odds than controls of NSAID, LDA, and warfarin use, OR 8.3 (95% CI, 3.8-18.3), OR 2.1 (95% CI, 1.15-3.67), and OR 2.6 (95% CI, 1.24-5.56), respectively. Patients with ischemic colitis were more likely than controls to use LDA, OR 2.3 (95% CI, 1.14-4.45).

CONCLUSIONS

NSAIDs, LDA, and warfarin were associated with ALGIB and diverticular bleeding. These drugs may have a role in other etiologies of ALGIB and seem to increase the risk of clinically significant bleeding.

Anticoagulant-related gastrointestinal bleeding--could this facilitate early detection of benign or malignant gastrointestinal lesions?

INTRODUCTION

The higher incidence of gastrointestinal (GI) bleeding with the non-vitamin K oral anticoagulants (NOACs) may be related to pre-existing malignancies; diagnostic measures triggered by these bleedings could lead to early detection of these malignancies.

METHODS

We retrieved the preferred terms on GI bleeding and GI cancer reported as adverse events (AEs) from phase III studies in patients with atrial fibrillation for each NOAC on ClinicalTrials.gov . We also analyzed the RE-LY trial database.

RESULTS

From ClinicalTrials.gov , AE-GI bleeding incidence was: dabigatran 110 mg b.i.d. (D110: 1.42% versus 1.37%), dabigatran 150 mg b.i.d. (D150: 1.93% versus 1.37%), rivaroxaban (3.52% versus 2.68%), and apixaban (1.93% versus 1.59%), compared with warfarin, respectively. The incidence of AE-GI cancer was similar between the NOACs (D110 [0.79%], D150 [0.61%], rivaroxaban [0.83%], and apixaban [0.69%]), but numerically higher compared with warfarin (0.37%; 0.73%; 0.57%, respectively). In the RE-LY database, the same pattern was seen for dabigatran, with an association between GI bleeding and GI cancer diagnosis.

CONCLUSION

Anticoagulant-related GI bleeding may represent the unmasking of pre-existing malignancies leading to increased detection of GI cancer. This may be especially in the first month of treatment and could explain the numerically higher numbers of GI malignancies observed with NOACs.

Bleeding-related symptoms in colorectal cancer: a 4-year nationwide population-based study

BACKGROUND

Little is known about the major presenting features of patients with colorectal cancer (CRC) in a population-based setting, especially regarding bleeding-related symptoms.

AIM

To determine the proportion of CRC patients presenting with bleeding-related symptoms, to compare bleeders and nonbleeders and to explore the role of anticoagulants in bleeders.

METHODS

This was a nationwide, population-based, retrospective study, investigating all patients diagnosed with CRC in Iceland from 2008 to 2011. Bleeding-related symptoms were defined as overt bleeding, iron deficiency anaemia or a positive faecal occult blood test. Obstructive symptoms were defined as a confirmed diagnosis of ileus or dilated intestines on imaging.

RESULTS

Data were available for 472/496 (95%) patients, males 51%, mean age 69 (±13) years. In all, 348 (74%) patients had bleeding-related symptoms; of these 348 patients, 61% had overt bleeding. Bleeders were less likely than nonbleeders to have metastases at diagnosis, 19% vs. 34% (P < 0.001). Overt bleeders were less likely than nonbleeders to have obstructive symptoms, 2% vs. 16% respectively (P < 0.0001). Occult bleeders were more likely to have proximal cancer (69%) than both overt (17%) and nonbleeders (44%) (P < 0.0001); however, they were less likely than nonbleeders to have metastases (22% vs. 35%, P < 0.05). Bleeders were more likely to use warfarin than nonbleeders (9% vs. 3%, P < 0.05); the use of low-dose aspirin was the same (24%).

CONCLUSIONS

The majority of patients with CRC present with bleeding-related symptoms. Bleeders with CRC present earlier than nonbleeders. Warfarin use may induce bleeding in some patients, resulting in an earlier diagnosis.