Hold Blood Thinners During Thyroid Nodule Biopsy?

The routine practice of holding use of blood-thinning medications at the time of an ultrasound‐guided thyroid nodule fine needle aspiration (FNA) biopsy shows no significant safety benefit in preventing the risk of complications such as hematomas or nondiagnostic results; however, experts suggest using individualized decision-making with the practice.

"Our data indicates that there is no need to routinely hold anticoagulation or antiplatelet therapy prior to thyroid nodule FNA biopsy," first author Michelle Lundholm, MD, of the Cleveland Clinic, in Cleveland, Ohio, told Medscape Medical News.

"[The practice] impacts neither the safety of the FNA procedure nor the adequacy of the sample," she said.

The late-breaking research was presented at the American Thyroid Association (ATA) Annual Meeting and Centennial Celebration.

Key concerns in the use of anticoagulants and/or antiplatelet medications during thyroid nodule FNA biopsy include the increased risk of postprocedural hematoma or nondiagnostic results, with, for instance, one study showing higher rates of nondiagnostic results among patients remaining on aspirin therapy during the FNA biopsy.

However, holding the medically indicated therapies can have risks of its own, including concerns of thrombotic events such as deep vein thrombosis or stroke. However, evidence comparing the risks with each strategy in thyroid nodule FNA is lacking.

To investigate, Lundholm, her co-author Pratibha Roa, MD, and colleagues conducted a retrospective review of data on 2945 patients who had undergone a total of 4741 thyroid nodule FNAs in the Cleveland Clinic’s diverse network of centers between 2010 and 2023. The patients had a mean age of 66.2; 69.6% were female and 75.7% were White.

All patients had an active prescription for an anticoagulant or antiplatelet medication up to 10 days prior to their thyroid nodule FNA biopsy. Specifically, 73.7% were on 81 mg aspirin, 8.5% were on 325 mg aspirin, 7.4% were taking other antiplatelet medication such as clopidogrel or ticagrelor; 7.0% were on warfarin, 8.2% were on a direct oral anticoagulant (DOAC); 6.3% were on heparin products; and 10.3% of patients were on two or more blood-thinning medications.

The results show that overall, 13.0% (n = 614) of the thyroid nodule FNA biopsies had nondiagnostic results, which is within the average rates in the literature ranging from 6% to 36%, Lundholm noted.

Blood-thinning medications were held in 20.8% of the FNA biopsies, however, there were no differences in nondiagnostic results between those who had drugs held (12.2%) or who continued on the medications (13.2%; P = .41).

After multivariate adjustment for age and sex, the lack of significant differences in receiving nondiagnostic results among those who did or did not continue blood thinners was consistent overall (odds ratio [OR] 1.10; P = .38), and in the specific groups of 81 mg aspirin (OR 1.00; P = .99); 325 mg aspirin or clopidogrel/ticagrelor (OR 1.50; P = .15); or warfarin, DOAC, or heparin/enoxaparin (OR 1.27; P = .27).

In terms of hematoma risk, emergency department records within 48 hours of the FNA showed that such events were rare, with only one hematoma occurring overall, involving a patient who was on 81 mg of aspirin for secondary stroke prevention that was not interrupted for FNA biopsy. The patient was discharged and did not require medical intervention.

Four other hematomas occurred among patients who were not being treated with blood thinners, with none requiring intervention.

The findings indicate that "hematoma can happen in any patient, but rarely requires intervention," Lundholm said.

However, while thrombotic events were also rare, serious events occurred in three patients within 48 hours of the thyroid nodule FNA biopsy when a blood thinner was withheld, including ischemic strokes among two patients who were on a DOAC and 81 mg of aspirin that were withheld, and one myocardial infarction occurring in a patient on a DOAC that was held for the FNA.

Unlike hematomas, the thrombotic events each had significant long‐term sequelae, Lundholm noted.

"Having these ischemic strokes and heart attack really led to a change in these patients’ lives," she said. "While we can never assume that [the events occurred] because the blood-thinner therapy was held, the timing within 48 hours is certainly very suspicious."

There were no deep vein thrombosis or pulmonary embolism events.

Withholding Practices Vary

In a previous survey of 60 clinicians conducted by Lundholm and her colleagues, wide variation was reported in the rates of withholding antiplatelet or anticoagulant medications prior to thyroid nodule FNA biopsy.

The survey of endocrinologists, interventional radiologists, and ear, nose, and throat providers showed rates of withholding 81 mg of aspirin prior to FNA biopsy of just 13.3%, withholding 325 mg of aspirin, 15%, other antiplatelets, 41.7%, warfarin, 73.3%, DOACs, 43.3%, and heparin, 43.3%.

"We found heterogeneity in withholding patterns even within the same department," she said. "This is reflective of the fact that evidence is mixed."

Guidelines on the issue from the Society of Interventional Radiology and the International Society on Thrombosis and Hemostasis recommend that providers consider the balance of the procedure and patient bleeding risk vs the clotting risk, Lundholm noted.

However, a caveat is that those recommendations are based on pooled data from similar minimal risk procedures, she explained.

"There is a lack of data on bleeding risks for individual interventions like thyroid biopsy, and, as such, there is no specific procedure-related risk determination."

Meanwhile, Lundholm said that notable limitations regarding the current research include that the study may not have caught all patient cases that presented with complications to an outside emergency department.

Furthermore, the study results pertain to the safety of blood thinners in routine use, with key aspects that can influence complication rates, such as provider experience, needle size, and nodule features unavailable for analysis.

At MD Anderson, Case-by-Case

Commenting on the research, Anastasios Maniakas, MD, PhD, of the Department of Head and Neck Surgery, Division of Surgery, University of Texas MD Anderson Cancer Center, Houston, said the study is important, noting that, at his institution, the approach regarding holding blood-thinning medications is generally determined on an individual basis.

"I think this was a good retrospective study, but I don’t think it can be generalized to all patients. These decisions must be made on a case-by-case basis," Maniakas, who co-moderated the session, told Medscape Medical News.

"At MD Anderson, we probably have one of the highest volumes in the country for thyroid nodule FNAs, and we almost always do hold blood thinners,” he said.

“Our patients often have to undergo multiple passages to create cell blocks, and/or we may have to use large bore needles if we have to biopsy suspicious thyroid nodules that require molecular testing, increasing the risk of hematomas,” Maniakas said.

"If you’re going to use perhaps the smallest possible gauge needle, then I think it is reasonable to not hold blood thinners, but if you’re going to be doing multiple passages and you need to do a core biopsy and use a large needle, then it is wiser to try to hold the medications for a day or 2, if the patient’s medical history permits it.

"We haven't had any complications from holding anticoagulation, but I think there's still a lot of apprehension within our team to not hold blood thinners," Maniakas said. "So, overall, I think the message is that it has to be on a case-by-case basis."

Lundholm and Maniakas report no relevant financial relationships.

American Thyroid Association (ATA) Annual Meeting and Centennial Celebration. Late Breaking Abstract #40. Presented September 29, 2023.

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