Is obesity a contraindication for the use of low molecular weight Heparin (LMWH) or thrombolytic agents, such as tissue plasminogen activator (tPA) (t-PA), in patients with thrombotic conditions?

From the Guidelines

Obesity is not a contraindication for tranexamic acid (TXA) use, and TXA can be safely administered to obese patients at standard dosing without specific dose adjustments based on weight alone. The typical dosing for TXA is 1 gram intravenously over 10 minutes, followed by 1 gram over 8 hours for trauma or surgical bleeding, or 10-25 mg/kg for other indications 1. When administering TXA to obese patients, healthcare providers should monitor for the same potential side effects as in non-obese patients, including nausea, vomiting, hypotension, and the risk of thrombotic events. While obesity itself is associated with a pro-thrombotic state, this does not preclude TXA use, though clinicians should consider the overall thrombotic risk profile of the patient 1.

Some key points to consider when using TXA in obese patients include:

• The risk of thrombosis and bleeding in obese patients, which may be influenced by the patient's body mass index (BMI) and other factors 1
• The potential for altered drug pharmacokinetics (PK) in obese patients, which may affect the efficacy and safety of TXA 1
• The importance of monitoring for potential side effects and adjusting the dose as needed to minimize the risk of adverse events 1

It is also important to note that the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy and the European Society of Cardiology Working Group on Thrombosis have published a clinical consensus statement on antithrombotic therapy and body mass, which provides guidance on the use of antithrombotic drugs, including TXA, in patients with obesity 1. Additionally, other studies have investigated the use of TXA in obese patients, including a study published in the European Heart Journal, which found that TXA can be safely used in obese patients without significant increases in the risk of thrombotic events 1.

In terms of specific dosing recommendations, the typical dosing for TXA is 1 gram intravenously over 10 minutes, followed by 1 gram over 8 hours for trauma or surgical bleeding, or 10-25 mg/kg for other indications 1. However, the dose may need to be adjusted in patients with renal impairment, as TXA is primarily eliminated through the kidneys 1.

Overall, the use of TXA in obese patients should be guided by the patient's individual risk factors and medical history, and healthcare providers should carefully monitor for potential side effects and adjust the dose as needed.

From the Research

Obesity and tPA Use

• Obesity has been shown to have a complex relationship with tPA use, with some studies suggesting that obese patients may have decreased mortality rates compared to non-obese patients after mechanical thrombectomy 2.
• However, other studies have found that obesity is associated with impaired endothelial t-PA release, which can be improved with regular aerobic exercise 3.
• The relationship between obesity and tPA use is further complicated by the role of plasminogen activator inhibitor-1 (PAI-1), which is involved in the physiopathologic mechanisms of many diseases and metabolic disorders, including obesity and thrombotic cerebrovascular diseases 4.

Contraindications for tPA Use

• There is no clear evidence to suggest that obesity is a contraindication for tPA use, although obese patients may be at higher risk for certain complications, such as hemorrhage 5, 6.
• The decision to use tPA in obese patients should be made on a case-by-case basis, taking into account the individual patient's risk factors and medical history.
• Further research is needed to fully understand the relationship between obesity and tPA use, and to determine the best course of treatment for obese patients with acute ischemic stroke.

Key Findings

• Obese patients who undergo mechanical thrombectomy may have decreased mortality rates compared to non-obese patients 2.
• Regular aerobic exercise can improve endothelial t-PA release in overweight and obese adults 3.
• PAI-1 plays a complex role in the relationship between obesity and thrombotic cerebrovascular diseases 4.
• tPA use is not associated with favorable recanalization or functional outcomes in mechanical thrombectomy for acute ischemic stroke, although it may be associated with decreased rates of periprocedural hemorrhage 6.