Deep vein thrombosis (DVT) occurs when a blood clot forms in a large (deep) vein. Proximal DVTs occur in deep veins above the knee and isolated, distal DVTs can occur when smaller blood clots form in the veins below the knee. But the differences between the clinical presentation, short-term and long-term outcomes for patients with isolated distal DVT (smaller thrombi in veins below the knee) versus proximal DVT have been unclear. A new study led by investigators from Brigham and Women’s Hospital highlights key differences in clinical features and co-morbidities, as well as short-term and also long-term outcomes for patients with distal DVT versus proximal DVT. The team found that patients with isolated distal DVT had lower co-morbidity burden and a lower risk of 90-day mortality. They were also at lower risk of developing a pulmonary embolism or a new venous thromboembolism in one year. The authors note that some of the differences in the outcomes are attributable to the risk profile of these patients. Patients with distal DVT were younger, more likely to have had DVT in the setting of transient provoking factors such as surgery or hormonal use but less likely to have serious co-morbidities such as cancer or anemia.
“Our findings may have implications for risk stratification and for practice,” said corresponding author Behnood Bikdeli, MD, MS, of the Brigham’s Division of Cardiovascular Medicine. “While we find less ominous outcomes for isolated, distal DVTs, they are not entirely benign. Even among patients who received initial anti-coagulation treatment, almost half had signs or symptoms of post thrombotic syndrome, a chronic manifestation of these clots. Randomized clinical trials are needed to assess the best long-term management for patients who have had isolated, distal DVT.”
Read more in JAMA Cardiology.
Method of Research
Subject of Research
Clinical Presentation and Short- and Long-term Outcomes in Patients With Isolated Distal Deep Vein Thrombosis vs Proximal Deep Vein Thrombosis in the RIETE Registry
Article Publication Date
The RIETE registry has been supported by Sanofi Spain, Leo Pharma, and Rovi with an unrestricted educational grant. Dr Bikdeli reported receiving consulting fees serving as an expert on behalf of the plaintiff for litigation related to 2 specific brand models of inferior vena cava filters. Dr Krumholz reported receiving personal fees from UnitedHealth, Element Science, Aetna, Reality Labs, F-Prime, Tesseract/4Catalyst, Martin/Baughman Law Firm, Arnold and Porter Law Firm, and Siegfried and Jensen Law Firm; being a cofounder of HugoHealth, a personal health information platform; being a cofounder of Refactor Health, an Enterprise Health Care artificial intelligence–augmented data management company; having contracts with the Centers for Medicare & Medicaid Services Association through Yale New Haven Hospital, to develop and maintain performance measures that are publicly reported; and receiving grants from Johnson & Johnson outside the submitted work. Dr Monreal reported receiving grants from Sanofi and Rovi sponsorship of the RIETE registry outside the submitted work. No other disclosures were reported.