Damian McNamara

May 16, 2016

SAN FRANCISCO — For patients with deep vein thrombosis, mortality rates and the prevalence of hemodynamically unstable pulmonary embolism are significantly higher when the upper extremities are involved than when lower extremities are involved, a large study of hospitalized patients demonstrates.

Mortality and hemodynamic instability are "much more common in upper-extremity DVTs"; however, we don't think of them as significant, said George Williams, DO, from the University of Tennessee Health Science Center in Memphis.

"We focus more on the lower extremities. There are not a whole lot of studies that focus on upper extremity DVT," he said during a poster discussion here at the American Thoracic Society 2016 International Conference.

There are some smaller studies that add up to about 400 or 500 patients total, but "we don't investigate this as much as we should," he told Medscape Medical News.

To evaluate the different conditions, Dr Williams and his colleagues identified more than 15 million unique hospitalizations in 2009 and 2010 from the National Inpatient Sample. They used International Classification of Diseases, Ninth Revision codes to assess risk factors and outcomes in 30,137 patients with upper-extremity deep vein thrombosis and 151,535 patients with lower-extremity deep vein thrombosis.

Table. Risk Factors for Deep Vein Thrombosis and Outcomes by Location

Variable Upper Extremity, % Lower-Extremity, % P Value
Risk Factor      
   Central venous catheterization 30.6 11.0 <.001
   Intracardiac device 6.5 2.9 <.001
   Mechanical ventilation 12.1 4.6 <.001
   History of venous thromboembolism 5.2 9.5 <.001
Outcome      
   Progression to pulmonary embolism 5.4 27.9 <.001
   Hemodynamically unstable pulmonary embolism 5.2 3.6 <.001
   Inpatient mortality 7.6 4.2 <.001

 

Upper-extremity deep vein thrombosis is less prevalent than lower-extremity deep vein thrombosis (0.19 vs 0.96 per 100,000 hospitalizations), but the outcomes are worse, Dr Williams reported.

"It's interesting that people with clots in their upper limb had more mortality," said Benjamin Fox, MD, from the Rabin Medical Center in Petach Tikva, Israel.

"It's a very big study. The researchers screened millions of cases and ended up with hundreds of thousands of patients," he told Medscape Medical News.

He added that it might be that patients with upper-extremity deep vein thrombosis tend to be sicker. In this study, the group primarily included cancer patients with a peripherally inserted central catheter for the administration of chemotherapy, he explained.

Interestingly, the location of the upper-extremity deep vein thrombosis did not affect progression to pulmonary embolism. For example, the risk was not significantly different between patients with radial or ulnar deep vein thrombosis and in those with axillary or brachial deep vein thrombosis (5.9% vs 5.1%; P = .12). It was also no different between axillary or brachial deep vein thrombosis and subclavian deep vein thrombosis (5.1% vs 5.0%; = .97).

Dr Williams and Dr Fox have disclosed no relevant financial relationships.

American Thoracic Society (ATS) 2016 International Conference: Abstract 7768. Presented May 15, 2016.

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