Researchers are asking if physicians still are on a learning curve when it comes to catheter-directed thrombolysis (CDT) for proximal deep vein thrombosis (DVT) patients after noting no improvements over anticoagulant therapy in a study published July 21 in JAMA: Internal Medicine.

Despite increased use of CDT since 2006, the research team led by Riyaz Bashir, MD, of Temple University School of Medicine in Philadelphia, found that outcomes have not improved. Utilizing a cohort of 90,618 patients culled from 2005 to 2010 data in the Nationwide Inpatient Sample of the Agency for Healthcare Research and Quality Health Care Cost and Utilization Project, Bashir and colleagues attempted to compare outcomes and trends in use of anticoagulants vs. CDT in proximal DVT patients.

Treatment through CDT occurred in 4.1 percent of patients. Bashir et al found that usage of the CDT technique increased from 2.3 percent in 2005 to 5.9 percent in 2010.

Mortality rates between the two procedures were similar. Anticoagulant therapy had a slightly lower mortality rate at 0.9 percent, while CDT had 1.2 percent mortality rate. CDT, however proved to have higher rates of other adverse events as compared to anticoagulant therapy. The research team reported rates of pulmonary embolism, intracranial hemorrhage and blood transfusions in the CDT group to be 17.6 percent, 0.9 percent and 11.1 percent. For anticoagulant therapy patients these adverse events were seen 11.4 percent, 0.3 percent and 6.5 percent, respectively.

Hospital stays were longer in the CDT group. CDT patients had a mean stay of 7.2 days as opposed to 5.8 days for anticoagulant therapy patients. CDT patients were also charged almost four times as much as those on anticoagulation ($85,094 vs. $28,164).

Inferior vena cava filter placement occurred in 34.8 percent of CDT patients, as opposed to 15.6 percent of anticoagulant patients. While in and of itself, these high rates are notable, Bashir et al noted concern about vena cava filters due to lack of evidence benefit for patients.

This study was largely comparable to previous studies on CDT, which explored survivability and rates of post-thrombolysis syndrome: improvements were seen but safety remained a concern. Bashir et al noted improved post-thrombolysis outcomes and improving complication rates over time for CDT patients, but could not speak to how well these patients did in longer term outcomes due to the nature of the available data.

Bashir et al recommended restricting CDT use to patients with high risk for post-thrombolysis syndrome and low bleeding risks.