In the first comparative trial of its kind, the Catheter-Directed Venous Thrombolysis (CaVenT) study determined that treating a clot directly with the recombinant, antithrombotic agent alteplase reduced the frequency of postthrombotic syndrome (PTS) and improved long-term outcome in patients with proximal deep-vein thrombosis (DVT) compared with standard anticoagulation methods.
PTS can greatly affect a patient’s quality of life: 1 in 4 patients with DVT will experience PTS, despite having been treated according to current clinical guidelines.
To offset the risk of PTS, alteplase has been used in this setting. “This interventional therapy is expensive,” said CaVenT lead investigator Tone Rønnaug Enden, MD, PhD, of Oslo University Hospital in Norway. “It is also associated with life-threatening bleeding. However, it has become standard care in some centers, despite a complete lack of evidence from randomized, controlled trials.”
This multicenter investigation enrolled 209 adults who had experienced an objectively verified DVT within 21 days of study entry and who met other entry criteria. Patients were randomized to standard treatment (ie, control group) with heparin/warfarin anticoagulation for 6 months, in addition to the use of elastic compression stockings for 24 months, or to standard treatment plus catheter-directed thrombolysis (CDT) with alteplase for up to 96 hours, but not exceeding 20 mg/day.
“This is a minimally invasive percutaneous technique performed with local anesthesia,” said Dr Enden.
End points included measures of outcome for patient-rated criteria of pain, cramps, heaviness, pruritus, and clinician-rated criteria of edema, skin induration, hyperpigmentation, venous ectasia, and ultrasound examination.
At 24-month follow-up, 37 (41.1%) patients in the CDT group had PTS compared with 55 (55.6%) patients in the control group, an absolute risk reduction of 14.4%.
Regarding adverse events, 20 bleeding complications were reported—3 were classified as major and 5 as clinically relevant. The majority of bleeds were related to the puncture site, and no bleeding related to CDT led to a permanently reduced outcome.
Dr Enden concluded that the addition of CDT to standard treatment improved long-term outcomes and should be considered for patients with iliofemoral DVT when there is no contraindicating risk of bleeding. “These results should be taken into account when guidelines are revised.”