The limitations of the ATTRACT trial, which was conceived more than 5 years ago, have arisen primarily from advances in the field rather than problems with the design, Dr. Soukas explained. IVUS was not the preferred method for deep vein thrombosis evaluation then as it is now, and there have been several advances in current models of pharmacomechanical devices, which involve catheter-directed delivery of fibrinolytic therapy into the thrombus along with mechanical destruction of the clot.
Although further steps beyond clot lysis, such as stenting, were encouraged in ATTRACT to maintain venous patency, Dr. Soukas questioned whether these were employed sufficiently. For example, the rate of stenting in the experimental arm was 28%, a rate that “is not what we currently do” for patients at high risk of PTS, Dr. Soukas said.
In ATTRACT, major bleeding events were significantly higher in the experimental group (1.7% vs. 0.3%; P = .049). The authors cited this finding when they concluded that the experimental intervention was ineffective. Dr. Soukas acknowledged that bleeding risk is an important factor to consider, but he also emphasized the serious risks for failing to treat patients at high risk for PTS.