Tod Engelhardt, MD, Discusses Data on Ultrasound-Accelerated Thrombolysis for Pulmonary Embolism

Dr. Engelhardt: When the right heart’s larger than the left side, it’s a harbinger of bad things to come. So we need to, as physicians, realize that the more quickly we reverse that ratio and get the right heart to normal size, the better off the patient’s going to be in the short term, to save the life of a patient and then in the long-term as well to prevent pulmonary hypertension.

I hate to say, but right now the standard of care is to treat all three of these categories the same way and all three of these categories obviously have certain mortality rates associated with them. The more major categories — submassive and massive — obviously carry a higher mortality rate. So we believe that we are not treating those patients adequately. And I think that we have a tool now that combines catheter direction and delivery of a clot-dissolving drug directly into the pulmonary artery that uses ultrasound to enhance delivery of the drug. So I think that this is probably a major step forward in showing the public and physicians that we have a tool that will do something more than the standard of care, which is anticoagulation alone. And we have now, in my institution, single-center experience — single-operator experience of about 55 patients that were treated, both massive and submassive, with an ultrasonic-enhanced catheter and we’ve had excellent results. We’ve seen that reversal of the ratio with the right heart and everybody has survived with minimal complications and we are using TPA, which is a clot-dissolving drug, in a much lower dosage than normally we would use in an intravenous dose and because of that we are seeing much less bleeding complications.

Certainly more studies need to be done. We are actually doing the study now called the SEATTLE II study. It’s 120 patients that will be signed up for the study in about 19 different centers. We’re halfway through enrolling the patients now. Hopefully by the end of next year, that study will be completed and we will have the results. But in my personal study, in my personal series of 55 patients, they’ve all done really well and I’m really convinced that this is the way we should treat PE.

VDM: What results has your study shown when comparing this therapy to anticoagulation alone?

Dr. Engelhardt: We’ve seen a dramatic decrease in length of stay in the hospital and length of stay in the intensive care unit in addition to a rapid reversal in right heart size and decrease in the incidence of pulmonary hypertension so I think that this study is going to hopefully prove to the public and medical community that we should be doing something more for submassive and massive pulmonary embolism patients.