Dec 19, 2019
Episode 2: Oren Friedman interviews Ken Rosenfield on
catheter directed lytics.
Cardiac Surgery ICU
Ken Rosenfield, MD,
Vascular Medicine and Intervention
What is catheter directed thrombolysis
- Placing a catheter via femoral or IJs into pulmonary arteries
and infusing low dose thrombolytic over extended period.
- Percutaneous mechanical thrombectomy differs as it
involves extracting thrombus from pulmonary artery. (mostly from
proximal pulmonary arteries, and no thrombolytic regimen used in
MOA of CDT compared to peripheral systemic
- More clot bound thrombolytic directly into the clot compared to
around the clot with systemic tPA.
- Increased local thrombolytic concentration.
- Reduced tPA and longer duration of infusion—reason for
increased safety profile for ICH and major bleeding compared to
full dose systemic tPA. (dose is 100 mg, ICH rates 3-5%)
- CDT also allows improve tPA infusion to into distal pulmonary
circulation bed. (Vs percutaneous mechanical embolectomy)
Technical aspects of CDT:
- Pulmonary angiogram is not always needed at time of CDT or post
- Decision to place unilateral or bilateral catheters (right,
left or both branches of pulmonary artery) depends on location of
clot based on CTA.
- Patient are usually monitored in ICU while drugs are infusing,
close monitoring and experienced clinical nursing staff should be
- Heparin during CDT: fix dose 300-500 unit/per catheter sheaths.
Hard to achieve targeted aPTT (40-60) given very short duration of
infusion. Fibrinogen to guide tPA duration- limited to no data
- Catheter directed thrombolysis with (EKOS) ultrasound or
without ultrasound: We just don’t know. The available data stems
from prospective clinical trials with ultrasound catheters.
- Sedation: be careful with sedation. Use minimum. Avoid
intubation for procedure itself.
What is successful CDT?
- Goal is to improve hemodynamics, not to remove all thrombus.
Drop in pulmonary artery pressures (if monitoring available) or
improved RV/LV ratio in pre-vs Post intervention imaging. [Echo or
Data on CDT
- Impact on RV/LV ratio, as primary goal of improvement in many
trials (see Table below)
- ULTIMA trial: Heparin Vs CDT, with EKOS catheters. Rapid
normalization of RV/LV ratio compared to heparin alone in immediate
period. No difference at 90 days. Small numbers to show impact on
- SEATTLE II trial -- also included massive PE patients.
- PERFECT registry: prospective registry showing safety and
efficacy of CDT.
- OPTALYSE trial: compared different CDT dosing regimens.
- Impact on long term disability like CTED or CTEPH remains to be
Dosing regimens for of CDT: (See Table
- Higher risk bleeding patients: use as low as dose
- OPTALYSE trial: Lower dose (as low as 4-8 mg) and shorter
duration are effective for hemodynamic improvement. Higher doses
were associated with better Miller clot burden improvement with
increased risk of bleeding. (2 ICH incidents)