Thread by @AkivaRosenzveig

1/ We clinched the Dx, but how do we treat it?
Are these clot 📸 the best approach for #PE Rx?

Let’s dive into the 🌎 of "escalation of care" therapies

@CardioNerds 🧵 part 2...

Hold on to your 🎩 for this one
@PERTConsortium #PERT #CardioTwitter #ACCMedStudent

https://twitter.com/AkivaRosenzveig/status/1628442948047077376

2/ Why is PE so dangerous❓

⚠️thrombus in 🫁 ➡️obstruction ➡️ sudden ⬆️ RV afterload ➡️ pressure➕volume overload ➡️ ⬇️RV output➕RV ischemia ➡️ ⬇️LV preload ➡️ ⬇️ 🫀output ➡️ shock ❤️‍🔥

⚠️Hypoxic & neurohormonal mediated pulmonary vasoconstriction ➡️ ⬆️ RV afterload

3/ How do we treat❓

Based on risk stratification, we have several options: ⭐️Anticoagulation (AC) alone

Escalation of Care (EOC) therapies:
⭐️Systemic Thrombolysis (ST)
⭐️Catheter Directed Therapies (CDT)
⭐️Surgical Embolectomy (SE)
⭐️ECMO

4/
▶️High Risk
👉ESC class IIa: SE or CDT (if failed ST)
▶️Low Risk
👉Anticoagulation
👉ESC class IIa: IVC filter if failed or ineligible for AC
▶️Intermediate Risk
🔥area of active research

Let's get to the 🥩 & 🥔 and the nuances of intermediate-risk PE Rx

5/ AC alone in intermediate risk: 3%-4% mortality rate
jamanetwork.com/journals/jama/…

What about ST❓

👉PEITHO study: tenecteplase vs AC
▶️ ⬇️☠️ or hemodynamic (HD) collapse (2.6% vs 5.6%)
▶️ BUT ⬆️ major 🩸 (6.3% vs 1.5%) and Intracranial hemorrhage (ICH) (2% vs 0.2%)

6/
👉In a meta-analysis of ST trials
▶️⬇️☠️ (2.2% vs 3.9%) but ⬆️ICH (1.5% vs 0.2%)

👉MOPETT trial
▶️Reduced-dose ST
▶️no🩸in 👫 who didn't qualify for full-dose ST

🛑ST definitely has its drawbacks

What if we get closer to the thrombus & minimize bleeding?!

7/ Let's talk about Catheter Directed therapies

⭐️Catheter Directed Thrombolysis (CDT)

▶️Catheters are passed into the 🫁 arteries & deliver thrombolytic agents over longer duration
▶️1/4 of the ST dose
▶️ensure thrombolytics get to the right place

8/ Two approaches for thrombolytic delivery:

1️⃣Give the drug locally to attempt thrombus breakdown
2️⃣Break up the thrombus to increase surface area for thrombolytic access

9/
⭐️Catheter-directed lytic therapy with infusion catheters
▶️placing a catheter through the thrombus & delivering local tPA (thrombolytic)

Commonly used catheters:

▶️Unifuse
▶️Cragg-McNamara

⚠️Limitation: tPA may not have access to the entire thrombus

10/ How can we lighten the load for our friendly thrombolytics❓

1️⃣Utilize ultrasound waves to break up fibrin strands
2️⃣Mechanically disrupt the thrombus (pharma-mechanical CDT)

11/ The predominant ultrasound-assisted thrombolysis (USAT) catheter used is the EKOS catheter

12/ To mechanically disrupt or macerate the thrombus, options include:

▶️Pigtail catheter with a guide-wire or peripheral balloons
▶️Bashir Catheter: expandable basket of 6 Nitinol-reinforced infusion limbs

13/
✔️ less thrombolytics
✔️ thrombus maceration can THEORETICALLY partially decompress the RV by quickly establishing forward flow

⚠️ Beware of distal embolization‼️

14/ The RESCUE trial showed improvement in RV/LV ratio at 48 hrs in intermediate-risk pts using the Bashir catheter with 7 mg tPA

Caveat: not powered for clinical outcomes

jacc.org/doi/10.1016/j.…

15/
⚠️limitation of CDT
▶️as long as you’re using thrombolytics,🩸is a concern

What if we can take out the thrombus itself without the need for lytics at all 🤯❓

Two main forms of embolectomy:

1️⃣Rheolytic thrombectomy
2️⃣Mechanical thrombectomy

16/
⭐️Rheolytic thrombectomy utilizes the Bernoulli principle

▶️High speed saline jets sent backwards from the catheter➡️⬆️ speed➡️⬇️ pressure➡️creating a pressure gradient➡️vacuum the thrombus

17/
⭐️Mechanical Thrombectomy utilizes aspiration to suction 🪠the thrombus🩸

▶️Ideally obviates the need for thrombolytics

The main catheters being studied:
⭐️Flowtriever system, AlphaVac system (manual suction)
⭐️Indigo Thrombectomy System (continuous suction)

18/
What are the risks❓
⚠️Hemodynamic collapse from rapid changes in RV afterload with the passage of wires and catheters (rare)
⚠️Perforation, tamponade
⚠️Ventricular arrhythmias triggered by catheters through the RV
⚠️Vascular access complications

19/
⚠️Acute respiratory collapse due to:
▶️pulmonary hemorrhage
▶️sudden changes in ventilation/perfusion from distal embolization
⚠️Bleeding (meta-analysis) (CDL)
▶️4.5% non-ICH major bleeding
▶️0.7% ICH

20/ The big question: Do EOC therapies work⁉️

▶️Studies to date have shown short-term improvement in RV/LV ratio compared with ST but no mortality difference & no long-term difference in RV/LV ratio.

Here’s a quick overview….

21/
💠CANARY Trial: CDT vs AC
▶️No difference in RV/LV ratio at 3 months, but ⬇️👫with RV/LV ratio >0.9 at 72 hrs
▶️1 case of Major 🩸

👉If you haven’t yet, you MUST check out the 🥇#CardsJC by #HouseThomas and their summary
cardionerds.com/cardsjc-canary/

22/
USAT:
💠ULTIMA
▶️Reduced RV/LV ratio at 24 hrs but no dif. at 90 days, no major 🩸
💠SEATTLE II
▶️Reduced RV/LV ratio at 48 hrs, moderate 🩸 10%, major 🩸 0.7%
💠OPTALYSE-PE
▶️Reduced RV/LV ratio, 4% Major 🩸 , 1 attributable ICH

23/
USAT vs CDT:
💠SUNSETsPE
▶️No difference btwn USAT vs CDL

Mechanical Embolectomy:
💠EXTRACT-PE
▶️Reduced RV/LV ratio at 48 hrs, avoided thrombolytics in 98.3%, 1.7% major 🩸

24/
💠FLARE
▶️Intermediate-risk patients
▶️Reduced RV/LV at 48 hrs, 98.1% avoided thrombolytics, 1.0% major 🩸
💠FLASH
▶️93.2% intermediate-high risk, 6.8% high risk
▶️All-cause mortality: 0.3% 48 hrs, 0.8% 30d
▶️Reduced RV/LV ratio, 1.2% major 🩸

25/
Here are some studies to keep an 👁️ out for in intermediate-risk PE:
💠HI-PEITHO: USAT vs AC
💠PEERLESS: Mechanical Thrombectomy vs CDT
💠APEX-AV: Single arm study of AlphaVac
💠PE-Tract: Catheter-based therapy vs AC

Bottom Line: promising results but…..VERDICT PENDING!

26/ Want to learn more? check out this great case from the vascular medicine team at @MGHHeartHealth

cardionerds.com/226-case-repor…

27/ Once again, a HUGE shoutout to @dinubalanescu for guiding me through this 🧵 and to @AmitGoyalMD @TDonisan and @Gurleen_Kaur96 for reviewing!

28/ Want to read more?

Check out these references:
ahajournals.org/doi/full/10.11…
structuralheartjournal.org/article/S2474-…
pubmed.ncbi.nlm.nih.gov/31185730/
pubmed.ncbi.nlm.nih.gov/36112184/