#238 DVT / PE Triple Distilled

October 22, 2020 | By Matthew Watto, MD

Our favorite VTE pearls summarized in this fast paced recap 

DVT / PE Triple Distilled! Our favorite VTE pearls summarized in this fast paced recap gleaned from our discussions with Dr Oren Friedman #92 Pulmonary Embolism for the Internist and hematologist, heavy metal enthusiast, Dr Michael Streiff #154 DVT and PE Master Class. Introducing our new Triple Distilled sub-series offering shorter episodes that reinforce and refresh key concepts from past shows along with any pertinent updates. 

Listeners can claim Free CE credit through VCU Health at http://curbsiders.vcuhealth.org/ (CME goes live at 0900 ET on the episode’s release date).

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Credits

• Written and Produced by: Matthew Watto MD, FACP
• Cover Art by: Matthew Watto MD, FACP
• Hosts: Stuart Brigham MD; Matthew Watto MD, FACP; Paul Williams MD, FACP   
• Editor: Matthew Watto MD (written materials); Clair Morgan of nodderly.com

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Time Stamps

• 00:00 Intro, disclaimer
• 01:40 Making the diagnosis of VTE
• 09:07 Triage and risk stratify Pulmonary Embolism
• 14:00 Anticoagulant choice; Duration of therapy after unprovoked DVT / PE
• 21:00 Workup for unprovoked DVT / PE; DOACs in special populations: at extremes of weight,  advanced CKD and in antiphospholipid syndrome
• 28:22 IVC filters
• 30:20 Outro

Top Pearls on DVT / PE 

Diagnose DVT / PE

• Risk factors for VTE include recent surgery (100 fold increased risk, hospitalization), OCPs (mainly at the time they are started), testosterone supplementation, pregnancy and obesity (two fold increased risk). 
• Useful clinic risk tools include: DVT Wells score, PE Wells Score, or Geneva score. Wells is the most validated and most commonly used clinical prediction tool for VTE, but it should only be used in the outpatient setting!
• Dr Streiff likes to start with a D-dimer. D-dimers can be age-adjusted to help reduce unnecessary imaging (Schouten BMJ 2013).
• Symptoms for PE can be very mild: exertional dyspnea, mild back pain, or just feeling tired (PIOPED II Am J Med 2007). 
• V/Q scans are indeterminate for PE about 30% of the time (Sostman 2008) so go with a CT angio to confirm diagnosis of PE. 

Assess PE severity

• Risk stratification: High mortality risk if hypotension present. Low if minimal symptoms, and lack of RV strain on imaging or positive biomarkers. Intermediate-low and intermediate-high are a spectrum that includes some or all of RV dysfunction, elevated sPESI score, worrisome vitals and positive cardiac biomarkers (European Society of Cardiology Guidelines). 
• Dr Friedman gets nervous about patients with any of the following features: elevated lactate, syncope, HR >110 bpm, a patient who “looks sick”, high clot burden and RV strain (expert opinion).
• Patients with pulmonary embolism and a score of zero on the sPESI (Zhou, 2012) or HESTIA criteria might be candidates for outpatient therapy.  Note: Clinical gestalt should trump the score. If you’re worried about a patient then observe them!
• sPESI: age >80; h/o cancer, CHF, chronic lung disease; HR >110 bpm; systolic BP <100 mmHg; SaO2 <90%. Zero = low risk. One or above = high risk.

Choice of anticoagulant for DVT / PE

• Warfarin is no longer preferred for most patients (CHEST Guidelines 2016)
• Low risk patients: Start them on a DOAC. Dr Streiff likes apixaban better than rivaroxaban if he has a choice, but either is approved. 
• Intermediate risk patients: Both Dr Streiff and Dr Friedman recommend using IV unfractionated heparin or LMWH injections for intermediate risk patients who might end up needing a thrombectomy or thrombolysis (expert opinion).

Cancer

• DOACs are now commonly used in the cancer patient population (SELECT-D, Hokusai cancer study) even with active chemotherapy. They are more convenient than injections with LMWH.
• Dr Streiff warns about potential for increased bleeding in folks with upper GI malignancy, specifically with rivaroxaban (Young, 2018) since it may exert a topical effect in the stomach.

Extremes of weight

• Stuart points out that DOACs are absorbed throughout the GI tract vs warfarin which has impaired absorption in folks with altered GI anatomy and/or malabsorption. 
• Historically, there’s been concern for a reduced peak level of DOACs when a patient’s BMI is greater than 40. Blood volume goes up with body weight. In RE-LY study, dabigatran drug levels were lower in higher weights.
• ISTH Guideline Summary on DOAC treatment: ”Pending further evidence in patients at the extremes of weight (e.g., <50 kg, >120 kg or BMI ≥ 35 kg/m2) it is advisable to limit DOAC use to situations where vitamin K antagonists cannot be used.” 
• Update: On this episode, Stuart cites two recent publications by ASH in patients at extreme BMI showing safety of DOACs Apixaban is safe in patients with BMI >40 (Blood (2017) 130 (Supplement 1): 1105. https://doi.org/10.1182/blood.V130.Suppl_1.1105.1105) and Outcomes using DOACs for VTE in Morbidly Obese patients (Blood (2019) 134 (Supplement_1): 4973. https://doi.org/10.1182/blood-2019-132202) 

Advanced CKD

• Dr Streiff mentioned that he uses normal doses of apixaban, but we still don’t know enough to make a formal recommendation and this is an evolving area. For now we suggest that you consult your local hematologist and/or pharmacist. 

When to use an IVC filter in DVT / PE

• Always controversial, but the only clear indication is the patient with VTE who cannot receive anticoagulation. Both Drs. Streiff and Friedman note that some experts place a temporary filter if “large clot burden” and “low cardiopulmonary reserve”, but long term benefit has not been shown and future DVT risk increases (Duffet, 2017). 
• IVC filters have been shown to decrease pulmonary embolism in some cases, but they increase DVTs and in RCTs it’s not clear that they have a mortality benefit (PREPIC), though a recent observational study suggests possible benefit for massive PE (Osman, 2020). 
• Drs. Streiff and Friedman both highlight that IVC filters can fracture, migrate, perforate the IVC and cause recurrent clots. 
• Evidence does not support prophylactic IVC filter placement in massive trauma patients. Instead, Dr. Streiff recommends using sequential compression devices (SCDs) and pharmacological prophylaxis early. 

Unprovoked DVT / PE

Cancer workup need?

Dr Streiff simply answered, No. (van Es, 2017)

Thrombophilia (hypercoagulable) workup?

Dr Streiff says no unless antiphospholipid antibody syndrome is suspected. This would generally be a young person with unprovoked arterial or venous clotting, patients with lupus or women with recurrent fetal loss and other pregnancy related complications (Erkan, 2020)

Treatment duration for DVT / PE

• Treatment is 3 – 6 months if a trigger is identified (e.g. surgery, hospitalization, OCPs) and has been removed. This can be based on risk stratification. 
• If there is no identified trigger (i.e. an unprovoked clot) or there is an ongoing risk factor that is not removed (e.g. active malignancy), treatment duration is indefinite.  
• For female patients with first unprovoked VTE that want to discontinue anticoagulation, they can be risk stratified using the HERDOO2 calculator. This has been well validated (Rodger, 2017). If low risk, there is a  <3% of recurrence.
• Dr. Streiff points out that men have twice the risk for recurrence so there is no true “low risk.” (Expert Opinion). Treat indefinitely. 
• One strategy is to check a D-dimer while the patient is still on therapy using >250 to identify those at higher risk (expert opinion).

Links*

Check out the full show notes from previous Curbsiders’ shows covering VTE. 

1. Dr Oren Friedman #92 Pulmonary Embolism for the Internist
2. Dr Michael Streiff #154 DVT and PE Master Class

Goals

Listeners will feel confident in the diagnosis and management of VTE

Learning objectives

After listening to this episode listeners will…

1. Diagnose (VTE) DVT and PE using imaging, risk scores and clinical gestalt
2. Risk stratify patients with pulmonary embolism
3. Choose the appropriate initial anticoagulant for VTE
4. Decide duration of anticoagulation for VTE
5. Recall real risks and questionable benefits of IVC filters in DVT / PE
6. Determine need for cancer or thrombophilia workup in unprovoked DVT / PE

Disclosures

The Curbsiders report no relevant financial disclosures.

Citation

Watto MF, Williams PN, Brigham SK, Watto MF. “#238 DVT / PE Triple Distilled”. The Curbsiders Internal Medicine Podcast. http://thecurbsiders.com/episode-list Final publishing date October 22, 2020.