What is the Role of Thrombus Removal in Acute Proximal DVT after ATTRACT? Mitchell J. Silver DO FACC FSVM RPVI Director, Center for Critical Limb Care Riverside Methodist Hospital Ohio Health Heart and Vascular Columbus, Ohio X Copy Here Boston Scientific, Gore Medical, Contego Medical, Bristol Myers, Pfizer, Deep Venous Thrombosis Spectrum Risk of Acute Leg Complications & Pulmonary Emboli Risk of Post- Thrombotic Syndrome Calf Deep Venous Thrombosis Low Low The Easy One.. Femoral-Popliteal Deep Venous Thrombosis Iliofemoral Deep Venous Thrombosis High High
Phlegmasia Cerulea Dolens Phlegmasia Cerulea Dolens Markedly painful!!! Massive red/purple turgid swelling Diminished or absent pulses Limb and life threatening emergency!!! A true vascular emergency Emergency consult to endovascular specialist Start IV unfractionated heparin (weight adjusted) Rapid triage to catheterization suite for catheter thrombectomy and probable thrombolysis Consider early intervention in patients with impending or clinical signs of pre-phlegmasia Iliofemoral Deep Venous Thrombosis What is the Prevalence of the Post thrombotic syndrome after standard anticoagulation? The Not So Easy One.. Patients with just a proximal DVT Chronic leg complications: Calf DVT ~ 10 % Femoropopliteal DVT ~ 20 30 % Iliofemoral DVT* > 50 %, 90 % in some series (historic) ATTRACT TRIAL 48%!!!! Akesson et al. Eur J Vasc Surg 1990;4:43-8 N Engl J Med 2017:377:2240-52
Now Comes the ATTRACT trial.. SOBERING The conclusion: Among patients with acute proximal DVT, PCDT did not prevent PTS, but did increase major bleeding. It is sobering to all of us in the vascular community that the ATTRACT trial, A PROSPECTIVE RANDOMIZED NIH study, found a near 50% rate of PTS in both treatment arms at 2 years. WE ARE DOING SOMETHING WRONG!! WE MUST DO BETTER FOR OUR PATIENTS!! N Engl J Med 2017:377:2240-52 HOW CAN THIS BE? BACK TO THE QUESTION Breast cancer Located to breast 99% 5 year survival Positive lymph nodes 85% 5 year survival Acute stroke Organized acute stroke care intervention significantly better survival than no intervention STEMI 30 day mortality 13% with medical therapy 30 day mortality 3% with primary PCI What is the Role of Thrombus Removal in Acute Proximal DVT after ATTRACT???
The Real Question? Detective Joe Friday from Dragnet would say.. Should the Results from the ATTRACT Trial Influence Our Approach to Managing Acute Proximal DVT in the Year 2018??? FACT #1 The ATTRACT results do not apply to the patients we treat everyday.. 28,507 patients met inclusion criteria 26,715 were excluded 1,100 declined to participate THEREFORE ONLY 1/50 PATIENTS SCREENED WERE RANDOMIZED. THESE RESULTS ARE NOT GENERALIZABLE!! FACT #2 There was not true clinical equipoise among the ATTRACT investigators: Equipoise occurs when there is uncertainty in the expert medical community over whether a treatment will be beneficial.so doctors are OK with randomizing patients in research studies. Not the case in ATTRACT!! LONG TIME TO COMPLETE TRIAL 2009 2014 WITH 56 sites (2 3 pts/year at each site over 5 years!!) INVESTIGATORS WERE NOT WILLING TO HAVE THEIR PATIENTS RANDOMIZED!!
FACT #3 The primary endpoint was flawed, the Villalta score was applied in a binary fashion, PTS yes or no. Not simply the presence or absence of a Villalta score of > 5 should define lack of clinical benefit!!! Too stringent to be the primary endpoint!!! Change from baseline should have been primary endpoint Measure actual improvement, that is what is important to patients Remember many patients have venous ectasia and hyperpigmentation at baseline that effect the Villalta score. Real world: The use of the Villalta score misclassified 42% of patients CVD at Jobst Vasc Clinic (AVF, Feb 2018) Fact #4 ATTRACT was underpowered to look at the group that has the highest risk of PTS, and benefits the most from intervention. Femoral/popliteal DVTs were randomized (43%!!) Only 57 % of patients had IF DVT CaVent study IF DVT - 14% absolute risk reduction in PTS at 24 months, and 28% at 5 years!! ATTRACT did find: intervention may reduce the risk of moderate-to-severe PTS. The signal of benefit was in the IF DVT group!! Fact #5 Fact #6 There was a substantial number of missing assessments of the post-thrombotic syndrome. 2/3 of the total patients missed were in the control group. Only 68% (243/355) patients in control arm completed the full 24 month follow up. This likely underestimated the benefit of interventional treatment. Standard venography is not good enough to guide clinical decisions. Per ATTRACT protocol : Stenting was encouraged for lesions of > 50% narrowing, robust collaterals, and pressure gradient > 2 mmhg. Not sure what all that means??. IVUS WAS NOT USED TO GUIDE DECISIONS!!
Importance of IVUS Venography underestimates the degree of narrowing: A direct comparison study: Standard venography had poor sensitivity (45%) and negative predictive value (49%) in the detection of a venous area stenosis of > 70% when compared to IVUS. IVUS shows spurs, webs, extrinsic compression IVUS shows dynamic changes in vein with respiration/valsalva Venography is not good enough!!! Neglen, Raju 2002 JVS IVUS demonstrated predictive accuracy for imaging and guiding treatment of iliofemoral venous lesions, whereas venography did not display significant predictive usefulness The VIDIO Trial Fact #7 IVUS imaging changed the treatment plan!! Changed type of therapy in 60/100 patients Changed number of stents placed in 50/100. Without IVUS, iliofemoral vein occlusive disease would have been undertreated in the majority of patients studied. A large number of patients in ATTRACT were likely left with significant outflow obstructions. This causes PTS. 58% of patients had iliofemoral DVT 62% had left lower ext DVT (likely May Thurner) ONLY 28% (82/297) received a stent!! J Vasc Surg Venous Lymphat Disord. 2018 Jan;6(1):48-56
Acute Iliofemoral DVT: Evaluation of Underlying Anatomic Abnormalities by Spiral CT Venography 56 pts with acute IF DVT evaluated via CT venography Left: 44 [79%] Right: 9 [16%] BL: 3 [5%] Left sided: 37/44 [84%] anatomic abnormalities of the iliac v or IVC [most common = May-Thurner anomaly] Right sided: 6/9 [67%] anatomic abnormalities eg, encasement, extrinsic compression, and stricture without compression BL: 2/3 [67%] anatomic abnormalities Conclusion: The majority of pts presenting with acute IF DVT have underlying anatomic abnormalities! Fact #8 ATTRACT did not answer the open vein hypothesis. Only a subgroup had follow up duplex at one year 20% of all patients!!! (142/692 ) Post procedure imaging was not uniformly applied in ATTRACT. Chung, et al. J Vasc Interv Radiol 2004;15:249-56 Fact #9 Primary outcome stated and did result in a higher risk of major bleeding. Median tpa duration was 21 hours!! Minority of patients had adjunctive treatments which we know shorten treatment times. 22 % AngioJet 15 % Trellis High volume vein centers don t see these treatment times in the year 2018. Shorter time treatment = less bleeding. Now What????? For patients with acute iliofemoral DVT, venous intervention must still be part of the treatment algorithm.. Onset of symptoms with 21 days (relative) Good functional status Reasonable life expectancy Low bleeding risk Local expertise is available
DO NOT let ATTRACT be the final chapter for our patients!!!! Back to the drawing board. Complete a study of Iliofemoral DVT using modern era interventional techniques and uniform post procedure imaging!!! THE FINAL FACT A modern era DVT trial is in planning stage: The right population: IF DVT Mandated IVUS Mandated Pharmacomechanical Thrombolysis Shorten treatment times = decreased bleeding Mandated post procedure imaging at one year, answer the open vein hypothesis The question will be answered!!!!! Is ATTRACT the Final Word on Lysis of Proximal Deep Vein Thrombosis? NO IT IS NOT!!!!! 31