low , somewhere around 1 %. Referring to the stir caused by the Makkar et al . study published in 2015 in the New England Journal of Medicine , 10 which showed that subclinical leaflet thrombosis was seen in 40 % of bioprosthetic aortic valves , he stressed that reduced leaflet motion leading to symptoms was seen in less than 1 % of patients , making it “ a frequent event with rare clinical impact that , when it occurs , can be treated easily if necessary .” Five-year data from the PARTNER trial confirm that valve thrombosis is rare and there is no clear signal “ so far ” that there is a major issue with structural valve deterioration that requires re-intervention .
“ But it occurs , and when it occurs it is possible to institute treatment and it is usually effective ,” said Dr . Colombo . He cited a study published by his group that showed an incidence of transcatheter heart valve thrombosis of 0.61 % out of 4,266 patients undergoing TAVR in 12 centers . 11 “ This may be a little underestimated , I admit , but you can round it up to 1 %.”
The median time to transcatheter heart valve thrombosis was 181 days and the most common clinical presentation was exertional dyspnea in 65 %, whereas 31 % of patients had no worsening of symptoms . Echocardiography was “ very instrumental ” in showing increased valve gradient in 92 % of patients .
“ The good news is that 4 days of anticoagulation with heparin was most of the time sufficient to clear the valve of thrombotic material ,” reported Dr . Colombo .
To further stress the downside of routine anticoagulation in TAVR patients , he cited a recent study by Abdul-Jawad Altisent et al . that showed that during 13 months of follow-up , the addition of one antiplatelet therapy to anticoagulation ( in those with a clear indication for OAC after TAVR ), increased bleeding from 15 % to 24 % ( p = 0.04 ) ( TABLE ). 12 “ The real problem is the addition of an antiplatelet to a vitamin K antagonist ,” he explained .
He concluded his remarks thus : “ Most TAVI
TABLE Selected Efficacy and Safety Outcomes According to Antithrombotic Therapy ( Warfarin Alone vs . Warfarin Plus Antiplatelet Therapy )
Monotherapy
Multiple Antithrombotic Therapy
Stroke |
5 % |
5.2 % |
1.25 |
|
|
|
( 0.45 to 3.48 ;) |
Major Adverse Cardiovascular Events
13.9 % |
16.3 % |
1.33 |
|
|
( 0.75 to 2.36 ) |
Death |
22.8 % |
19.2 % |
0.93 |
|
|
|
( 0.58 to 1.50 ) |
Major or Life-threatening Bleeding
CI = confidence interval patients are elderly with a high risk for bleeding and I see no reason to pay the price of bleeding to prevent a rare and treatable event .”
Countering this approach , Dr . Sondergaard suggested that TAVR patients are under continuous short- and long-term risk for thromboembolic events , which favors anticoagulation , although he also acknowledged that most TAVR patients are elderly and have comorbidities , which increase bleeding risk .
“ I don ’ t think the ideal post-procedural antithrombotic therapy exists ,” he said , “ but we have to look at each individual and try to tailor the best medical treatment , and that is going to include anticoagulation for some of those patients .”
He also noted some evidence that the risk of structural valve deterioration is higher in the absence of continued OAC . In those with subclinical leaflet thrombosis , 3 months of VKA therapy will resolve it , he said , emphasizing that the data support VKAs in this regards , not NOACs or antiplatelet agents .
“ Oral anticoagulation , but not antiplatelet therapy , protects against and resolves leaflet thrombosis ” irrespective of whether there are symptoms , Dr . Sondergaard argued , in contradiction to Dr . Colombo ’ s argument that most leaflet thrombosis is subclinical and therefore not warranting OAC . In his coauthored New England Journal of Medicine paper that alerted the TAVR world to this issue , 10 there was a nonsignificant trend towards increased thromboembolic risk with subclinical leaflet thrombosis , but these data need to be confirmed in larger studies , he noted . Along with protecting against leaflet thrombosis , VKA therapy for 3 to 6 months seems to guard against structural valve deterioration after bioprosthetic valve implantation , both in the surgical and transcatheter data .
Certainly , there is no arguing that patients with atrial fibrillation ( AF ) undergoing TAVR require continued OAC , and clinical trial data suggest that up to 40 % of TAVR patients have pre-existing AF . But new-onset AF is also a significant issue to be
14.9 % |
24.4 % |
1.85 |
|
|
( 1.05 to 3.28 ) |
Adjusted Hazard Ratio ( 95 % CI ) p Value
0.67
0.33
0.76
0.04 considered , said Dr . Sondergaard . He cited unpublished data from NOTION-1 showing that after 2 months , all surgical AVR patients and 80 % of TAVR patients had an episode of AF detected on continuous cardiac monitoring . For these individuals , antiplatelet therapy is inferior to OAC with regards to efficacy and safety , he said , and it is as efficient and safer than OAC plus antiplatelet therapy , citing the just published study by Abdul- Jawad Altisent et al . 12 To balance competing risks of thromboembolism and bleeding , he suggested using the CHA 2
DS 2
-VASc and HAS-BLED scores and considering left atrial appendage occlusion so as to not compromise with OAC those at high risk for bleeding .
There are three ongoing trials that will offer much more information on this topic in the next few years — GALILEO , ATLANTIS , and POPULAR- TAVI . These studies will test multiple antiplatelet and anticoagulation options both in those with and without indications for OAC . In his concluding remarks , Dr . Windecker encouraged attendees to try to include their patients into one of these ongoing trials .
Stress Testing for Intermediate-risk Stable CAD This debate session was provocatively named , “ Stress testing thrown to the lions .” Stephan Windecker , MD , ( University Hospital Bern , Switzerland ) presented arguments supporting the use of invasive imaging for stable CAD as the standard approach , and Roxy Senior , MD , ( Imperial College London , UK ), argued against relying on angiography as “ the standard .”
In her introductory review of the topic , Roxana Mehran , MD , ( Icahn School of Medicine at Mt . Sinai , New York ) noted that it is difficult to diagnose CAD based on symptoms alone . Clearly in those with unstable presentations , angiography is warranted , as it is in those with pre-test-probability > 85 % for the presence of coronary stenosis . She added that the guideline-recommended CAD Consortium tool , as opposed to the old Diamond Forrester score , best estimates pre-test probability .
In a similar vein , among patients at low risk (< 15 % likelihood of coronary stenosis ), generally younger patients who perhaps present with atypical symptoms , there is consensus that these patients need no testing and no medication . The issue is the middle group — those with stable presentations and an intermediate likelihood of having significant CAD . Is there real value in stress testing or are they best served by invasive angiography ?
Currently , the guidelines propose non-invasive testing for intermediate-risk patients , and this might entail treadmill exercise electrocardiogram , stress echo , stress magnetic resonance or nuclear medicine , or another noninvasive test .
“ Unfortunately , the sensitivity and specificity [ for the wide array of noninvasive tests available ] is all over the map . There isn ’ t one noninvasive
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