Author + information
- Lars Sondergaard, MD, DMSc∗ ()
- ↵∗The Heart Center, Rigshospitalet, Blegdamsvej 9, Copenhagen 2100, Denmark
Neuss et al. (1) report a case of fatal thrombotic occlusion of the left main trunk after transcatheter aortic valve replacement (TAVR). The 81-year-old patient was previously successfully treated with a Portico valve (St. Jude Medical, St. Paul, Minnesota) for severe aortic stenosis. Post-procedural antithrombotic treatment included 6 months dual antiplatelet followed by monotherapy with aspirin. After 2 years without symptoms, the patient developed acute chest pain and shock. Echocardiography showed globally impaired left ventricular systolic function, but normal aortic valve function. Coronary angiography revealed thrombotic occlusion of the left main stem, and a contrast defect on the aortic root injection was interpreted as a large thrombosis on the bioprosthetic aortic valve.
The authors correctly state that clinical thrombosis on transcatheter bioprosthetic aortic valves is rare. Latib et al. (2) reported 26 cases (0.61%) of transcatheter heart valve thrombosis among 4,266 patients. These patients were symptomatic and often had an increased transvalvular gradient. This is in contrast to subclinical leaflet thrombosis, which may be seen as hypoattenuated leaflet thickening (HALT) on computed tomography (CT) scanning in up to 40% of patients with bioprosthetic aortic valve (3).
Neuss et al. (1) related their case report to HALT and stated that HALT is a phenomenon particularly found after TAVR with the Portico valve. However, HALT causes neither symptoms nor an increased transvalvular gradient, and increased risk of thromboembolic events and impaired leaflet durability is speculative. Furthermore, HALT has been described in both surgical and transcatheter bioprosthetic aortic valves with no statistically significant differences in the frequency between brands.
In the reported case, there was no confirmation of HALT by CT scan or transesophageal echocardiography. Furthermore, there was a normal gradient across the aortic valve, which would be expected in thrombosis with a clinically relevant impact on valve function.
The U.S. Food and Drug Association has reviewed data currently available on HALT and has not recommended a change in current antithrombotic therapy for TAVR patients. Instead, antithrombotic therapy decisions should be tailored for each patient with careful consideration of their specific risk/benefit profile.
The unsubstantiated association between this unfortunate rare case and HALT could spread unsupported alarm. A more thorough evaluation of all potential contributors, for example, atrial fibrillation, coagulopathies, age, and sex of the patient, should be undertaken before linking the event to an otherwise subclinical observation.
Please note: Dr. Sondergaard has received honoraria and research grants from Boston Scientific, Edwards Lifesciences, Medtronic, St. Jude Medical, and Symetis.
- American College of Cardiology Foundation
- Neuss M.,
- Kaneko H.,
- Tambor G.,
- et al.
- Latib A.,
- Naganuma T.,
- Abdel-Wahab M.,
- et al.