https://orcid.org/0000-0001-7201-8136
A 17 year-old male with trisomy 21 and corrected Fallot tetralogy with transannular patch met indication for percutaneous pulmonary valve implantation.
A Venus P-valve (VenusMedtech, Hangzhou, China) (34/25 mm) was implanted uneventfully. Sizing was planned on pre-procedural computed tomography (CT) and intra-procedural balloon sizing (34 mm, Abbott, Chicago, IL, USA) demonstrating a waist of 31 mm diameter on full inflation.
Post-procedural antithrombosis was achieved by two therapeutic dose of unfractionated heparin over 24 h, followed by dual antiplatelet therapy (DAT) with aspirin 100 mg and clopidogrel 75 mg. Echocardiogram performed 2 days after the procedure showed a normal competent pulmonary valve, good leaflet motion, and no significant peak gradient (12 mmHg).
Routine follow-up CT scan at 3 months after showed reduced movement of one leaflet (Panel; see Supplementary data online, Videos S1 and S2) and thickening of three leaflets/commissural regions, suggestive of microthrombosis. Echocardiography showed mild pulmonary regurgitation and no gradient. DAT was substituted with warfarin for 6 months with a target prothrombin time/INR between 1.8 and 2.5.
Subsequent echocardiogram at 6 months showed normal functioning of pulmonary valve.
To our knowledge, this is the first report on microthrombosis in self-expandable pulmonary valve prosthesis. The real significance is not yet clear, but it could be the trigger for valve dysfunctioning and infection.
The underlying cause of microthrombosis is not known, with multiple hypotheses surrounding patient’s thrombogenic tendency, anatomy of the outflow tract, oversizing, undersizing, and traumatic injury during crimping.
Enhanced anticoagulation therapy might be needed in patients undergoing percutaneous Venus P-valve implantation, particularly in the first 3 months after the procedure. Regular surveillance is essential.
Supplementary data are available at European Heart Journal - Cardiovascular Imaging online.
Funding: None declared.
Data availability: No new data were generated or analysed in support of this research.
Author notes
Conflict of interest: None declared.
