Natural History of Leaflet Thrombosis After Transcatheter Aortic Valve Replacement: A 5‐Year Follow‐Up Study

Abstract

Background Subclinical leaflet thrombosis, characterized by hypoattenuated leaflet thickening (HALT) on multidetector computed tomography, is common after transcatheter aortic valve replacement (TAVR). Because little is known about the long‐term natural history of subclinical HALT, we aimed to investigate this in patients who underwent TAVR without using additional anticoagulation. Methods and Results We retrospectively evaluated patients who underwent TAVR with the Edwards SAPIEN‐XT at our institute between October 2013 and December 2015. Patients were grouped according to the presence or absence of HALT within 1 year after TAVR (HALT and No‐HALT groups). The primary outcome, defined as the composite of all‐cause mortality, heart failure readmission, and ischemic stroke, was compared. Valve performance was assessed over time by transthoracic echocardiography. Among 124 patients (men: 29.1%; median age, 85 years), 27 (21.8%) showed HALT on multidetector computed tomography within 1 year after TAVR. No patient required additional anticoagulation for treating HALT because of the absence of valve‐related symptomatic deterioration. During the median follow‐up period of 4.7 years (interquartile range, 4.0–5.6), the rate of primary outcome and valve performance was not statistically different between the 2 groups (37.0% versus 38.1%; log‐rank test P =0.92; mean pressure gradient, 9 mm Hg [8–14 mm Hg] versus 10 mm Hg [7–15 mm Hg]; P =0.51, respectively). Conclusions Approximately 20% of patients after TAVR had HALT within 1 year; however, that did not change the risk of subsequent adverse cardiovascular events or the valve performance with statistical significance for up to 5 years despite no additional anticoagulation therapy.

Impact of balloon post‐dilation on valve durability and long‐term clinical outcomes after self‐expanding transcatheter aortic valve implantation

“…Notwithstanding, the impact of subclinical leaflet thrombosis on subsequent thromboembolic complications and valve function has reported conflicting results. 31 Similarly, no statistically significant differences were observed between groups in other adverse events which could have been potentially originated at long-term follow-up after BPD such as endocarditis or intravalvular leak. In addition, changes in mean aortic gradient over time were similar between groups.…”

Hyperacute Sapien Aortic Valve thrombosis in a patient with Antiphospholipid Syndrome (APS)

“…7 However, HALT was not associated with mortality or cerebrovascular events but only with symptomatic hemodynamic valve deterioration. 8,9 Our patient did not undergo a postoperative repeat CT angiography in the presence of mild renal failure, whereas the radiological features were already obtained preoperatively. Procoagulant conditions such as inherited or acquired thrombophilias, including Primary antiphospholipid syndrome (APS)-all increase the predisposition to thrombotic events, 10 and APS has been specifically associated with described cases of prosthetic valve thrombosis.…”

“…Patients with HALT were more likely to develop HVD, require repeat valve intervention and have higher trans‐valvular gradients at up to 3‐year follow‐up 7 . However, HALT was not associated with mortality or cerebrovascular events but only with symptomatic hemodynamic valve deterioration 8,9 …”

Putting a Halt to HALT: Does Anticoagulation Matter?

“…In the current study in this issue of the Journal of the American Heart Association ( JAHA ), Imaeda et al have retrospectively reviewed patients who had implantation of the Edwards Sapien XT TAVR, performed during October 2013 to December 2015. 8 Their analysis of MDCT data included the presence or absence of HALT at 1 year, and further reviewed outcomes out to a median follow‐up period of 4.7 years. Valve function was assessed with transthoracic echocardiography and included indexed effective orifice area, mean pressure gradient, and indexed stroke volume.…”

“…The anticoagulation strategy used by Imaeda et al consisted of dual antiplatelet therapy for 6 months, followed by indefinite therapy with either aspirin or clopidogrel. 8 Significantly, if HALT was detected, the therapy was not altered or expanded. In the current study, this approach did not alter the incidence of either the composite primary outcome or ischemic stroke.…”