Early and Late Leaflet Thrombosis After Transcatheter Aortic Valve Replacement

The occurrence and clinical impact of untreated subclinical leaflet thrombosis beyond 1 year after transcatheter aortic valve replacement still remain unclear.

In a multicenter transcatheter aortic valve replacement registry, we analyzed data from 485 patients who underwent 4-dimensional multidetector computed tomography posttranscatheter aortic valve replacement performed to survey hypoattenuated leaflet thickening with reduced leaflet motion compatible with thrombus at a median of 3 days, 6 months, 1 year, 2 years, and 3 years. Incidence, predictors, and clinical outcomes of early (median 3 days) and late (>30 days) leaflet thrombosis were assessed. Additional anticoagulation was not administered because of subclinical findings at the time of computed tomography in all patients. Early leaflet thrombosis occurred in 45 (9.3%) of 485 patients. Mean pressure gradient at discharge was higher in patients with early leaflet thrombosis than in those without. Independent predictors of early leaflet thrombosis in balloon-expandable prostheses were low-flow, low-gradient aortic stenosis, severe prosthesis-patient mismatch, and 29-mm prostheses. No predictors could be identified for self-expanding prosthesis. Cumulative event rates of death, stroke, or rehospitalization for heart failure over 2 years were 10.7% and 16.9% in patients with and without early leaflet thrombosis, respectively ( P=0.63). Late leaflet thrombosis occurred late up to 3 years, and male sex and paravalvular leak less than mild were independent predictors.

Untreated early leaflet thrombosis did not affect the cumulative event rates of death, stroke, and rehospitalization for heart failure. Late leaflet thrombosis was newly detected during 3-year follow-up. Visual Overview: A visual overview is available for this article.