The duration of percutaneous aortic valve implants can be increasingly observed over time, regardless of their corresponding surgical risk. In the follow-up of different registries, the presence of subclinical valvular thrombosis, evidenced in tomographic studies as an increase in valvular thickness with hypoattenuation (a term known as HALT), was observed from protocolized images.
This subclinical thrombosis was observed more frequently in transcatheter aortic valve replacement (TAVR) patients compared with patients undergoing surgical replacement. However, little is known about how its presence impacts clinical outcomes.
The Japanese group Imaeda et al. conducted a retrospective analysis of its own database to investigate the natural history of HALT and its relationship with long-term outcomes.
All patients underwent SAPIEN-XT valve implantation and follow-up with echocardiography and multidetector computed tomography (MDCT) at discharge, at 6 months, and at an annual follow-up for 5 years.
Data were obtained from 124 patients, who received dual antiplatelet therapy (DAPT) for 6 months, divided into two groups: HALT and non-HALT. The primary endpoint (PEP) was a composite of all-cause mortality, hospitalization for heart failure (HF), and ischemic stroke. Secondary endpoints were the incidence of all-cause mortality, cardiovascular death, HF hospitalization, and ischemic stroke. In turn, valvular performance was assessed using indexed effective orifice area, mean pressure gradient, and indexed stroke volume as variables.
Read also: We Should Treat Significant Stable CAD in Patients Undergoing TAVR.
The incidence of HALT at one year was 21.8%; there were no significant differences in baseline characteristics, except for a greater presence of CF III dyspnea or higher in the non-HALT group (p = 0.04). In the mean follow-up of 4.7 years, there were no significant differences in the PEP, with an incidence of 37% in the HALT group vs. 38.1% in the non-HALT group (log-rank test, p = 0.92). There were no significant differences in secondary endpoints such as all-cause mortality (p = 0.97), cardiovascular death (p = 0.86), hospitalization for HF (p = 0.54), and ischemic stroke (p = 0.88).
The presence of HALT was not associated with decreased effective orifice area (p = 0.59), increased gradient (p = 0.76), or decreased stroke indexed volume (p = 0.29).
CONCLUSIONS
In this study, the incidence of HALT was 21.8%, and its presence did not imply changes in the clinical endpoints and in valvular performance at the 5-year follow-up of these patients. This dedicated study allows us to develop hypotheses regarding the innocent nature of this entity. However, due to the small sample size, derived from a single center, reliable conclusions cannot be drawn.
Dr. Omar Tupayachi.
Member of the editorial board of SOLACI.org.
Original Title: Natural History of Leaflet Thrombosis After Transcatheter Aortic Valve Replacement: A 5-Year Follow-Up Study.
Reference: Imaeda, Shohei et al. “Natural History of Leaflet Thrombosis After Transcatheter Aortic Valve Replacement: A 5-Year Follow-Up Study.” Journal of the American Heart Association vol. 11,23 (2022): e026334. doi:10.1161/JAHA.122.026334.
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