Left Atrial Appendage Thrombosis Frequent After Transfemoral TAVI, Particularly in Patients With AF

Left atrial appendage thrombosis (LAAT) was found to occur frequently in patients who undergo transfemoral transcatheter aortic valve implantation (TF-TAVI), but was not found to be associated with an increased risk for periprocedural complications, according to a study published in the Canadian Journal of Cardiology.

In this retrospective analysis, the data of 2527 patients who had TF-TAVI performed at a single center, were examined. The study’s primary outcome was early safety at 30 days, which consisted of a composite of all-cause mortality, stroke, life-threatening bleeding, acute kidney injury stage 2 and 3, coronary obstruction requiring intervention, major vascular complication, and valve-related dysfunction requiring repeat procedure. All-cause and cardiovascular mortality rates were also assessed 30 days and 3 years after intervention.

In this cohort, 193 patients (7.6%) experienced LAAT, as indicated by transesophageal echocardiography (TEE). Of the 1099 patients with a history of atrial fibrillation (AF), 182 (16.6%) had LAAT. Patients with LAAT had higher rates of pre-existing AF compared with control INDIVIDUALS (94.8% vs 40.1%, respectively; P <.001).

At baseline, patients with vs without LAAT had a higher Society of Thoracic Surgeons (STS) score (9.2% vs 6.4%, respectively; P <.001),  greater burden of comorbidities, including diabetes (52.1% vs 43.2%, respectively; P =.017) and chronic kidney disease stage ≥3b (43.2% vs 28.6%, respectively; P <.001), and had lower left ventricular ejection fraction (52% vs 58%, respectively; P <.001) and lower aortic valve area (0.6 vs 0.7 cm², respectively; P =.005).

The rate of stroke at 30 days, as defined by the Valve Academic Research Consortium-2 (VARC-2), was similar in the LAAT and non-LAAT group (5.9% vs 4.7%, respectively; P =.495). Early safety at 30 days, as defined by the VARC-2 was comparable in the LAAT and non-LAAT group (29.2% vs 24.2%, respectively; P =.123). Early safety at 30 days (29.1% vs 22.9%; P =.072) and stroke rate (5.6% vs 3.3%; P =.142) were comparable in patients with AF with LAAT vs without LAAT.

No association was established between LAAT and 2-year mortality in the entire cohort and in the subgroup with AF. However, 2-year all-cause mortality in the entire cohort was associated with STS-score (hazard ratio [HR], 1.05; 95% CI 1.04-1.07; P <.001), New York Heart Association (NYHA) III/IV at baseline (HR, 1.81; 95% CI, 1.37-2.40; P <.001), and AF (HR, 1.32; 95% CI, 1.09-1.61; P =.005). In the AF cohort, independent predictors of 2-year all-cause mortality were male sex (HR, 1.42; 95% CI, 1.10-1.82; P =.007), STS-Score (HR, 1.05; 95% CI, 7 1.03-1.07; P <.001), and NYHA III/IV at baseline (HR, 1.59; 95% CI, 1.09-2.33; P =.017).

Limitations of the study include its retrospective, single-center design as well as the lack of complete data on stroke and bleeding rates beyond 30 days.

“Not LAAT but its underlying diseases were associated with 2-year all-cause mortality indicating that LAAT should be considered as a marker for patients who are at risk for worse outcome due to a higher comorbidity burden,” noted the study authors.

Reference

Stachel G, Woitek FJ, Crusius L, et al. Left atrial appendage thrombosis in patients with severe aortic stenosis undergoing transcatheter aortic valve implantation [published online May 22, 2020]. Can J Cardiol. doi:10.1016/j.cjca.2020.05.025