597 Comparison between low versus intermediate-high risk patients in a contemporary real-world multicentre TAVI registry using self-expanding supra-annular valves: a propensity score matched analysis
Authors: Sticchi Alessandro , Gallo Francesco , Benenati Stefano , Won-keun Kim , Khokhar Arif A , Zeus Tobias , Toggweiler Stefan , De Marco Federico , Reimers Bernhard , Nombela-franco Luis , Barbanti Marco , Brugaletta Salvatore , Piva Tommaso , Rodes-cabau Joseph , Porto Italo , Colombo Antonio , Giannini Francesco 
Published: December 2021

Abstract

Aims
Recent ESC VHD guidelines from 2021 recommend TAVI for intermediate-risk and in certain cases low-risk populations. There is relatively little data regarding the impact of transcatheter heart valve design in these populations. The aim of this study was to investigate the clinical outcomes of low-risk versus intermediate-high risk patients following TAVI in a large real-world contemporary registry.

Methods
In a large TAVI registry using self-expanding supra-annular bioprosthesis, we performed a comparison between low vs. intermediate-high risk population. Primary outcome was 1-year mortality and secondary outcomes, defined according to Valve Academic Research Consortium 2 criteria, included major and minor vascular complications, annular rupture, myocardial infarction, cardiac tamponade, new permanent pacemaker, stroke, and major and minor bleeding. Finally, we assessed the same investigation applying a propensity score matched (PSM) analysis.

Results
In the unmatched comparison, the low-risk (LR) group included 1698 patients compared to the 1690 patients of the Intermediate-to-high risk group (IHR). The IHR population showed a mean age of 84 years old vs. 81 of the LR (P&lt;0.001), a higher prevalence of male sex (41% vs. 30%, P&lt;0.001) and increased prevalence of co-morbidities as evidenced by the higher mean STS score 5.80% vs. 2.63% (P&lt;0.001). About the echocardiographic characteristics, the LR presented a higher mean gradient (45.9±15 mmHg vs. 43.7±16.8 mmHg, P&lt;0.001) but similar area compared to the IHR group (0.7 [0.8–0.6] for LR and 0.7 (0.8–0.55) for IHR, P=0.096). In the first unmatched comparison, we found a higher rate of major vascular complications (5.4% vs. 7.3%, P=0.026), new permanent pacemaker (10.5% vs. 13.7%, P=0.006) and major bleeding (2.9% vs. 5.0%, P=0.002) for the IHR group. After the PSM, we obtained 1015 matched patients observing similar outcomes except for minor vascular complications (7.4% vs. 11%, P=0.014) for the IHR group. At a median follow-up of 368 days, the mortality rate was 12.2% (104/1559) vs. 6.8% (104/1520) for the un-matched populations (P&lt;0.001), and 10.4% (98/940) vs. 7.9% (71/898) for the matched patients (P=0.100), respectively for the IHR and the LR group.

Conclusions
In this large, contemporary real-world registry of TAVI patients, there was no difference in mortality observed between LR and IHR populations at a 1-year follow-up. This data suggests that additional factors beyond surgical risk scores should be considered during heart team evaluation of patients with severe aortic stenosis towards a single-patient tailored approach.