Outcomes after transcatheter aortic valve replacement in patients with low versus high gradient severe aortic stenosis in the setting of preserved left ventricular ejection fraction.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) for low gradient (LG) severe aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF) remains an area of clinical uncertainty. METHODS: Retrospective review identified 422 patients who underwent TAVR between September 4, 2014 and July 1, 2016. Procedural indication other than severe AS (n = 22) or LVEF <50% (n = 98) were excluded. Outcomes were defined by valve academic research consortium two criteria when applicable and compared between LG (peak velocity <4.0 m/s and mean gradient <40 mmHg; n = 73) and high gradient (HG) (n = 229) groups. The LG group was further categorized as low stroke volume index (SVI) (n = 41) or normal SVI (n = 32). Median follow-up was 747 days [interquartile range 220-1013]. RESULTS: Baseline thirty-day mortality risk (LG 6.2% [3.8-8.1] vs HG 5.7% [4.1-7.4], P = 0.43) did not differ between groups. Short-term outcomes, including procedural success rate (86.1% vs 88.8%, P = 0.53), peri-procedural complications (intra-procedural heart block: 6.8% vs 7.9%, P = 0.99; permanent pacemaker placement: 11.0% vs 13.6%, P = 0.69; moderate paravalvular regurgitation: 2.7% vs 1.3%, P = 0.60), and all-cause in-hospital mortality (2.7% vs 0.9%, P = 0.25) did not differ between LG and HG groups. On long-term follow-up, all-cause mortality also did not differ between LG and HG groups (6.8% vs 10.0%, plog-rank = 0.33) or between the LG low SVI (9.8%), LG normal SVI (3.1%), and HG (10.0%) groups (plog-rank = 0.39). CONCLUSION: Patients with preserved LVEF undergoing TAVR for severe AS with LG, including LG with low SVI, have no significant difference in adverse outcomes when compared to patients with HG.