Transcatheter aortic valve implantation outcomes in patients with low flow low gradient aortic stenosis

Abstract

Background There are limited data about the outcomes of transcatheter aortic valve implantation (TAVI) in patients with low flow – low gradient (LF-LG) aortic stenosis (AS), but some studies suggest that these patients may have worse results. Purpose To compare outcomes between LF-LG AS and high gradient AS patients submitted to TAVI. Methods Retrospective analysis of consecutive patients (P) submitted to TAVI between 2009 and 2020 in a tertiary center. Baseline characteriscs and outcomes after the procedure were collected. LF-LG AS was considered in patients with mean gradient <40mmHg, valve area <1mm2, stroke volume index <35mL/m2 and at least one other criteria of contractile reserve confirmed by stress echocardiography, with elevation of mean gradient to >40mmHg, or high aortic calcium score in angio-CT. Results A total of 480P (56.9% female) were included, with a mean age of 82±7 years. Patients with LF-LG AS (81P, 16.9%) had worse baseline characteriscs, with higher new euroscore (10.4% vs 6.3%, p<0.0001), and natriurec peptide B (11252 vs 3095 pg/mL, p=0.001), more frequent left ventricular ejection fraction (LVEF) <40% (33.3% vs 8.8%, p<0.0001), more coronary artery disease (58% vs 37.1%, p<0.0001), including previous myocardial infarction (28.4% vs 14.1%, p=0.002) and coronary artery bypass graft (29.6% vs 12.3%, p<0.0001). In univariable analysis, LF-LG AS was associated with worse 1 year and long-term functional class (NYHA 3–4 – 17.8% vs 3.8% p<0.0001 and 20.5% vs 6.0%, p<0.0001, respectively), 1 year mortality (21.3% vs 10.8%, p=0.012) and 1 year and long-term heart failure hospitalizations (16.6% vs 3.3%, p<0.0001 and 24.3% vs 6.3%, p<0.0001). When adjusted to the differences in baseline characteristics, in a mulvariable analysis, LF-LG AS was still associated with worse functional class at 1 year (p=0.023) and long-term (p=0.004) and with heart failure hospitalizations at 1 year and long-term (p=0.001 and p<0.0001, respectively). In a sub-analysis considering only the patients with LF-LG AS, those with LVEF <40% have the worst outcomes, with more global, intra-hospital and 30 days mortality (48.1% vs 18.5%, p=0.005; 14.8% vs 1.9%, p=0.040; 18.5% vs 1.9%, p=0.014), global cardiovascular mortality (25.9% vs 7.4%, p=0.036), worse 1 year functional class (31.8% vs 11.8%, p=0.040) and more long-term heart failure hospitalizations (40.9% vs 17.3%, p=0.031). Conclusion Patients with LF-LG AS have worse short and long-term outcomes, even when adjusted for baseline characteriscs differences. The sub-group of patients with LVEF <40% have the worst global outcomes. Funding Acknowledgement Type of funding sources: None.