Outcomes of patients with low‐pressure aortic gradient undergoing transcatheter aortic valve implantation

BACKGROUND: The risk/benefit balance of transcatheter aortic valve implantation (TAVI) in patients with low-gradient aortic stenosis (LGAS) remains to be well defined. Aim of the study was to investigate the impact of LGAS in patients undergoing TAVI. METHODS: Medline, Cochrane Library, and Scopus were searched for articles reporting outcome of patients with LGAS undergoing TAVI. The primary endpoint was 12-months all-cause mortality and the secondary endpoint was 30-day all-cause mortality. Using event-rates as dependent variable, a meta-regression was performed to test for interaction between baseline clinical features (age, gender, diabetes mellitus, coronary artery disease, left ventricular ejection fraction (LVEF) and type of implanted valve) and transaortic gradient for the primary endpoint. RESULTS: Eight studies with a total of 12,589 patients were included. Almost one-third of the patients presented with LGAS (27.3%: 24.4-29.2). Median LVEF was 48% in patients with LGAS and 56% in patients with high-gradient AS. Patients with LGAS were more likely to have diabetes mellitus, previous coronary artery disease, higher mean Logistic EuroSCORE, and lower EF. At 12 (12-16.6) months, low transaortic gradient emerged as independently associated with all-cause death, both if evaluated as a dichotomous and continuous value (respectively OR 1.17; 1.11-1.23 and OR 1.02; 1-1.04, all CI 95%). Clinical variables, including EF did not affect this result. CONCLUSIONS: In a population of TAVI patients, LGAS appears to be independently related to dismal prognosis.