(HealthDay News) – While all-cause mortality is high in low-flow, low-gradient aortic stenosis patients receiving transcatheter aortic valve implantation (TAVI), surviving patients show significant improvements.

Michael Gotzmann, MD, from the BG University-Hospital Bergmannsheil in Bochum, Germany, and colleagues studied 167 consecutive patients with native severe aortic stenosis and an excessive operative risk who underwent TAVI. Of these, 15 patients presented with low-flow, low-gradient aortic stenosis (aortic valve area <1cm², left ventricular (LV) ejection fraction <40%, aortic mean gradient <40mmHg). The CoreValve prosthesis 18-F-generation (Medtronic) was inserted retrograde. Six months following the procedure, clinical follow-up and echocardiography were performed.

The researchers found that patients with low-flow, low-gradient aortic stenosis (mean LV ejection fraction 32 ± 6% and a mean aortic gradient 27 ± 7mmHg) had significantly higher all-cause mortality six months after TAVI compared to patients without low-flow, low-gradient aortic stenosis (33 vs.13%). In the surviving 10 patients with low-flow, low-gradient aortic stenosis, LV ejection fraction significantly increased (34 ± 6% before vs. 46 ± 11% six months after TAVI) and the patient covered significantly more distance in the six-minute walk test (218 ± 102m before vs. 288 ± 129m six months after TAVI).

“Our study suggests that TAVI is feasible in patients with severe comorbidities and low-flow, low-gradient aortic stenosis,” the authors write.

One author is a physician proctor for CoreValve (Medtronic).

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