Clinical outcome of transcatheter aortic valve implantation in patients with low‐flow, low gradient aortic stenosis

Abstract

Low-flow, low-gradient aortic stenosis is associated with relevant postoperative mortality whereas conservative management results in dismal prognosis. We present the initial experience of low-flow, low-gradient aortic stenosis treated with transcatheter aortic valve implantation (TAVI). From June 2008 to December 2010 167 consecutive patients with native severe aortic stenosis and an excessive operative risk underwent TAVI. Of these, 15 patients presented with low-flow, low-gradient aortic stenosis (aortic valve area < 1 cm(2) , left ventricular (LV) ejection fraction < 40%, aortic mean gradient < 40 mm Hg). The CoreValve prosthesis 18-F-generation (Medtronic, Minneapolis, Minnesota) was inserted retrograde. Clinical follow-up and echocardiography were performed 6 months after procedure. Patients with low-flow, low-gradient aortic stenosis (mean LV ejection fraction 32 ± 6%, mean aortic gradient 27 ± 7 mm Hg) had higher all-cause mortality 6 months after TAVI compared to patients without low-flow, low-gradient aortic stenosis (33% vs. 13%, P = 0.037). In the surviving 10 patients with low-flow, low-gradient aortic stenosis, LV ejection fraction increased (34 ± 6% before vs. 46 ± 11% 6 months after TAVI, p = 0.005) and more distance covered in the 6-minute walk test (218 ± 102 meters before vs. 288 ± 129 meters 6 months after TAVI, p = 0.038). Our study suggests that TAVI is feasible in patients with severe co-morbidities and low-flow, low-gradient aortic stenosis. Within the first 6 months after treatment all-cause mortality was considerable high, but the surviving patients showed symptomatic benefit and significant improvement of myocardial function and exercise capacity.