In particular, we observed no differences with regard to all-cause mortality, incidence of peri-procedural myocardial infarction or major stroke. The most frequently encountered periprocedural complications were bleeding events and vascular complications, which occurred with similar frequency in both groups. The overall incidence of adverse events was WY 14643 comparable with previous reports of patients undergoing TAVI and suggests that TAVI in patients with severely reduced left ventricular function is not associated with an increased perioperative risk. This finding contrasts with data from the surgical literature showing an increased risk of adverse events of patients with reduced LVEF. For instance, Sharony et al reported a 30-day mortality of 9.6% among patients with LVEF#40% in a series of 260 patients. Several factors might explain the negligible role of a diminished LVEF during the peri-procedural phase of TAVI: the strategy of a pure percutaneous approach using local anesthesia and mild conscious sedation reduces the risk of unfavorable hemodynamics during the intervention and the need of vasoactive drugs. Positioning of the stiff wire in the left ventricle and the deployment of the bioprosthesis is considered to be easier in patients with an enlarged ventricle with low output compared with patients with a small, hypertrophic and hypercontractile ventricle. Furthermore, TAVI provides the possibility of valve implantation without cardiac arrest and its sequelae like the need for prolonged ventilation, the risk of renal failure, infection and neurologic complications. Our data show, that the combination of severe aortic stenosis and severely reduced left ventricular function is associated with a dismal prognosis if treated conservatively. In our cohort, more than half of the patients died within six months of evaluation for potential intervention and almost 80% died within one year. The present findings therefore suggest that severely impaired left ventricular function should not serve as a reason to deny transcatheter aortic valve implantation. The favorable periprocedural outcome was accompanied by a rapid recovery in LVEF already during the in-hospital phase and eventually translated into favorable long-term survival comparable to patients with normal or moderately reduced LVEF. Of note, the mean aortic transvalvular gradient in patients with LVEF#30 amounted to 35616 mmHg indicating that low-flow, low-gradient aortic stenosis was encountered relatively infrequently and a majority of patients may have maintained some contractile function. Since we did not routinely perform dobutamine stress echocardiography the issue whether contractile reserve plays an important role with respect to prognosis remains unanswered. Nevertheless, patients with LVEF#30% assigned to medical treatment exhibited similar transvalvular gradients and were found to have a considerably higher mortality rate as compared to medically treated patients with LVEF.30%.