View clinical trials related to Aortic Stenosis.
Filter by:The aortic valve is the main outlet valve from the heart. This valve can become diseased and narrowed when it needs to be replaced with an artificial valve. Currently, this is the commonest reason for someone to undergo a heart valve operation in the UK. Unfortunately, there are no medical treatments that can prevent or delay the progression of this disease process. Here, the investigators propose to use new state-of-the-art imaging techniques to better understand the disease process so that the investigators can effectively design and assess potential new treatments. The ultimate aim is to stop this disease before patients need to have surgery. In addition the investigators believe this technique will allow us to predict the rate of progression of the disease
This study is being done to determine whether or not new blood test(s) can determine the severity of heart conditions. Aortic stenosis, hypertrophic cardiomyopathy, mitral regurgitation, aortic regurgitation, artificial heart valve regurgitation or stenosis, and tricuspid valve regurgitation associated with pacemaker leads are the cardiac disorders under study. The blood tests involve analysis for von Willebrand Factor antigen and activity, von Willebrand Factor multimers, and brain natriuretic peptide (BNP) levels. The results of the blood tests will be compared to the information from the clinically-indicated echocardiogram and one blood test compared to another.
The use of MRI have shown that the incidence of postoperative cerebral lesions due to cerebral embolization is high (1). Nonetheless the extent of postoperative neurological dysfunction is only a fraction of the actual amount of new postoperative changes detected on MRI. Transcranial Doppler (TCD) has shown the occurrence of extensive microembolic signals in intracerebral arteries during open heart procedures (2). The clinical significance of cerebral microemboli is not clear (3-5). The use of serological markers to assess cerebral injury after open cardiac surgery is difficult to interpret. The levels of markers seems to be contaminated from extracerebral sources (6). In order assess the release of markers of neuronal damage after open aortic valve surgery the investigators intend to examine the levels of S-100B, NSE and Tau in cerebrospinal fluid (CSF) by comparing the levels preoperative with the levels one day after surgery. Furthermore the investigators will determine the total amount of cerebral microembolic signals during the surgical procedure by means of TCD. The investigators will statistically test if there is any correlation between the increase in cerebrospinal fluid levels of S-100B,NSE and Tau and the cerebral embolic load.
Transcatheter Aortic Valve Implantation (TAVI) using femoral access is an option for definitive treatment of aortic stenosis when open-heart surgery is considered inappropriate. By avoiding the effects of cardiopulmonary bypass on cerebral hemodynamics and microembolic load, TAVI is assumed to be beneficial regarding risk for neurological complications. We anticipated that the extensive endovascular retrograde manipulation in ascending aorta and aortic root would generate a detectable cerebral microembolic load, and thus an increase in serological markers of neuronal injury postoperatively. Our hypothesis is that there is a positive correlation between the total amount of cerebral microembolic events during the TAVI procedure and the Area under curve (AUC24hrs) for the release pattern of two markers of neuronal injury. We also wish to describe the extent and distribution of microembolisms during the TAVI procedure using Transcranial Doppler (TCD).
The overall research plan is to test the hypothesis that intraoperative treatment of hyperinsulinemic normoglycemic clamp (HNC) in cardiac surgical patients improves myocardial function and short-term outcomes compared with standard glucose management.
The optimal timing of surgical intervention remains controversial in asymptomatic patients with very severe aortic stenosis. The investigators therefore try to compare long-term clinical outcomes of early surgery with those of conventional treatment strategy in a prospective randomized trial.
Purpose: The effect of intravenous glutamate infusion on myocardial diastolic function and overall hemodynamics were studied in patients undergoing elective aortic valve replacement with severe aortic stenosis and associated left ventricular hypertrophy . Methods: 25 patients will be included in this double-blind randomized placebo-controlled study. Glutamate was administered intravenously immediately after aortic cross-clamp release. The patients receive either a low dose of 30mg kg-1 h-1 (LG-group) or high dose of 60 mg kg-1 h-1 (HG-group) or placebo (P-group) at a rate of 3.3ml kg-1h-1 for 2h. Transesophageal echocardiography (TEE) is used to measure diastolic and systolic ventricular function before sternotomy (T0), and 2h (T2), 3h (T3) and 6h (T4) after release of cross clamp. Additionally routine hemodynamic parameters are measured intraoperatively.
The purpose of this clinical investigation is to demonstrate the safety and effectiveness of the Freedom SOLO heart valve.
Pulmonary hypertension is common in patients with aortic stenosis and is associated with worse operative and long-term outcomes. Sildenafil has been shown to reduce pulmonary artery pressure and improve exercise performance in patients with left-sided heart failure, but this has not been tested in patients with aortic stenosis. We hypothesize that Sildenafil will produce a clinically significant decrease in pulmonary artery pressure in patients with severe aortic stenosis. The dose of Sildenafil that produces a significant decrease in pulmonary artery pressure will be safe and well tolerated in patients with and without a depressed ejection fraction.
Patients with severe aortic stenosis often suffer from an acquired Von Willebrand syndrome by degeneration of the polymers during passage through the narrow valve leading to turbulences. We hypothesized that the diagnosis of acquired von Willebrand syndrome influence perioperative blood loss in patients undergoing open cardiac valve replacement.