View clinical trials related to Aortic Stenosis.
Filter by:The purpose of this study is to test the prognostic value of autonomic markers in patients with aortic stenosis.
Trans-apical aortic valve replacement is a new treatment for severe aortic stenosis. It is offered to elderly patients with medical problems that would markedly increase the risk of conventional cardiac surgery. The rate of delirium (acute confusional state) after surgery in these patients may exceed 50%. Estimated hospital costs associated with delirium at Toronto General Hospital last year exceeded $1-million CAD. Pain after surgery and the use of opioids (morphine type of pain-relief drugs) are known to increase the risk of delirium. The investigators plan to minimize the use of opioids and improve pain management by replacing the standard intravenous opioid-based pain management with the paravertebral nerve block using only the local anesthetic. These two management strategies will be compared with respect to the rate of delirium, duration of hospital stay, and the overall costs. Hypothesis: Paravertebral analgesia with LA decreases the incidence of delirium after trans-apical AVR when compared to standard systemic opioid-based analgesia.
Polymorphisms in the vitamin D system appear to affect the serum 25(OH)D levels. If so one would expect these polymorphisms to be associated with vitamin D related conditions and diseases, which will be tested in the present study including DNA analyses in 9700 subjects
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.
Currently, aortic stenosis (AS) is considered a "surgical disease" with no medical therapy available to improve any clinical outcomes, including symptoms, time to surgery, or long-term survival. Thus far, randomized studies involving statins have not been promising with respect to slowing progressive valve stenosis. Beyond the valve, two common consequences of aortic stenosis are hypertrophic remodeling of the left ventricle (LV) and pulmonary venous hypertension; each of these has been associated with worse heart failure symptoms, increased operative mortality, and worse long-term outcomes. Whether altering LV structural abnormalities, improving LV function, and/or reducing pulmonary artery pressures with medical therapy would improve clinical outcomes in patients with AS has not been tested. Animal models of pressure overload have demonstrated that phosphodiesterase type 5 (PDE5) inhibition influences nitric oxide (NO) - cyclic guanosine monophosphate (cGMP) signaling in the LV and favorably impacts LV structure and function, but this has not been tested in humans with AS. Studies in humans with left-sided heart failure and pulmonary venous hypertension have shown that PDE5 inhibition improves functional capacity and quality of life, but patients with AS were not included in those studies. The investigators hypothesize that PDE5 inhibition with tadalafil will have a favorable impact on LV structure and function as well as pulmonary artery pressures. In this pilot study, the investigators anticipate that short-term administration of tadalafil to patients with AS will be safe and well-tolerated.
Currently, aortic stenosis (AS) is considered a "surgical disease" with no medical therapy available to improve any clinical outcomes, including symptoms, time to surgery, or long-term survival. Thus far, randomized studies involving statins have not been promising with respect to slowing progressive valve stenosis. Beyond the valve, two common consequences of aortic stenosis are hypertrophic remodeling of the left ventricle (LV) and pulmonary venous hypertension; each of these has been associated with worse heart failure symptoms, increased operative mortality, and worse long-term outcomes. Whether altering LV structural abnormalities, improving LV function, and/or reducing pulmonary artery pressures with medical therapy would improve clinical outcomes in patients with AS has not been tested. Animal models of pressure overload have demonstrated that PDE5 inhibition influences NO-cGMP signaling in the LV and favorably impacts LV structure and function, but this has not been tested in humans with AS. Studies in humans with left-sided heart failure and pulmonary venous hypertension have shown that PDE5 inhibition improves functional capacity and quality of life, but patients with AS were not included in those studies. The investigators hypothesize that PDE5 inhibition with tadalafil will upregulate NO-cGMP signaling, reduce oxidative stress, and have a favorable impact on LV structure and function as well as pulmonary artery pressures and quality of life. In this pilot study, the investigators anticipate that short-term administration of tadalafil to patients with AS will be safe and well-tolerated.
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.