View clinical trials related to Aortic Stenosis.
Filter by:Aortic stenosis has been thought to be a degenerative process basically induced by long-lasting mechanical stress, and hemodynamic factors such as shear forces, acceleration of blood flow, hypertension and rapid heart rate might contribute to progression of aortic stenosis. Peak aortic jet velocity is known to be associated with clinical outcomes in mild and moderate AS, and our previous study showed that rate of progression was significantly associated with baseline aortic jet velocity in mild aortic stenosis. Because beta-blocker therapy would decrease aortic jet velocity and heart rate, it might decrease hemodynamic stress and eventually slow down the degenerative process in patients whose disease is not too advanced for therapy to be effective. The investigators hypothesized that a beta-blocker therapy would decrease the rate of progression of aortic stenosis by modifying hemodynamic factors favorably in patients with mild to moderate aortic stenosis.
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.
NASA has outlined the most urgent threats to life and health in manned spaceflight. One of the threats is the risk of trauma and acute medical problems. One of the most important provisions of acute and chronic medical services in space is the availability of high quality diagnostic imaging with the potential for either ground based or onsite interpretation. The principle diagnostic imaging modality for space crew use in space will be ultrasound. The aim of the study is as follows: -To use state of the art 3 dimensional CT scanner to acquire images for segmentation and registration supplying a template to judge physiologic or pathologic changes observed in space with 3D ultrasound
One hundred patients with moderate to severe asymptomatic aortic stenosis (AS) will be asked to exercise on a treadmill. NT-pro-BNP levels will be drawn before and after exercise. Changes in NT-pro-BNP levels will be correlated to outcomes at one year. In the pilot phase an additional 10 control subjects without AS will be enrolled to document the control response of NT-pro-BNP elevations with exercise.
In patients with aortic stenosis and low ejection fraction, how can we predict who will recover their ejection fraction after aortic valve replacement? We plan to observe 50 patients with Low EF aortic stenosis and perform serial echocardiograms pre and post-aortic valve replacement and analyze regional wall motion contractility with a new software application called speckle tracking imaging.