Progress in cardiovascular diseases
-
Prog Cardiovasc Dis · May 2014
ReviewBalloon-expandable prostheses for transcatheter aortic valve replacement.
The implantation of a transcatheter heart valve (THV) through a balloon-expandable system played a major role in the early stages of transcatheter aortic valve replacement (TAVR). The technology consists of sewing a foldable biological cardiac valve inside a metallic stent frame, and then crimping the device into a balloon in order to implant the valve at the level of the aortic annulus through balloon inflation. The use of balloon-expandable valves underwent a rapid expansion in the years following the pioneering experience of 2002, and recent large multicenter trials and registries have confirmed the safety and efficacy of TAVR using balloon-expandable valves. ⋯ Valve durability studies with up to 5-year follow-up have shown maintained valve hemodynamics over time with only a minimal decrease in valve area and no increase in aortic regurgitation. Future improvements in the balloon-expandable THV technology such as implementing anti-paravalvular leak features (ex. Sapien 3 valve), and showing its efficacy for the treatment of non-high risk patients (ongoing PARTNER II trial) will probably lead to broader use in a lower risk population in the near future.
-
Prog Cardiovasc Dis · May 2014
ReviewSelf-expanding prostheses for transcatheter aortic valve replacement.
Transcatheter aortic valve replacement (TAVR) has emerged as an alternative to surgical aortic valve replacement in patients who are considered high surgical risk or inoperable due to advanced age and comorbidities. Randomized trial and registry data have demonstrated the safety and efficacy of TAVR in such patients. ⋯ This article reviews several designs of self-expanding THVs that are currently available or have undergone successful implantation in humans. Additional studies are required to compare the relative performance of these devices.
-
Prog Cardiovasc Dis · May 2014
ReviewPatient evaluation and selection for transcatheter aortic valve replacement: the heart team approach.
Transcatheter aortic valve replacement (TAVR) has been shown to significantly impact mortality and quality of life in patients with severe aortic stenosis (AS) who are deemed high risk for surgical aortic valve replacement (SAVR). Essential to these outcomes is proper patient selection. ⋯ The heart team is critical in determining patient eligibility and benefit and the optimal operative approach for TAVR. The future of structural heart disease will certainly require a team approach, and the TAVR heart team will serve as the successful model.
-
In the general population, obesity is associated with increased cardiovascular risk and decreased survival. In patients with end-stage renal disease (ESRD), however, an "obesity paradox" or "reverse epidemiology" (to include lipid and hypertension paradoxes) has been consistently reported, i.e. a higher body mass index (BMI) is paradoxically associated with better survival. This survival advantage of large body size is relatively consistent for hemodialysis patients across racial and regional differences, although published results are mixed for peritoneal dialysis patients. ⋯ The obesity paradox may have significant clinical implications in the management of ESRD patients especially if obese dialysis patients are forced to lose weight upon transplant wait-listing. Well-designed studies exploring the causes and consequences of the reverse epidemiology of cardiovascular risk factors, including the obesity paradox, among ESRD patients could provide more information on mechanisms. These could include controlled trials of nutritional and pharmacologic interventions to examine whether gain in lean body mass or even body fat can improve survival and quality of life in these patients.
-
Prog Cardiovasc Dis · Jan 2014
ReviewOverview of epidemiology and contribution of obesity to cardiovascular disease.
The prevalence of obesity has increased worldwide and is a source of concern since the negative consequences of obesity start as early as in childhood. The most commonly used anthropometric tool to assess relative weight and classify obesity is the body mass index (BMI); BMI alone shows a U- or a J-shaped association with clinical outcomes and mortality. Such an inverse relationship fuels a controversy in the literature, named the 'obesity paradox', which associates better survival and fewer cardiovascular (CV) events in patients with elevated BMI afflicted with chronic diseases compared to non-obese patients. ⋯ Obesity, particularly visceral obesity, also induces a variety of structural adaptations/alterations in CV structure/function. Adipose tissue can now be considered as an endocrine organ orchestrating crucial interactions with vital organs and tissues such as the brain, the liver, the skeletal muscle, the heart and blood vessels themselves. Thus, the evidence reviewed in this paper suggests that adipose tissue quality/function is as important, if not more so, than its amount in determining the overall health and CV risks of overweight/obesity.