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Introduction Continuous-flow (CF) left ventricular assist devices (LVADs) are widely used to treat end-stage heart failure. Despite substantial improvement in clinical results, numerous complications remain associated with this technology. Worsening renal function is one, associated with morbidity and mortality in patients supported by CF LVADs. The effects of CF LVAD support on renal function have been investigated since the mid-1990s by many research groups. Areas covered We review the current status of LVAD therapy, experimental results regarding the effects of types of flow generated by LVADs on renal function and pathology, changes in renal function after LVAD implant, the influence of renal function on outcomes, and risk factors for renal dysfunction post implant. This information was obtained through online databases and direct extraction of single studies. Expert commentary Immediately after CF LVAD implantation, renal function improves temporarily as patients recover from the kidneys' previously low perfusion and congestive state. However, many studies have shown that this initially recovered renal function gradually declines during long-term CF LVAD support. Although it is known that CF LVAD support adversely affects renal function over the long term, just how it does has not yet been clearly defined in terms of clinical symptoms or signs.

Heart failure (HF) remains a major global burden in terms of morbidity and mortality. Despite advances in pharmacological and resynchronization device therapy, many patients worsen to end-stage HF. Although the gold-standard treatment for such patients is heart transplantation, there will always be a shortage of donor hearts. Areas covered: A left ventricular assist device (LVAD) is a valuable option for these patients as a bridge measure (to recovery, to candidacy for transplant, or to transplant itself) or as destination therapy. This review describes the current indications for and complications of the most commonly implanted LVADs. In addition, we review the potential and promising new LVADs, including the HeartMate 3, MVAD, and other LVADs. Studies investigating each were identified through a combination of online database and direct extraction of studies cited in previously identified articles. Expert commentary: The goal of LVADs has been to fill the gap between patients with end-stage HF who would likely not benefit from heart transplantation and those who could benefit from a donor heart. As of now, the use of LVADs has been limited to patients with end-stage HF, but next-generation LVAD therapy may improve both survival and quality of life in less sick patients.

SUMMARYA total artificial heart (TAH) is the sole remaining option for patients with biventricular failure who cannot be rescued by left ventricular assist devices (LVADs) alone. However, the pulsatile TAH in clinical use today has limitations: large pump size, unknown durability, required complex anticoagulation regimen, and association with significant postsurgical complications. That pump is noisy; its large pneumatic driving lines traverse the body, with bulky external components for its drivers. Continuous-flow pumps, which caused a paradigm shift in the LVAD field, have already contributed to the rapidly evolving development of TAHs. Novel continuous-flow TAHs are only in preclinical testing or developmental stages. We here review the current state of TAHs, with recommended requirements for the TAH of the future.

Heart transplantation remains the gold standard for long-term cardiac replacement, but a shortage of donor organs will always limit this option. For both transplant-eligible and noneligible patients, advances in mechanical circulatory support have revolutionized the options for the management of end-stage heart failure, and this technology continues to bring us closer to a true alternative to heart transplantation. This review provides a perspective on the past, present and future of mechanical circulatory support and addresses the changes in technology, patient selection and management strategies needed to have this therapy fully embraced by the heart failure community, and perhaps replace heart transplantation either as the therapy of choice or as a strategy by which to delay transplantation in younger patients.

Mitral valve (MV) regurgitation is the most prevalent form of heart valve disease. As it comes to surgical repair or replacement of the diseased valves, the procedure has been established as safe and effective; however, its invasiveness still carries considerable risk of significant morbidity and mortality. With aging comes increased MV dysfunction, and thus minimally invasive technology is rapidly evolving to meet the challenges of older patients' preoperative comorbidities and risks associated with surgery. In comparison, in high-risk patients with aortic stenosis, percutaneous transcatheter technologies offer a viable alternative to surgery; however, catheter-based procedures for MV disease are limited only to repair. MV surgeries have limitations and carry the potential for serious complications in high-risk elderly patients. A fast, reliable sutureless or catheter-based means of MV replacement is needed. Although transcatheter devices are still only in preclinical testing or developmental stages, the authors here review various sutureless MV and transcatheter-based concepts and devices for MV replacement.

The purpose of the present study was to evaluate the effects of pulsatile cardiopulmonary bypass (CPB) on sheep regional renal blood flow by comparing pulsatile and non-pulsatile perfusion at two different flow rates.Seven female Suffolk sheep were used and the animals were perfused with pulsatile and non-pulsatile CPB at flow rates of 60 and 100 ml/min/kg. Regional renal blood flow was measured by the colored microsphere method. General linear model ANOVA was performed to analyze the data.Regional renal blood flow was significantly higher in both outer and middle cortices of pulsatile CPB compared with non-pulsatile CPB (outer cortex: pulsatile CPB, 381+/-192 ml/min/100 g, non-pulsatile CPB, 255+/-151 ml/min/100g, p=0.002; middle cortex: pulsatile CPB, 239+/-114 ml/min/100 g, non-pulsatile CPB, 176+/-80 ml/min/100 g, p=0.02). The increase of flow rate from 60 to 100 ml/min/kg improved renal cortical blood flow significantly.The regional renal blood flow was significantly higher in both outer and middle cortices of pulsatile CPB compared with the non-pulsatile CPB.