Patient Selection for Long-Term Mechanical Circulatory Support: Is It Ever too Early for the NYHA Class III Patient?

TAVI in a Heart Transplant Recipient-Rare Case Report and Review of the Literature

The global demand for cardiac transplants continues to rise, even with advancements in assistive devices. Currently, the estimated annual mortality rate stands at 3-5%, and patients often face a waiting time of approximately four years on transplant waiting lists. Consequently, many transplant centers have started to consider heart transplants from donors who may be deemed "less than ideal" or marginal. However, the decision to accept such donors must be highly individualized, taking into consideration the risks associated with remaining on the waiting list versus those posed by the transplantation procedure itself. A potential solution lies in the creation of two distinct recipient lists, matched with donor criteria, allowing marginal donors to provide the lifeline that selected patients require. This paper follows a two-step approach. Firstly, it offers an overview of the current state of affairs regarding the topic of transcatheter aortic valve implantation (TAVI) in orthotopic heart transplant (OHT) patients. Secondly, it presents firsthand experience from our clinical center with a comprehensive case presentation of a patient in this unique medical context. The clinical case refers to a 62-year-old male patient, a smoker with a history of hypertension, dyslipidemia, and a prior OHT a decade earlier, who presented with fatigue during minimal physical exertion. The Heart Team carefully reviewed the case, considering the patient's immunosuppressed status and the heightened risk associated with a repeat intervention. In this instance, transcatheter aortic valve implantation (TAVI) was deemed the appropriate treatment. The TAVI procedure yielded successful results, leading to improved clinical status and enhanced cardiac function. The inclusion of marginal donors has introduced novel challenges related to the utilization of previously diseased marginal organs. TAVI has already demonstrated its efficacy and versatility in treating high-risk patients, including heart transplant recipients. Consequently, it emerges as a vital tool in addressing the unique challenges posed by the inclusion of marginal donors.

The Evolution of Durable, Implantable Axial-Flow Rotary Blood Pumps

Left ventricular assist devices (LVADs) are increasingly used to treat patients with end-stage heart failure. Implantable LVADs were initially developed in the 1960s and 1970s. Because of technological constraints, early LVADs had limited durability (eg, membrane or valve failure) and poor biocompatibility (eg, driveline infections and high rates of hemolysis caused by high shear rates). As the technology has improved over the past 50 years, contemporary rotary LVADs have become smaller, more durable, and less likely to result in infection. A better understanding of hemodynamics and end-organ perfusion also has driven research into the enhanced functionality of rotary LVADs. This paper reviews from a historical perspective some of the most influential axial-flow rotary blood pumps to date, from benchtop conception to clinical implementation. The history of mechanical circulatory support devices includes improvements related to the mechanical, anatomical, and physiologic aspects of these devices. In addition, areas for further improvement are discussed, as are important future directions-such as the development of miniature and partial-support LVADs, which are less invasive because of their compact size. The ongoing development and optimization of these pumps may increase long-term LVAD use and promote early intervention in the treatment of patients with heart failure.

New methodologies to accurately assess circulating active transforming growth factor-β1 levels: implications for evaluating heart failure and the impact of left ventricular assist devices

Transforming growth factor-β1 (TGF-β1) has been used as a biomarker in disorders associated with pathologic fibrosis. However, plasma TGF-β1 assessment is confounded by the significant variation in reported normal values, likely reflecting variable release of the large pool of platelet TGF-β1 after blood drawing. Moreover, current assays measure only total TGF-β1, which is dominated by the latent form of TGF-β1 rather than the biologically active form. To address these challenges, we developed methodologies to prevent ex vivo release of TGF-β1 and to quantify active TGF-β1. We then used these techniques to measure TGF-β1 in healthy controls and patients with heart failure (HF) before and after insertion of left ventricular assist devices (LVAD). Total plasma TGF-β1 was 1.0 ± 0.60 ng/mL in controls and 3.76 ± 1.55 ng/mL in subjects with HF (P < 0.001), rising to 5.2 ± 2.3 ng/mL following LVAD placement (P = 0.006). These results were paralleled by the active TGF-β1 values; controls had 3-16 pg/mL active TGF-β1, whereas levels were 2.7-fold higher in patients with HF before, and 4.2-fold higher after, LVAD implantation. Total TGF-β1 correlated with levels of the platelet-derived protein thrombospondin-1 (r = 0.87; P < 0.001), suggesting that plasma TGF-β1 may serve as a surrogate indicator of in vivo platelet activation. von Willebrand factor high molecular weight multimers correlated inversely with TGF-β1 levels (r = -0.63; P = 0.023), suggesting a role for shear forces in loss of these multimers and platelet activation. In conclusion, accurate assessment of circulating TGF-β1 may provide a valuable biomarker for in vivo platelet activation and thrombotic disorders.