Transcatheter Interatrial Shunts for the Treatment of Heart Failure with Preserved Ejection Fraction

Abstract Heart failure with preserved ejection fraction (HFpEF) is a clinical syndrome, which accounts for about 50% of patients with heart failure (HF). The morbidity and mortality associated with HFpEF is similar to HFrEF. Clinical trials to date have failed to show a benefit of medical therapy for HFpEF, which may due to lack of uniform phenotypes and heterogeneous population. In addition, medical therapy proven for HFrEF may not address the pathophysiologic basis for HFpEF. Left atrial remodeling and dysfunction is central to HFpEF and accounts for secondary pulmonary hypertension and pulmonary vascular congestion that frequently occurs with exertion. Interatrial shunts represent a novel treatment modality for HFpEF. These shunts allow for left atrial decongestion and a reduction in pulmonary venous hypertension during exercise leading to improvements in hemodynamics, functional status and quality of life. Trials to date have demonstrated safety and short-term efficacy of these devices for HFpEF. The long-term benefits are currently being evaluated in ongoing trials. If effective, the use of interatrial shunts may be a new therapeutic paradigm for the treatment of HFpEF.

Genetic transformation of Robinia pseudoacacia by Agrobacterium tumefaciens.

Transgenic Robinia pseudoacacia plants were obtained by Agrobacterium tumefaciens mediated gene transfer. Agrobacterium strain LBA4404 harbouring a binary vector that contained the chimeric neomycin phosphotransferase II (NPTII) and beta-glucuronidase (GUS) genes was co-cultivated with hypocotyl segments of in vitro raised seedlings of Robinia. Parameters important for high efficiency regeneration and transformation rates included type of explant, pre-conditioning of explants and appropriate length of co-cultivation period with Agrobacterium. A transformation frequency 16.67% was obtained by 48 hr of pre-conditioning followed by 48 hr of co-cultivation. Transformed tissue was selected by the ability to grow on kanamycin containing medium. Successful regeneration was followed after histochemical GUS assay for the detection of transgenic tissue. This transformation procedure has the potential to expand the range of genetic variation in Robinia.