The SGLT2i Dapagliflozin Reduces RV Hypertrophy Independent of Changes in RV Pressure Induced by Pulmonary Artery Banding

Background— Sodium glucose linked transporter 2 (SGLT2) inhibition not only reduces morbidity and mortality in patients with diagnosed heart failure but also prevents the development of heart failure hospitalization in those at risk. While studies to date have focused on the role of SGLT2 inhibition in left ventricular failure, whether this drug class might be similarly efficacious in the treatment and prevention of right heart failure has not been unexplored. Hypothesis: We hypothesized that SGLT2 inhibition would reduce the structural, functional and molecular responses to pressure overload of the right ventricle. Methods: Thirteen-week-old Fischer F344 rats underwent pulmonary artery banding (PAB) or sham surgery prior to being randomized to receive either the SGLT2 inhibitor: dapagliflozin (0.5mg/kg/day) or vehicle by oral gavage. After six weeks of treatment, animals underwent transthoracic echocardiography and invasive hemodynamic studies. Animals were then terminated, and their hearts harvested for structural and molecular analyses. Results: PAB induced features consistent with a compensatory response to increased right ventricular (RV) afterload with elevated mass, end systolic pressure, collagen content and alteration in calcium handling protein expression (all p<0.05 when compared to sham + vehicle). Dapagliflozin reduced RV mass, including both wet and dry weight as well as normalizing the protein expression of SERCA 2A, AMPkinase and LC3I/II ratio expression (all p<0.05). Significance: Dapagliflozin reduces the structural, functional, and molecular manifestations of right ventricular pressure overload. Whether amelioration of these early changes in the RV may ultimately lead to a reduction in RV failure remains to be determined.

Expectant management of prolonged hemolysis following complete transcatheter coil closure of a patent ductus arteriosus after previous pulmonary artery banding: a case report

Background Transcatheter coil occlusion has been the treatment of choice for closure of small patent ductus arteriosus (PDA). In spite of its safety, complications such as hemolysis still occasionally occur. And the hemolysis almost always occurs following partial transcatheter closure of PDA; hence, it occurs extremely rarely following complete transcatheter closure of PDA without residual ductal flow. Case presentation Here, we describe a male newborn who developed prolonged hemolysis following complete transcatheter coil closure of his PDA after previous palliative pulmonary artery banding. Over the following days, we corrected his refractory anemia by repeated blood transfusion with packed red blood cells and frequently monitored his hemoglobin, serum total bilirubin, and serum lactate dehydrogenase. We speculated that the high-velocity pulmonary blood flow jet coming into contact with the extruded part of the coil led to red blood cell mechanical injury, thereby resulting in the hemolysis. We adopted expectant management in expectation of the endothelialization of the coil with a resultant reduction in the hemolysis. The hemolysis, as expected, was reduced gradually until it spontaneously resolved 81 days after coil implantation. Conclusions This case reminds us that hemolysis can still potentially occur following complete transcatheter coil closure of PDA. It also highlights the importance of preventing coils from extruding into the pulmonary artery in patients after previous pulmonary artery banding.

The SGLT2i Dapagliflozin Reduces RV Hypertrophy Independent of Changes in RV Pressure Induced by Pulmonary Artery Banding

Background— Sodium glucose linked transporter 2 (SGLT2) inhibition not only reduces morbidity and mortality in patients with diagnosed heart failure but also prevents the development of heart failure hospitalization in those at risk. While studies to date have focused on the role of SGLT2 inhibition in left ventricular failure, whether this drug class might be similarly efficacious in the treatment and prevention of right heart failure has not been unexplored.Hypothesis: We hypothesized that SGLT2 inhibition would reduce the structural, functional and molecular responses to pressure overload of the right ventricle.Methods: Thirteen-week-old Fischer F344 rats underwent pulmonary artery banding (PAB) or sham surgery prior to being randomized to receive either the SGLT2 inhibitor: dapagliflozin (1.5mg/kg/day) or vehicle by oral gavage. After six weeks of treatment, animals underwent transthoracic echocardiography and invasive hemodynamic studies. Animals were then terminated, and their hearts harvested for structural and molecular analyses.Results: PAB induced features consistent with a compensatory response to increased right ventricular (RV) afterload with elevated mass, end systolic pressure, collagen content and alteration in calcium handling protein expression (all p<0.05 when compared to sham + vehicle). Dapagliflozin reduced RV mass, including both wet and dry weight as well as normalizing the protein expression of SERCA 2A, AMPkinase and LC3I/II ratio expression (all p<0.05).Significance: Dapagliflozin reduces the structural, functional, and molecular manifestations of right ventricular pressure overload. Whether amelioration of these early changes in the RV may ultimately lead to a reduction in RV failure remains to be determined.

Novel Therapeutic Targets for the Treatment of Right Ventricular Remodeling: Insights from the Pulmonary Artery Banding Model

Right ventricular (RV) function is the main determinant of the outcome of patients with pulmonary hypertension (PH). RV dysfunction develops gradually and worsens progressively over the course of PH, resulting in RV failure and premature death. Currently, approved therapies for the treatment of left ventricular failure are not established for the RV. Furthermore, the direct effects of specific vasoactive drugs for treatment of pulmonary arterial hypertension (PAH, Group 1 of PH) on RV are not fully investigated. Pulmonary artery banding (PAB) allows to study the pathogenesis of RV failure solely, thereby testing potential therapies independently of pulmonary vascular changes. This review aims to discuss recent studies of the mechanisms of RV remodeling and RV-directed therapies based on the PAB model.