Heterotopic and Orthotopic Tracheal Transplantation in Mice used as Models to Study the Development of Obliterative Airway Disease

Obliterative airway disease (OAD) is the major complication after lung transplantations that limits long term survival (1-7)

Physical and mental recovery after aortic valve surgery in non-elderly patients: native valve-preserving surgery vs. prosthetic valve replacement

Background: Exercise capacity and patient-reported outcomes are increasingly considered crucial following aortic valve (AV) surgery in non-elderly adults. We aimed to prospectively evaluate the effect of native valve preservation compared with prosthetic valve replacement. Methods: From October 2017 to August 2020, 100 consecutive non-elderly patients undergoing surgery for severe AV disease were included. Exercise capacity and patient-reported outcomes were evaluated upon admission, and 3 months and 1 year postoperatively. Results: In total, 72 patients underwent native valve-preserving procedures (AV repair or Ross procedure, NV group), and 28 patients, prosthetic valve replacement (PV group). Native valve preservation was associated with an increased risk of reoperation (weighted hazard ratio: 10.57 (95% CI: 1.24–90.01), p = 0.031). The estimated average treatment effect on six-minute walking distance in NV patients at 1 year was positive, but not significant (35.64 m; 95% CI: −17.03–88.30, adj. p = 0.554). The postoperative physical and mental quality of life was comparable in both groups. Peak oxygen consumption and work rate were better at all assessment time points in NV patients. Marked longitudinal improvements in walking distance (NV, +47 m (adj. p < 0.001); PV, +25 m (adj. p = 0.004)) and physical (NV, +7 points (adj. p = 0.023); PV, +10 points (adj. p = 0.005)) and mental quality of life (NV, +7 points (adj. p < 0.001); PV, +5 points (adj. p = 0.058)) from the preoperative period to the 1-year follow-up were observed. At 1 year, there was a tendency of more NV patients reaching reference values of walking distance. Conclusions: Despite the increased risk of reoperation, physical and mental performance markedly improved after native valve-preserving surgery and was comparable to that after prosthetic aortic valve replacement

Early outcomes of endoscopic papillary muscle relocation for secondary mitral regurgitation type IIIb in patients with severe left ventricular dysfunction

Objective: Subannular mitral valve (MV) repair techniques have been developed to address increased rates of recurrent mitral regurgitation (MR) in patients with secondary MR (SMR) type IIIb. Endoscopic papillary muscle relocation (PMR) is feasible via minithoracotomy. Nevertheless, the periprocedural outcome of patients with severe left ventricular (LV) dysfunction remains unknown. Methods: A total of 98 consecutive patients with SMR type IIIb underwent PMR at our institution. Due to concomitant coronary artery bypass grafting, 62 patients underwent sternotomy and were excluded from the current analysis, whereas 36 patients were treated by a minimally invasive technique using 3-dimensional endoscopy. Of these, 18 patients had severely depressed LV ejection fraction (LVEF) ≤35% (study group) and were compared to the remaining 18 patients with LVEF >35% (control group). Periprocedural outcome was retrospectively analyzed. Results: Although LVEF was significantly worse in the study group (30% ± 4% vs 43% ± 6%, P < 0.001), the severity of SMR and the degree of MV leaflet tethering were similar. The prevalence of concomitant procedures and the duration of surgery, cardiopulmonary bypass, and aortic cross-clamp were comparable. Periprocedural low cardiac output syndrome was favorably low in both groups (16.7% vs 5.6%, P = 0.29). Postoperative ventilation time (5.7 h [4.2 to 8.7 h] vs 6.0 h [4.6 to 9.8 h], P = 0.43) and duration of intensive care unit stay (2 days [1 to 3 days] vs 2 days [1 to 3 days], P = 0.22) were similar. There was no 30-day mortality in either group. Conclusions: Standardized endoscopic PMR resulted in favorable periprocedural outcomes in patients with severe LV dysfunction, suggesting that minimally invasive surgery can safely be extended to this patient population

Resting membrane potential is less negative in trabeculae from right atrial appendages of women, but action potential duration does not shorten with age

Aims: The incidence of atrial fibrillation (AF) increases with age. Women have a lower risk. Little is known on the impact of age, sex and clinical variables on action potentials (AP) recorded in right atrial tissue obtained during open heart surgery from patients in sinus rhythm (SR) and in longstanding AF. We here investigated whether age or sex have an impact on the shape of AP recorded in vitro from right atrial tissue. Methods: We performed multivariable analysis of individual AP data from trabeculae obtained during heart surgery of patients in SR (n = 320) or in longstanding AF (n = 201). AP were recorded by sharp microelectrodes at 37 °C at 1 Hz. Impact of clinical variables were modeled using a multivariable mixed model regression. Results: In SR, AP duration at 90% repolarization (APD90) increased with age. Lower ejection fraction and higher body mass index were associated with smaller action potential amplitude (APA) and maximum upstroke velocity (Vmax). The use of beta-blockers was associated with larger APD90. In tissues from women, resting membrane potential was less negative and APA as well as Vmax were smaller. Besides shorter APD20 in elderly patients, effects of age and sex on atrial AP were lost in AF. Conclusion: The higher probability to develop AF at advanced age cannot be explained by a shortening in APD90. Less negative RMP and lower upstroke velocity might contribute to lower incidence of AF in women, which may be of clinical relevance.</p

Antegrade axillary arterial perfusion in 3D endoscopic minimally-invasive mitral valve surgery

Background Minimally-invasive (MIS) mitral valve (MV) surgery has become standard therapy in many cardiac surgery centers. While femoral arterial perfusion is the preferred cannulation strategy in MIS mitral valve surgery, retrograde arterial perfusion is known to be associated with an increased risk for cerebral atheroembolism, particularly in atherosclerosis patients. Therefore, antegrade perfusion may be beneficial in such cases. This analysis aimed to compare outcomes of antegrade axillary vs. retrograde femoral perfusion in the MIS mitral valve surgery. Methods This analysis includes 50 consecutive patients who underwent MIS between 2016 and 2020 using arterial cannulation of right axillary artery (Group A) due to severe aortic arteriosclerosis. Perioperative outcomes of the study group were compared with a historical control group of retrograde femoral perfusion (Group F) which was adjusted for age and gender (n = 50). Primary endpoint of the study was in-hospital mortality and perioperative cerebrovascular events. Results Patients in group A had a significantly higher perioperative risk as compared to Group F (EuroSCORE II: 3.9 ± 2.5 vs. 1.6 ± 1.5; p = 0.001; STS-Score: 2.1 ± 1.4 vs. 1.3 ± 0.6; p = 0.023). Cardiopulmonary bypass time (group A: 172 ± 46; group F: 178 ± 51 min; p = 0.627) and duration of surgery (group A: 260 ± 65; group F: 257 ± 69 min; p = 0.870) were similar. However, aortic cross clamp time was significantly shorter in group A as compared to group F (86 ± 20 vs. 111 ± 29 min, p < 0.001). There was no perioperative stroke in either groups. In-hospital mortality was similar in both groups (group A: 1 patient; group F: 0 patients; p = 0.289). In group A, one patient required central aortic repair due to intraoperative aortic dissection. No further cardiovascular events occurred in Group A patients. Conclusion Selective use of antegrade axillary artery perfusion in patients with systemic atherosclerosis shows similar in-hospital outcomes as compared to lower risk patients undergoing retrograde femoral perfusion. Patients with higher perioperative risk and severe atherosclerosis can be safely treated via the minimally invasive approach with antegrade axillary perfusion

Sex Differences in Immunology: More Severe Development of Experimental Pulmonary Hypertension in Male Rats Exposed to Vascular Endothelial Growth Factor Receptor Blockade

Background. The epidemiology of pulmonary hypertension (PH) is characterized by a female preponderance, whereas males share higher severity of the disease. Objective. To compare the severity of experimental PH between male and female athymic rats. Methods. PH was induced in 11 male and 11 female athymic rats (resp., SU_M and SU_F groups) using an inhibitor of VEGF-receptors I and II, semaxanib (40 mg/kg). After 28 days, right ventricular (RV) remodeling, systolic function, and hemodynamics were measured using echocardiography and a pressure-volume admittance catheter. Morphometric analyses of lung vasculature and RV myocardium were performed. Results. Four weeks after semaxanib injection, RV end-systolic pressure was higher in SU_M than in SU_F. Males developed marked RV enlargement and systolic dysfunction compared to females. Impairment of RV-PA coupling efficiency was observed only in SU_M. The smooth muscle cells of the pulmonary arteries switched from a contractile state to a dedifferentiated state only in males. Conclusions. Female athymic rats were protected against the development of severe PH. RV-PA coupling was preserved in females through limitation of pulmonary artery muscularization. Control of smooth muscle cells plasticity may be a promising therapeutic approach to reverse established vascular remodeling in PH patients