Intraoperative Use of Intra-Aortic Balloon Pump to Generate Pulsatile Flow During Heart Transplantation: A Single-Center Experience.

The physiologic impact of pulsatile flow (PF) on end-organ perfusion during cardiopulmonary bypass (CPB) is controversial. Using an intra-aortic balloon pump (IABP) to maintain PF during CPB for patients undergoing heart transplantation (HT) may impact end-organ perfusion, with implications for postoperative outcomes. A single-center retrospective study of 76 patients bridged to HT with IABP was conducted between January 2018 and December 2022. Beginning in May 2022, patients received IABP-generated PF during CPB at an internal rate of 80 beats/minute. Fifty-eight patients underwent HT with the IABP turned off (IABP-Off), whereas 18 patients underwent HT with IABP-generated PF (IABP-On). The unmatched IABP-On group experienced shorter organ ischemia times (180 vs . 203 minutes, p = 0.015) and CPB times (104 vs . 116 minutes, p = 0.022). The cohort was propensity matched according to age, organ ischemia time, and CPB time. Elevations in postoperative lactates in the immediate (2.8 vs . 1.5, p = 0.062) and 24 hour (4.7 vs . 2.4, p = 0.084) postoperative periods trended toward significance in the matched IABP-Off group. There was no difference in postoperative vasoactive inotropic score (VIS), postoperative creatinine, or length of stay. This limited preliminary data suggest that maintaining counterpulsation to generate PF during CPB may improve end-organ perfusion in this patient population as suggested by lower postoperative lactate levels.

Midterm outcomes of aortic valve replacement using a rapid-deployment valve for aortic stenosis: TRANSFORM trial.

Background: The use of rapid-deployment valves (RDVs) has been shown to reduce the operative time for surgical aortic valve replacement (AVR). Long-term core laboratory-adjudicated data are scarce, however. Here we report final 7-year data on RDV use. Methods: TRANSFORM was a prospective, nonrandomized, multicenter, single-arm trial implanting a stented bovine pericardial valve with an incorporated balloon-expandable sealing frame. A prior published 1-year analysis included 839 patients from 29 centers. An additional 46 patients were enrolled and implanted, for a total of 885 patients. Annual clinical and core laboratory-adjudicated echocardiographic outcomes were collected through 8 years. Primary endpoints were structural valve deterioration (SVD), all-cause reintervention, all-cause valve explantation, and all-cause mortality. Secondary endpoints included hemodynamic performance assessed by echocardiography. The mean duration of follow-up was 5.0 ± 2.0 years. Results: The mean patient age was 73.3 ± 8.2 years. Isolated AVR was performed in 62.1% of the patients, and AVR with concomitant procedures was performed in 37.9%. Freedom from all-cause mortality at 7 years was 76.0% for isolated AVR and 68.2% for concomitant AVR. Freedom from SVD, all-cause reintervention, and valve explantation at 7 years was 97.5%, 95.7%, and 97.8%, respectively. The mean gradient and effective orifice area at 7 years were 11.1 ± 5.3 mm Hg and 1.6 ± 0.3 cm2, respectively. Paravalvular leak at 7 years was none/trace in 88.6% and mild in 11.4%. In patients undergoing isolated AVR, the cumulative probability of pacemaker implantation was 13.9% at 30 days, 15.5% at 1 year, and 21.8% at 7 years. Conclusions: AVR for aortic stenosis using an RDV is associated with low rates of late adverse events. This surgical pericardial tissue platform provides excellent and stable hemodynamic performance through 7 years.

Colorimetric Detection of Mutant ß-Amyloid(1-40) Membrane-Active Aggregation with Biosensing Vesicles.

Alzheimer's disease (AD) is a protein misfolding disease commonly characterized by neuritic amyloid plaques and proteinaceous fibrillar aggregate deposits composed of ß-amyloid (Aß) aggregates. The dynamic aggregation of Aß forms toxic, nanoscale aggregate species which proceed from oligomers to fibrils. Currently, there is need for rapid and direct detection of Aß peptide aggregation and interaction with lipid membranes, as detecting an interaction with various lipid environments will provide insights to better understand how interactions may modulate membrane function on cellular surfaces, leading to the progression of AD. The goal of this study was to utilize a colorimetric, biomimetic, vesicle-binding assay as a biosensor to detect and investigate the occurrence of neurodegenerative disease-associated protein aggregation and interaction with lipid membranes. Lipid/polydiacetylene (PDA) vesicles were exposed to monomeric preparations of Wild Type Aß(1-40) or point mutations in Aß with amino acid substitutions that are commonly associated with familial AD (E22G Arctic, E22Q Dutch, A21G Flemish, D23N Iowa, and E22K Italian). We investigated how these substitutions affect Aß(1-40) aggregation and interaction with lipid vesicles designed to mimic biological membranes. Time-resolved colorimetric measurements were obtained and reveal that exposure to lipid/PDA vesicle biosensors results in the direct detection of mutant Aß(1-40) peptide-lipid interaction events. Aß(1-40) peptide aggregate membrane activity varies among Aß peptide variants and lipid composition. In addition, we used atomic force microscopy and Thioflavin T fluorescence assays to distinguish the stages of Aß(1-40) aggregate formation, morphology, and membrane activity. These studies provide a simple means of aggregate detection and insight into the role of cellular surfaces in the mechanism of AD aggregation.