Advanced artificial intelligence-guided hemodynamic management within cardiac enhanced recovery after surgery pathways: A multi-institution review.

Objective: The study objective was to report early outcomes of integrating Hypotension Prediction Index-guided hemodynamic management within a cardiac enhanced recovery pathway on total initial ventilation hours and length of stay in the intensive care unit. Methods: A multicenter, historical control, observational analysis of implementation of a hemodynamic management tool within enhanced recovery pathways was conducted by identifying cardiac surgery cases from 3 sites during 2 time periods, August 1 to December 31, 2019 (preprogram), and April 1 to August 31, 2021 (program). Reoperations, emergency (salvage), or cases requiring mechanical assist were excluded. Data were extracted from electronic medical records and chart reviews. Two primary outcome variables were length of stay in the intensive care unit (using Society of Thoracic Surgeons definitions) and acute kidney injury (using modified Kidney Disease Improving Global Outcomes criteria). One secondary outcome variable, total initial ventilation hours, used Society of Thoracic Surgeons definitions. Differences in length of stay in the intensive care unit and total ventilation time were analyzed using Kruskal-Wallis and stepwise multiple linear regression. Acute kidney injury stage used chi-square and stepwise cumulative logistic regression. Results: A total of 1404 cases (795 preprogram; 609 program) were identified. Overall reductions of 6.8 and 4.4 hours in intensive care unit length of stay (P = .08) and ventilation time (P = .03) were found, respectively. No significant association between proportion of patients identified with acute kidney injury by stage and period was found. Conclusions: Adding artificial intelligence-guided hemodynamic management to cardiac enhanced recovery pathways resulted in associated reduced time in the intensive care unit for patients undergoing nonemergency cardiac surgery across institutions in a real-world setting.

Mid-term outcomes of concomitant Cox-Maze IV: Results from a multicenter prospective registry.

BACKGROUND: Benefits of concomitant atrial fibrillation (AF) surgical treatment are well established. Cardiac societies support treating AF during cardiac surgery with a class I recommendation. Despite these guidelines, adoption has been inconsistent. We report results of routine performance of concomitant Cox-Maze IV (CMIV) from participating centers using a standardized, prospective registry. METHODS: Nine surgeons at four cardiac surgery programs enrolled 807 patients undergoing concomitant CMIV surgery over 12 years. Lesions were created using bipolar radiofrequency clamps and cryoablation probes. Follow-up occurred at 3- and 6-months, then annually for 3 years. Freedom from AF was defined as no episode >30 s of atrial arrhythmia. RESULTS: Sixty-four percent of patients were male, mean age 69 years, mean left atrial size 4.6 cm, mean preoperative AF duration 4.0 years, mean EuroSCORE 6.4, and mean CHADS2 score 3.1. Thirty-day postoperative mortality and neurologic event rates were 3.3% and 1.3%, respectively. New pacemaker implant rate was 6.3%. Freedom from AF rates at 1- and 3-years stratified by preoperative AF type were: paroxysmal 94.6% and 87.5%, persistent 82.1% and 81.9%, and longstanding persistent 84.1% and 78.1%. At 3-year follow up, 84% of patients were off antiarrhythmic drugs and 74% of sinus rhythm patients were off oral anticoagulants. CONCLUSIONS: Routine CMIV is safe and effective. Acceptable outcomes can be achieved across multiple centers and multiple operators even in a moderate risk patient population undergoing more complex procedures. Surgeons and institutions should be encouraged by all cardiac societies to adopt the CMIV procedure to maximize patient benefit.

Long-term Results With CorMatrix Extracellular Matrix Patches After Carotid Endarterectomy.

BACKGROUND: Previous reports of extracellular matrix (ECM) patch use after carotid endarterectomy (CEA) have noted an approximately 10% rate of pseudoaneurysm (PSA) formation. PSA-related rupture of ECM patches has also been described after femoral artery repair. In these studies, different thicknesses (4-ply versus 6-ply) and no standard length of soaking the patch in saline before implantation were used. Herein, we describe our experience with ECM CorMatrix patches in 291 CEAs with 6-ply patches. METHODS: The records of 275 consecutive patients undergoing 291 CEAs with CorMatrix 6-ply patches beginning in November of 2011 and extending until 2015 were reviewed. Only 6-ply patches and a 1 min hydration time in saline were used in all patients. No shunts were used. RESULTS: There were three deaths within the first 30 d secondary to subsequent cardiac surgical procedures. Nine patients experienced a perioperative stroke (3.1%), only one of which occurred secondary to an occluded internal carotid artery. One patient had a transient ischemic attack with a patent endarterectomy site. In follow-up, 11 patients (4.5%) developed severe recurrent stenoses requiring reintervention. Only one patient (0.34%) developed a PSA at 2 years possibly secondary to chronic infection. The median follow-up was 72 mo. CONCLUSIONS: Our experience with 6-ply CorMatrix ECM patches and a brief period of soaking demonstrated that these patches performed well in patients requiring a CEA. Only one PSA was noted.

Supplemental enteral arginine is metabolized to ornithine in injured patients.

BACKGROUND: Arginine has been added to immune enhancing diets that may improve patient outcomes, but little is known about the metabolic fate of supplemental arginine. We hypothesize that supplemental enteral arginine in injured patients is metabolized to ornithine by increased activity of the enzyme arginase. MATERIALS AND METHODS: Twenty-five adult patients with injury severity scores > or =20 received up to 14 days of enteral nutrition supplemented with arginine (30 g/day) or placebo in a prospective, randomized, blinded study. Plasma arginine, citrulline, and ornithine concentrations and peripheral blood mononuclear cell (PBMC) arginase activity were measured at baseline and on days 1, 3, 5, 7, 10, and 14. Clinical data collected included demographics, injury patterns, lengths of stay, and infectious complications. Data were analyzed using ANOVA and t test. RESULTS: PBMC arginase activity was elevated in all patients. In the supplemented group, plasma arginine concentrations increased at days 7, 10, and 14 when compared to baseline (P < 0.05) and were higher at day 14 when compared to those of controls (P < 0.05). Citrulline concentrations in both groups were unchanged over time. Ornithine concentration increased within 24 h of arginine supplementation and remained elevated when compared to baseline (P < 0.01). Ornithine concentration in the supplemented group was higher at days 1, 3, 5, and 7 when compared to that of controls (P < 0.05). There were no differences in clinical outcomes. CONCLUSIONS: Supplemental enteral arginine is absorbed in injured patients and increases arginine levels. Supplemental arginine appears to be metabolized to ornithine. Increased arginase enzyme activity in peripheral blood mononuclear cells may be a contributor.

Regulation of arginase expression by T-helper II cytokines and isoproterenol.

BACKGROUND: Trauma causes a release of catecholamines, transforming growth factor-beta (TGF-beta), and T-helper II cytokines (TH2). Individually, these substances also induce arginase in macrophages. The purpose of this study was to determine the synergistic interactions between isoproterenol, TGF-beta, and TH2 cytokines on arginase expression in macrophages. METHODS: Confluent RAW 264.7 macrophages were incubated with various combinations of interleukins 4, 10, and 13 (IL-4, IL-10, IL-13), and TGF-beta with isoproterenol over 48 hours. Arginase activity, as well as arginase I expression by Western blot and reverse transcriptase-polymerase chain reaction, were measured. RESULTS: Although isoproterenol, IL-4, IL-10, and IL-13 individually induced arginase, significant synergy between the combination of isoproterenol with either TGF-beta or the TH2 cytokines was observed. All cytokines except IL-10 also induced arginase I protein and mRNA. Arginase II protein was detected in cells exposed to IL-10. CONCLUSIONS: We conclude that isoproterenol synergizes with IL-4, IL-13, and TGF-beta to increase arginase I mRNA and protein, as well as arginase activity in RAW 264.7 macrophages. Further, IL-10 synergizes with isoproterenol to increase arginase activity and arginase II protein. These synergistic mechanisms may compete with nitric oxide synthase for l-arginine substrate, thus shunting away available arginine from nitric oxide production and contributing to cellular immunosuppression observed after trauma.