Development and validation of mortality prediction models for heart transplantation using nutrition-related indicators: a single-center study from China.

Objective: We sought to develop and validate a mortality prediction model for heart transplantation (HT) using nutrition-related indicators, which clinicians could use to identify patients at high risk of death after HT. Method: The model was developed for and validated in adult participants in China who received HT between 1 January 2015 and 31 December 2020. 428 subjects were enrolled in the study and randomly divided into derivation and validation cohorts at a ratio of 7:3. The likelihood-ratio test based on Akaike information was used to select indicators and develop the prediction model. The performance of models was assessed and validated by area under the curve (AUC), C-index, calibration curves, net reclassification index, and integrated discrimination improvement. Result: The mean (SD) age was 48.67 (12.33) years and mean (SD) nutritional risk index (NRI) was 100.47 (11.89) in the derivation cohort. Mortality after HT developed in 66 of 299 patients in the derivation cohort and 28 of 129 in the validation cohort. Age, NRI, serum creatine, and triglyceride were included in the full model. The AUC of this model was 0.76 and the C statistics was 0.72 (95% CI, 0.67-0.78) in the derivation cohort and 0.71 (95% CI, 0.62-0.81) in the validation cohort. The multivariable model improved integrated discrimination compared with the reduced model that included age and NRI (6.9%; 95% CI, 1.8%-15.1%) and the model which only included variable NRI (14.7%; 95% CI, 7.4%-26.2%) in the derivation cohort. Compared with the model that only included variable NRI, the full model improved categorical net reclassification index both in the derivation cohort (41.8%; 95% CI, 9.9%-58.8%) and validation cohort (60.7%; 95% CI, 9.0%-100.5%). Conclusion: The proposed model was able to predict mortality after HT and estimate individualized risk of postoperative death. Clinicians could use this model to identify patients at high risk of postoperative death before HT surgery, which would help with targeted preventative therapy to reduce the mortality risk.

Case report: Successful percutaneous extracorporeal magnetic levitation ventricular assist device support in a patient with left heart failure due to dilated cardiomyopathy.

Introduction: Mechanical circulatory support (MCS) can help to maintain hemodynamic stability, improve cardiac function, reduce cardiac load, and is an important method for the treatment of advanced heart failure. However, traditional MCS systems [IABP, Impella, TandemHerat, veno-arterial extracorporeal membrane oxygenation (VA-ECMO)] are associated with limitations including trauma, a high rate of complications (hemolysis, bleeding) and require complex care from nurses. Case summary: We report a case of left heart failure resulting from dilated cardiomyopathy in a 24 years-old man. A catheter was placed through the right jugular vein and a drainage tube was positioned under ultrasound guidance through the superior vena cava, right atrium, atrial septum, to the left atrium, and returned to the axillary artery using an extracorporeal magnetic levitation ventricular assist device (VAD). The patient was successfully supported for 10 days and bridged to heart transplant. Discussion: To the best of our knowledge, this is the first report of the use of an extracorporeal magnetic levitation VAD for MCS via a percutaneous approach. Our findings support the wider use of this strategy for patients awaiting myocardial recovery or who require heart bridging or transplantation.

Aorta Regulatory T Cells with a Tissue-Specific Phenotype and Function Promote Tissue Repair through Tff1 in Abdominal Aortic Aneurysms.

In addition to maintaining immune tolerance, Foxp3+ regulatory T cells (Tregs) perform specialized functions in tissue homeostasis and remodeling. However, whether Tregs in aortic aneurysms have a tissue-specific phenotype and function is unclear. Here, a special group of Tregs that potentially inhibit abdominal aortic aneurysm (AAA) progression are identified and functionally characterized. Aortic Tregs gradually increase during the process of AAA and are mainly recruited from peripheral circulation. Single-cell TCR sequencing and bulk RNA sequencing demonstrate their unique phenotype and highly expressed trefoil factor 1 (Tff1). Foxp3cre/cre Tff1flox/flox mice are used to clarify the role of Tff1 in AAA, suggesting that aortic Tregs secrete Tff1 to regulate smooth muscle cell (SMC) survival. In vitro experiments confirm that Tff1 inhibits SMC apoptosis through the extracellular signal-regulated kinase (ERK) 1/2 pathway. The findings reveal a tissue-specific phenotype and function of aortic Tregs and may provide a promising and novel approach for the prevention of AAA.