Relation of body mass index to long-term survival and cardiac remodelling for patients undergoing mitral valve replacement surgery.

BACKGROUND AND AIMS: Studies have demonstrated that obesity is paradoxically associated with reduced mortality following cardiac surgery. However, these studies have treated various types of cardiac surgery as a single entity. With mitral valve (MV) surgeries being the fastest-growing cardiac surgical interventions in North America, the purpose of this study was to identify the impact of body mass index (BMI) on long-term survival and cardiac remodelling of patients undergoing MV replacement (MVR). METHODS AND RESULTS: In this retrospective, single-center study, 1071 adult patients who underwent an MVR between 2004 and 2018 were stratified into five BMI groups (<20, 20-24.9, 25-29.9, 30-34.9, >35). Cox proportional hazard regression models were used to determine the association between BMI and all-cause mortality. Patients who were underweight had significantly higher all-cause mortality rates at the longest follow-up (median 8.2 years) than patients with normal weight (p = 0.01). Patients who were in the obese group had significantly higher readmission rates due to myocardial infarction (MI) at the longest follow-up (p = 0.017). Subgroup analysis revealed a significant increase in long-term all-cause mortality for female patients who were underweight. Significant changes in left atrial size, mitral valve peak and mean gradients were seen in all BMI groups. CONCLUSIONS: For patients undergoing mitral valve replacement, BMI is unrelated to operative outcomes except for patients who are underweight.

Resveratrol attenuates stimulated T-cell activation and proliferation: potential therapy against cellular rejection in organ transplantation.

BACKGROUND: Pharmaceuticals to inhibit mammalian target of rapamycin (mTOR) protein, which plays an integral role in T cell survival and function, have been used to prevent complications associated with organ transplantation. Although studies have individually shown that resveratrol can inhibit mTOR and that inhibiting mTOR leads to attenuated immune function, no studies to date have examined these two functions conjointly under one study. Therefore, we hypothesize that resveratrol will decrease mTOR activation and expression as well as attenuate stimulated T cell activation and proliferation in peripheral blood mononuclear cells (PBMC). METHODS AND MATERIALS: Human PBMC were isolated and cultured. The cells were pre-treated with resveratrol (50 µM) overnight (18 hrs) before stimulation. The cells were collected for subsequent biochemical analysis after 1, 3, and 5 days. Additionally, the cells were stained with proliferation dye and cultured for 24 hours in PMA/Ionomycin with resveratrol for flow cytometry analysis. RESULTS: Resveratrol treated stimulated PBMCs displayed a significant decrease in activated phosphorylation of mTOR at days 1, 3, and 5 (P < 0.0329). Markers of T cell activation, tumour necrosis factor-alpha (TNF-α) and interferon-gamma (INF-γ), were also significantly reduced along with T cell proliferation following stimulated PBMC resveratrol treatment when compared to vehicle-treated controls (P < 0.01). CONCLUSION: Taken together, our data suggest that resveratrol can decrease the immune response of stimulated T-cells and inhibit the expression and activation of mTOR mediated cellular signalling under the same study setting. Therefore, resveratrol proposes a possible adjunctive therapy option for patients undergoing organ transplantation.