Con: Can We Influence Postoperative Outcomes of Frail Patients After Cardiac Surgery?

Frail patients are scheduled routinely for elective cardiovascular surgery. Despite the proven association between frailty and postoperative outcomes, currently, there is no consistent evidence that the preoperative optimization of frail patients with preoperative nutrition support and exercise programs can alter postoperative mortality. Established frailty diagnostic tools are not sufficient to grasp the multidimensional nature of frailty in cardiovascular patients. Prehabilitation programs and preoperative nutritional support are time- and resource-consuming and, therefore, are hard to implement in routine clinical practice.

Impact of Immunonutrition on T Cell Activation: A Randomized Control Study in Cardiac Surgery Patients.

Background: Cardiac surgery provokes an intense inflammatory response that can cause an immunosuppressive state and adverse postoperative outcomes. We recently showed that postoperative immunonutrition with glutamine in "fragile" low-risk cardiac surgery patients was associated with a significantly increased level of CD3+ and CD4+ T cells. In order to clarify the biological relevance and clinical importance of these findings, we investigated whether an increase in the CD4+ T cell level was caused by changes in the systemic inflammatory response (caused by surgery or infection) and if it was associated with their activation status. Methods: A randomized control study of low operative risk but "fragile" cardiac surgery patients was performed. Patients were randomized into immunonutrition (IN) and control groups (C). The IN group received normal daily meals plus special immune nutrients for 5 days postoperatively, while the C group received only normal daily meals. Laboratory parameters were investigated before surgery and on the sixth postoperative day and the groups were compared accordingly. The expression of the CD69+ marker was investigated to determine T cell activation status. Serum concentrations of cytokines (interleukin-10 (IL-10), tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6)) and C-reactive protein (CRP) were determined to assess the systemic inflammatory response, while procalcitonin (PCT) levels were evaluated to confirm or deny possible bacterial infection. Results: Fifty-five patients were enrolled in the study. Twenty-seven (49.1%) were randomized in the IN group. Results show that on the sixth postoperative day, the CD4+CD69+ and CD8+CD69+ counts did not differ between the IN and C groups, accordingly 0.25 [0.16-0.50] vs 0.22 [0.13-0.41], p=0.578 and 0.13 [0.06-0.3] vs 0.09 [0.05-0.14], p=0.178. Also, statistically significant differences were not observed in the cytokine levels (IN and C groups: TNF-α 8.13 [7.32-10.31] vs 8.78 [7.65-11.2], p=0.300; IL-6 14.65 [9.28-18.95] vs 12.25 [8.55-22.50], p=0.786; IL-10 5.0 [5.0-5.0] vs 5.0 [5.0-5.0], p=0.343 respectively), which imply that an elevated T cell count is not associated with the systemic inflammatory response. Also, PCT (IN and C groups: 0.03 [0.01-0.09] vs 0.05 [0.03-0.08], p=0.352) and CRP (IN and C groups 62.7 [34.2-106.0] vs 63.7 [32.9-91.0], p=0.840) levels did not differ between the two groups. Moreover, low levels of PCT indicated that the increase in T cell count was not determined by bacterial infection. Conclusions: Our findings showed that CD4+ T cell levels were associated with neither the systemic inflammatory response nor bacterial infection. Secondly, increases in T cells are not accompanied by their activation status. These results suggest a hypothesis that a higher postoperative T cell concentration may be associated with postoperative immunonutrition in low-risk cardiac surgery patients with intact cellular vitality, i.e. "fragile". However, immunonutrition alone did not affect T cell activation status.

The efficacy of early postoperative enteral immunonutrition on T-lymphocyte count: A randomised control study in low-risk cardiac surgery patients.

BACKGROUND: Patients undergoing cardiac surgery have a pronounced immune response that leads to a reduction in cellular immunity. Immune-modulating nutritional supplements are considered to be beneficial for patients undergoing major surgery. However, due to the lack of studies in the cardiac surgery population, the effect of immunonutrition remains unclear in this patient group. OBJECTIVE: Our purpose was to research the efficacy of early postoperative enteral immunonutrition on T-lymphocyte count in the cardiac surgery population. METHODS: This was a randomised control study of low operative risk adult patients, who underwent elective cardiac surgery. These patients were randomised into immunonutrition and control groups. The immunonutrition group was supplemented with immune nutrients for five postoperative days. The counts of T-lymphocytes, as well as the counts for the CD4+ and CD8+ cell subpopulations were determined on the day of surgery and on the sixth postoperative day. RESULTS: Fifty-five patients were enrolled in the study, the mean age was 69.7 ± 6.3 years, 28 (50.9%) of them were males, the median operative risk was 1.75%. Twenty-seven (49.1%) were randomised into the immunonutrition group. The control and the immunonutrition groups were similar before the intervention. The counts of the CD3+ T cells and CD4+ T cells on the sixth postoperative day were significantly higher in the immunonutrition group compared to the control group with 1.42 ± 0.49 vs. 1.12 ± 0.56 (∗109/l), p = 0.035 and 1.02 ± 0.36 vs. 0.80 ± 0.43 (∗109/l), p = 0.048, respectively. Regression analysis was performed to determine the efficacy of the immunonutrition on the counts of the CD3+ and CD4+ T cells; CD3+ T and CD4+ T cell counts were increased to 0.264 (∗109/l), p = 0.039 and 0.232 (∗109/l), p = 0.021, respectively. CONCLUSIONS: Early postoperative immunonutrition increases the count of the CD3+ and CD4+ T cells in cardiac surgical patients. Clinical trials identifier number: NCT04047095.