Early Postoperative Undernutrition Following Aortic Valve Replacement Surgery

Background: Experiencing loss of appetite after cardiac surgery is often noted during daily care and has been described by several studies. However, no information is available on either energy needs or spontaneous food intake following aortic valve replacement surgery. The goal of this study was to assess the risk of early postoperative undernutrition following aortic valve replacement in a group of patients who were preoperatively well-nourished.

Methods: Anthropometrics data (body mass index, fat free mass index, albuminemia and prealbuminemia, extracellular water), energy balance and appetite were assessed in a cross-over prospective observational study. . Each subject was enrolled in two procedures: surgery and routine coronary angiograms which were used for control matched assessment. Data were assessed during the pre-procedure period (d-15 to d-1) and the post-procedure period (d0 to d+4). Energy expenditure was determined by indirect calorimetry.

Results: 15 patients median aged 73 years old [65-77] were included in the study. In post-surgery period, weight and extracellular water were increased and correlated (r2 = 0.571, p = 0.003). CRP was increased from 2 [2;3] to 91 [73;138] (p = 0.001). Ingested calories decreased from 1451 [1272-1640] kcal to 372 [22-528] kcal (p = 0.001) while energy expenditure was increased from 1358 [1180-1559] kcal to 1613 [1472-1670] kcal (p = 0.002). A severe loss of appetite was noted (p = 0.011). None of these changes were observed in the control phase.

Conclusion: Energy balance was strongly negative after cardiac surgery. Cardiac surgery increased endogenous metabolism by 20% and a severe loss of appetite decrease food intake by 75%, which does not make it possible to compensate for the increase in resting energy expenditure.