Surgical Treatment of Patients With Cardiac Cachexia: Appendix
The second purpose of preoperative nutritional support is an earlier resumption of postoperative IVH. Anthropometric studies have revealed that body protein composition is catabolized when glucose is relatively depleted. Even though oral intake could be started in the early stages after cardiac surgery, inadequate oral intake may last for a long time afterwards, causing poor recovery in plasma protein levels. Most patients with cardiac cachexia need a longer period of postoperative respiratory support than patients with normal nutritional status. In these patients, an earlier resumption of nutritional support after surgery is necessary to provide glucose intravenously, prevent metabolic catabolism, and aid the excretion of metabolic end products in urine.
From an immunologic perspective, immunologic reaction was reported to be worse in patients with cardiac cachexia than in patients with normal nutrition. According to the report of Hirose et al, most perioperative deaths were related to multiple organ failure triggered by or followed by pulmonary infection. Hirose et al also suggested a close relationship between nutritional status and immunologic reaction, and advocated that patients with malnutrition be put on preoperative nutritional support to improve their immunologic condition. Actually, based on our present series, it is more likely that prolonged respiratory failure leads to serious pulmonary infection and multiple organ failure more antibiotics online. Furthermore, we noticed a trend in which patients with cardiac cachexia demonstrated a negative skin reaction, but this became positive in a few patients after preoperative nutritional support for longer than 4 weeks. From these reports and our experience, we consider that malnutrition associated with cardiac cachexia and immunologic reaction are closely related. Generally, many immunologic deficits, like reduction in thymic activity, depletion of lymphocytes in the spleen, and decreased production of several cytokines, have been noted in malnourished patients, although the data linking these deficits to patient outcome are still equivocal.
After an average follow-up of more than 5 years, late mortality (24 percent) has been high even though patients were able to survive the operation. The chief factor jeopardizing late survival was progressive congestive heart failure due to myocardial damage, more common with long-term disease, despite the successful intracardiac repair. Patients whose preoperative myocardium was severely compromised would require more careful postoperative follow-up on an outpatient basis, as a potentially safe condition can soon become unduly risky due to factors that are not apparent at hospital discharge.
In summary, overall operative mortality was un-acceptably high in patients with cardiac cachexia associated with mitral valve disease. However, preoperative nutritional support by IVH resulted in a significant decrease in the incidence of postoperative respiratory failure, as well as in operative mortality. In contrast, postoperative respiratory failure occurred in a high percentage of patients who did not have preoperative nutritional support, even if left atrial plication was successfully performed. On the basis of these data, we recommend that preoperative nutritional intervention as well as earlier resumption of postoperative IVH should be conducted to improve the nutritional status of patients whose oral intake remains inadequate for more than several postoperative days.