Impact of Coronary Artery Bypass Grafting on Muscle Mass Reduction on the 7th Postoperative Day

Ischemic heart failure is a chronic and degenerative disease with high morbidity and mortality in the world. Coronary artery bypass grafting is indicated as elective treatment and may cause a catabolic state that depletes energy reserves. Data on body composition evaluation in the postoperative period of major cardiac surgery are limited. Objective: To evaluate the influence of elective coronary artery bypass grafting on body composition on the seventh postoperative day of patients with ischemic heart failure. Methods: A cross-sectional study was carried out in which eighteen volunteers with New York Heart Association Class II and III heart failure underwent coronary artery bypass grafting. The energy and protein reserves of the participants were evaluated by anthropometry in the preoperative and on the seventh postoperative day. Paired t-Test or Mann-Whitney test was used if applicable. A significance level was considered at p value < 0.05. Results: A significant loss of muscle mass was observed through the reduction of arm muscle circumference after surgery (4.2%, p 0.007). Major surgery causes hypermetabolic state and systemic inflammatory stimulus, due to the release of hormones and cytokines that may justify the observed loss of muscle mass. Conclusion: Coronary artery bypass grafting had an impact on muscle mass reduction seven days after surgery in patients with ischemic heart failure

L-carnitine supplementation in the recovery of plasma L-carnitine in patients with heart failure submitted to coronary artery bypass grafting.

Coronary artery bypass grafting reduces plasma L-carnitine and may impair the production of myocardial energy. L-carnitine supplementation may elevate plasma L-carnitine and increase cardiac mechanical efficiency. The objective of this study was to verify the recovery of preoperative plasma LC in patients with heart failure undergoing coronary artery bypass grafting supplemented with a daily oral dose of 50 mg / kg. Volunteers with ischemic heart failure who underwent surgery were randomized into a supplemented group (A-received 50 mg / kg L-carnitine) or placebo group (B) for 60 days. Supplementation was started on the third postoperative day. The spectrophotometric enzymatic method was used to quantify plasma L-carnitine. In the preoperative period, both groups had plasma L-carnitine adequate to the reference range (18.9-71.1 µM). On the second postoperative day, there was a reduction in plasma L-carnitine in groups A (17.4%) and B (14.4%). In the comparison between the groups, plasma L-carnitine was higher in group A than B in 10º (p = 0.024), 30º (p = 0.001), and 60º postoperative day (p = 0.008). Supplementation of L-carnitine at a daily oral dose of 50 mg / kg in patients with heart failure undergoing coronary artery bypass grafting may recover preoperative plasma L-carnitine within 10 days.

Effect of L-Carnitine Supplementation on Reverse Remodeling in Patients with Ischemic Heart Disease Undergoing Coronary Artery Bypass Grafting: A Randomized, Placebo-Controlled Trial.

During cardiac failure, cardiomyocytes have difficulty in using the substrates to produce energy. L-carnitine is a necessary nutrient for the transport of fatty acids that are required for generating energy. Coronary artery graft surgery reduces the plasma levels of L-carnitine and increases the oxidative stress. This study demonstrates the effect of L-carnitine supplementation on the reverse remodeling of patients undergoing coronary artery bypass graft. Patients with ischemic heart failure who underwent coronary graft surgery were randomized to group A - supplemented with L-carnitine or group B controls. Left ventricular ejection fraction, left ventricular systolic and diastolic diameters were assessed preoperatively, 60 and 180 days after surgery. Our study included 28 patients (26 [93.0%] males) with a mean age ± SD of 58.1 ± 10.5 years. The parameters for the evaluation of reverse remodeling did not improve after 60 and 180 days of coronary artery bypass grafting in comparison between groups (p > 0.05). Evaluation within the L-carnitine group showed a 37.1% increase in left ventricle ejection fraction (p = 0.002) and 14.3% (p = 0.006) and 3.3% (p > 0.05) reduction in systolic and diastolic diameters, respectively. L-carnitine supplementation at a dose of 50 mg/kg combined with artery bypass surgery did not demonstrate any additional benefit in reverse remodeling. However, evaluation within the L-carnitine group may indicate a clinical benefit of L-carnitine supplementation.