Simple Blood and Weight Index Predicts Complications After Heart Bypass Surgery in the Elderly

Coronary artery bypass grafting, one of the most common and demanding operations in cardiac surgery, saves countless lives each year, but its outcomes in older patients remain stubbornly unpredictable. Now, a research team in China reports that a remarkably simple number, calculated from just two blood fat measurements and a patient’s body weight, may predict which elderly patients are most likely to suffer complications after the procedure. The study, published in BMC Geriatrics, suggests that this composite measure, known as the triglycerides-total cholesterol-body weight index, or TCBI, outperforms established nutritional screening tools in identifying surgical risk before the operation even begins.

The research, led by Pan Peng of the Institute of Nursing Research at Wuhan University of Science and Technology together with colleagues at Wuhan Asian Heart Hospital, focused on a population where the stakes are especially high. Elderly patients undergoing coronary artery bypass grafting face a well-documented elevated risk of postoperative problems, including infections, arrhythmias, renal dysfunction, and prolonged hospital stays. One of the key contributors to this vulnerability is malnutrition, which is both widespread in older adults and frequently overlooked in the busy preoperative workup. The challenge for clinicians has been finding a reliable, inexpensive way to assess nutritional status in this group before they enter the operating room.

TCBI was designed with simplicity in mind. It is calculated by multiplying a patient’s triglyceride level by their total cholesterol level and their body weight, then dividing the product by one thousand. All three inputs are routinely measured in any patient being prepared for cardiac surgery, which means the index can be computed without additional tests, specialized equipment, or extra cost. Previous studies had already linked TCBI to prognosis in patients with heart failure and aortic dissection, but until now, no research had examined whether the index could predict outcomes in patients undergoing coronary artery bypass grafting.

To fill that gap, the team conducted a retrospective analysis of 343 elderly patients who underwent coronary artery bypass grafting at Wuhan Asian Heart Hospital between January 2022 and May 2023. The researchers gathered preoperative data on each patient, including blood lipid values, body weight, and a range of clinical variables, and then tracked whether complications occurred after surgery. Of the 343 patients studied, 126, or 36.7 percent, experienced postoperative complications, a figure that underscores the scale of the problem in this age group.

The analytical approach combined modern statistical techniques with classical risk modeling. The team first used least absolute shrinkage and selection operator, or LASSO, regression, a method that compresses the influence of weak predictors and selects the most informative variables from a large pool, to identify candidate factors associated with complications. They then applied multivariate logistic regression to determine which of those candidates remained independently predictive. TCBI emerged as an independent influencing factor for postoperative complications, with an odds ratio of 0.995 per unit increase and a 95 percent confidence interval of 0.994 to 0.997, a result that was highly statistically significant. In practical terms, the lower a patient’s TCBI, the greater their odds of suffering a complication after surgery.

The dose-response pattern in the data was striking. When patients were divided into four groups, or quartiles, according to their TCBI values, the incidence of complications rose progressively from the highest quartile to the lowest. Patients in the highest TCBI quartile fared best, while those in the lowest quartile experienced the highest complication rates, and the trend across the groups was statistically significant. This graded relationship, which the researchers also examined using restricted cubic splines, strengthens the argument that the association between TCBI and surgical outcomes is not a statistical fluke but a genuine biological signal.

Perhaps the most consequential finding came when the researchers pitted TCBI against three established nutritional assessment tools: the Controlling Nutritional Status score, the Prognostic Nutritional Index, and the Geriatric Nutritional Risk Index. Using receiver operating characteristic curves, which measure how well a test distinguishes between patients who will and will not experience an outcome, the team calculated the area under the curve for each index. TCBI achieved an area under the curve of 0.820, with a 95 percent confidence interval of 0.777 to 0.864, a level of discrimination generally considered good. Pairwise comparisons using DeLong’s test showed that TCBI’s predictive performance was significantly better than that of all three competing indices, with p values below 0.001.

The analysis also yielded a practical threshold. The optimal cut-off value for TCBI was determined to be 510.75, a level at which the index achieved a sensitivity of 74.7 percent, meaning it correctly identified nearly three quarters of patients who went on to develop complications, and a specificity of 77.0 percent, meaning it correctly cleared more than three quarters of patients who did not. For a tool that costs nothing beyond tests already being performed, that combination of sensitivity and specificity is notable, and it gives clinicians a concrete number they can act on during preoperative planning.

The biological rationale behind the index is grounded in the interplay between lipid metabolism and nutritional reserves. Triglycerides and total cholesterol reflect both metabolic state and the availability of energy stores, while body weight serves as a rough proxy for overall nutritional reserves and lean mass. In elderly surgical patients, low values across all three components may indicate depleted reserves and a diminished capacity to withstand the physiological stress of major cardiac surgery, including the inflammatory response triggered by cardiopulmonary bypass and the catabolic demands of wound healing. A patient entering surgery with inadequate nutritional reserves is less equipped to mount that response, which may help explain why low TCBI values track so closely with postoperative complications.

The authors conclude that TCBI may serve as a novel and effective nutritional assessment indicator for predicting postoperative complications in elderly patients undergoing coronary artery bypass grafting, and they recommend that healthcare professionals pay close attention to preoperative TCBI scores in order to reduce the incidence of complications. If the findings are confirmed in prospective and multi-center studies, a single calculation performed during routine preoperative blood work could help surgical teams identify high-risk elderly patients early, allowing time for nutritional optimization, intensified monitoring, and tailored perioperative care before the patient reaches the operating table. For a population in which more than one in three patients currently experiences a complication after bypass surgery, a free and simple number that flags risk in advance could prove a genuinely valuable addition to cardiac surgical practice.

Subject of Research: Predictive value of the triglycerides-total cholesterol-body weight index for postoperative complications in elderly coronary artery bypass grafting patients

Article Title: Predictive value of triglycerides-total cholesterol-body weight Index for postoperative complications in elderly patients undergoing coronary artery bypass grafting

Article References: Peng, P., Zhou, S., Liu, Y., Yang, Q., Zou, Q., Geng, L., Zhang, W., & Zhang, Y. (2026). Predictive value of triglycerides-total cholesterol-body weight Index for postoperative complications in elderly patients undergoing coronary artery bypass grafting. BMC Geriatrics. https://doi.org/10.1186/s12877-026-08406-6

Image Credits: AI Generated

DOI: 10.1186/s12877-026-08406-6

Keywords: TCBI, coronary artery bypass grafting, elderly patients, nutritional assessment, postoperative complications, triglycerides, total cholesterol, body weight, ROC analysis, LASSO regression, cardiac surgery, malnutrition