Published online Oct 26, 2020. doi: 10.4330/wjc.v12.i10.492
Peer-review started: November 26, 2019
First decision: March 18, 2020
Revised: June 8, 2020
Accepted: August 25, 2020
Article in press: August 25, 2020
Published online: October 26, 2020
Abdominal complications in patients who underwent cardiac surgery are rare but the associated mortality varies from 11.0% to 74.0%, which makes the problem relevant. One reason for high mortality rates is late diagnosis. Certain difficulties in diagnosing these complications are associated with the peculiarities of postoperative management and unclear clinical picture due to sedation, analgesia, prolonged mechanical ventilation, and the use of extracorporeal membrane oxygenation. Determining the risk factors for abdominal complications and identifying high-risk groups is an urgent task that may help diagnose abdominal complications and reduce related mortality.
The topic of this study is the identification of leading risk factors for abdominal complications in patients after coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) and the development of a prediction score based on perioperative predictors to reveal patients at a high risk of abdominal complications.
The objectives of this study were to identify risk factors for abdominal complications according to clinical, laboratory, and imaging findings, to determine their rank influence on the development of early abdominal complications after CABG with CPB, and to develop a risk prediction score. The risk score makes it possible to perform early screening and to develop an algorithm of therapeutic and diagnostic measures for the prevention, early diagnosis, and treatment of this pathology.
The factors taken for evaluation were compared between patients with early abdominal complications (n = 73) and without them (n = 6513), and the relative risks were calculated. Statistical data processing was performed using Statistica 10.0 (Statsoft, Tulsa, OK, United States) and SPSS 23.0 (IBM Corp., Armonk, NY, United States). In order to describe the risks, contingency tables were used to calculate the relative risk and the odds ratio. An integrated score for assessing the risk of early abdominal complications was created on the basis of the above-mentioned factors by using multivariate logistic regression analysis. The presence or absence of complications was a dependent variable, while the above-mentioned factors were independent variables. Then, the obtained risk score was evaluated by using a receiver operating characteristic curve analysis. The presence or absence of early abdominal complications was an outcome variable. The ordinate axis (sensitivity) corresponded to the true positive rate; the abscissa axis (1-specificity) corresponded to the false positive rate. It is generally supposed that the area under the receiver operating characteristic curve that is in the range of 0.9-1.0 should be considered as an indicator of the highest informativeness of the diagnostic method. The range of 0.8-0.9 is good, 0.7-0.8 is acceptable, 0.6-0.7 is weak, and 0.5-0.6 is extremely weak.
The leading risk factors of the early abdominal complications after CABG with CPB were multifocal atherosclerosis, extracorporeal membrane oxygenation, intra-aortic balloon pump, atrial fibrillation, perioperative myocardial infarction, and need for resternotomy in the postoperative period. After calculating a score for each of the leading risk factors, we counted a total score for each particular patient. The highest risk was noted in patients with a total score of 7 or more. Further research may be devoted to a prospective assessment of the proposed scale for the prediction of the risk of abdominal complications and the development of an algorithm for the management of high-risk patients.
The developed score predicts the risk of early abdominal complications after CABG with CPB and makes it possible to stratify patients by risk groups. It is important for timely treatment and diagnosis and, ultimately, will help to reduce postoperative mortality in this group of patients.
Future studies should prospectively assess the effectiveness of the proposed method, as well as to create a protocol for the prevention, early diagnosis, and treatment of abdominal complications in high-risk patients.