Non-coronary Surgery Research Articles

Hybrid feature selection in a machine learning predictive model for perioperative myocardial injury in noncoronary cardiac surgery with cardiopulmonary bypass.

Perioperative myocardial injury (PMI) is associated with increased mobility and mortality after noncoronary cardiac surgery. However, limited studies have developed a predictive model for PMI. Therefore, we used hybrid feature selection (FS) methods to establish a predictive model for PMI in noncoronary cardiac surgery with cardiopulmonary bypass (CPB). This was a single-center retrospective study conducted at the Fuwai Hospital in China. Patients aged 18-70years who underwent elective noncoronary surgery with CPB at our institution from December 2018 to April 2021 were enrolled. The primary outcome was PMI, defined as the postoperative cardiac troponin I (cTnI) levels exceeding 220 times of upper reference limit (URL). Statistical analyses were conducted by Python (Python Software Foundation, version 3.9.7 and integrated development environment Jupyter Notebook 1.1.0) and SPSS software version 26.0 (IBM Corp., Armonk, New York, USA). A total of 1130 patients were eventually eligible for this study. The incidence of PMI was 20.3% (229/1130) in the overall patients, 20.6% (163/791) in the training dataset, and 19.5% (66/339) in the testing dataset. The logistic regression model performed the best AUC of 0.6893 (95 CI%: 0.6371-0.7382) by the traditional selection method, and the random forest model performed the best AUC of 0.6937 (95 CI%: 0.6416-0.7423) by the union of Wrapper and Embedded method, and the CatBoost model performed the best AUC of 0.6828 (95 CI%: 0.6304-0.7320) by the union of Embedded and forward logistic regression technique, and the Naïve Bayes model achieved the best AUC with 0.7254 (95 CI%: 0.6746-0.7723) by forwarding logistic regression method. Moreover, the decision tree, KNeighborsClassifier, and support vector machine models performed the worse AUC in all selection forms. Furthermore, the SHapley Additive exPlanations plot showed that prolonged CPB, aortic clamp time, and preoperative low platelets count were strongly related to the PMI risk. In total, four category feature selection methods were utilized, comprising five individual selection techniques and 15 combined methods. Notably, the combination of logistic regression and embedded methods demonstrated outstanding performance in predicting PMI risk. We also concluded that the machine learning model, including random forest, catboost, and Naive Bayes, were suitable candidates for establishing PMI predictive model. Nevertheless, additional investigation and validation are imperative for substantiating these finding.

Minimized extracorporeal circulation in non-coronary surgery.

Minimally invasive extracorporeal circulation (MiECC) technology is characterized by improved biocompatibility due to closed-loop design, minimized priming, and markedly reduced artificial surface. Despite well-evidenced clinical advantages in coronary surgery, MiECC penetration in complex open-heart surgery is low. Concerns have been raised by surgeons and perfusionist regarding safety of perfusion in situations when the heart is opened and air is entering the closed system. Moreover, issues of blood and volume management are deemed impractical without having a reservoir. In the evolution of MiECC safety aspects as well as means of air and volume management have been addressed. The integration of active air removal devices, and the possibility of venting and volume buffering made MiECC suitable for valvular or even more complex surgery. However, typical clinical benefits found with MiECC in coronary artery bypass grafting (CABG) surgery, in particular blood sparing effects, were not reproducible. Air handling and blood management remain the main issues of MiECC in non-coronary surgery. With the introduction of modular (type IV) MiECC systems containing a second, accessory circuit for immediate conversion to open cardiopulmonary bypass (CPB), the last obstacles seem to be cleared away. The first reports using this latest development in MiECC technology sound promising. It is now up to the cardiac surgical community to adopt this technology and produce data helping to answer the question whether MiECC is the best perfusion strategy for all comer's cardiac surgery.

Safe cross-clamp time using Custodiol®-histidine-tryptophan-ketoglutarate cardioplegia in the adult.

Safe cross-clamp time using single-dose Custodiol®-histidine-tryptophan-ketoglutarate cardioplegia has not been established conclusively. Immediate post-operative outcomes of 1,420 non-consecutive, cardiac surgery patients were reviewed retrospectively. Predictors of a combined endpoint made of in-hospital mortality and any major complication post-surgery were found with the multivariable method. Analysis of variance was used to evaluate the impact of cross-clamp time on most relevant complications. Discriminatory power and cut-off value of cross-clamp time were established for in-hospital mortality and each of the major complications (receiver operating characteristic curve analysis). A comparative analysis (with propensity matching) with multidose cold blood cardioplegia on in-hospital mortality post-surgery was performed in non-coronary surgery patients. Coronary, aortic valve and mitral valve surgery and surgery on thoracic aorta were performed in 45.4%, 41.9%, 49.5%, 20.6% of cases, respectively. In-hospital mortality and the rate of any major complication post-surgery were 6.5% and 41.9%, respectively. Cross-clamp time had significant impact on in-hospital mortality and almost all major post-operative complications, except neurological dysfunctions (p = 0.084), myocardial infarction (p = 0.12) and mesenteric ischaemia (p = 0.85). Areas under the receiver operating characteristic curve and the optimal cut-off values for in-hospital mortality and any major complication were of 0.657, 0.594, >140 and >127 minutes, respectively. Comorbidities-adjusted odds ratio for any major complication of cross-clamp time <127 minutes was 1.86 (p < 0.0001). Despite similar in-hospital mortality (p = 0.57), there was an earlier significant increase of mortality in Custodiol-HTK than in multidose cold blood propensity-matched, non-coronary surgery patients. The use of Custodiol-HTK cardioplegia is associated with a low risk of serious post-operative complications provided that cross-clamp time is of 2 hours or less.

Non-coronary cardiac surgery and percutaneous cardiology procedures in aircrew.

This manuscript focuses on the broad aviation medicine considerations that are required to optimally manage aircrew following non-coronary surgery or percutaneous cardiology interventions (both pilots and non-pilot aviation professionals). Aircrew may have pathology identified earlier than non-aircrew due to occupational cardiovascular screening and while aircrew should be treated using international guidelines, if several interventional approaches exist, surgeons/interventional cardiologists should consider which alternative is most appropriate for the aircrew role being undertaken; liaison with the aircrew medical examiner is strongly recommended prior to intervention to fully understand this. This is especially important in aircrew of high-performance aircraft or in aircrew who undertake aerobatics. Many postoperative aircrew can return to restricted flying duties, although aircrew should normally not return to flying for a minimum period of 6 months to allow for appropriate postoperative recuperation and assessment of cardiac function and electrophysiology.

EP11 DOES TYPE OF CARDIOPLEGIA AFFECT THE INCIDENCE OF POSTOPERATIVE PAROXYSMAL ATRIAL FIBRILLATION IN PATIENTS UNDERGOING CARDIAC SURGERY?

Abstract Background and Aim: Paroxysmal atrial fibrillation (PAF) is the most frequent complication following cardiac surgery. Despite high incidence, its etiology remains uncler. Aim of our investigation was to analyze retrospectively the pathogenetic role of different types of cardioplegia on the onset of PAF. Methods: Sixty-hundred and sixty patients underwent on-pump cardiac surgery between January 2015 and October 2016. Redo operations and emergency surgery were excluded. The types of cardiolplegic solution administered were warm blood cardioplegia (Calafiore, n = 480), cold crystalloid extracellular cardioplegia (St. Thomas, n = 71), cold crystalloid intracellular cardioplegia (Custodiol, n = 109). The way of admistation was antegrade for all types of cardioplegic solution. Results: The incidence of postoperative PAF was 36.2% (239 patients). Two-hundred patients were initially treated by mens of amiodarone infusion that successfully allowed cardioversion in 167 cases (83.5%); in the other 39 patients were initially administered other drugs (i.e. verapamil e.v./per os, beta-blokers per os). A relation between the type of cardioplegic solution and the onset of postoperative PAF was not found (Calafiore, n = 180, 37.5%; St. Thomas, n = 22, 31%; Custodiol, n = 37, 34%; p = NS). Advanced age at operation (71.3 ± 8.7 vs. 65.7 ± 11 years) was the only independent predictor of PAF (p &lt; 0.001). Non-coronary surgery was found as risk factor for PAF at the univariate analysis only (p &lt; 0.01). Conclusions: The use of different type of cardioplegic solutions, and at different temperatures, does not correlate with the onset of postoperative PAF. Initial treatment strategy with amiodarone infusion allows pharmacological cardioversion of PAF in over 80% of cases.

AS-28: Patients Aged over 70 and 80 years in the Worldwide e-HEALING Registry: A High Risk Population with Favorable Outcome after Genous Stent Implantation

The e-HEALING registry is a prospective observational trial designed to capture real-world data on the use of the Genous EPC (Endothelial Progenitor Cells) capture R stent). Elderly patients (pts) revascularized by coronary angioplasty (percutaneous coronary intervention; PCI) constitutes a high-risk pt subgroup for bleeding events with the use of long-term dual antiplatelet therapy. Even more important, the need to suppress antiplatelet treatment because of comorbidities or for noncoronary surgery after stent implantation may increase the risk of stent thrombosis.

Cardiac Protection by Volatile Anaesthetics: A Review

Ischaemic preconditioning, a response to brief sublethal episodes of ischaemia leading to a pronounced protection against subsequent lethal ischaemia, is mimicked by some pharmacological agents. Halogenated anaesthetics alone exhibit cardioprotective properties at therapeutic doses, independent of their anaesthetic and haemodynamic effect, leading to the concept of anaesthetic preconditioning. Only recently has research turned to clinical application of preconditioning protocols, and anaesthetic preconditioning has indeed been demonstrated in randomised clinical trials conducted in patients undergoing cardiac surgery - mostly coronary artery bypass graft. Most of these trials demonstrate cardiac protection by assessing postprocedural release of cardiac troponin or early postoperative cardiac function. Few studies focus on clinical outcomes, and none demonstrates an advantage in terms of mortality or cardiac morbidity. A recent meta-analysis, pooling data regarding the use of desflurane and sevoflurane, found significant reductions of in-hospital mortality, myocardial infarction rate, intensive care unit and hospital stay, time on mechanical ventilation and incidence of long term cardiac events. In conclusion, the use of desflurane and sevoflurane appears to yield a better outcome, in terms of mortality and cardiac morbidity, in patients undergoing cardiac surgery. A definitive demonstration of this concept represents a difficult task because of the low mortality rate in modern cardiac surgery and because of the number of interfering factors. Whether these cardioprotective properties also exist in non-coronary surgery settings is still controversial owing to the scarce available data.

Risk Factors Profile for Acute Kidney Injury after Cardiac Surgery Is Different According to the Level of Baseline Renal Function

Acute kidney injury (AKI) occurs frequently after cardiac surgery. Although numerous variables were identified as predictors for AKI, there is a lack of information about possible differences in risk factors according to the level of preoperative renal function. Preoperative, intraoperative, and postoperative data from 4118 adult patients submitted to cardiac surgery from January 1, 2000, to December 31, 2005, were included in the study. AKI was defined by an increase in serum creatinine (SCr) ≥ 0.3 mg/dL after surgery. Patients were stratified into two groups: group 1, CCr ≥ 60 mL/min/1.73 m2 BSA; group 2, CCr < 60 mL/min/1.73 m2 BSA. Risk factors were assessed using a multiple logistic regression model. In all, 749 patients (42.5%) developed AKI. The mortality rate of the entire population was a 5.2%. In patients of group 1 (n = 2678), the variables independently associated with the onset of AKI were age, diabetes, preoperative use of diuretics, non-scheduled surgery, cardiopulmonary by-pass (CPB) time, CPB mean arterial pressure, hemodilution, and postoperative use of norepinephrine. Baseline SCr was associated with AKI only in patients of group 2 (n = 1440). Age, EuroSCORE, non-coronary surgery, hemodilution, and postoperative use of vasoactive drugs were also predictors of AKI in this group of patients. The mortality rate was significantly higher in group 2 than group 1 (8.5% vs. 3.6%, p = 0.000). In conclusion, the present study demonstrated a difference in variables associated with postoperative AKI, according to baseline renal function. The degree of preoperative renal function was a predictor of AKI only in patients with CKD stages 3–4, as well as other risk factors. In addition to other well known risk factors for AKI in this setting, the use of diuretics in patients of group 1 and the level of hemodilution during CPB in both groups should be emphasized, as they are potentially modifiable.

Semi-skeletonized internal mammary grafts and phrenic nerve injury: Cause-and-effect analysis

Phrenic nerve injury after cardiac surgery increases postoperative pulmonary complications. The purpose of this study was to analyze the causes and effects of phrenic nerve injury after cardiac surgery. Prospectively collected data on 2084 consecutive patients who underwent cardiac surgery from Jan. 1995 to Feb. 2002 were analyzed. Twenty-eight preoperative and operation related variables were subjected to logistic analysis with the end point being phrenic nerve injury. Then phrenic nerve injury and 6 perioperative morbidities were included in the analysis as variables to determine their independent predictive value for perioperative pulmonary morbidity. An identical approach was used to identify the independent risk factors for perioperative mortality. There were 53 phrenic nerve injuries (2.5%). There was no phrenic nerve injury in non-coronary surgery or coronary surgery using conduits other than the internal mammary artery. The independent risk factors for phrenic nerve injury were the use of internal mammary artery (Odds ratio (OR) = 14.5) and thepresence of chronic obstructive pulmonary disease (OR = 2.9). Phrenic nerve injury was an independent risk factor (OR = 8.1) for perioperative pulmonary morbidities but not for perioperative mortality. Use of semi-skeletonized internal mammary artery harvesting technique and drawing attention to possible vascular or mechanical causes of phrenic nerve injury may reduce its occurrence. Unilateral phrenic nerve injury, although rarely life-threatening, is an independent risk factor for postoperative respiratory complications. When harvesting internal mammary arteries, it should be kept in mind avoiding stretching, compromising, or inadvertently dissecting phrenic nerve is as important as avoiding damage of internal mammary artery itself.

Anaesthetic Considerations for Noncoronary Surgery on a Perfused Beating Heart under Cardiopulmonary Bypass.

Myocardial revascularisation on a beating heart with or without cardiopulmonary bypass has significantly reduced the incidence of cardioplegic myocardial injury. With this advantage in view, noncoronary open heart surgery was performed on a beating heart under cardiopulmonary bypass. We discuss the anaesthetic management of such cases. Thirty-three patients aged 14-56 years underwent open heart surgery on a perfused beating heart. Eleven of them underwent open mitral valvotomy, eighteen underwent mitral valve replacement, repair of atrial septal defect was performed in 3 patients and one had removal of left atrial myxoma. Cardiopulmonary bypass was instituted with aortic and bicaval cannulation. At normothermia, aorta was cross-clamped and continuous coronary perfusion was maintained through an aortic root needle at a rate of 4-6 mL/Kg/minute facilitating a beating heart. Trans-oesophageal echocardiography was routinely deployed. Anaesthetic considerations were focused towards the maintenance of the beating state of the heart, that included, strict control of electrolyte balance, maintenance of adequate perfusion pressure and ST segment monitoring. All the patients could be weaned off cardiopulmonary bypass without defibrillation or significant inotropic support. There was no operative mortality. Open heart surgery on a beating heart for non-coronary cardiac conditions appears to be a good and reproducible option to protect the myocardium from deleterious effects of cardioplegic arrest.

A new aspect of coronary artery spasm induced by cardiac surgery

Five patients developed coronary artery spasm during open heart surgery in our institute between 1984 and 1988. One patient was undergoing coronary artery bypass grafting and the other four valvular surgery or surgery for congenital heart disease. In one of the patients undergoing non-coronary surgery, the preoperative induction of right coronary artery spasm by ergonovine had been documented angiographically while the remaining three patients did not possess organic or functional coronary disease. All five patients exhibited a sudden onset of hemodynamic collapse with ventricular tachyarrhythmias or ST elevation during the early period of reperfusion, the time to onset being 89.2 +/- 84.8 minutes after unclamping of the aorta. In addition, contraction of the right ventricular free wall was severely impaired. Although one patient died due to left ventricular rupture caused by direct cardiac massage, the early mortality thus being 20 per cent, the other four were successfully treated with the intravenous administration of nitroglycerin and diltiazem. Three patients required the assistance of intraaortic balloon pumping for severe cardiac failure. Thus, during open heart surgery, coronary artery spasm can occur even in patients without organic coronary lesions and the possible mechanisms of this condition are discussed herein.