2021 MiECTiS focused update on the 2016 position paper for the use of minimal invasive extracorporeal circulation in cardiac surgery

Postoperative bleeding in myocardial revascularization under cardiopulmonary bypass for patients treated with aspirin or dual antiplatelet therapy using reduced goal-directed anticoagulation

OBJECTIVES

Antiplatelet therapy increases the risk of bleeding and transfusion in patients undergoing extracorporeal circulation. Reduced goal-directed anticoagulation is a personalized approach to reduce the anticoagulation based on a lower targeted activated clotting time. We assessed whether reduced goal-directed anticoagulation using optimized extracorporeal circulation alleviates the risk of severe bleeding in patients treated by dual antiplatelet therapy (DAPT) compared to aspirin alone during coronary artery bypass grafting (CABG).

METHODS

A total of 2275 patients undergoing CABG from 2002 to 2022 were selected after propensity matching from a retrospective cohort of 3018 patients. Patients treated with a combination of aspirin and prasugrel or ticagrelor or clopidogrel were included in the DAPT group (n = 1111). Patients treated with aspirin alone (ASA) constituted the control group (n = 1164). Optimized extracorporeal circulation was conducted under reduced systemic anticoagulation with a target activated clotting time 250 s. Severe bleeding was assessed using 3 validated scores of bleeding: UDPB, E-CABG, and BARC-4.

RESULTS

While all scores showed low ranges of severe bleeding (<6%), they were significantly higher after DAPT compared to ASA (P values for UDPB, E-CABG, and BARC-4 at 0.016, 0.006, and 0.063, respectively). Higher maximal activated clotting time was associated with higher rate of transfusion (P < 0.001) and bleeding (P < 0.001) after multivariate adjustment. Mortality was 1.24% in DAPT vs 0.94% in ASA group (P = NS), whereas cardiac death, myocardial infarction, stroke, and transient ischaemic attack were low (<1%) and similar between groups.

CONCLUSIONS

Despite higher bleeding under DAPT compared to ASA alone, optimized extracorporeal circulation with reduced goal-directed anticoagulation alleviated severe bleeding which remained low in patients undergoing CABG.

Benefit of minimally invasive extracorporeal circulation on minimally invasive aortic valve replacement through right lateral mini-thoracotomy using femoral cannulation: a propensity-matched analysis

OBJECTIVES

The objective of this study was to evaluate the impact of minimally invasive extracorporeal circulation on blood transfusion and asymptomatic brain injury in comparison to conventional extracorporeal circulation in the context of minimally invasive aortic valve replacement through right lateral mini-thoracotomy surgery.

METHODS

This was a retrospective observational study. Patients who underwent isolated aortic valve replacement through right lateral mini-thoracotomy surgery were divided into two groups: the minimally invasive extracorporeal circulation group and the conventional extracorporeal circulation group. Propensity matching was employed for further analysis.

RESULTS

Of 242 patients, the minimally invasive group and conventional group comprised 166 patients and 76 patients, respectively. In the matched cohort of 71 pairs, the two groups had similar preoperative characteristics. Extracorporeal circulation time was similar between the minimally invasive and conventional groups: 113 and 115 min, respectively, as was aortic clamp time: 86 and 82 min, respectively. Estimated amount of haemodilution was lower in the minimally invasive group (16.8 vs. 18.8%, P = 0.006). Blood transfusion frequency during surgery was less than half of conventional in the minimally invasive group (12.7 vs. 31.0%, P = 0.01). There were no deaths or stroke in either group during the hospital stay. Asymptomatic brain injury rate was the same for the two groups (35.2 vs. 35.2%, P = 1.00).

CONCLUSIONS

Minimally invasive extracorporeal circulation was associated with fewer patients requiring transfusion than conventional extracorporeal circulation without an increase of asymptomatic brain injury in minimally invasive aortic valve replacement through right lateral mini-thoracotomy surgery.

Individualized heparin monitoring and management reduces protamine requirements in cardiac surgery on minimal invasive extracorporeal circulation; A prospective randomized study

INTRODUCTION

Individualized heparin and protamine management is increasingly used as a strategy to reduce coagulation activation and bleeding complications. While it is associated with increased heparin requirements during Cardiopulmonary Bypass (CPB), the impact on protamine administration remains controversial. We aim to investigate the effect of heparin level-guided monitoring on protamine dosing during cardiac surgery where low-anticoagulation protocols are implemented.

METHODS

This is a prospective, randomized, controlled trial. A total of 132 patients undergoing elective full-spectrum cardiac surgery with Minimal Invasive Extracorporeal Circulation (MiECC) were recruited. All patients were managed by the same anaesthetic, surgical and perfusion team. Patients were randomly allocated in two groups; the individualized heparin-protamine titration (IHPT) group and the conventional heparinization and reversal group by using ACT (cACT) with a 0.75:1, protamine: heparin ratio. Titration was accomplished with the Hepcon HMS Plus (Medtronic, Minneapolis, MN) system. The primary outcome of the study was the total protamine dose used. Secondary outcomes comprised of the total heparin dose, the percentage of patients achieving target ACT, 24-h transfusion requirements, postoperative bleeding, duration of mechanical ventilation, major morbidity and length of hospital stay. Patients in each group were divided in two subgroups according to the target ACT; those operated for coronary artery bypass grafting (CABG) using a target ACT >300 s and the rest (non-CABG) patients operated with a target ACT >400 s, respectively.

RESULTS

Protamine requirements were significantly reduced when IHPT was implemented; CABG (118 ± 24 mg vs 163 ± 61 mg; p < 0.001) and non-CABG cases (151 ± 46 mg vs 197 ± 45 mg; p < 0.001). Moreover, heparin requirements were significantly higher in the non-CABG subgroup managed with IHPT (34,539 ± 7658 IU vs 29,893 ± 9037 IU; p = 0.02). In overall, no significant differences were detected with respect to postoperative bleeding, transfusion of RBC or other blood products.

CONCLUSIONS

Individualized heparin monitoring and management reduces protamine requirements in cardiac surgery with MiECC implementing reduced anticoagulation strategy.

TRIAL REGISTRATION

clinicaltrials.gov; NCT04215588.

Comparable bleeding and inflammation outcomes between heparin-coated and uncoated minimal invasive extracorporeal circuits in isolated coronary artery bypass surgery - A double-blinded randomized control trial

OBJECTIVE

Minimally invasive extracorporeal circulation has been shown to be non-inferior or even superior to conventional cardiopulmonary bypass circuits in isolated coronary artery bypass grafting, but there is little evidence whether the addition of a heparin-coated circuit can further reduce the inflammatory response and amount of bleeding in these patients.

METHODS

A single-center randomized control trial enrolled 49 adult patients scheduled to undergo isolated coronary artery bypass grafting with minimally invasive extracorporeal circulation (MiECC) between January 2015 and December 2018. Patients were randomized 1:1 to either the heparin-coated circuit group, or the uncoated (control) circuit group. The primary outcome was chest tube output 18 h after weaning from MiECC, and secondary outcomes included inflammatory (TNF-α, IL-6, IL-8, IL-10) and complement (C3a, C4d, C5a, sC5b-9) biomarkers, platelet count and function (D2D, TAT, SDC1, PF4), number of transfused blood products, and 30-day survival.

RESULTS

Patients were randomized to undergo myocardial revascularization using heparin-coated circuits (n = 25), and to the uncoated MiECC circuit (n = 24), with comparable baseline demographics. No significant difference was observed in chest tube output and for all secondary outcomes. IL-6 and IL-8 were increased from baseline at 18 h after weaning (effect size 0.29 and 0.05, respectively) and sC5b-9 was lower (effect size 0.11) in the heparin-coated than in the uncoated MiECC, although not significantly different.

CONCLUSIONS

Compared with an uncoated MiECC circuit, heparin-coated MiECC circuit was not associated with a reduction in postoperative bleeding, transfusion, inflammation, complement activation, and platelet biomarkers, following isolated coronary artery bypass grafting.

The emerging role of minimally invasive extracorporeal circulation in totally endoscopic and robotic-assisted cardiac surgery procedures

Background: This review explores the potential benefits of combining totally endoscopic and robotic-assisted cardiac surgery with minimally invasive extracorporeal circulation (MiECC). Robotic techniques herald a new era of surgical precision, leveraging advanced instrumentation and enhanced visualization to navigate cardiac anatomy with unprecedented accuracy. Purpose: Concurrently, MiECC systems provide tailored physiological support during cardiopulmonary bypass, meticulously managing perfusion parameters to safeguard vital organs' function. Results: The convergence of these cutting-edge technologies marks a paradigmatic shift in cardiac surgical practice, with potential mitigation of invasiveness, attenuation of perioperative complications, and expedite postoperative recovery. Conclusions: This review also addresses prevailing challenges and limitations, including technological complexities and procedural intricacies, while elucidating the strategic imperatives for optimizing their collaborative utilization.

Minimally invasive extracorporeal circulation versus conventional cardiopulmonary bypass in patients undergoing cardiac surgery (MiECS): Rationale and design of a multicentre randomised trial

INTRODUCTION

The ultimate answer to the question whether minimal invasive extracorporeal circulation (MiECC) represents the optimal perfusion technique in contemporary clinical practice remains elusive. The present study is a real-world study that focuses on specific perfusion-related clinical outcomes after cardiac surgery that could potentially be favourably affected by MiECC and thereby influence the future clinical practice.

METHODS

The MiECS study is an international, multi-centre, two-arm randomized controlled trial. Patients undergoing elective or urgent coronary artery bypass grafting (CABG), aortic valve replacement (AVR) or combined procedure (CABG + AVR) using extracorporeal circulation will be randomized to MiECC or contemporary conventional cardiopulmonary bypass (cCPB). Use of optimized conventional circuits as controls is acceptable. The study design includes a range of features to prevent bias and is registered at clinicaltrials.gov (NCT05487612).

RESULTS

The primary outcome is a composite of postoperative serious adverse events that could be related to perfusion technique occurring up to 30 days postoperatively. Secondary outcomes include use of blood products, ICU and hospital length of stay (30 days) as well as health-related quality of life (30 and 90 days).

CONCLUSIONS

The MiECS trial has been designed to overcome perceived limitation of previous trials of MiECC. Results of the proposed study could affect current perfusion practice towards advancement of patient care.

Conventional versus minimally invasive extra-corporeal circulation in patients undergoing cardiac surgery: A randomized controlled trial (COMICS)

INTRODUCTION

The trial hypothesized that minimally invasive extra-corporeal circulation (MiECC) reduces the risk of serious adverse events (SAEs) after cardiac surgery operations requiring extra-corporeal circulation without circulatory arrest.

METHODS

This is a multicentre, international randomized controlled trial across fourteen cardiac surgery centres including patients aged ≥18 and <85 years undergoing elective or urgent isolated coronary artery bypass grafting (CABG), isolated aortic valve replacement (AVR) surgery, or CABG + AVR surgery. Participants were randomized to MiECC or conventional extra-corporeal circulation (CECC), stratified by centre and operation. The primary outcome was a composite of 12 post-operative SAEs up to 30 days after surgery, the risk of which MiECC was hypothesized to reduce. Secondary outcomes comprised: other SAEs; all-cause mortality; transfusion of blood products; time to discharge from intensive care and hospital; health-related quality-of-life. Analyses were performed on a modified intention-to-treat basis.

RESULTS

The trial terminated early due to the COVID-19 pandemic; 1071 participants (896 isolated CABG, 97 isolated AVR, 69 CABG + AVR) with median age 66 years and median EuroSCORE II 1.24 were randomized (535 to MiECC, 536 to CECC). Twenty-six participants withdrew after randomization, 22 before and four after intervention. Fifty of 517 (9.7%) randomized to MiECC and 69/522 (13.2%) randomized to CECC group experienced the primary outcome (risk ratio = 0.732, 95% confidence interval (95% CI) = 0.556 to 0.962, p = 0.025). The risk of any SAE not contributing to the primary outcome was similarly reduced (risk ratio = 0.791, 95% CI 0.530 to 1.179, p = 0.250).

CONCLUSIONS

MiECC reduces the relative risk of primary outcome events by about 25%. The risk of other SAEs was similarly reduced. Because the trial terminated early without achieving the target sample size, these potential benefits of MiECC are uncertain.

Comparison of minimal invasive extracorporeal circulation versus standard cardiopulmonary bypass systems on coronary artery bypass surgery

Background

In this study, we shared our experience with the minimal invasive extracorporeal circulation system for coronary artery bypass grafting patients.

Methods

A total of 163 patients were included in the retrospective study, with 83 patients (63 males, 20 females; mean age: 61.9±8.9 years; range, 35 to 81 years) undergoing coronary artery bypass grafting with minimal invasive extracorporeal circulation and 80 patients (65 males, 15 females; mean age: 60.5±8.8 years; range, 43 to 82 years) undergoing coronary artery bypass grafting with conventional cardiopulmonary bypass between July 2021 and April 2023. Elective coronary bypass performed by same surgical team were included in the study. Mortality, major adverse cardiac and cerebrovascular event, hospital stays and transfusion requirements were evaluated.

Results

There were no significant differences in sex distribution, age, comorbidities, and blood values between the two groups. Intraoperatively, the minimal invasive extracorporeal circulation group had a slightly higher number of distal anastomoses and comparable times for aortic cross-clamp and cardiopulmonary bypass. Postoperative outcomes such as tamponade, bleeding, atrial fibrillation, left ventricular ejection fraction improvement or reduction, and postoperative drainage were similar between the two groups. However, the minimal invasive extracorporeal circulation group had fewer transfusions of packed red blood cells and fresh frozen plasma and a shorter length of stay in the intensive care unit.

Conclusion

The minimal invasive extracorporeal circulation system effectively preserves blood, works with lower activated clotting time values without additional complications in coronary artery bypass grafting, and could present a better option for patients with anemia or patients with a relatively high risk for high-dose heparinization.

Procalcitonin for the diagnosis of postoperative bacterial infection after adult cardiac surgery: a systematic review and meta-analysis

BACKGROUND AND AIMS

Patients undergoing cardiac surgery are subject to infectious complications that adversely affect outcomes. Rapid identification is essential for adequate treatment. Procalcitonin (PCT) is a noninvasive blood test that could serve this purpose, however its validity in the cardiac surgery population is still debated. We therefore performed a systematic review and meta-analysis to estimate the accuracy of PCT for the diagnosis of postoperative bacterial infection after cardiac surgery.

METHODS

We included studies on adult cardiac surgery patients, providing estimates of test accuracy. Search was performed on PubMed, EmBase and WebOfScience on April 12th, 2023 and rerun on September 15th, 2023, limited to the last 10 years. Study quality was assessed with the QUADAS-2 tool. The pooled measures of performance and diagnostic accuracy, and corresponding 95% Confidence Intervals (CI), were calculated using a bivariate regression model. Due to the variation in reported thresholds, we used a multiple-thresholds within a study random effects model for meta-analysis (diagmeta R-package).

RESULTS

Eleven studies were included in the systematic review, and 10 (2984 patients) in the meta-analysis. All studies were single-center with observational design, five of which with retrospective data collection. Quality assessment highlighted various issues, mainly concerning lack of prespecified thresholds for the index test in all studies. Results of bivariate model analysis using multiple thresholds within a study identified the optimal threshold at 3 ng/mL, with a mean sensitivity of 0.67 (0.47-0.82), mean specificity of 0.73 (95% CI 0.65-0.79), and AUC of 0.75 (IC95% 0.29-0.95). Given its importance for practice, we also evaluated PCT's predictive capability. We found that positive predictive value is at most close to 50%, also with a high prevalence (30%), and the negative predictive value was always > 90% when prevalence was < 20%.

CONCLUSIONS

These results suggest that PCT may be used to help rule out infection after cardiac surgery. The optimal threshold of 3 ng/mL identified in this work should be confirmed with large, well-designed randomized trials that evaluate the test's impact on health outcomes and on the use of antibiotic therapy. PROSPERO Registration number CRD42023415773. Registered 22 April 2023.

Monitoring the Cerebral Oximetry Index Along With In-line Cardiopulmonary Bypass Parameters in a High-Risk Patient Undergoing Cardiac Surgery: A Case Report

The quest to minimize the morbidity and mortality of patients undergoing cardiac surgery is ongoing. Impaired cerebral autoregulation and tissue malperfusion are linked with neurological complications. The cerebral oximetry index (COx) has been introduced as an index of cerebral autoregulation, while in-line monitoring enables the detection and prevention of metabolic disturbances during cardiopulmonary bypass (CPB). This report presents the case of a 58-year-old female patient scheduled for aortic valve replacement under minimally invasive extracorporeal circulation (MiECC). Her medical history consisted of epilepsy, multiple ischemic strokes, heavy smoking, and brachiocephalic artery stenosis. We sought to investigate the limits of autoregulation and the role of metabolic indices of perfusion on COx. Mean arterial blood pressure (ABP), cerebral oximetry (rSO₂), and in-line perfusion data during CPB were recorded at 10s intervals. The lower limit of autoregulation was 44mmHg on both sides and the upper limit was 98mmHg on the right and 107mmHg on the left side. A multiple linear regression analysis was performed to identify any potential predictors of COx values. Hemoglobin (Hb), PCO₂, flow, DO₂ index (DO₂i), Ο₂ extraction ratio (O₂ER), and perfusion ratio (PR) were included in the analysis. Significant equations were found on both sides. Predicted COx left was equal to 5.8 - 11.04O₂ER - 0.04Hb (p=0.001, R²= 0.15). Predicted COx right was equal to 3.06 - 0.3flow - 6.8O₂ER -0.03Hb + 0.02PCO₂ + 0.004DO₂i(p=0.03, R²=0.13). Targeting physiological perfusion and monitoring perfusion during CPB may have an additional impact on cerebral autoregulation and should be studied further.