Intraoperative conversion to on-pump coronary artery bypass grafting is independently associated with higher mortality in patients undergoing off-pump coronary artery bypass grafting: A propensity-matched analysis

Predictors and Causes of Intraoperative Conversion From Off-Pump to On-Pump Coronary Artery Bypass: A Retrospective Study

OBJECTIVE

This study evaluated the incidence, causes, and predictors of intraoperative conversion from off-pump coronary artery bypass grafting (OPCAB) to on-pump coronary artery bypass grafting (ONCAB), identifying risk factors to improve surgical planning.

METHODS

This retrospective case-control study included patients who underwent OPCAB at the Peshawar Institute of Cardiology, Peshawar, Pakistan, between December 8, 2021, and December 7, 2023. Among 714 patients, 27 (3.78%) required conversion to ONCAB. For comparison, 108 (15.1%) controls were randomly selected from those who completed OPCAB successfully. Preoperative and intraoperative data were analyzed, and logistic regression identified predictors of conversion.

RESULTS

The most frequent cause of conversion was hemodynamic instability, which occurred in 18 (66.67%) cases. Persistent hypotension and ST-segment changes lasting approximately 10-20 minutes were primary indicators before conversion, highlighting the need for close intraoperative monitoring. Left main coronary artery stenosis of 50%-70% emerged as the only independent predictor of conversion (odds ratio (OR) 7.60, 95% CI: 2.91-19.83, p < 0.001). This study emphasizes the importance of robust patient selection criteria, especially for cases with borderline coronary anatomy.

CONCLUSION

Hemodynamic instability and moderate left main coronary artery stenosis significantly contribute to OPCAB-to-ONCAB conversion. Enhanced preoperative imaging and hemodynamic management protocols can potentially reduce conversion rates, improving surgical outcomes.

No association between pulmonary artery catheter use and postoperative complications in off-pump coronary artery bypass grafting: a single-center pilot study

BACKGROUND

A pulmonary artery catheter is often used in cardiac surgery despite its uncertain effectiveness. The aim of this pilot study was to investigate the associations between the use of a pulmonary artery catheter and clinical outcomes in off-pump coronary artery bypass grafting.

METHODS

Patients over 20 years of age who had undergone off-pump coronary artery bypass grafting between December 2018 and November 2021 were enrolled in this single-center retrospective pilot study. The propensity score of pulmonary artery catheterization was calculated. Multivariate analysis including the propensity score as a covariate was performed to assess clinical outcomes. The primary outcome was the composite outcome of in-hospital death, unplanned intraoperative conversion to cardiopulmonary bypass, resuscitated cardiac arrest, mechanical circulatory support, myocardial infarction, stroke, new initiation of renal replacement therapy, inhaled nitric oxide, re-intubation and tracheostomy.

RESULTS

Among the 315 patients who were enrolled, 298 were included in the final analysis. A pulmonary artery catheter was inserted in 131 patients. There were 50 patients with the composite outcome including two in-hospital deaths. Multivariate logistic regression analysis showed that pulmonary artery catheterization was not significantly related to the composite outcome. Clinical outcomes worsened significantly as the number of anastomoses increased (odds ratio: 1.450, 95% confidence interval: 1.040-2.040, P=0.029).

CONCLUSIONS

Pulmonary artery catheterization did not improve the clinical outcomes in off-pump coronary artery bypass grafting in this pilot study.

Rapid cardiac ischemia detection with an epicardial graphene probe

Introduction

In this study, a new probe was designed to enable electrocardiography of a rotated heart during cardiac surgery when skin electrodes became non-functional. This probe adhered non-invasively to the epicardium and collected the ECG signal independently from the position of the heart. The study compared the accuracy of cardiac ischemia detection between classic skin and epicardial electrodes in an animal model.

Methods

Using six pigs, an open chest model was devised with cardiac ischemia induction by coronary artery ligation in two non-physiologic heart positions. Both the accuracy and the time of detection of electrocardiographic symptoms of acute cardiac ischemia were compared between skin and epicardial methods of signal collection.

Results

Heart rotation to expose either the anterior or the posterior wall resulted in a distortion or loss of the ECG signal collected by skin electrodes after coronary artery ligation, standard skin ECG monitoring did not reveal any ischemia symptoms. Attachment of an epicardial probe on the anterior and posterior walls helped in the recovery of the normal ECG wave. After ligation of the coronary artery, the epicardial probes recorded cardiac ischemia within 40 s.

Discussion

This study highlighted the effectiveness of ECG monitoring with epicardial probes in a rotated heart. It can be concluded that epicardial probes can detect the presence of acute ischemia of a rotated heart when skin ECG monitoring becomes ineffective.

Cardiovascular Death Risk in Primary Central Nervous System Lymphoma Patients Treated With Chemotherapy: A Registry-Based Cohort Study

Purpose

To study the cardiovascular death (CVD) risk in primary central nervous system lymphoma (PCNSL) patients with chemotherapy.

Methods

We obtained 2,020 PCNSL participants and 88,613 non-central nervous system lymphoma (NCNSL) participants with chemotherapy from Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2015. A 1:3 propensity score matching (PSM) was used to reduce the imbalance between PCNSL participants with and without chemotherapy, as well as the imbalance between PCNSL and NCNSL participants with chemotherapy. Competing risks regressions were conducted to evaluate the independent influence of chemotherapy on CVD.

Results

After 1:3 PSM, the CVD risk in PCNSL patients with chemotherapy was lower than those without chemotherapy [decreased 53%, adjusted HR, 0.469 (95% CI, 0.255–0.862; P = 0.015)] as well as NCNSL patients with chemotherapy [decreased 36%, adjusted HR in model 1, 0.636 (95% CI, 0.439–0.923; P = 0.017)]. The CVD risk of chemotherapy decreased in PCNSL patients with age at diagnosis >60 years old [adjusted HR, 0.390 (95% CI, 0.200–0.760; P = 0.006)], and those patients diagnosed at 2010 to 2015 [adjusted HR, 0.339 (95% CI, 0.118–0.970; P = 0.044)].

Conclusion

PCNSL patients with chemotherapy are associated with lower CVD risk. Our findings may provide new foundations for that chemotherapy is the first-line treatment for PCNSL patients, according to a cardiovascular risk perspective.

Feasibility of off-pump coronary artery grafting for patients with impaired left ventricular ejection fraction: A retrospective cohort study from a single institutional database

OBJECTIVE

Despite substantial advances in surgical practice, the management of patients with impaired left ventricular ejection fraction (LVEF) remains challenging. Furthermore, evidence on the outcomes of off-pump coronary artery bypass (OPCAB) surgery in this population is inconsistent. We conducted the present study to compare the short- and long-term outcomes of OPCAB in patients with different ejection fractions.

METHODS

This retrospective cohort study used data from the Hua-Shan Cardiac Surgery and included consecutive patients aged ≥ 18 years who underwent OPCAB procedures during 2016-2019. The patients included in the study were followed up until death or the end of data collection. Patients with different ejection fractions were matched 1:2 using propensity score matching. Factors associated with short-term outcomes were determined using logistic regression, and Kaplan-Meier survival analyses for the differences in all-cause death were generated.

RESULTS

The two propensity score matched groups consisted of 40 left ventricular dysfunction (LVD) and 80 normal left ventricular function (NLVF) patients. No significant intergroup differences were observed in the postoperative outcomes for the occurrence of left heart failure (22.5% in LVD vs. 5.0% in NLVF, p = .009). Age (odds ratio = 1.11, 95% confidence interval = 1.04-1.18) but not the preoperative LVEF was shown to be a strong predictor of short-term events in logistic regression analyses. Kaplan-Meier curves displayed similar freedom from all-cause death (p = .119) or cardio-death (p = .092) between groups.

CONCLUSION

The immediate postoperative outcomes and long-term outcomes were similar between the groups, indicating that OPCAB is a safe and effective choice for patients with LVD.

Preoperative right ventricular dysfunction requires high vasoactive and inotropic support during off-pump coronary artery bypass grafting

Objectives

The association of preoperative RV function with hemodynamics during OPCAB or emergency conversion is not clear. The aim of this study was to investigate the association of vasoactive-inotropic score with tricuspid annular plane systolic excursion and tricuspid regurgitation in off-pump coronary artery bypass grafting, and to calculate the optimal cut-off value of tricuspid annular plane systolic excursion to predict emergency conversion to cardiopulmonary bypass.

Methods

Patients over 20 years of age who had undergone off-pump coronary artery bypass grafting between April 2015 and March 2020 were enrolled in this study. We retrospectively assessed the association of intraoperative maximum “vasoactive-inotropic score”, a weighted sum of various inotropes and vasoconstrictors, with tricuspid annular plane systolic excursion and tricuspid regurgitation. A receiver operating characteristic curve of conversion on tricuspid annular plane systolic excursion was also constructed.

Results

135 patients were included in final analysis. Conversion was performed in 10 cases. Multiple regression analysis showed that tricuspid annular plane systolic excursion, mild or more tricuspid regurgitation and experienced surgeon were significantly related to vasoactive-inotropic score. The receiver operating characteristic curve to predict conversion by tricuspid annular plane systolic excursion showed an optimal cut-off value of 15.0 mm and area under the curve of 0.808.

Conclusions

Tricuspid annular plane systolic excursion and tricuspid regurgitation were associated with vasoactive-inotropic score in off-pump coronary artery bypass grafting. The optimal cut-off value of tricuspid annular plane systolic excursion to predict emergency conversion was 15 mm.

Conversion during off-pump coronary artery bypass graft surgery: A case-control study

Objectives:

Off pump coronary artery bypass (OPCAB) surgery is carried out as an alternative to conventional coronary artery bypass grafting using cardiopulmonary bypass (CPB). At times ‘conversion’ to CPB may be required to bail out a situation resulting from acute decompensation of the heart. It is reported that such conversion carries significant mortality risk. Since we conduct coronary revascularization by OPCAB technique as the preferred technique, we conducted this study with an aim to identify the markers of adverse outcome during conversion in Indian patients.

Design:

Case control retrospective study.

Setting:

Tertiary referral center.

Participants:

We conducted three thousand two hundred OPAB surgeries in the period between 2013 to16. Ninety patients (3.1%) required conversion to complete the revascularization (Con version group). Twice the number of patients who underwent OPCAB surgery without conver sion were chosen as controls (Control group).

Intervention:

OPCAB surgery

Results:

Mortality in the conversion group was 5.56% in contrast to 0.06% in the controls (P = 0.01). The conversion group had higher left ventricular end diastolic pressure, incidence of endarterectomy, and intra-aortic balloon counter pulsation requirement. Female gender was also predictive of conversion. The total chest drain, duration of ventilation, ICU stay and hospital stay were also higher in the conversion group. Conversion was associated with 9.47 times the odds for mortality.

Conclusion:

Conversion during OPCAB is associated with significantly increased mortality. Female gender, increased left ventricular end diastolic pressure and preoperative requirement of Intra-aortic balloon are markers of increased risk of mortality when converted.

Early and Medium Outcomes of On-Pump Beating-Heart versus Off-Pump CABG in Patients with Moderate Left Ventricular Dysfunction

OBJECTIVE

This study aims to compare the early and medium outcomes of on-pump beating-heart (OPBH) coronary artery bypass grafting (CABG) and off-pump CABG (OPCABG) in patients with left ventricular ejection fraction (LVEF) between 30% and 40%.

METHODS

This is a retrospective study of ischemic heart disease patients with LVEF between 30% and 40% who underwent surgical revascularization from January 2013 to December 2017. Patients were divided into OPBH group (n=44) and OPCABG group (n=68), according to the surgical method. Clinical material with early and medium outcomes were investigated and compared between these groups.

RESULTS

The two groups had similar baseline. Two OPBH patients and 3 OPCABG patients died in the hospital, which had no statistical significance (P>0.05). OPBH patients received a greater number of grafts (3.74±0.84) and presented more improved LVEF (45.92±7.11%) than OPCABG patients (3.36±0.80) and (42.81±9.29%), respectively, which had statistical significance (P<0.05). An increased amount of drainage during the first 12 hours was found in the OPBH group (P<0.05). Reoperation for bleeding, duration of mechanic ventilation, and other early outcomes had no statistical significance between the two groups. During the medium-time follow-up, OPBH patients showed significantly lower major adverse cardiovascular events (MACE)-free survival time (P=0.049) than OPCABG patients.

CONCLUSION

The OPBH technique was a safe and an acceptable alternative for surgical revascularization in patients with moderate left ventricular dysfunction which provided better mid-term MACE-free survival compared with OPCABG.