Off-pump coronary artery bypass prevents visceral organ damage

Optimum heparin dose in off-pump coronary artery bypass grafting: A systematic review and meta-analysis

INTRODUCTION

Off-pump coronary artery bypass grafting (OPCABG) was introduced many years ago aiming to reduce the known complications of conventional on-pump coronary surgeries. Heparin is required during the procedures, but the available protocols have diverse dosage regimens. The primary objective of this systematic review is to examine the effect of different heparin doses on the outcomes of OPCABG.

EVIDENCE ACQUISITION

MEDLINE and EMBASE were searched. Four reviewers identified eligible clinical trials. Two reviewers extracted data and independently assessed the risk of bias using Cochrane tool. The primary outcome was the activated clotting time (ACT) at three minutes. The secondary outcomes were proportion of patients requiring blood products and the length of hospital stay. An aggregate data approach was used.

EVIDENCE SYNTHESIS

Three single-center randomized studies recruiting 256 patients were included. The studies compared low-dose (1.5-2 mg/kg) and high-dose (3 mg/kg) heparin boluses. The overall mean difference for ACT after three minutes between low- and high-dose heparin is - 126.16 (95% CI: - 142.19, - 110.14). The proportion of patients requiring blood products after surgery [odd ratio 1.27 (95% CI: 0.69, 2.32)] or the overall length of stay [mean difference -0.15 (95% CI: -0.84, 0.53)] did not differ between the heparin doses.

CONCLUSIONS

In OPCABG, high-dose compared with low-dose heparin did not affect the utilization of more blood products or increased the overall length of stay. Unsurprisingly, ACT values were higher in the high-dose heparin group. Larger and adequately powered randomized clinical trials are indicated to resolve the uncertainty.

Extracorporeal life support system during cardiovascular procedures: Insights from the German Lifebridge registry

The frequency of mechanical circulatory support (MCS) device application has increased in recent years. Besides implantation in the emergency setting, such as circulatory arrest, MCS is also increasingly used electively to ensure hemodynamic stability in high-risk patients, for example, during percutaneous coronary interventions (PCI), valve interventions or off-pump coronary bypass surgery. Lifebridge (Zoll Medical GmbH, Germany) is a compact percutaneous MCS device widely used in daily clinical routine. The present study aimed to investigate the indications, feasibility, and outcomes after use of Lifebridge in cardiac interventions, evaluating a large-scale multicenter database. A total of 60 tertiary cardiovascular centers were questioned regarding application and short-term outcomes after the use of the Lifebridge system (n = 160 patients). Out of these 60 centers, eight consented to participate in the study (n = 39 patients), where detailed data were collected using standardized questionnaires. Demographic and clinical characteristics of the patient population, procedural as well as follow-up data were recorded and analyzed. In 60 interrogated centers, Lifebridge was used in 74% of emergency cases and 26% in the setting of planned interventions. The subcohort interrogated in detail displayed the same distribution of application scenarios, while the main cardiovascular procedure was high-risk PCI (82%). All patients were successfully weaned from the device and 92% (n = 36) of the patients studied in detail survived after 30 days. As assessed 30 days after insertion of the device, bleeding requiring red blood cell (RBC) transfusion constituted the main complication, occurring in 49% of cases. In our analysis of clinical data, the use of Lifebridge in cardiac intervention was shown to be feasible. Further prospective studies are warranted to identify patients who benefit from hemodynamic MCS support despite the increased rate of RBC transfusion due to challenges in access sites during cardiovascular procedures.

Establishment of Predictive Models for Nonocclusive Mesenteric Ischemia Comparing 8,296 Control with 452 Study Patients

OBJECTIVE

The aim of this study was to develop clinical preoperative, intraoperative, and postoperative scores for early identification of patients who are at risk of nonocclusive mesenteric ischemia (NOMI).

DESIGN

A retrospective analysis.

SETTING

Single center.

PARTICIPANTS

From January 2008 to December 2014, all patients from the Department of Thoracic and Cardiovascular Surgery were included on the basis of the hospital database.

INTERVENTIONS

All mesenteric angiographically identified NOMI patients were compared with non-NOMI patients.

MEASUREMENTS AND MAIN RESULTS

The study population of 8,748 patients was randomized into a cohort for developing the scores (non-NOMI 4,214 and NOMI 235) and a cohort for control (non-NOMI 4,082 and NOMI 217). Risk factors were identified using forward and backward Wald test and were included in the predictive scores for the occurrence of NOMI. C statistic showed that the scores had a high discrimination for the prediction of NOMI preoperatively (C statistic 0.79; p < 0.001), intraoperatively (C statistic 0.68; p < 0.001), and postoperatively (C statistic 0.85; p < 0.001). A combination of the preoperative, intraoperative, and postoperative risk scores demonstrated the highest discrimination (C statistic 0.87; p < 0.001). The combined score included the following risk factors: renal insufficiency (preoperative); use of cardiopulmonary bypass and intra-aortic balloon pump support (intraoperative); and reexploration for bleeding, renal replacement therapy, and packed red blood cells ≥ 4 units (postoperative). The results were similar in the control group.

CONCLUSIONS

These scores could be useful to identify patients at risk for NOMI and promote a rapid diagnosis and therapy.

Comparison of two doses of heparin on outcome in off-pump coronary artery bypass surgery patients: A prospective randomized control study

Introduction:

While off pump coronary artery bypass surgery is practiced with an intention to reduce the morbidity associated with cardiopulmonary bypass, the resultant ‘hypercoagulability’ needs to be addressed. Complications such as cavitary thrombus possibly due to the hyper coagulability after off pump coronary artery bypass surgery have been described. Many clinicians use higher doses of heparin - up to 5 mg/kg in order to thwart this fear. Overall, there appears to be no consensus on the dose of heparin in off pump coronary artery bypass surgeries.

Aim of the Study:

The aim of the study was understand the differences in outcome of such as transfusion requirement, myocardial ischemia, and morbidity when two different doses were used for systemic heparinization.

Methods:

Elective patients scheduled for off pump coronary artery bypass surgery were included. Ongoing anti platelet medication was not an exclusion criteria, however, anti platelet medications were ceased about a week prior to surgery when possible. Thoracic epidural anesthesia was administered as an adjunct in patients who qualified for it. By computer generated randomization chart, patients were chosen to receive either 2 or 3 mg/kg of intravenous unfractioned heparin to achieve systemic heparinization with activated clotting time targeted at >240 secs. Intraoperative blood loss, postoperative blood loss, myocardial ischemic episodes, requirement of intraaortic balloon counter pulsation and transfusion requirement were analyzed.

Results:

Sixty two patients participated in the study. There was one conversion to cardiopulmonary bypass. The groups had comparable ACT at baseline (138.8 vs. 146.64 seconds, P = 0.12); 3 mg/kg group had significantly higher values after heparin, as expected. But after reversal with protamine, ACT and need for additional protamine was similar among the groups. Intraoperative (685.56 ± 241.42 ml vs. 675.15 ± 251.86 ml, P = 0.82) and postoperative blood loss (1906.29 ± 611.87 ml vs 1793.65 ± 663.54 ml, p value 0.49) were similar among the groups [Table 4]. The incidence of ECG changes of ischemia, arrhythmias, conversion to CPB, or need for intra-aortic balloon counter pulsation were not different.

Conclusions:

Use of either 2 or 3 mg/kg heparin for systemic heparinization in patients undergoing OPCAB did not affect the outcome.