Objectives: The benefit of preoperative intra-aortic balloon pump implantation in high-risk cardiac surgery patients is still debated. The role of preoperative intra-aortic balloon pump insertion in acute myocardial infarction patients without cardiogenic shock undergoing off-pump coronary artery bypass grafting remains unknown. This study aimed to determine the efficacy and safety of the preoperative intra-aortic balloon pump insertion in those patients undergoing off-pump coronary artery bypass grafting. Methods: A total of 421 consecutive acute myocardial infarction patients without cardiogenic shock who underwent isolated off-pump coronary artery bypass grafting were enrolled in this retrospective observational propensity score–matched analysis study. Patients who received intra-aortic balloon pump before off-pump coronary artery bypass grafting (the intra-aortic balloon pump group, n = 157) were compared with those who had not (control group, n = 264). The 30-day postoperative survival, postoperative complications, and postoperative hospital length of stay were compared between the two groups. Results: A total of 99 pairs of patients were matched. The preoperative intra-aortic balloon pump did not show a 30-day postoperative survival benefit compared with the control group (hazard ratio, 0.9; 95% confidence interval, 0.2-4.2; p = 0.92). Patients with preoperative intra-aortic balloon pump were more likely to have shorter postoperative lengths of stay (8 (6-11) days vs. 10 (6-15) days, p = 0.02) and decreased total days in the hospital (median days: 18.2 vs. 21.8, p = 0.02) compared to patients without balloon pumps. Conclusion: Preoperative intra-aortic balloon pump insertion in acute myocardial infarction patients without cardiogenic shock undergoing off-pump coronary artery bypass grafting improved convalescence as shown by significantly shorter postoperative lengths of hospital stay.

BACKGROUND:Little is known about the effect of mean arterial blood pressure (MAP) augmentation on the microcirculation in cardiogenic-shock patients with peripheral veno-arterial extracorporeal membrane oxygenation (ECMO) support. We investigated the effect of increasing MAP on the microcirculation in cardiogenic-shock patients with ECMO support.METHODS:A single-center prospective observational study under taken in ICU patients undergoing ECMO support for post-cardiotomy cardiogenic shock was carried out. Patients with MAP <60 mmHg treated with ECMO support were the study cohort. Inotropic and vasopressor agents (dopamine, dobutamine, norepinephrine or epinephrine) were administered to maintain the MAP at 60-90 mmHg. Hemodynamic and microcirculatory data were obtained at a baseline MAP of <60 mmHg and 1 h after target MAP was reached. As parameters of microcirculation, we measured thenar eminence tissue oxygenation (StO2) and its change during the vessel obstruction test and cerebral tissue oxygenation (rSO2) with near-infrared spectroscopy.RESULTS:Seventeen patients were enrolled in the study. MAP of all patients increased and reached predefined therapeutic targets (52 [50-54.5] vs.74 [70-78.5] mmHg; p < 0.001). To obtain these targets, doses of inotropic agents were increased (inotrope score increased from 14 [15.5-28] μg/kg/min; p < 0.001). No obvious changes were observed in thenarmuscleStO2 and cerebral rSO2. Thenar muscle StO2 desaturation slope and resaturation slopes during the vessel obstruction test were also unchanged.CONCLUSIONS:Increasing MAP from <60 mmHg to 60-90 mmHg did not affect microcirculation variables in cardiogenic-shock patients with ECMO support.

INTRODUCTION:A number of large-scale retrospective studies revealed that off-pump coronary artery bypass (OPCAB) was superior to on-pump coronary artery bypass (ONCAB). The aim of the study was to investigate risk factors for mortality when OPCAB is converted to ONCAB. METHODS:Patients who underwent OPCAB conversion to ONCAB at the Beijing Anzhen Hospital between January 2003 and January 2013 were assigned to the non-survivor and survivor groups. Background demographics, illness history and preoperative, intraoperative and postoperative variables were compared. RESULTS:Of the 247 cases, 15.4% of the patients died. Patients in the non-survivor group were older and more frequently had diabetes mellitus (DM), arrhythmia, myocardial infarction (MI) in the past 30 days (all p<0.05) and MI combined with mitral regurgitation (p<0.0001); they more frequently had bigger left ventricular end-diastolic dimension (p=0.0019), greater fall in blood pressure, ventricular fibrillation for longer periods, longer conversion time and bypass graft occlusion. All patients in the non-survivor group received intra-aortic balloon pump compared to 89.5% in the survivor group and extracorporeal membrane oxygenation was more common. Left main coronary artery disease (OR=4.431, 95%CI: 2.440-8.048, p<0.0001), blood pressure decline ⩽40 mmHg (OR=0.509, 95%CI: 0.447-0.580, p<0.0001) and time for conversion to ONCAB ⩾20 min were independently associated with mortality. Rates of postoperative complications, such as renal failure, cerebral infarction or hemorrhage, MI and redo sternotomy, were higher in the non-survivor group. CONCLUSIONS:Conversion from OPCAB to ONCAB is associated with high mortality. Risk factors include left main artery disease and duration of blood pressure decline >40 min.

We aimed to evaluate the timing of preoperative intra-aortic balloon pump (IABP) placement and outcomes in patients undergoing off-pump coronary artery bypass grafting (OPCAB). Patients with prophylactic IABP placement before OPCAB presenting between January 1, 2010 and December 31, 2013 were included. Patients were categorized into two groups based on the timing of preoperative IABP placement: less than 2 h (Group A, n = 223) and more than 2 h (Group B, n = 94). According to the European System for Cardiac Operative Risk Evaluation (EuroSCORE), patients were divided into two subgroups: middle-low EuroSCORE (<6, Groups A1 and B1) and high EuroSCORE (≥6, Groups A2 and B2). Clinical data were compared between groups. Groups contained the following numbers of patients: Group A1, 163; Group A2, 60; Group B1, 60; and Group B2, 34. There was a significant difference in length of ICU and hospital stay between Group A and Group B, respectively (40.5 [22, 64] vs. 26.25 [18, 46.5] hours, P = 0.006; 16 [11, 22] vs. 11 [8, 14] days, P = 0.000). Duration of IABP support, ICU length of stay, hospital length of stay, and cost of hospitalization were significantly higher in Group A1 than in Group B1, respectively (73.69 ± 44.12 vs. 64.03 ± 40.93 h, P = 0.013; 36 [20, 56.5] vs. 25.5 [17, 43.75] hours, P = 0.035; 15(11,21) vs. 9(7.25, 12) days, P = 0.000; 109.53(101.20, 131.1) vs. 102.7(95.94, 115.32) thousands CNY, P = 0.009). The length of hospital stay was also significantly higher in Group A2 than in Group B2 (18(13, 26) vs. 13(11, 15) hours, P = 0.000). Preoperative placement of IABP greater than 2 h prior to OPCAB is of benefit, especially in those with high EuroSCORE. The optimal time for prophylactic IABP placement requires further study.

Severe left ventricular (LV) dysfunction patients undergoing off-pump coronary artery bypass grafting (OPCAB) are often associated with a higher mortality. The efficacy and safety of the preoperative prophylactic intra-aortic balloon pump (IABP) insertion is not well established. 416 consecutive patients with severe LV dysfunction (ejection fraction ≤35%) undergoing isolated OPCAB were enrolled in a retrospective observational study. 191 patients was enrolled in the IABP group; the remaining 225 patients was in control group. A total of 129 pairs of patients were propensity-score matched. No significant differences in demographic and preoperative risk factors were found between the two groups. The postoperative 30-day mortality occurred more frequently in the control group compared with the IABP group (8.5% vs. 1.6%, p = 0.02). There was a significant reduction of low cardiac output syndrome in the IABP group compared with the control group (14% vs. 6.2%, p = 0.04). Prolonged mechanical ventilation (≥48 h) occurred more frequently in the control group (34.9% vs. 20.9%, p = 0.02). IABP also decreased the postoperative length of stay. Preoperative IABP was associated with a lower 30-day mortality, suggesting that it is effective in patients with severe LV dysfunction undergoing OPCAB.

Human albumin is the conventional cardiopulmonary bypass circuit primer. However, it has high manufacturing costs. Crystalloid and colloid solutions have been developed as alternatives, including a new generation of non-ionic hydroxyethyl starch (HES). The efficacy of hydroxyethyl starch with a 130 molecular weight and substitution degree of 0.4 (hydroxyethyl starch 130/0.4) was compared with human albumin for use in cardiopulmonary bypass surgery in American Society of Anesthesiologists' grade I-II pediatric congenital heart disease patients. Efficacy was evaluated by comparing perioperative hemodynamic parameters, including plasma colloid osmotic pressure, renal function, blood loss, allogeneic blood volumes and plasma volume substitution. The hydroxyethyl starch group exhibited significantly higher preoperative colloid osmotic pressure (p<0.01) and significantly lower operative renal function and postoperative allogeneic blood volumes than the human albumin group. No significant differences were observed in serum creatinine, glucose, hematocrit or lactic acid levels (p>0.05). Our results indicate that hydroxyethyl starch may be a viable alternative to human albumin in pediatric patients undergoing relatively simple cardiopulmonary bypass surgeries.

The purpose of this investigation was to use combined transcranial cerebral Doppler (TCD) and near-infrared spectroscopy cerebral oxygen saturation (NIRS) during total aortic arch replacement (TAAR) to monitor middle cerebral artery blood flow velocity and regional cerebral oximetry (rSO2) changes to provide a clinical basis for protective measures that may decrease injury of the central nervous system. Consecutive 12 adult patients underwent deep hypothermic circulatory arrest (DHCA) and antegrade selective cerebral perfusion (ASCP) during TAAR. A TCD probe was placed at the temporal windows after induction of anesthesia and the NIRS probe placed on the forehead of patients to collect perioperative, intraoperative, and postoperative hemodynamic parameters, and cerebral blood flow (CBF) and rSO2 during cardiopulmonary bypass (CPB). In this retrospective case series, all patients survived, and there were no postoperative neurologic complications. There was no significant correlation between the mean arterial pressure and rSO2. The middle cerebral artery mean velocity (VmMCA) and rSO2 were significantly correlated, and main pump flow significantly correlated with rSO2. After ASCP, VmMCA, rSO2, and venous oxygen saturation were significantly lower than before ASCP, but VmMCA and rSO2 returned to pre-CPB levels postoperatively. After off pump, the flow of ASCP showed a significant positive correlation with VmMCA and rSO2. During DHCA when ASCP flow was lower than 5 ml/kg/min, TCD could not detect the MCA blood flow signal. When the flow of ASCP was above keeping around 10 ml/kg/min, MCA CBF velocity was maintained and rSO2 > 45%. The combination of TCD and NIRS can be effective in monitoring brain function during DHCA with ASCP and may provide a guide for decreasing brain injury during the TAAR procedure.

Background: It is well documented that trans-membrane pressure drop (TMPD) of hollow-fiber membrane oxygenators (HFMO) may lead to hemolysis, damage to platelets, and systemic inflammatory response. The purpose of this study was to evaluate five commercially available adult oxygenators in terms of pressure drop during normothermic and hypothermic cardiopulmonary bypass (CPB).Materials and Methods: In a clinical setting, 5 different adult HFMOs were tested in terms of TM-PDs. Forty patients scheduled for cardiac surgery were enrolled in the study and were divided into 5 groups according to the type of oxygenator used during CPB: group J (Maquet Quardox n=8), group A (Affinity NT n=8), group P (Polystan Safe Maxi n=8), group T (Terumo Capiox SX 18 n=8) and group C (COBE APEX-TM n=8). Clinical parameters were collected during CPB, including mean arterial pressure (MAP), pump flow, temperature, hematocrit, duration of CPB, cross-clamp time and bypass time. TMPDs of pre-oxygenator and post-oxygenator pressures were recorded at the start of systemic cooling (T1), 10 min after stable hypothermia at 30 degrees C (T2), and at termination of rewarming before the end of CPB (T3).Results: There were no significant differences among the 5 groups in pump-flow rate, temperature, hematocrit, and mean arterial pressure during CPB. TMPDs of group J were the lowest at different time-points (T1, 30.71 +/- 8.42mmHg; T2, 25.71 +/- 5.41 mmHg; T3, 27.42 +/- 13.01 mmHg). Compared to the other 3 groups (P, C and T groups), TMPDs of groups J and A at various time-points were lower (J group compared with the other three groups (p<0.001). Although TMPDs in groups A, P and T during hypothermia were higher than during normothermia and post-rewarming, there was no significant statistical difference (p>0.05).Conclusions: These results suggest that the HFMOs in groups J and A produced significantly lower TMPDs and pre- and post-oxygenator extracorporeal circuit pressures during normothermic and hypothermic CPB.

Received July 25, 2008; accepted for publication March 8, 2009 Address reprint requests to Yi Luo, MD: Department of Cardiac Surgery, Beijing Anzhen Hospital, Beijing Institute of Heart, Lung, & Vascular Diseases, Capital Medical University, No. 2, Anzhen Road, Anzhen Li, Anding Menwai, Beijing 100029, China. ©2009 The Editorial Committee of Annals of Thoracic and Cardiovascular Surgery. All rights reserved. To the Editor:

BACKGROUND:Although adenosine (ADO) has been shown to have beneficial effects against tissue injury after myocardial ischaemia, the controversy still remains regarding the optimal timing, dose, temperature, method of ADO administration and duration of exposure to the drug. This study investigates the cardioprotective effect of exogenous ADO pretreatment as an adjunct to 1 mmol l(-1) ADO cold (12 degrees C) blood cardioplegia during heart valve replacement surgery. MATERIALS AND METHODS:Thirty patients with rheumatic heart valve disease undergoing heart valve replacement operations were randomly assigned to two groups: group C (n=15) and group A (n=15). Patients in group C were the control group and received antegrade cold (12 degrees C) high-potassium ([K(+)]=20 mol l(-1)) institute blood cardioplegia. The patients in group A received 10-min 100 microgkg(-1)min(-1) ADO pretreatment before application of the aortic cross-clamp and antegrade 1 mmol l(-1) adenosine high-potassium ([K(+)]=20 mol l(-1)) cold (12 degrees C) blood cardioplegia. Clinical outcomes were observed before, during and after the operation. Plasma level markers of myocardial damage: cardiac Troponin I (cTnI), creatine kinase (CK-MB) and inflammatory factors (interleukin (IL)-6 and IL-8) were obtained from serial venous blood samples after induction, 5 min after cross-clamp of aorta, 10 min after clamp-off, 1h after return to ICU and postoperatively 24 h and 48 h. Right atrial samples were harvested before cross-clamp and after clamp-off. RESULTS:Heart valve replacement was successful in all patients. There were no differences regarding operative parameters in the two groups. Time to arrest (during cardiolegia perfusion electrocardiography (ECG) change to a line) was shorter in group A compared to group C (19.9+/-4.6s vs 29.3+/-10.6s; p=0.03). Group A also had lower cTnI and IL-8 levels (p=0.03) at 10 min after aortic declamping, and lower IL-6 (p=0.04) at 24h postoperatively as well. Ultrastructural changes were slighter in group A than group C after clamp-off. Compared to group C, post-reperfusion biopsies in group A displayed only slight overall ultrastructural changes, and scored significantly better on mitochondrial damage (group A 2.23+/-0.65 vs group C 2.85+/-0.66) (p=0.04). CONCLUSION:Compared with simple cold blood cardioplegia in heart valve replacement patients, ADO pretreatment as an adjunct to 1 mmol l(-1) ADO cold blood cardioplegia may reduce cTnI, IL-6 and IL-8 release, resulting in reduced myocardial injury in ultrastructure after surgery.

Although intra-aortic balloon pumping (IABP) has been used widely as a routine cardiac assist device for perioperative support in coronary artery bypass grafting (CABG), the optimal timing for high-risk patients undergoing first-time CABG using IABP is unknown. The purpose of this investigation is to compare preoperative and preventative IABP insertion with intraoperative or postoperative obligatory IABP insertion in high-risk patients undergoing first-time CABG. We reviewed our IABP patients' database from 2002 to 2007; there were 311 CABG patients who received IABP treatment perioperatively. Of 311 cases, 41 high-risk patients who had first-time on-pump or off-pump CABG (presenting with three or more of the following criteria: left ventricular ejection fraction less than 0.45, unstable angina, CABG combined with aneurysmectomy, or left main stenosis greater than 70%) entered the study. We compared perioperatively the clinical results of 20 patients who underwent preoperative IABP placement (Group 1) with 21 patients who had obligatory IABP placement intraoperatively or postoperatively during CABG (Group 2). There were no differences in preoperative risk factors, except left ventricular aneurysm resection, between the two groups. There were no differences in indications for high-risk patients between the two groups. The mean number of grafts was similar. There were no significant differences in the need for inotropes, or in cerebrovascular, gastrointestinal, renal, and infective complications postoperatively. There were no IABP-related complications in either group. Major adverse cardiac event (severe hypotension and/or shock, myocardial infarction, and severe hemodynamic instability) was higher in Group 2 (14 [66.4%] vs. 1 [5%], P < 0.0001) during surgery. The time of IABP pumping in Group 1 was shorter than in Group 2 (72.5 +/- 28.9 h vs. 97.5 +/- 47.7 h, P < 0.05). The duration of ventilation and intensive care unit stay in Group 1 was significantly shorter than in Group 2, respectively (22.0 +/- 1.6 h vs. 39.6 +/- 2.1 h, P < 0.01 and 58.0 +/- 1.5 h vs. 98.5 +/- 1.9 h, P < 0.005). There were no differences in mortality between the two groups (n = 1 in Group 1 and n = 3 in Group 2). Preoperative and preventative insertion of IABP can be performed safely in selected high-risk patients undergoing CABG, with results comparable to those in patients who received obligatory IABP intraoperatively and postoperatively. Therefore, earlier IABP support as part of surgical strategy may help to improve the outcome in high-risk first-time CABG patients.