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OBJECTIVES Obesity is associated with increased burden of cardiovascular risk factors, morbidity and mortality. However, several studies have counterintuitively shown better outcome after cardiac surgery in obese than in normal weight patients, a phenomenon known as obesity paradox. Furthermore, obesity has been linked with decreased need of red blood cell (RBC) transfusions. The purpose of this study was to evaluate the impact of body mass index (BMI) on 30-day mortality and RBC transfusions in patients undergoing cardiac surgery, a clinically important topic with conflicting previous data. METHODS We retrospectively investigated 1691 patients who underwent coronary and/or valve or aortic root surgery using cardiopulmonary bypass between 2013 and 2016. The patients were categorized by BMI based on the World Health Organization classification. For analysis, logistic regression was used with adjustment for potential confounding factors. RESULTS Of the patients, 28.7% were normal weight, 43.3% overweight, 20.5% mildly obese and 7.5% severely obese. Thirty-day mortality was 1.9% without significant differences between the BMI groups. 41.0% of patients received RBC transfusion. Overweight [odds ratio (OR) 0.75, 95% confidence interval (CI) 0.56–0.99, P = 0.045], mildly (OR 0.65, 95% CI 0.46–0.92, P = 0.016) and severely obese (OR 0.41, 95% CI 0.24–0.70, P = 0.001) patients needed less frequently RBC transfusions than patients with normal weight. CONCLUSIONS Obesity was not associated with 30-day mortality but was associated with lower use of RBC transfusions in cardiac surgery.

Objective: Minimal invasive extracorporeal circulation may decrease the need of packed red blood cell transfusions and reduce hemodilution during cardiopulmonary bypass. However, more data are needed on the effects of minimal invasive extracorporeal circulation in more complex cardiac procedures. We compared minimal invasive extracorporeal circulation and conventional extracorporeal circulation methods of cardiopulmonary bypass. Methods: A total of 424 patients in the minimal invasive extracorporeal circulation group and 844 patients in the conventional extracorporeal circulation group undergoing coronary artery bypass grafting and more complex cardiac surgery were evaluated. Age, sex, type of surgery, and duration of perfusion were used as matching criteria. Hemoglobin Results: Red blood cell transfusions were needed less often in the minimal invasive extracorporeal circulation group compared to the conventional extracorporeal circulation group (26.4% vs. 33.4%, p = 0.011, odds ratio 0.72, 95% confidence interval 0.55-0.93), especially in coronary artery bypass grafting subgroup (21.3% vs. 35.1%, p < 0.001, odds ratio 0.50, 95% confidence interval 0.35-0.73). Hemoglobin drop after onset of perfusion was also lower in the minimal invasive extracorporeal circulation group than in the conventional extracorporeal circulation group (24.2 ± 8.5% vs. 32.6 ± 12.6%, p < 0.001). Postoperative bleeding from the chest tube did not differ between the groups (p = 0.808). Conclusion: Minimal invasive extracorporeal circulation reduced the need of red blood cell transfusions and hemoglobin drop when compared to the conventional extracorporeal circulation group. This may have implications when choosing the perfusion method in cardiac surgery.

Purpose: Patients scheduled to undergo the transcatheter aortic valve replacement (TAVR) are usually octogenarians with severe co-morbidities and an increased risk of surgery-associated complications. The aim of this study was to determine the incidence of insufficient oxygen delivery as measured by mixed venous oxygen saturation (SvO2) via invasive continuous cardiopulmonary monitoring and the low cardiac output syndrome (LCOS) in patients undergoing the TAVR procedure. The second objective was to examine how these hemodynamic measurements would change during critical events, such as rapid ventricular pacing (RVP) during this procedure. Methods: This prospective, observational study, examined twenty patients undergoing TAVR under general anesthesia. Hemodynamic variables, SvO2 and the continuous cardiac output (CO) were assessed using pulmonary artery catheter (PAC) and a Vigilance® monitor. Insufficient oxygen delivery was defined as a SvO2 value under 58% and LCOS as a cardiac index (CI) under 2 L/min/m2. Total intravenous anesthesia and hemodynamic management protocol were standardized. RVP was induced twice during the procedure at a frequency of 180 - 200/min. Predefined clinical endpoints were assessed during the procedure and hemodynamic values were analyzed before and after twelve critical events. Results: The data of twenty patients with a mean age of 80 ± 4 years and EuroSCORE 18 ± 10 were analyzed. Fourteen (70%) of the TAVR procedures were performed transapically, the other six (30%) transfemorally. The SvO2 value under 58% (mean 54 ± 6) and the CI under 2 L/min/m2 (mean 1.6 ± 0.2) were detected in 60% of patients (n = 12) before the use of RVP. All of these patients received perioperative inotropic medication and required norepinephrine infusion for maintenance of adequate blood pressure. The SvO2, CO and CI were significantly decreased after the use of RVP (P 2 reverted rapidly to the same level as before the application of RVP (1 min), CO, and CI 10 min later. At the end of the operation SvO2 values were at same level as before RVP and CO and CI were higher than before RVP. Conclusion: A high incidence of insufficient oxygen delivery and low cardiac output syndrome were detected in patients undergoing TAVR procedures. Nonetheless, all hemodynamic values returned rather rapidly to the same level as before the use of the RVP and were at the optimal level at the end of the procedure. According to the current study, the most hemodynamically hazardous steps during TAVR are the use of RVP sequences, the induction of anesthesia and the initiation of surgery.

Introduction Red blood cell (RBC) transfusions are common in cardiac surgery and reportedly associated with increased mortality and morbidity, including increased risk of postoperative new-onset atrial fibrillation (NOAF). The aim of this study was to compare minimal invasive extracorporeal circulation (MiECC) and conventional extracorporeal circulation (CECC) in terms of RBC transfusions and the incidence of NOAF in mitral valve surgery. Methods The study population consisted of 89 MiECC and 169 CECC patients undergoing mitral valve surgery as an isolated procedure (80.6% of the patients) or in combination with coronary artery bypass grafting (19.4% of patients). 79.4% of the patients were male and the mean age was 62.1 years. Results 30.0% of patients aged < 65 years and 48.1% of patients aged ≥ 65 years needed RBC transfusion. The overall need for RBC transfusions did not differ between the treatment groups. Among patients < 65 years of age transfusions of ≥ 3 units were less frequent in MiECC than in CECC patients (OR 0.31, 95% CI 0.10–0.98, p = 0.045). The overall incidence of NOAF was 41.8% with no significant difference between MiECC and CECC groups. Red blood cell transfusions were associated with an increased risk of NOAF in an unadjusted analysis but not after adjustment for age and sex (OR 1.25, 95% CI 0.64–2.43, p = 0.515). Conclusions In mitral valve surgery MiECC compared to CECC was associated with less need of RBC units and platelets, particularly in patients aged < 65 years. Use of RBC transfusions was associated with increased risk of NOAF significantly only in unadjusted analysis.

Postoperative atrial fibrillation (POAF) is the most common arrhythmia after cardiac surgery with an incidence between 15% and 50% and pathophysiology not fully known. By choosing the method of extracorporeal circulation with focus on the reduction of systemic inflammatory response, one can potentially decrease the risk of POAF. In this prospective, randomized trial, we compared minimal invasive extracorporeal circulation (MiECC) with conventional extracorporeal circulation (CECC) in the prevention of POAF after coronary artery bypass surgery (CABG). A total of 240 patients who were scheduled for their first on-pump CABG, were randomized to MiECC or CECC. The primary outcome measure was the incidence of first POAF during the first 84 hours after surgery. POAF occurred in 42/120 (35.0%) MiECC patients and 43/120 (35.8%) CECC patients with nonsignificant difference between the groups (OR 1.043, 95% CI 0.591-1.843, P = .884). The first postoperative creatine kinase-MB mass (CK-MBm) value was lower in the MiECC group, 13.95 [10.5-16.7] (median [IQR]) than in the CECC group, 15.30 [11.4-18.9] (P = .036), whereas the use of perioperative dobutamine was higher in the MiECC group, 18/120 (15.0%), than in the CECC group 8/120 (6.7%) (P = .038). The incidence of a stroke, perioperative myocardial infarction, and resternotomy caused by bleeding did not differ in the MiECC and CECC groups. Age (OR 1.08, 95% CI 1.04-1.13, P = .000) and peak postoperative CK-MBm (OR 1.57, 95% CI 1.06-2.37, P = .026) were independent predictors of POAF. MiECC compared to CECC was not effective in reducing the incidence of POAF in patients undergoing CABG.

Purpose Cardiac surgery and conventional extracorporeal circulation (CECC) impair the bioavailability of drugs administered by mouth. It is not known whether miniaturized ECC (MECC) or off-pump surgery (OPCAB) affect the bioavailability in similar manner. We evaluated the metoprolol bioavailability in patients undergoing CABG surgery with CECC, MECC, or having OPCAB. Methods Thirty patients, ten in each group, aged 44-79 years, scheduled for CABG surgery were administered 50 mg metoprolol by mouth on the preoperative day at 8-10 a.m. and 8 p.m., 2 h before surgery, and thereafter daily at 8 a.m. and 8 p.m. Blood samples were collected up to 12 h after the morning dose on the preoperative day and on first and third postoperative days. Metoprolol concentration in plasma was analyzed using liquid chromatography-mass spectrometry. Results The absorption of metoprolol was markedly reduced on the first postoperative day in all three groups, but recovered to the preoperative level on the third postoperative day. The geometric means (90% confidence interval) of AUC(0-12) on the first and third postoperative days versus the preoperative day were 44 (26-74)% and 109 (86-139)% in the CECC-group, 28 (16-50)% and 79 (59-105)% in the MECC-group, and 26 (12-56)% and 96 (77-119)% in the OPCAB-group, respectively. Two patients in the CECC-group and two in the MECC-group developed atrial fibrillation (AF). The bioavailability and the drug concentrations of metoprolol in patients developing AF did not differ from those who remained in sinus rhythm. Conclusion The bioavailability of metoprolol by mouth was markedly reduced in the early phase after CABG with no difference between the CECC-, MECC-, and OPCAB-groups.