Suzanne Kats

Risk factors for red blood cell transfusion after coronary artery bypass graft surgery.

OBJECTIVES Perioperative transfusion of red blood cells is associated with increased morbidity and mortality. The authors investigated the correlation between preoperative risk factors and the number of red blood cell units received in patients undergoing coronary artery bypass graft surgery. DESIGN A retrospective analysis of prospectively collected data. SETTING A single-center study performed in an educational hospital. PARTICIPANTS All patients who underwent isolated coronary artery bypass graft surgery between 1998 and 2007 (N = 10,626) were included. INTERVENTIONS Isolated coronary artery bypass graft surgery. MEASUREMENTS AND MAIN RESULTS Univariate and multivariate logistic regression analyses were performed to investigate the impact of preoperative and perioperative factors on transfusion of 1 or more units of red blood cells. The following independent risk factors for receiving red blood cell units were identified: age, female sex, low body surface area, low left ventricular ejection fraction (<35%), emergency operation, previous cardiac surgery, low preoperative hemoglobin, and low preoperative creatinine clearance. Perioperative risk factors were the use of extracorporeal circulation, longer bypass time, use of crystalloid cardioplegia, the need for intra-aortic balloon pump, perioperative myocardial infarction, and re-exploration for any cause. CONCLUSIONS In this study, the authors identified risk factors for receiving red blood cells in patients undergoing coronary artery bypass graft surgery. The authors were able to implement these factors in their daily practice by sharpening the criteria for the direct availability of red blood cells in the operating room.

Endotoxin release in cardiac surgery with cardiopulmonary bypass: pathophysiology and possible therapeutic strategies. An update

Cardiac surgery with cardiopulmonary bypass provokes a systemic inflammatory response syndrome caused by the surgical trauma itself, blood contact with the non-physiological surfaces of the extracorporeal circuit, endotoxemia, and ischemia. The role of endotoxin in the inflammatory response syndrome has been well investigated. In this report, we reviewed recent advances in the understanding of the pathophysiology of the endotoxin release during cardiopulmonary bypass and the possible therapeutic strategies aimed to reduce the endotoxin release or to counteract the inflammatory effects of endotoxin. Although many different strategies to detoxify endotoxins were evaluated, none of them were able to show statistically significant differences in clinical outcome.

Anti-Inflammatory Effects of Alkaline Phosphatase in Coronary Artery Bypass Surgery with Cardiopulmonary Bypass

Laboratory and clinical data have implicated endotoxin as an important factor in the inflammatory response to cardiopulmonary bypass. Alkaline phosphatase prevents endotoxin-induced systemic inflammation in animals and humans. We assessed the effects of the administration of bovine intestinal alkaline phosphatase on surgical complications in patients undergoing coronary artery bypass grafting. In a double blind, randomized, placebo-controlled study, a total of 63 patients undergoing coronary artery bypass grafting were enrolled. Bovine intestinal alkaline phosphatase or placebo was administered as an intravenous bolus followed by continuous infusion for 36 hours. The primary endpoint was reduction of post-surgical inflammation. No significant safety concerns were identified. The overall inflammatory response to coronary artery bypass grafting with cardiopulmonary bypass was low in both placebo and bovine intestinal alkaline phosphatase patient group. Five patients in the placebo group displayed a significant TNFalpha response followed by an increase in plasma levels of IL-6 and IL-8. Such a TNFalpha response was not observed in the bovine intestinal alkaline phosphatase group, suggesting anti-inflammatory activity of bovine intestinal alkaline phosphatase. Other variables related to systemic inflammation showed no statistically significant differences. Bovine intestinal alkaline phosphatase can be administered safely in an attempt to reduce the inflammatory response in coronary artery bypass grafting patients with a low to intermediate EuroSCORE. The anti-inflammatory effects might be more pronounced in patients developing more fulminant postoperative inflammatory responses. This will be investigated in a further trial with inclusion of patients undergoing complicated cardiac surgery, demanding extended cardiopulmonary bypass and aortic cross clamp time. In this review article some recent patents related to the field are also discussed.

Prophylactic treatment with alkaline phosphatase in cardiac surgery induces endogenous alkaline phosphatase release.

Introduction Laboratory and clinical data have implicated endotoxin as an important factor in the inflammatory response to cardiopulmonary bypass. We assessed the effects of the administration of bovine intestinal alkaline phosphatase (bIAP), an endotoxin detoxifier, on alkaline phosphatase levels in patients undergoing coronary artery bypass grafting. Methods A total of 63 patients undergoing coronary artery bypass grafting were enrolled and prospectively randomized. Bovine intestinal alkaline phosphatase (n=32) or placebo (n=31) was administered as an intravenous bolus followed by continuous infusion for 36 hours. The primary endpoint was to evaluate alkaline phosphatase levels in both groups and to find out if administration of bIAP to patients undergoing CABG would lead to endogenous alkaline phosphatase release. Results No significant adverse effects were identified in either group. In all the 32 patients of the bIAP-treated group, we found an initial rise of plasma alkaline phosphatase levels due to bolus administration (464.27±176.17 IU/L). A significant increase of plasma alkaline phosphatase at 4–6 hours postoperatively was observed (354.97±95.00 IU/L) as well. Using LHA inhibition, it was shown that this second peak was caused by the generation of Tissue Non Specific Alkaline Phosphatase (TNSALP-type alkaline phosphatase). Conclusions Intravenous bolus administration plus 8 hours continuous infusion of alkaline phosphatase in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass results in endogenous alkaline phosphatase release. This endogenous alkaline phosphatase may play a role in the immune defense system.

Modalities and Effects of Left Ventricle Unloading on Extracorporeal Life support: a Review of the Current Literature

Veno‐arterial extracorporeal membrane oxygenation (V‐A ECMO) support is increasingly used in refractory cardiogenic shock and cardiac arrest, but is characterized by a rise in afterload of the left ventricle (LV) which may ultimately either further impair or delay cardiac contractility improvement. The aim of this study was to provide a comprehensive overview regarding the different LV venting techniques and results currently available in the literature.

Mobile respiratory rescue support by off-centre initiation of extracorporeal membrane oxygenation

Severe pulmonary injury may rapidly progress into lifethreatening respiratory distress despite optimal mechanical ventilation. In a subset of patients, the initiation of veno-venous extracorporeal membrane oxygenation (vv-ECMO) poses the ultimate supportive option. Yet, the risks of inter-hospital transport to an ECMO centre restricts access to a potentially life-saving intervention, especially in unstable and rapidly deteriorating patients.1 Off-centre initiation of ECMO by a dedicated team allows for clinical stabilization and safe transport.2 However, vv-ECMO is typically performed by dual-site, femoral-jugular cannulation, whereas single-site vascular access may be advantageous, especially in an offcentre setting. This paper describes the initial experience of applying off-centre vv-ECMO by a mobile team employing a novel bedside approach, using echocardiographyguided, single-site cannulation with a bicaval, duallumen catheter.

Severely Thrombosed Transcatheter Aortic Valve 9 Months After Implantation

Bioprosthetic aortic valve thrombosis is a rare complication after transcatheter aortic valve implantation; however, one with a high mortality. We describe the case of a patient with a completely thrombosed transcatheter aortic valve prosthesis 9 months after implantation and review the diagnosis and management of this complication.

Value of Multidimensional Modeling in Planning Surgery for a Dissecting Ventricular Septal Hematoma Following Aortic Valve Sparing Root Reimplantation

We report a technique of multidimensional modeling (MDM) used to assist in the planning of a repair of a dissecting ventricular septal hematoma (DVSH) following a David procedure. doi: 10.1111/jocs.12757 (J Card Surg 2016;31:390–393)

Reservations about the Selvester QRS score in left bundle branch block — Experience in patients with transcatheter aortic valve implantation ☆

BACKGROUND The Selvester QRS score (S-score) estimates myocardial scar using electrocardiographic criteria. We evaluated the S-score for left bundle branch block (LBBB). MATERIAL AND METHODS Studied were 36 patients who developed persistent LBBB upon transcatheter aortic valve implantation (TAVI, TAVI-LBBB group) and 36 matched patients with persistent narrow QRS (TAVI-nQRS group). Electrocardiograms were recorded before and briefly after TAVI and during ~6months follow-up. S-score was calculated using criteria for hypertrophic (in absence of LBBB) or LBBB hearts. RESULTS In TAVI-LBBB patients correlation between S-scores pre-TAVI and post-TAVI was absent (R2=0.023). High S-scores post-TAVI occurred in patients with low pre-TAVI scores. Pre-post TAVI scores correlated weakly in TAVI-nQRS (R2=0.182), indicating a possible influence of ventricular unloading by TAVI. In both groups S-scores at post-TAVI and follow-up compared reasonably (R2=0.389 and R2=0.386), indicating reproducibility in more stable conditions. CONCLUSION This study indicates that the use of the LBBB S-score criteria overestimates scar size and that caution is recommended in the use of the score in patients with LBBB.

Protracted aortic valve closure during peripheral veno-arterial extracorporeal life support: is intra-aortic balloon pump an effective solution?

Background: Left ventricular (LV) afterload increase with protracted aortic valve (AV) closure may represent a complication of veno-arterial extracorporeal membrane oxygenation (V-A ECMO). The aim of the present study was to assess the effects of an intra-aortic balloon pump (IABP) to overcome such a hemodynamic shortcoming in patients submitted to peripheral V-A ECMO. Methods: Among 184 adult patients who were treated with peripheral V-A ECMO support at Medical University Center Maastricht Hospital between 2007 and 2018, patients submitted to IABP implant for protracted AV closure after V-A ECMO implant were retrospectively identified. All clinical and hemodynamic data, including echocardiographic monitoring, were collected and analyzed. Results: During the study period, 10 subjects (mean age 60 years old, 80% males) underwent IABP implant after peripheral V-A ECMO positioning due to the diagnosis of protracted AV closure and inefficient LV unloading as assessed by echocardiography and an absence of pulsation in the arterial pressure wave. Recovery of blood pressure pulsatility and enhanced LV unloading were observed in 8 patients after IABP placement, with no significant differences in the main hemodynamic parameters, inotropic therapy or in the ECMO flow (p=0.48). The weaning rate in this patient subgroup (mean ECMO duration 8 days), however, was only 10%, with another patient finally transplanted, leading to a 20% survival-to-hospital discharge. Conclusion: IABP placement was an effective solution in order to reverse the protracted AV closure and impaired LV unloading observed during peripheral V-A ECMO support. However, the impact on the weaning rate and survival needs further investigations.