Jonas Holm

Mixed venous oxygen saturation predicts short- and long-term outcome after coronary artery bypass grafting surgery: a retrospective cohort analysis

BACKGROUND Complications of an inadequate haemodynamic state are a leading cause of morbidity and mortality after cardiac surgery. Unfortunately, commonly used methods to assess haemodynamic status are not well documented with respect to outcome. The aim of this study was to investigate Sv(O2) as a prognostic marker for short- and long-term outcome in a large unselected coronary artery bypass grafting (CABG) cohort and in subgroups with or without treatment for intraoperative heart failure. METHODS Two thousand seven hundred and fifty-five consecutive CABG patients and subgroups comprising 344 patients with and 2411 patients without intraoperative heart failure, respectively, were investigated. Sv(O2) was routinely measured on admission to the intensive care unit (ICU). The mean (sd) follow-up was 10.2 (1.5) yr. RESULTS The best cut-off for 30 day mortality related to heart failure based on receiver-operating characteristic analysis was Sv(O2) 60.1%. Patients with Sv(O2) <60% had higher 30 day mortality (5.4% vs 1.0%; P<0.0001) and lower 5 yr survival (81.4% vs 90.5%; P<0.0001). The incidences of perioperative myocardial infarction, renal failure, and stroke were also significantly higher, leading to a longer ICU stay. Similar prognostic information was obtained in the subgroups that were admitted to ICU with or without treatment for intraoperative heart failure. In patients admitted to ICU without treatment for intraoperative heart failure and Sv(O2) ≥60%, 30 day mortality was 0.5% and 5 yr survival 92.1%. CONCLUSIONS Sv(O2) <60% on admission to ICU was related to worse short- and long-term outcome after CABG, regardless of whether the patients were admitted to ICU with or without treatment for intraoperative heart failure.

Mixed venous oxygen saturation is a prognostic marker after surgery for aortic stenosis

Background: Adequate monitoring of the hemodynamic state is essential after cardiac surgery and is vital for medical decision making, particularly concerning hemodynamic management. Unfortunately, commonly used methods to assess the hemodynamic state are not well documented with regard to outcome. Mixed venous oxygen saturation (SvO2) was therefore investigated after cardiac surgery.

EuroSCORE II and N-terminal pro-B-type natriuretic peptide for risk evaluation : an observational longitudinal study in patients undergoing coronary artery bypass graft surgery

BACKGROUND Postoperative heart failure remains the major cause of death after cardiac surgery. As N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a predictor for postoperative heart failure, the aim was to evaluate if preoperative NT-proBNP could provide additional prognostic information to the recently launched EuroSCORE II. METHODS A total of 365 patients with acute coronary syndrome (ACS) undergoing isolated coronary artery bypass graft (CABG) surgery were studied prospectively. Preoperative NT-proBNP and EuroSCORE II were evaluated with regard to severe circulatory failure after operation according to prespecified criteria. To assess what clinical outcomes are indicated by NT-proBNP levels in different risk categories, the patients were stratified according to EuroSCORE II. Based on receiver operating characteristics analysis, these cohorts were assessed with regard to preoperative NT-proBNP below or above 1028 ng litre(-1). The follow-up time averaged 4.4 (0.7) yr. RESULTS Preoperative NT-proBNP≥1028 ng litre(-1) [odds ratio (OR) 9.9, 95% confidence interval (CI) 1.01-98.9; P=0.049] and EuroSCORE II (OR 1.24, 95% CI 1.06-1.46; P=0.008) independently predicted severe circulatory failure after operation. In intermediate-risk patients (EuroSCORE II 2.0-10.0), NT-proBNP≥1028 ng litre(-1) was associated with a higher incidence of severe circulatory failure (6.6% vs 0%; P=0.007), renal failure (14.8% vs 5.4%; P=0.03), stroke (6.6% vs 0.7%; P=0.03), longer intensive care unit stay [37 (35) vs 27 (38) h; P=0.002], and worse long-term survival. CONCLUSIONS Combining EuroSCORE II and preoperative NT-proBNP appears to improve risk prediction with regard to severe circulatory failure after isolated CABG for ACS. NT-proBNP may be particularly useful in patients at intermediate risk according to EuroSCORE II. CLINICAL TRIAL REGISTRATION NCT00489827.

Preoperative NT-proBNP independently predicts outcome in patients with acute coronary syndrome undergoing CABG

Abstract Objectives. The predictive value of preoperative N-terminal pro-B-type natriuretic peptide (NT-proBNP) was evaluated in patients with acute coronary syndrome undergoing coronary artery bypass grafting (CABG). Design. As a substudy to a clinical trial 383 patients with acute coronary syndrome undergoing CABG were studied. 17 patients had a concomitant procedure. NT-proBNP was measured immediately preoperatively and evaluated with regard to in-hospital mortality, and severe circulatory failure postoperatively according to prespecified criteria. Follow-up was 3.2 ± 0.9 years. Results. In patients with isolated CABG, receiver operating characteristics (ROC) analysis showed an area under the curve (AUC) of 0.82 for in-hospital mortality and 0.87 for severe circulatory failure respectively with a best cut-off for preoperative NT-proBNP of 1028 ng/L. This cut-off level independently predicted severe circulatory failure. Patients with NT-proBNP < 1028 ng/L had significantly better long-term survival (p = 0.004). Preoperative NT-proBNP was higher in patients with concomitant procedure than isolated CABG (2146 ± 1858 v 887 ± 1635 ng/L; p = 0.0005). In patients with concomitant procedure ROC analysis showed an AUC of 0.93 for severe circulatory failure with a best cut-off for preoperative NT-proBNP of 3145 ng/L. Conclusions. Preoperative NT-proBNP predicted in-hospital mortality, severe circulatory failure postoperatively and long-term survival in patients undergoing surgery for acute coronary syndrome but a higher threshold was found in patients having concomitant procedures. Trial registration: ClinicalTrials.gov identifier: NCT00489827.

GLUTAMICS—a randomized clinical trial on glutamate infusion in 861 patients undergoing surgery for acute coronary syndrome

OBJECTIVE Glutamate has been claimed to protect the heart from ischemia and to facilitate metabolic and hemodynamic recovery after ischemia. The GLUTAmate for Metabolic Intervention in Coronary Surgery trial investigated whether an intravenous glutamate infusion given in association with surgery for acute coronary syndrome could reduce mortality and prevent or mitigate myocardial injury and postoperative heart failure. METHODS In the present prospective, triple-center, double-blind study, 861 patients undergoing surgery for acute coronary syndrome were randomly assigned to an intravenous infusion of glutamate (n = 428) or saline (n = 433) perioperatively. RESULTS The incidence of the primary endpoint--a composite of 30-day mortality, perioperative myocardial infarction, and left ventricular heart failure at weaning from cardiopulmonary bypass-was 7.3% versus 5.8% (P = .41) in the glutamate and control groups, respectively. Patients with left ventricular failure at weaning from cardiopulmonary bypass had a shorter median intensive care unit stay (25 vs 92 hours; P = .02) if they were treated with glutamate. In patients with unstable angina (Canadian Cardiovascular Society class IV) undergoing isolated coronary artery bypass grafting (n = 458), the incidence of severe circulatory failure according to the prespecified criteria was significantly lower in the glutamate group (1.3% vs 6.9%; P = .004). On multivariate analysis, glutamate infusion was associated with a reduced risk of developing severe circulatory failure (odds ratio, 0.17; 95% confidence interval, 0.04-0.72; P = .02). A relative risk reduction exceeding 50% for developing severe circulatory failure was seen in most risk groups undergoing isolated coronary artery bypass grafting, with those with diabetes a notable exception. CONCLUSIONS The primary endpoint did not differ significantly between the groups. The secondary outcomes and post hoc analyses warrant additional studies with regard to the potential beneficial effect of glutamate on postischemic myocardial recovery.

The S-100B substudy of the GLUTAMICS-trial : glutamate infusion not associated with sustained elevation of plasma S-100B after coronary surgery

BACKGROUND & AIMS Concerns have been raised about potential neurological injury related to exogenous glutamate. In cardiac surgery glutamate has been administered as a putative cardioprotective agent by cardioplegia or intravenous infusion. In the GLUTAMICS trial, in addition to surveillance of clinical neurological injuries, a prespecified subgroup was analyzed with regard to postoperative S-100B levels to detect potential subclinical neurological injury related to glutamate infusion. METHODS Sixty-nine patients operated on for unstable coronary syndrome were randomized to intravenous infusion of glutamate (n=35) or saline (n=34) perioperatively. Plasma levels of S-100B were obtained on the third postoperative day. RESULTS S-100B in the glutamate group and the control group were 0.079+/-0.034microg/L and 0.090+/-0.042microg/L respectively (p=0.245). There were no patients with stroke or mortality. Three patients in the control group and two in the glutamate group had postoperative confusion. These patients had significantly elevated S-100B compared with those without confusion (0.132+/-0.047vs 0.081+/-0.036microg/L; p=0.003). Overall, 21 patients had S-100B above reference level (> or =0.10microg/L) and these patients had significantly more calcifications in the ascending aorta on epiaortic scanning. CONCLUSIONS Intravenous glutamate infusion during surgery for unstable coronary artery disease did not initiate a sustained elevation of plasma S-100B. Thus, no evidence for subclinical neurological injury related to glutamate infusion was found. In contrast, postoperative elevation of plasma S-100B was linked to calcification of the ascending aorta and postoperative confusion.

Endovascular stenting of an outflow graft thrombosis in a continuous-flow left ventricular assist device.

We report the endovascular stenting of an outflow tract thrombosis in a left ventricular assist device in a patient with relative contraindications to sternotomy and pump exchange. This report highlights the importance of simultaneous prevention of stroke using filter devices in the common carotid arteries.

Impact of underlying heart disease per se on the utility of preoperative NT-proBNP in adult cardiac surgery

Objective The primary aim was to investigate the role of underlying heart disease on preoperative NT-proBNP levels in patients admitted for adult cardiac surgery, after adjusting for the known confounders age, gender, obesity and renal function. The second aim was to investigate the predictive value of preoperative NT-proBNP with regard to severe postoperative heart failure (SPHF) and postoperative mortality. Methods A retrospective cohort study based on preoperative NT-proBNP measurements in an unselected cohort including all patients undergoing first time surgery for coronary artery disease (CAD; n = 2226), aortic stenosis (AS; n = 406) or mitral regurgitation (MR; n = 346) from April 2010 to August 2016 in the southeast region of Sweden (n = 2978). Concomitant procedures were not included, with the exception of Maze or tricuspid valve procedures. Results Preoperative NT-proBNP was 1.67 times (p<0.0001) and 1.41 times (p<0.0001) higher in patients with AS or MR respectively, than in patients with CAD after adjusting for confounders. NT-proBNP demonstrated significant discrimination with regard to SPHF in CAD (AUC = 0.79, 95%CI 0.73–0.85, p<0.0001), MR (AUC = 0.80, 95%CI 0.72–0.87, p<0.0001) and AS (AUC = 0.66, 95%CI 0.51–0.81, p = 0.047). In CAD patients NT-proBNP demonstrated significant discrimination with regard to postoperative 30-day or in-hospital mortality (AUC = 0.78; 95%CI 0.71–0.85, p<0.0001). The number of deaths was too few in the AS and MR group to permit analysis. Elevated NT-proBNP emerged as an independent risk factor for SPHF, and postoperative mortality in CAD. Conclusions Patients with AS or MR have higher preoperative NT-proBNP than CAD patients even after adjusting for confounders. The predictive value of NT-proBNP with regard to SPHF was confirmed in CAD and MR patients but was less convincing in AS patients.

Early Experience of Implantation of a New Pulsatile Total Artificial Heart (TAH) in the Pig

The shortage of donor hearts and the physiological impact of pulsatile perfusion have driven technical innovation research efforts to create a positive displacement total artificial heart that can produce pulsatile flow and has a reasonable size for long-term assist in chronic heart failure. Such a product is the Scandinavian Real Heart 8 (SRH8); a new pulsatile total artificial heart. We here describe the basic principles of the surgical and anesthesiologic techniques we have developed for implantation of the latest prototype of this device.

Rise and fall of NT-proBNP in aortic valve intervention

Objectives To describe the dynamics of N-terminal pro-B-type natriuretic peptide (NT-proBNP) from preoperative evaluation to 6-month follow-up in patients undergoing aortic valve intervention, and to evaluate NT-proBNP with regard to 1-year mortality. Methods At preoperative evaluation, we prospectively included 462 patients accepted for aortic valve intervention. The median time to surgical aortic valve replacement (SAVR; n=336) or transcatheter aortic valve implantation (TAVI; n=126) was 4 months. NT-proBNP was measured at enrolment for preoperative evaluation, on the day of surgery, postoperatively on day 1, day 3 and at the 6-month follow-up. Subgroups of patients undergoing SAVR with aortic regurgitation and aortic stenosis with and without coronary artery bypass were also analysed. Results NT-proBNP remained stable in all subgroups during the preoperative waiting period, but displayed a substantial transient early postoperative increase with a peak on day 3 except in the TAVI group, which peaked on day 1. At the 6-month follow-up, NT-proBNP had decreased to or below the preoperative level in all groups. In the SAVR group, NT-proBNP preoperatively and on postoperative days 1 and 3 revealed significant discriminatory power with regard to 1-year mortality (area under the curve (AUC)=0.79, P=0.0001; AUC=0.71, P=0.03; and AUC=0.79, P=0.002, respectively). This was not found in the TAVI group, which had higher levels of NT-proBNP both preoperatively and at the 6-month follow-up compared with the SAVR group. Conclusions The dynamic profile of NT-proBNP differed between patients undergoing TAVI and SAVR. NT-proBNP in the perioperative course was associated with increased risk of 1-year mortality in SAVR but not in TAVI.