Sedation or general anesthesia for transcatheter aortic valve implantation (TAVI).

Transfemoral transcatheter aortic valve implantation (TAVI) is nowadays a routine therapy for elderly patients with severe aortic stenosis (AS) and high perioperative risk. With growing experience, further development of the devices, and the expansion to "intermediate-risk" patients, there is increasing interest in performing this procedure under conscious sedation (TAVI-S) rather than the previously favoured approach of general anesthesia (TAVI-GA). The proposed benefits of TAVI-S include; reduced procedure time, shorter intensive care unit (ICU) length of stay, reduced need for intraprocedural vasopressor support, and the potential to perform the procedure without the direct presence of an anesthetist for cost-saving reasons. To date, no randomized trial data exists. We reviewed 13 non-randomized studies/registries reporting data from 6,718 patients undergoing TAVI (3,227 performed under sedation). Patient selection, study methods, and endpoints have differed considerably between published studies. Reported rates of in-hospital and longer-term mortality are similar for both groups. Up to 17% of patients undergoing TAVI-S require conversion to general anesthesia during the procedure, primarily due to vascular complications, and urgent intubation is frequently associated with hemodynamic instability. Procedure related factors, including hypotension, may compound preexisting age-specific renal impairment and enhance the risk of acute kidney injury. Hypotonia of the hypopharyngeal muscles in elderly patients, intraprocedural hypercarbia, and certain anesthetic drugs, may increase the aspiration risk in sedated patients. General anesthesia and conscious sedation have both been used successfully to treat patients with severe AS undergoing TAVI with similar reported short and long-term mortality outcomes. The authors believe that the significant incidence of complications and unplanned conversion to general anesthesia during TAVI-S mandates the start-to-finish presence of an experienced cardiac anesthetist in order to optimize patient outcomes. Good quality randomized data is needed to determine the optimal anesthetic regimen for patients undergoing TAVI.

Serum concentrations and pharmacokinetics of moxifloxacin in patients undergoing coronary artery bypass graft surgery with cardiopulmonary bypass.

Although cephalosporins are recommended as primary agents, moxifloxacin may be a suitable second-line antibiotic in cardiac surgery, especially if additional Gram-negative coverage is warranted. Cardiopulmonary bypass (CPB) may alter the pharmacokinetics of drugs in numerous ways. Since no such data exist, the aim of this study was to assess the serum concentrations and pharmacokinetics of moxifloxacin in patients undergoing cardiac surgery with CPB. Fourteen coronary artery bypass graft surgery patients received an intravenous infusion of 400 mg moxifloxacin as peri-operative antibiotic prophylaxis. At 15 time points throughout a 24-h period, serum samples were obtained to measure moxifloxacin concentrations using high-performance liquid chromatography. In addition, a non-compartmental pharmacokinetic analysis, i.e. area under the concentration-time curve (AUC), volume of distribution at steady state (V(SS)), drug clearance (CL), elimination half-life (t(1/2)) and mean residence time (MRT), was performed in five patients. Apart from a slight transient decrease in moxifloxacin concentration at the onset, CPB did not affect the concentration-time curve. Mean ± standard deviation maximum drug concentration (C(max)) (5.12 ± 1.58 µg/mL), AUC (36.5 ± 5.40 µgh/mL), VSS (2.03 ± 0.30 L/kg), CL (11.2 ± 1.91 L/h), t(1/2) (9.47 ± 0.92 h) and MRT (12.9 ± 1.52 h) were comparable with historical data for healthy volunteers. We conclude that CPB does not alter the pharmacokinetics of moxifloxacin. No dose adjustments, especially with regard to the CPB circuit and its priming volume, are necessary in cardiac surgical patients.

Use of automated external defibrillators in the occupational setting in Germany: a pilot study.

OBJECTIVE: Automated external defibrillators (AEDs) are widely used to increase survival of patients with sudden cardiac arrest (SCA). Despite these experiences only few data exist dealing with SCA at the workplace or AED usage in the occupational setting. METHODS: In a pilot study, occupational physicians throughout Germany were contacted and queried about the utilization of AED and the primary success rate (return of spontaneous circulation; ROSC). RESULTS: Of 232 occupational physicians, 155 (67%) stated that the enterprise provided at least one AED. Overall, 63 AED utilizations were analyzed. An ROSC was reported in 42 patients (67%). In 48% (n = 20) ROSC was established before the arrival of the EMS. CONCLUSION: Our study showed a high proportion of patients with ROSC after SCA. Increased attention should be turned to workplace SCA and AED programs.

Dexamethasone pretreatment provides antiinflammatory and myocardial protection in neonatal arterial switch operation.

BACKGROUND: This prospective double-blinded randomized study tested the hypothesis that preoperative treatment with dexamethasone would attenuate inflammatory priming of the myocardium, reduce the systemic inflammatory reaction upon cardiac operation, and provide organ protection in neonates. METHODS: Twenty neonates (age, 8 to 21 days) with transposition of the great arteries scheduled for arterial switch operation were included. Nine received dexamethasone (1 mg/kg body weight) 4 hours before cardiopulmonary bypass, and 11 received natrium chloride. We studied intramyocardial messenger RNA expression of interleukin (IL)-6, IL-8, IL-1ß, and tumor necrosis factor-α (TNF-α), as well as IL-10 and expression of TNF-α on protein level in right atrial tissue taken before institution of CPB. We measured plasma levels of IL-6, IL-10, lipopolysaccharide binding protein, and cardiac troponin T. Cytokine expression was related to postoperative outcome. RESULTS: Pretreatment with dexamethasone led to a significant decrease in myocardial expression of IL-6, IL-8, IL-1ß, and TNF-α messenger RNA and to a decrease in protein synthesis of TNF-α. Plasma concentrations of IL-6 were significantly lower and those of IL-10 significantly higher in pretreated patients. This was associated with lower cardiac troponin T values and lower dobutamine requirement. Levels of lipopolysaccharide binding protein were significantly higher postoperatively in pretreated neonates. CONCLUSIONS: Dexamethasone administration before arterial switch operation leads to a shift in the myocardial and systemic cytokine expression profile in neonates with transposition of the great arteries, with downregulation of proinflammatory and upregulation of antiinflammatory cytokines. Lower myocardial cell damage and lower catecholamine requirement suggest myocardial protection in treated patients.

Improvements in transcatheter aortic valve implantation outcomes in lower surgical risk patients: a glimpse into the future.

OBJECTIVES: The purpose of this study was to investigate the evolution of patient selection criteria for transcatheter aortic valve implantation (TAVI) and its impact on clinical outcomes. BACKGROUND: Anecdotal evidence suggests that patient selection for TAVI is shifting toward lower surgical risk patients. The extent of this shift and its impact on clinical outcomes, however, are currently unknown. METHODS: We conducted a single-center study that subcategorized TAVI patients into quartiles (Q1 to Q4) defined by enrollment date. These subgroups were subsequently examined for differences in baseline characteristics and 30-day and 6-month mortality rate. The relationship between quartiles and mortality rate was examined using unadjusted and adjusted (for baseline characteristics) Cox proportional hazard models. RESULTS: Each quartile included 105 patients (n = 420). Compared with Q4 patients, Q1 patients had higher logistic EuroSCORES (25.4 ± 16.1% vs. 17.8 ± 12.0%, p < 0.001), higher Society of Thoracic Surgeons scores (7.1 ± 5.5% vs. 4.8 ± 2.6%, p > 0.001), and higher median N-terminal pro-B-type natriuretic peptide levels (3,495 vs. 1,730 ng/dl, p < 0.046). From Q1 to Q4, the crude 30-day and 6-month mortality rate decreased significantly from 11.4% to 3.8% (unadjusted hazard ratio [HR]: 0.33; 95% confidence interval [CI]: 0.11 to 1.01; p = 0.053) and from 23.5% to 12.4% (unadjusted HR: 0.49; 95 CI: 0.25 to 0.95; p = 0.07), respectively. After adjustment for baseline characteristics, there were no significant differences between Q1 and Q4 in 30-day mortality rate (adjusted HR ratio: 0.29; 95% CI: 0.08 to 1.08; p = 0.07) and 6-month mortality rate (HR: 0.67; 95% CI: 0.25 to 1.77; p = 0.42). CONCLUSIONS: The results of this study demonstrate an important paradigm shift toward the selection of lower surgical risk patients for TAVI. Significantly better clinical outcomes can be expected in lower than in higher surgical risk patients undergoing TAVI.

Neither moxifloxacin nor cefuroxime produces significant attenuation of inflammatory mediator release in patients exposed to cardiopulmonary bypass: a randomized controlled trial.

OBJECTIVES: In vitro and experimental studies in animals have established the anti-inflammatory effects of moxifloxacin. Cardiopulmonary bypass (CPB) leads to an inflammatory response. The aim of this study was to assess whether the inflammatory cytokine response to CPB is reduced with a perioperative antibiotic prophylaxis, either moxifloxacin or cefuroxime (the standard prophylaxis). PATIENTS AND METHODS: Twenty-eight patients scheduled for elective coronary artery bypass grafting with CPB were randomly assigned to receive either moxifloxacin or cefuroxime as the perioperative antibiotic prophylaxis. Interleukin (IL)-6, -8, -10 and tumour necrosis factor-α (TNF-α) serum concentrations were determined at eight time points before and after CPB. RESULTS: In both groups, all cytokine concentrations significantly increased after the start of CPB. There were no statistically significant differences between the moxifloxacin and cefuroxime groups at any point; IL-6 concentrations [median (interquartile range)] 240 min after CPB, the primary endpoint, were 364 (192-598) and 465 (325-906) pg/mL (P = 0.323), respectively. CONCLUSIONS: Neither moxifloxacin nor cefuroxime produced significant attenuation of the inflammatory cytokine response to CPB. The reasons why moxifloxacin did not have significant anti-inflammatory effects in this unique clinical situation may be: (i) the inflammatory response to CPB may be different from that of infectious disease states that were used to establish the immunomodulatory effects of moxifloxacin; and (ii) a single intravenous dose, which was used in this investigation, may not lead to high enough plasma and intracellular concentrations.

Seizures after open heart surgery: comparison of ε-aminocaproic acid and tranexamic acid.

OBJECTIVE: Although the lysine analogs tranexamic acid (TXA) and aminocaproic acid (EACA) are used widely for antifibrinolytic therapy in cardiac surgery, relatively little research has been performed on their safety profiles, especially in the setting of cardiac surgery. Two antifibrinolytic protocols using either TXA or aminocaproic acid were compared according to postoperative outcome. DESIGN: A retrospective analysis. SETTING: A university-affiliated hospital. PARTICIPANTS: Six hundred four patients undergoing cardiac surgery. INTERVENTIONS: One cohort of 275 consecutive patients received TXA; a second cohort of 329 consecutive patients was treated with EACA. Except for antifibrinolytic therapy, the anesthetic and surgical teams and their protocols remained unchanged. MEASUREMENTS AND MAIN RESULTS: Besides major outcome criteria, namely postoperative bleeding, the need for allogeneic transfusions, operative revision because of bleeding, postoperative renal dysfunction, neurologic events, heart failure, and in-hospital mortality, the authors specifically sought differences between the groups concerning seizures. The 2 cohorts were comparable over a range of perioperative factors. Postoperative seizures occurred significantly more frequently in TXA patients (7.6% v 3.3%, p = 0.019), whereas EACA patients had a higher incidence of postoperative renal dysfunction (20.0% v 30.1%, p = 0.005). There were no differences in all other measured major outcome factors. CONCLUSION: Both lysine analogs are associated with significant side effects, which must be taken into account when performing risk-benefit analyses of their use. Their use should be restricted to patients at high risk for bleeding; routine use on low-risk patients undergoing standard surgeries should face renewed critical reappraisal.

Aortic annulus evaluation in transcatheter aortic valve implantation.

OBJECTIVES: We compared the annulus diameters measured by transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), and dual-source computed tomography (DSCT) before transcatheter aortic valve implantation (TAVI). BACKGROUND: In TAVI correct evaluation of the aortic annulus is mandatory to choose the correct prosthesis type and size and to prevent complications. There is no gold standard for the assessment of aortic annulus diameters. METHODS: Preoperative assessment of the aortic annulus with TTE, TEE, and DSCT was performed in 187 consecutive patients referred for TAVI between June 2007 and May 2009. RESULTS: The mean aortic annuli were 22.6 ± 2.0 mm measured with DSCT, 22.3 ± 2.5 mm with TTE, and 22.9 ± 2.2 mm with TEE. Despite a strong correlation between the measurement techniques, relevant statistical spread occurred with differences up to 3 mm in all measurement methods. Inter- and intraobserver variability was good for TEE and less satisfactory for DSCT measurements. TEE measurements taken as decisive parameter for the implantation changed the implantation strategy in 15.5% of patients and did not show an increased rate of procedural complications. CONCLUSION: Despite a strong correlation, the measurement techniques for the aortic annulus show relevant statistical spread, consequently one measurement technique cannot definitely predict another. TEE measurements show a more satisfactory intra- and interobserver variability than DSCT. Taking TEE annulus measurements as decisive parameter for the implantation has an impact on the implantation strategy and is safe with a low rate of procedural complications.

Efficiency and safety of preoperative autologous blood donation in cardiac surgery: a matched-pair analysis in 432 patients.

OBJECTIVE: A shortage of blood products is predicted for the near future in many countries all over the world. Preoperative autologous blood donation (PABD) in cardiac surgery is considered an option to reduce the need of allogeneic blood products. We analysed a 1-year period of our institutional database according to the safety and efficiency of our autologous blood donation programme. METHODS: All patients who donated autologous blood prior to cardiac surgery were matched to a non-donor according to age, body weight, body mass index, sex, haemoglobin concentration, EuroSCORE, antifibrinolytic therapy and risk for bleeding. We analysed the occurrence of adverse effects during donation in all donors as well as the main perioperative data, haemoglobin levels and the need for allogeneic blood transfusion in all patients. RESULTS: There were no major cardiac events such as myocardial infarction, worsened cardiac insufficiency or death in the donor group during the PABD process. A total of 216 patients could be matched. Exposure to allogeneic blood products was significantly reduced in the donor group (packed red cells 70 patients (pts) vs 118 pts (p<0.001), fresh frozen plasma 26 pts vs 54 pts (p=0.001), platelets 10 pts vs 22 pts (p=ns)). There were no reports of transfusion-related side effects. Further, there was no difference in haemoglobin concentrations at postoperative day 1 and at discharge. CONCLUSIONS: In this large matched-pair analysis without the need for risk stratification, PABD reduces the need for allogeneic blood products in adult cardiac surgery. In a carefully selected cohort, PABD is a safe and efficient alternative to allogeneic transfusion.

Transcatheter aortic valve implantation through the ascending aorta: an alternative option for no-access patients.

Retrograde transcatheter aortic valve implantation (TAVI) was successfully performed in an 80-year-old woman who had critical aortic stenosis but had no conventional access available because of severe calcifications of the femoral, iliac, and subclavian arteries. The TAVI procedure was performed with the CoreValve ReValving System. The currently available results obtained with TAVI show that such approaches provide significant clinical improvement in patients with severe aortic stenosis and unacceptable risk or contraindications for surgery. The ascending aorta approach might help to expand the implantation possibilities for those patients for whom the typical access sites are not available.

The blood sparing effect and the safety of aprotinin compared to tranexamic acid in paediatric cardiac surgery.

OBJECTIVE: Recently, the safety of aprotinin administration during open-heart surgery has been debated. The aim of the study was to compare the blood sparing effect and the side effects of aprotinin and tranexamic acid in paediatric cardiac surgery patients. METHODS: Perioperative data of 199 consecutive patients weighing less than 20kg undergoing open-heart cardiac surgery were prospectively collected between September 2005 and June 2006. During the first 5 months, 85 patients received aprotinin (group A); in the next 5 months, 114 patients were treated with tranexamic acid (group T). Except for antifibrinolytic therapy, the anaesthesiological and surgical protocols remained unchanged. Postoperative complications and in-hospital and 1-year mortality were considered as outcome parameters. RESULTS: The descriptive parameters and the intraoperative parameters were well comparable in the two groups. The blood loss was significantly lower in group A compared to group T at 6h [55 (35-82.5) vs 70 (45-100)ml, p=0.031], but not at 12 and 24h after operation. The incidence [9 (11%) vs 25 (22%), p=0.035] and the amount of red blood cell transfusion during the first 24h after surgery were also significantly lower in group A (0.1+/-0.4 vs 0.3+/-0.6 unit, p=0.036). There were significantly less rethoracotomies in group A [2 (2.4%) vs 11 (9.6%), p=0.039]. We found no difference in the incidence of the postoperative complications and in-hospital and 1-year mortality. There was a tendency for a higher incidence of seizures in group T [4 (3.5%) vs 0 (0%), p=0.14]. CONCLUSIONS: Aprotinin administration bears no additional risks compared to tranexamic acid and it has a stronger blood sparing effect in paediatric cardiac surgery. There were fewer rethoracotomies and less postoperative red blood cell transfusion in patients who received aprotinin.

The risks of aprotinin and tranexamic acid in cardiac surgery: a one-year follow-up of 1188 consecutive patients.

BACKGROUND: Our aim was to investigate postoperative complications and mortality after administration of aprotinin compared to tranexamic acid in an unselected, consecutive cohort. METHODS: Perioperative data from consecutive cardiac surgery patients were prospectively collected between September 2005 and June 2006 in a university-affiliated clinic (n = 1188). During the first 5 mo, 596 patients received aprotinin (Group A); in the next 5 mo, 592 patients were treated with tranexamic acid (Group T). Except for antifibrinolytic therapy, the anesthetic and surgical protocols remained unchanged. RESULTS: The pre- and intraoperative variables were comparable between the treatment groups. Postoperatively, a significantly higher incidence of seizures was found in Group T (4.6% vs 1.2%, P < 0.001). This difference was also significant in the primary valve surgery and the high risk surgery subgroups (7.9% vs 1.2%, P = 0.003; 7.3% vs 2.4%, P = 0.035, respectively). Persistent atrial fibrillation (7.9% vs 2.3%, P = 0.020) and renal failure (9.7% vs 1.7%, P = 0.002) were also more common in Group T, in the primary valve surgery subgroup. On the contrary, among primary coronary artery bypass surgery patients, there were more acute myocardial infarctions and renal dysfunction in Group A (5.8% vs 2.0%, P = 0.027; 22.5% vs 15.2%, P = 0.036, respectively). The 1-yr mortality was significantly higher after aprotinin treatment in the high risk surgery group (17.7% vs 9.8%, P = 0.034). CONCLUSION: Both antifibrinolytic drugs bear the risk of adverse outcome depending on the type of cardiac surgery. Administration of aprotinin should be avoided in coronary artery bypass graft and high risk patients, whereas administration of tranexamic acid is not recommended in valve surgery.

Extravasation of albumin after cardiopulmonary bypass in newborns.

OBJECTIVE: The systemic inflammatory response to cardiopulmonary bypass (CPB) possibly increases microvascular permeability to plasma proteins, leading to capillary leak syndrome. The study was conducted to elucidate any protein leakage in newborns using Evans blue dye as tracer. DESIGN: Prospective controlled study. SETTING: University-affiliated heart center. PARTICIPANTS: Eleven neonates with transposition of the great arteries. INTERVENTIONS: Plasma interleukin-6 (IL-6), IL-10, fractional escape rate (FER) of an intravenous bolus of Evans blue, and colloid osmotic pressure (COP) were assessed before and after surgery (statistics: median and 25th-75th percentile, Friedman's 2-way analysis of variance, and Wilcoxon matched-pairs signed-rank test [before and after surgery]). MEASUREMENTS AND MAIN RESULTS: All patients had an uneventful intraoperative course. The demographic and operative data were age 11 (10-13) days, body weight 3.2 (3.0-3.3) kg, CPB time 132 (123-144) minutes, and aortic cross-clamp time 66 (64-78) minutes. The proinflammatory IL-6 increased 60-fold and the anti-inflammatory IL-10 only 3-fold after CPB. FER, however, was not changed, whereas COP was significantly reduced after CPB. CONCLUSIONS: In contrast to the expectation, the escape rate of Evans blue, reflecting the extravasation of albumin, was not increased after CPB. However, reduced COP, hypothermia, and also a reduced lymphatic drainage may contribute to edema formation. The present data do not support the hypothesis of a capillary leak after CPB in newborns.

Graft function, histopathology and morphometry of radial arteries used as conduits for myocardial revascularization in patients beyond age 70.

BACKGROUND: Coronary artery bypass grafting (CABG) using radial arteries has become a standard procedure for younger patients in many centers. However, advanced atherosclerotic changes may limit its use in older patients. We studied the effects of age on morphologic and histopathologic findings in CABG patients aged 70 years and older. METHODS: In 31 consecutive patients aged 70-85 (mean 77+/-8 years) scheduled for elective CABG, the left or right radial artery (RA) was used to graft the second target vessel (first graft: LIMA-LAD). Preoperative Doppler flow and Allen's test were satisfactory. Intraoperatively the distal segment adjacent to the anastomosis site of the RA was collected for histologic evaluation. Intraoperative angiography, measurement of flow, and resistance index (PI) were performed to document graft quality. Histopathology and morphometry were used to measure intimal and medial areas (IA, MA; microm2), intimal thickening index (ITI), relation between intimal and medial width at maximum intimal thickness (IMR), and percentage of luminal narrowing (%LN). RESULTS: The RA showed no evidence for stenosis of the conduits or the anastomosis. In all grafts flow and PI were satisfactory (76+/-14 ml/min; PI: 2.2+/-0.9). Histopathology and morphometry showed atherosclerotic changes in all RA grafts: IA: 890+/-971 (range 286-5244), MA: 2751+/-818 (range 1357-4989), ITI: 0.26+/-0.09 (range 0.12-0.44), IMR: 0.59+/-0.28 (range 0.21-1.13) %LN: 38+/-5 (range 13.2-61.7). Age as well as classic risk factors including diabetes, hypertension, smoking, and hyperlipidemia did not correlate with RA atherosclerosis. CONCLUSIONS: Excellent macroscopic and angiographic results were obtained. All grafts used showed minor to moderate atherosclerotic changes without severely altered indices of intimal thickening or luminal narrowing. The radial artery must be used with caution; however, age should not be an exclusion criterion per se.