Jens Fassl

Transapical minimally invasive aortic valve implantation; the initial 50 patients §

OBJECTIVE To evaluate the feasibility of minimally invasive transapical beating heart aortic valve implantation (TAP-AVI) for high-risk patients with aortic stenosis. METHODS TAP-AVI was performed via a small anterolateral minithoracotomy in 50 patients from February 2006 to March 2007. A balloon expandable transcatheter xenograft (Edwards SAPIEN THV, Edwards Lifesciences, Irvine, CA, USA) was used. Mean age was 82.4+/-5 years and 39 (78%) were female. Implantation was performed in a hybrid operative theatre using fluoroscopic and echocardiographic visualization. Average EuroSCORE predicted risk for mortality was 27.6+/-12%. Seven (14%) patients were re-operations with patent bypass grafts. RESULTS TAP-AVI (13 patients 23 mm and 37 patients 26 mm) was successfully performed on the beating heart under temporary rapid ventricular pacing in 47 (94%) patients, and implantation was performed completely off-pump in 34 (68%) patients. Three patients required early conversion; two of them were successfully discharged. There was no prosthesis migration or embolization observed. Echocardiography revealed good hemodynamic function in all and minor incompetence in 23 patients, mostly paravalvular, without any signs of hemolysis. Mortality was due to the overall health condition and non-valve related in all patients. Actuarial survival at 1 month, 6 months and 1 year was 92+/-3.8%, 73.9+/-6.2% and 71.4+/-6.5%, respectively. CONCLUSIONS Transapical minimally invasive aortic valve implantation is feasible using an off-pump technique. Good results have been achieved in the initial 50 patients, especially when considering the overall high-risk profile of these patients.

Human minimally invasive off-pump valve-in-a-valve implantation.

Reoperative heart valve replacement for degenerated xenografts is associated with an increased surgical risk. We used our experience with transcatheter transapical aortic valve implantation to perform a transapical off-pump aortic valve-in-a-valve implantation. Hemodynamic function was excellent and the patient had a fast and uneventful recovery.

Randomized Comparison of Sevoflurane Versus Propofol to Reduce Perioperative Myocardial Ischemia in Patients Undergoing Noncardiac Surgery

Background— Volatile anesthetics provide myocardial preconditioning in coronary surgery patients. We hypothesized that sevoflurane compared with propofol reduces the incidence of myocardial ischemia in patients undergoing major noncardiac surgery. Methods and Results— We enrolled 385 patients at cardiovascular risk in 3 centers. Patients were randomized to maintenance of anesthesia with sevoflurane or propofol. We recorded continuous ECG for 48 hours perioperatively, measured troponin T and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) on postoperative days 1 and 2, and evaluated postoperative delirium by the Confusion Assessment Method. At 6 and 12 months, we contacted patients by telephone to assess major adverse cardiac events. The primary end point was a composite of myocardial ischemia detected by continuous ECG and/or troponin elevation. Additional end points were postoperative NT-proBNP concentrations, major adverse cardiac events, and delirium. Patients and outcome assessors were blinded. We tested dichotomous end points by &khgr;2 test and NT-proBNP by Mann–Whitney test on an intention-to-treat basis. Myocardial ischemia occurred in 75 patients (40.8%) in the sevoflurane and 81 (40.3%) in the propofol group (relative risk, 1.01; 95% confidence interval, 0.78–1.30). NT-proBNP release did not differ across allocation on postoperative day 1 or 2. Within 12 months, 14 patients (7.6%) suffered a major adverse cardiac event after sevoflurane and 17 (8.5%) after propofol (relative risk, 0.90; 95% confidence interval, 0.44–1.83). The incidence of delirium did not differ (11.4% versus 14.4%; P=0.379). Conclusions— Compared with propofol, sevoflurane did not reduce the incidence of myocardial ischemia in high-risk patients undergoing major noncardiac surgery. The sevoflurane and propofol groups did not differ in postoperative NT-proBNP release, major adverse cardiac events at 1 year, or delirium. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00286585.

Cardiac surgery fast-track treatment in a postanesthetic care unit: six-month results of the Leipzig fast-track concept.

Background:The authors compared the safety and efficacy of a newly developed fast-track concept at their center, including implementation of a direct admission postanesthetic care unit, to standard perioperative management. Methods:All fast-track patients treated within the first 6 months of implementation of our direct admission postanesthetic care unit were matched via propensity scores and compared with a historical control group of patients who underwent cardiac surgery prior to fast-track implementation. Results:A total of 421 fast-track patients were matched successfully to 421 control patients. The two groups of patients had a similar age (64 ± 13 vs. 64 ± 12 yr for fast-track vs. control, P = 0.45) and European System for Cardiac Operative Risk Evaluation–predicted risk of mortality (4.8 ± 6.1% vs. 4.6 ± 5.1%, P = 0.97). Fast-track patients had significantly shorter times to extubation (75 min [45–110] vs. 900 min [600–1140]), as well as shorter lengths of stay in the postanesthetic or intensive care unit (4 h [3.0–5] vs. 20 h [16–25]), intermediate care unit (21 h [17–39] vs. 26 h [19–49]), and hospital (10 days [8–12] vs. 11 days [9–14]) (expressed as median and interquartile range, all P < 0.01). Fast-track patients also had a lower risk of postoperative low cardiac output syndrome (0.5% vs. 2.9%, P < 0.05) and mortality (0.5% vs. 3.3%, P < 0.01). Conclusion:The Leipzig fast-track protocol is a safe and effective method to manage cardiac surgery patients after a variety of operations.

Anesthesia Management for Transapical Transcatheter Aortic Valve Implantation: A Case Series

OBJECTIVE The purpose of this study was to review the management of anesthesia for transapical transcatheter aortic valve implantation. DESIGN Retrospective review of collected data. SETTING University-affiliated heart center. PARTICIPANTS One hundred consecutive patients with severe aortic stenosis. INTERVENTIONS General anesthesia followed by an established fast-track protocol. MATERIALS AND METHODS A total of 100 patients with significant AS received transapical transcatheter aortic valve implantation. The patients were treated following a fast-track protocol. The mean arterial pressure was maintained above 65 mmHg by volume and/or inotropes during the procedure. The mean arterial pressure was increased above 75 mmHg to avoid hemodynamic deterioration before starting rapid ventricular pacing for the balloon valvuloplasty and the valve implantation. Transesophageal echocardiography was used to assess valve size and for hemodynamic monitoring. Eighty-one patients were treated completely off pump. There was a significant decline in mean arterial pressure from pre- to postvalvuloplasty (74.7 +/- 9.1 mmHg v 63.6 +/- 11.3 mmHg, p < 0.001) and from pre- to postimplantation (76.5 +/- 12.6 mmHg v 67.2 +/- 12.7, p < 0.001). The first 10 patients in the study intentionally were placed on cardiopulmonary bypass, and 9 patients required cardiopulmonary bypass because of hemodynamic deterioration. CONCLUSION A well-designed anesthetic plan as well as an understanding of the surgical procedure and the hemodynamic effects of rapid ventricular pacing are required to ensure successful outcomes in this new surgical option for high-risk patients.

Transfusion of allogeneic blood products in proximal aortic surgery with hypothermic circulatory arrest: effect of thromboelastometry-guided transfusion management.

OBJECTIVES Proximal aortic surgery with hypothermic circulatory arrest (HCA) commonly involves perioperative transfusion of allogeneic blood products, including red blood cells, plasma, and platelets. The authors hypothesized that surgery with HCA could be performed without allogeneic blood products and that a thromboelastometry-guided algorithm would reduce the transfusion of allogeneic blood products. DESIGN A retrospective analysis of prospectively collected data. Patients with and without thromboelastometry guidance were compared by case-control analysis (n = 62 matched patients) and multivariate regression (n = 194 patients). SETTING Single-center university hospital. PARTICIPANTS This study included 194 patients undergoing elective and emergent procedures with HCA involving the proximal aorta. INTERVENTIONS A thromboelastometry-guided treatment algorithm during surgery was used in 153 patients (79%), and conventional coagulation management was used in 41 patients (21%). MEASUREMENTS AND MAIN RESULTS During surgery and the following 24 hours, allogeneic blood products were transfused in 106 patients (55%). Median (interquartile range) number of allogeneic blood products transfused was 1 unit (0-6 units). Case-control analysis showed lower transfusion rates of red blood cells, plasma, and any allogeneic blood product (all p<0.050) in patients with thromboelastometry guidance. In the multivariate analysis, thromboelastometry guidance was associated with an odds ratio of 0.26 (95% confidence interval, 0.08-0.84; p = 0.025) for the transfusion of any allogeneic blood product. The use of thromboelastometry was not associated with adverse events (odds ratio 0.72; 95% confidence interval, 0.27-1.90; p = 0.507). CONCLUSIONS Allogeneic blood products were avoided in a proportion of patients. The findings further suggest that thromboelastometry-guided coagulation management promoting the use of coagulation factor concentrates decreased the use of allogeneic blood products during complex cardiac surgery.

The Year in Cardiothoracic and Vascular Anesthesia: Selected Highlights From 2009

The hybrid operating room is the venue for transcatheter therapy with the convergence of 3 specialties: cardiac surgery, cardiovascular anesthesiology, and interventional cardiology. Transcatheter aortic valve replacement is proof that cardiac specialists have embraced the endovascular revolution. Because pharmacologic conditioning and ischemic myocardial conditioning are safe and effective, they are currently the focus of multiple trials. Angiotensin blockade, anemia, and endoscopic saphenous vein harvesting worsen outcome after coronary artery bypass graft (CABG) surgery. Although off-pump CABG surgery is equivalent to on-pump CABG surgery, it may improve outcomes in high-risk groups. Although percutaneous coronary intervention (PCI) significantly decreases mortality after myocardial infarction, the evidence is less convincing for intra-aortic balloon counterpulsation. Even though prasugrel recently was approved for platelet blockade in PCI, it may be superseded by ticagrelor. Although PCI and CABG surgery appear equivalent for multivessel coronary disease, CABG surgery lowers revascularization rates and also has superior outcomes in diabetics and the elderly. Hetastarch and N-acetylcysteine both increase bleeding and transfusion in cardiac surgery. Factor VII can treat life-threatening bleeding, but its safety requires further evaluation. Because eltrombopag and romiplostim stimulate platelet production, they may have a future role in hemostasis after cardiac surgery. Even though fenoldopam, atrial natriuretic peptide, and sodium bicarbonate are nephroprotective, further trials must confirm these findings. Intensive insulin therapy offers no further outcome advantage and significantly increases hypoglycemic risk. The past year has witnessed the advent of a new clinical venue, new devices, and new drugs. The coming year will most likely advance these achievements.

Value of augmented reality-enhanced transesophageal echocardiography (TEE) for determining optimal annuloplasty ring size during mitral valve repair.

BACKGROUND Mitral valve (MV) annuloplasty is an integral part of MV repair, but sizing under direct vision is occasionally challenging. Furthermore, traditional sizing is not possible for percutaneous MV repair techniques. This study compared augmented reality-enhanced three-dimensional (3D) transesophageal echocardiography (TEE) for determining MV annuloplasty size with conventional surgical sizing. METHODS In patients undergoing elective MV repair, a 3D MV reconstruction was performed using TEE. Modified 4D valve assessment software was used to create 3D computer-aided design models of standard annuloplasty rings (28 to 36 mm), which were stored in a digital database. These virtual 3D annuloplasty ring templates were superimposed on the preoperative 3D TEE reconstructions of the MV, and results were compared with conventional sizing under direct vision. A post hoc validation of the 3D models was performed using the implanted rings as a control. The echocardiographer was blinded to the implanted ring size. RESULTS The study included 50 patients. The correlation between the selected 3D annuloplasty ring template and the implanted annuloplasty ring size was 0.83. Thirty ring templates (60%) were the same size as the implanted annuloplasty ring, 19 templates (38%) differed by +/-2 mm in size, and 1 template differed by +4 mm. Postoperatively, the validation protocol revealed a correlation of 0.94 between the size of the ring templates and the implanted annuloplasty prostheses. CONCLUSIONS Augmented reality-enhanced TEE for determining optimal annuloplasty ring size during MV repair correlates well with conventional surgical sizing and may facilitate future percutaneous MV repair techniques.

The Intravenous Anesthetic Propofol Inhibits Human L-Type Calcium Channels by Enhancing Voltage-Dependent Inactivation

Propofol is commonly used to induce anesthesia but has been associated with some negative cardiovascular side effects, including negative inotropy, hypotension, and bradycardia. This study investigated the effect of propofol on L‐type calcium current in acutely isolated human atrial myocytes to better understand the mechanism of these side effects. After informed consent was obtained, the atrial appendage was obtained from patients undergoing open‐heart surgery who required cardiopulmonary bypass. Atrial myocytes were isolated using enzymatic digestion, and L‐type calcium currents were recorded using the whole‐cell patch clamp technique. Propofol enhanced the magnitude and speed of voltage‐dependent inactivation of L‐current. As a result, the propofol‐induced inhibition was increased by protocols that increased inactivation such as longer voltage step duration, holding potential depolarization, and increased pulsing frequency. The preferential enhancement of L‐channel inactivation by propofol can explain the associated cardiovascular side effects. The depolarized resting potential of arterial smooth muscle may render the L‐channels in these cells particularly sensitive to propofol‐induced inhibition, which could explain the hypotension observed in some patients. The enhancement of both inactivation kinetics and steady‐state inactivation by propofol can also explain the negative inotropic effect. However, the enhanced voltage‐dependent inactivation and use dependence could have beneficial effects for patients prone to certain arrhythmias and tachycardia.

Effects of Inhalational Anesthetics on L-type Ca2+ Currents in Human Atrial Cardiomyocytes during β-adrenergic Stimulation

Background Anesthetics may cause cardiac side effects by their action on L-type Ca2+ channels. Direct effects on the channels have not yet been discriminated from an interference with the &bgr;-adrenergic channel regulation. The authors therefore studied the effects of halothane, sevoflurane, and xenon on human cardiac Ca2+ currents during stimulation with isoproterenol. Methods Currents through L-type Ca2+ channels were measured with the patch clamp technique in atrial cardiomyocytes obtained from patients undergoing cardiac surgery. Cells were superfused with solutions equilibrated with anesthetics at the desired concentrations. Ca2+ currents during pulses to 10 mV were evaluated with respect to their peak value (Imax) and to the total moved charge (Q). Results In the absence and in the presence of isoproterenol (1 &mgr;m), sevoflurane (0.29 mm, 1 minimum alveolar concentration [MAC]) significantly depressed Q by 37.8 ± 7.2% (mean ± SD) and 40.8 ± 10.3%, respectively. Imax was not significantly affected in comparison with control cells never exposed to an anesthetic. Xenon (65%, 1 MAC) did not evoke significant effects. Exposure to halothane (0.39 mm, 1 MAC) during stimulation with isoproterenol significantly reduced Q by 31.3 ± 23.3% (but not Imax). After washout of halothane, Q was increased above the level prior to the application of halothane. Moreover, whereas Q promptly declined to baseline levels after washout of isoproterenol in controls, the previous exposure to halothane markedly delayed this decline, leaving Q significantly elevated for several minutes. Conclusions Halothane exerts a dual effect on Ca2+ currents. The long-lasting stimulatory effect may contribute to the proarrhythmic potency of the drug that exceeds that of sevoflurane, which only depressed Ca2+ currents.