Simon H. Sündermann

Frailty is a predictor of short- and mid-term mortality after elective cardiac surgery independently of age†

OBJECTIVES Assessment of perioperative risk of elderly patients in cardiac surgery is difficult, and most of the common risk scores show over- or underestimation. Two frailty scores, the comprehensive assessment of frailty (CAF) score and the Frailty predicts death One yeaR after CArdiac Surgery Test (FORECAST), were developed as additional tools to estimate the preoperative mortality risk, taking into consideration the frailty status of elderly patients. METHODS Four hundred and fifty patients who were referred for elective cardiac surgery were included. All the patients were assessed with the CAF test and the FORECAST. Thirty-day and 1-year mortality were evaluated by telephone interview. Univariate and bivariate logistic regression were performed to test the predictive power of the tests on mortality. Correlation of the scores with age was calculated with Spearman ranks. Three commensurate groups were built for each of the frailty scores and the outcome was compared between the groups. All analyses were performed for Society of Thoracic Surgeons (STS) and European System for Cardiac Operative Risk Evaluation (EuroSCORE) accordingly. RESULTS A total of 227 male and 223 female patients were included. Thirty-day mortality was 6.1%, and 1-year mortality was 13.3%. Logistic regression showed that both scores are able to predict 30-day as well as 1-year mortality. Bivariate logistic regression showed that both frailty scores give relevant additional information to the STS and EuroSCORE for the prediction of 1-year mortality. The frailty scores were only weakly correlated with age in contrast to STS and EuroSCORE and therefore can be used as indicator of the biological age of patients besides the numerical age. Survival up to 1 year was relevantly reduced in the group of patients with the higher frailty scores. CONCLUSIONS CAF and FORECAST are additional tools to evaluate elderly patients adequately before elective cardiac surgery, and showed an association with short- and mid-term mortality independently of age.

Safety and feasibility of novel technology fusing echocardiography and fluoroscopy images during MitraClip interventions.

AIMS The EchoNavigator (EN) software (Philips Healthcare, Best, The Netherlands) enables real-time fusion of echocardiography and fluoroscopy by co-registration of the echocardiography probe on the x-ray image. We aimed to evaluate the feasibility and safety of this novel software during MitraClip procedures. METHODS AND RESULTS Twenty-one patients were treated with the support of EchoNavigator software (EN+ patients). The primary (safety) endpoint was the total radiation dose. Secondary endpoints were fluoroscopy and total procedure time. The measurements were compared to those of 21 patients treated immediately before the installation of EchoNavigator (EN- patients). More MitraClips (45 vs. 36) were implanted in the EN+ group, mirroring more complex interventions in this group. In EN+ patients, radiation dose (Gy/cm2) was similar compared to EN- patients (146.5±123.6 vs.146.8±134.1, p=0.9). Total procedure time (minutes) was similar in the EN+ group compared to EN- patients (136.2±50.2 vs. 125.7±51.2, p=0.5). The main benefit of the EchoNavigator is the automated real-time fusion of echocardiography and fluoroscopy, leading to easier catheter manipulation. CONCLUSIONS The use of EchoNavigator software was feasible and safe in all study patients. Further studies are necessary to confirm the benefits of using this software.

Feasibility of the Engager™ aortic transcatheter valve system using a flexible over-the-wire design.

OBJECTIVES The aim was to investigate the safety and feasibility of the redesigned Engager™ transcatheter aortic valve implantation (TAVI) system. METHODS Transapical aortic valve implantation with the Engager™ valve prosthesis was intended in 11 patients, and performed in 10. Endpoints were defined according to the valve academic research consortium recommendations for reporting outcomes of TAVI in clinical trials. RESULTS All 10 patients were implanted successfully. No devicerelated or delivery system complications like coronary obstruction or aortic dissection emerged. One patient (10%) died from non-device-related reasons at post-operative day 23 of multi-organ failure. The invasively measured peak-to-peak gradient after valve implantation was 7.1 ± 3.5 mmHg. In 90%, there was no or only trivial (≤grad I) aortic regurgitation due to paravalvular leakage. In 10% of the patients, aortic regurgitation grade I-II was observed. At 30-day follow up, the mean gradient was 15.6 ± 4.9 mmHg, and no more than a mild transvalvular and paravalvular aortic regurgitation was seen as assessed by transthoracic echocardiography. CONCLUSIONS Application of the Engager™ TAVI system is safe and feasible. Prosthesis deployment in an anatomically correct position was facilitated by the design of the valve prosthesis and was successful in all patients. No device or delivery-system-related complications emerged. Safety and feasibility endpoints were met. Good results concerning the aortic valve performance after implantation and at 30-day follow up were ascertained. These results encouraged the start of a European Pivotal trial including patients to date.

Simulation of transcatheter aortic valve implantation under consideration of leaflet calcification

Transcatheter aortic valve implantation (TAVI) is a minimally invasive off-pump procedure to replace diseased aortic heart valves. Known complications include paravalvular leaks, atrioventricular blocks, coronary obstruction and annular rupture. Careful procedure planning including appropriate stent selection and sizing are crucial. Few patient-specific geometric parameters, like annular diameters, annular perimeter and measurement of the distance to the coronary ostia, are currently used within this process. Biomechanical simulation allows the consideration of extracted anatomy and material parameters for the intervention, which may improve planning and execution phases. We present a simulation workflow using a fully segmented aortic root anatomy, which was extracted from pre-operative CT-scan data and apply individual material models and parameters to predict the procedure outcome. Our results indicate the high relevance of calcification location and size for intervention planning, which are not sufficiently considered at this time. Our analysis can further provide guidance for accurate, patient-specific device positioning and future adaptations to stent design.

Use of extracellular matrix materials in patients with endocarditis.

Tissue replacement is sometimes necessary during surgery for endocarditis. Commonly used materials are Dacron, expanded polytetrafluoroethlyene, or bovine pericardium. Those materials have no potential for bioresorption and cannot restore regional functionality. Extracellular matrices became available lately as patch material. Here we present two cases of patients with endocarditis. CorMatrix ECM (CorMatrix Cardiovascular, Inc., Atlanta, Georgia, United States) was used to repair intracardiac structures with good results in follow-up up to 3 months. CorMatrix ECM may be an adequate alternative to foreign material for patients with endocarditis.

Medtronic Engager™ bioprosthesis for transapical transcatheter aortic valve implantation.

1. Division of Cardiovascular Surgery, University Hospital Zurich, Zurich, Switzerland; 2. Clinic for Cardiac Surgery, Heart Center Leipzig, Leipzig, Germany; 3. Clinic for Cardiac Surgery, German Heart Center Munich, Munich, Germany; 4. Department of Cardiovascular Surgery, University Heart Center Hamburg, Hamburg, Germany

Surviving 20 Years After Heart Transplantation: A Success Story

BACKGROUND We report the long-term outcomes of patients who survived 20 years or greater after heart transplantation. METHODS From 1985 to 2012, 386 patients underwent heart transplantation at our institution. Patient data were analyzed retrospectively for transplants performed from 1985 to 1991. The Kaplan-Meier method was used for survival analyses. RESULTS In total, 133 patients were included. The mean age of the 20-year survivors at transplant was 43.6±11.4 years. The mean ischemic time was 71.2±34.0 minutes. The overall actuarial survival rates at 1, 10, and 20 years were 82.7%, 63.9%, and 55.6%, respectively. The most common causes of death were graft rejection (21%), malignancy (21%), infection (15%), and cardiac allograft vasculopathy (CAV, 14%). After 1, 10, and 20 years, the rejection-free survival rates were 19%, 13%, and 13%, respectively, and the malignancy-free survival rates were 99%, 67%, and 61%. The CAV-free survival rates were 97%, 48%, and 42%, respectively, and the infection-free survival rates were, respectively, 70%, 15%, and 14%. The actuarial diabetes-free survival rates at 1, 10, and 20 years were 85%, 80%, and 79%, respectively. Actuarial hypertension-free survival was 56% after 1 year and 26% after 10 and 20 years. Two patients received a second heart transplant. CONCLUSIONS A remarkable number of patients survived 20 years or greater after heart transplantation, confirming the procedure as the gold standard for end-stage heart failure. Complications resulting from immunologic events and immunosuppressive therapy determine post-transplant mortality and morbidity. Due to improvements in immunosuppressive management in recent years, long-term survival is likely to increase.

Implantation of personalized, biocompatible mitral annuloplasty rings: feasibility study in an animal model

OBJECTIVES Implantation of an annuloplasty ring is an essential component of a durable mitral valve repair. Currently available off-the-shelf rings still do not cover all the variations in mitral annulus anatomy and pathology from subject to subject. Computed tomography (CT) and echo imaging allow for 3-D segmentation of the mitral valve and mitral annulus. The concept of tailored annuloplasty rings has been proposed although, to date, no surgically applicable implementation of patient-specific annuloplasty rings has been seen. The objective of this trial was to prove the concept of surgical implantation of a model-guided, personalized mitral annuloplasty ring, manufactured based on individual CT-scan models. METHODS ECG-gated CT angiography was performed in six healthy pigs under general anaesthesia. Based on the individual shape of the mitral annulus in systole, a customized solid ring with integrated suturing holes was designed and manufactured from a biocompatible titanium alloy by a rapid process using laser melting. The ring was implanted three days later and valve function was assessed by intraoperative echocardiography. The macroscopic annulus-annuloplasty match was assessed after heart explantation. RESULTS CT angiography provided good enough image quality in all animals to allow for segmentation of the mitral annulus. The individually tailored mitral rings were manufactured and successfully implanted in all pigs. In 50%, a perfect matching of the implanted ring and the mitral annulus was achieved. In one animal, a slight deviation of the ring shape from the circumference was seen postoperatively. The rings implanted in the first two animals were significantly oversized but the deviation did not affect valve competence. CONCLUSIONS CT image quality and accuracy of the dimensions of the mitral annulus were sufficient for digital modelling and rapid manufacturing of mitral rings. Implantation of individually tailored annuloplasty rings is feasible.

Negative microbiological results are not mandatory in deep sternal wound infections before wound closure

OBJECTIVES To define the outcome of treatment for deep sternal wound infections (DSWIs) using direct wound closure (DC) or vacuum-assisted therapy (VAT) based on negative vs. positive microbiological results. METHODS Between 1999 and 2008, 7746 patients underwent median sternotomy for cardiac surgery at our institution. Patients were screened for DSWI and out of the cohort 159 were identified (2%). These patients were treated, either using DC or VAT with delayed wound closure. Outcomes were retrospectively analysed to determine the effect of negative cultures at the time of closure. RESULTS The indication for sternotomy was CABG 51%, isolated valve 18%, CABG/valve 18% and other related cardiovascular procedures 14%. Sixty-five percent of the wound infections was diagnosed during rehabilitation period. One hundred and five (66%) patients were treated with VAT vs. 54 (34%) patients with direct closure. Coagulase negative staphylococci were found in 48% of bacterial cultures. In 75% of the patients, the microbiological results were positive at time of wound closure (69.2% VAT vs. 87.0% direct closure, P = 0.014). Out of 159 patients, 5.0% were with positive microbiological results at the time of closure readmitted vs. 5.1% with negative microbiological results (P = 1.0). Patients with VAT stayed significantly longer in the hospital (mean 21 ± 16 vs. 13 ± 12, P = 0.002). CONCLUSIONS Negative microbiological results are not mandatory before wound closure, as the rate of readmissions for recurrence of infection showed no difference between groups. Our results also suggest that shortening of VAT despite positive microbiological results may be feasible.

Turbulent Kinetic Energy Assessed by Multipoint 4-Dimensional Flow Magnetic Resonance Imaging Provides Additional Information Relative to Echocardiography for the Determination of Aortic Stenosis Severity

Background— Turbulent kinetic energy (TKE), assessed by 4-dimensional (4D) flow magnetic resonance imaging, is a measure of energy loss in disturbed flow as it occurs, for instance, in aortic stenosis (AS). This work investigates the additional information provided by quantifying TKE for the assessment of AS severity in comparison to clinical echocardiographic measures. Methods and Results— Fifty-one patients with AS (67±15 years, 20 female) and 10 healthy age-matched controls (69±5 years, 5 female) were prospectively enrolled to undergo multipoint 4D flow magnetic resonance imaging. Patients were split into 2 groups (severe and mild/moderate AS) according to their echocardiographic mean pressure gradient. TKE values were integrated over the aortic arch to obtain peak TKE. Integrating over systole yielded total TKEsys and by normalizing for stroke volume, normalized TKEsys was obtained. Mean pressure gradient and TKE correlated only weakly (R2=0.26 for peak TKE and R2=0.32 for normalized TKEsys) in the entire study population including control subjects, while no significant correlation was observed in the AS patient group. In the patient population with dilated ascending aorta, both peak TKE and total TKEsys were significantly elevated (P<0.01), whereas mean pressure gradient was significantly lower (P<0.05). Patients with bicuspid aortic valves also showed significantly increased TKE metrics (P<0.01), although no significant difference was found for mean pressure gradient. Conclusions— Elevated TKE levels imply higher energy losses associated with bicuspid aortic valves and dilated ascending aortic geometries that are not assessable by current echocardiographic measures. These findings indicate that TKE may provide complementary information to echocardiography, helping to distinguish within the heterogeneous population of patients with moderate to severe AS.