Risks and Challenges of Surgery for Aortic Prosthetic Valve Endocarditis.

BACKGROUND: Prosthetic valve endocarditis is the most severe form of infective endocarditis. This study assessed the risks and challenges of surgery for aortic prosthetic valve endocarditis. METHODS: In total, 116 consecutive patients (98 males, age 65.2±12.7years), who underwent redo-surgery for active aortic prosthetic valve endocarditis between 2000 and 2014, were reviewed. Cox regression analysis was used to identify factors for aortic root destructions as well as for morbidity and mortality. Median follow-up was 3.8 years (0-13.9 years). RESULTS: Aortic root destructions (42 limited and 29 multiple lesions) were associated with early prosthetic valve endocarditis and delayed diagnosis (≥14 d), but not with mortality. There were 16 (13.8%) early (≤30 d) and 32 (27.6%) late (>30 days) deaths. Survival at 1, 5, and 10 years was 72±4.3%, 56±5.4%, and 46±6.4%, respectively. The cumulative incidence of death, reinfection, and reoperation was 19.0% at 30days and 36.2% at 1year. Delayed diagnosis, concomitant procedures, and EuroSCORE II >20% were predictors for early mortality and need for mechanical circulatory support, age >70years, and critical preoperative state were predictors for late mortality. In their absence, survival at 10 years was 70±8.4%. Reinfections and reoperations occurred more frequently if ≥1 risk factor for endocarditis and aortic root destructions were present. At 10 years, freedom from reinfection and reoperation was 89±4.2% and 91±4.0%. CONCLUSIONS: The risks of death, reinfection, and reoperation are significant within the first year after surgery for aortic prosthetic valve endocarditis. Early diagnosis and aortic root destructions are the most important challenges, but advanced age, critical preoperative state, and the need for mechanical circulatory support determine long-term survival.

Early hemodynamics and clinical outcomes of isolated aortic valve replacement with stentless or transcatheter valve in intermediate-risk patients.

OBJECTIVE: Stentless aortic valves have been developed to overcome obstructive limitations associated with stented bioprostheses. The aim of the current multi-institutional study was to compare hemodynamics of transcatheter (TAVR) and the Freedom SOLO Stentless (FS) valve in an intermediate risk population undergoing surgical aortic valve replacement. METHODS: From 2010 to 2014, 420 consecutive patients underwent isolated surgical aortic valve replacement with FS and 375 patients underwent TAVR. Only patients with intermediate operative risk (Society of Thoracic Surgeons score 4-10) and small aortic annulus (≤23 mm) were included. After a propensity matched analysis 142 patients in each group were selected. Thirty-day postoperative clinical and echocardiographic parameters were evaluated. RESULTS: Mean prosthesis diameter was 22.2 ± 0.9 mm for FS and 22.4 ± 1.0 mm for TAVR. In-hospital mortality was 2.1% for FS and 6.3% for TAVR (P = .02). Postoperative FS peak gradients were 19.1 ± 9.6 mm Hg (mean 10.8 ± 5.9 mm Hg); TAVR peak gradients were 20.2 ± 9.5 mm Hg (mean 10.7 ± 6.9 mm Hg) P = .57 (P = .88). Postoperative effective orifice area was 1.93 ± 0.52 cm2 for FS and 1.83 ± 0.3 cm2 for TAVR (P = .65). There was no prostheses-patient mismatch in either group. Postoperative grade 2-3 paravalvular leak was present in 3.5% for TAVR and 0.7% for FS. Postoperative permanent pacemaker implant rate was 12% for TAVR and only 1 case (0.7%) in the FS group (P < .001). CONCLUSIONS: In patients with small aortic annulus and intermediate risk, both FS and TAVR demonstrated similar excellent hemodynamic performance. TAVR demonstrated greater mortality and rates of pacemaker insertion. Further studies are warranted to validate TAVR indications in this subset of patients.

In situ observation of fracture processes in high-strength concretes and limestone using high-speed X-ray phase-contrast imaging.

The mechanical properties and fracture mechanisms of geomaterials and construction materials such as concrete are reported to be dependent on the loading rates. However, the in situ cracking inside such specimens cannot be visualized using traditional optical imaging methods since the materials are opaque. In this study, the in situ sub-surface failure/damage mechanisms in Cor-Tuf (a reactive powder concrete), a high-strength concrete (HSC) and Indiana limestone under dynamic loading were investigated using high-speed synchrotron X-ray phase-contrast imaging. Dynamic compressive loading was applied using a modified Kolsky bar and fracture images were recorded using a synchronized high-speed synchrotron X-ray imaging set-up. Three-dimensional synchrotron X-ray tomography was also performed to record the microstructure of the specimens before dynamic loading. In the Cor-Tuf and HSC specimens, two different modes of cracking were observed: straight cracking or angular cracking with respect to the direction of loading. In limestone, cracks followed the grain boundaries and voids, ultimately fracturing the specimen. Cracks in HSC were more tortuous than the cracks in Cor-Tuf specimens. The effects of the microstructure on the observed cracking behaviour are discussed.This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'.

The Ross Procedure in Adults: Long-Term Results of Homografts and Stentless Xenografts for Pulmonary Valve Replacement.

Background The Ross procedure is an established method to treat aortic valve disease, offering excellent hemodynamic characteristics, growth potential, low risk of thromboembolism and no need for anticoagulation. Limitation of homograft quality and availability led to the use of different stentless xenografts. Long-term outcome and implications are yet to be addressed. Methods Forty five adult patients (mean age 38.8 ± 9.6 years) with aortic valve stenosis and/or insufficiency, who underwent the Ross procedure between 1995 and 2002 were identified for long-term evaluation. Patients younger than 18 years, with previous heart surgery and endocarditis were excluded. Stentless xenografts were used in 22 cases (Group X) and homografts in 23 cases (Group H). After review of the patients' history, morbidity and mortality were analyzed and risk stratification was performed. Results Between groups, baseline characteristics and operative data did not differ significantly. Total follow-up was 621.0 patient-years and 98.8% complete. Overall freedom from reoperation at 15 years was 68.4 ± 10.6% in group X and 85. ± 7.9% in group H (p = 0.09), respectively. Freedom from aortic valve reoperation at 15 years was comparable (83.9 ± 8.5% in group X and 85.3 ± 7.9% in group H, p = 0.61), whereas freedom from pulmonary valve reoperation at 15 years was significantly lower in group X (78.9 ± 9.4% versus 100%, p = 0.02). Long-term survival at 15 years was 79.7 ± 9.3% in group X and 94.4 ± 5.4% in group H (p = 0.07), respectively. Conclusions Stentless xenografts used as pulmonary valve substitute in the Ross procedure led to lower freedom from pulmonary valve reoperation compared with homografts. Additionally, there was a trend to inferior long-term survival with xenografts. Therefore, homografts should remain the preferred option for pulmonary valve replacement in the Ross procedure.

Pericardial Stentless Valve for Aortic Valve Replacement: Long-Term Results.

BACKGROUND: The Freedom Solo (FS) bovine pericardial valve (Sorin Group, Milan, Italy) is a stentless bioprosthesis that was introduced in 2004 and approved by the United States Food and Drug Administration in 2014. No long-term follow-up series are available to date. We report the multicenter experience of 4 European institutions that began implanting FS extensively from its introduction, providing the largest series with long-term follow-up. METHODS: From 2004 to 2009, 565 patients (242 women [42.8%]; mean age, 74.6 ± 8.3 years) underwent isolated (n = 350) or combined (n = 215) aortic valve replacement with the FS. Mean follow-up, including clinical and strict echocardiographic evaluation, was 6.9 ± 3.7 years (maximum, 11.8 years; cumulative 2,965 patient-years). Primary end point was freedom from structural valve deterioration (SVD), and secondary end points were freedom from reoperation and overall survival. RESULTS: Mean logistic European System for Cardiac Operative Risk Evaluation I was 10.3% ± 6.7%. Overall 30-day mortality was 3.7%, and no deaths were valve related. There was no severe prostheses-patient mismatch, and moderate prostheses-patient mismatch occurred only in 1 patient (0.17%). Twenty-eight patients (5.2%) underwent reoperation (20 surgical replacements, 8 transcatheter aortic valve-in-valve replacements) due to endocarditis in 9, blunt trauma in 1, and SVD in 18. SVD was reported in 5 other patients alive at time of censoring. Freedom from SVD and reoperation was 90.8% (95% confidence interval, 89.1% to 92.5%) and 87.3% (95% confidence interval, 85.6% to 89.0%), respectively, at 10 years of follow-up, and the overall actuarial survival was 56.4% (95% confidence interval, 53.3% to 59.5%). CONCLUSIONS: The FS valve provided excellent long-term durability and hemodynamic performance in this large, multicenter European experience. Moreover, the FS, given the low rate of SVD, along with a simple implantability, proved to be a reliable bioprosthesis in the aortic position as a valid alternative to stented bioprostheses.

Long-Term Outcome of the Sorin Freedom SOLO Stentless Aortic Valve.

BACKGROUND AND AIM OF THE STUDY: The Sorin Freedom SOLO valve is a third-generation stentless aortic valve which shows beneficial hemodynamic performance compared to stented bioprostheses. Long-term results regarding hemodynamics, the durability of the valve, and patient outcome are scarce, and their acquisition was the aim of this single-center study. METHODS: Between 2005 and 2006, a total of 68 consecutive patients (30 males, 38 females; mean age at surgery 76.1 ± 6.3 years) underwent aortic valve replacement with a Sorin Freedom SOLO prosthesis. Indications were aortic stenosis (n = 50), aortic regurgitation (n = 1) and mixed lesions (n = 17). Associated procedures were performed in 31 patients (45.6%), most of which were coronary artery bypass grafting (68.8 %). The follow up was performed by telephone interviews, and clinical and echocardiographic examinations. Morbidity, mortality and echocardiographic data were analyzed. RESULTS: The total follow up was 501.1 patient-years, with a mean follow up of 7.4 ± 3.4 years (maximum 11.2 years). The follow up was 100% complete. Hospital mortality was 4.4% (n = 3). Actuarial survival at five and 10 years was 76.5 ± 5.1% and 41.5 ± 6.5%, respectively. Reinterventions were performed in eight patients; these included three reoperations due to endocarditis, four transcatheter aortic valve implantations, and one reoperation due to structural valve deterioration (SVD). The overall freedom from valve reintervention due to SVD at five and 10 years was 97.8 ± 2.2% and 82.9 ± 7.5%, respectively. After eight years, echocardiography demonstrated peak and mean transvalvular gradients of 18 ± 11 and 10 ± 7 mmHg, respectively. The overall effective and indexed aortic valve orifice areas were 1.73 ± 0.58 cm2 and 0.92 ± 0.33 cm2/m2, respectively. CONCLUSIONS: At long-term follow up the Sorin Freedom SOLO bioprosthesis was associated with favourable hemodynamic results and survival. Freedom from SVD was not superior to that occurring with stented bioprostheses.

The St. Jude Toronto stentless bioprosthesis: up to 20 years follow-up in younger patients.

BACKGROUND: A retrospective long-term evaluation of the St. Jude Toronto stentless bioprosthesis in patients aged 60 years or younger. METHODS: From 1994 to 1997, 50 patients underwent aortic valve replacement with the prosthesis. Patients mean age at surgery was 54.5±6.3 years. Follow-up data were acquired by patient file research and telephone interviews. Morbidity and mortality were evaluated with time-to-event analyses using the Kaplan-Meier-method. The log-rank test was used to determine influencing factors for long-term survival and reoperation. RESULTS: Mean follow-up was 13.5±6.3 years with a total follow-up of 661.8 patient-years and a maximum of 20.0 years. Follow-up was 97.8% complete. Associated procedures were performed in 12 patients (24%), including coronary artery bypass grafting, mitral valve replacement and replacement of the ascending aorta. Freedom from reoperation at 10 and 15 years was 76.0±6.7% and 44.1±8.9%, respectively. Reoperations (n=26) started 4.4 years after implantation and were necessary due to: valve degeneration with regurgitation in 79.2% and stenosis in 12.5%, endocarditis in 4.2% and sinus valsalva aneurysm in 4.2% of the cases. The log-rank test revealed that only body-mass-index>25 lowered freedom-from-reoperation, while renal dysfunction, diabetes mellitus and arterial hypertension were not. Overall long-term survival at 10 and 20 years was 82.3±5.7% and 49.9±8.9%, respectively. CONCLUSION: In younger patients the Toronto-bioprosthesis provided reliable long-term survival despite limited durability.

Hemodynamic behavior of stentless aortic valves in long term follow-up.

OBJECTIVES: Stentless aortic valve replacements show improved hemodynamics due to larger orifice area and lower transvalvular gradients in short and mid-term follow-up. Hemodynamic long-term behavior and the adaptation of the left ventricle as well as valve-durability in patients aged ≤60 years remains unclear. METHODS: 7 to 16 years after aortic valve replacement, 54 patients (mean age at operation 53.1 ± years) received echocardiography and clinical examination. Mean follow-up time was 10.8 ± 2.2 years. Evaluated were NYHA class, transvalvular gradients, estimated aortic valve orifice area, degree of aortic valve insufficiency, left ventricular mass and function. RESULTS: At follow-up only one patient presented with NYHA class III. All other patients were in NYHA class I or II. Maximum and mean pressure gradients of the prostheses were 16.3 ± 7.4 mmHg and 9.1 ± 4.2 mmHg, respectively. Compared to echocardiography at discharge the mean pressure gradients dropped 18.0% (2.0 ± 0.9 mmHg) and stayed stable until 14 years after the operation. Only 5 patients showed relevant regurgitation (at 13-16 years after valve replacement), 49 showed no or trivial regurgitation. Left ventricular mass had decreased 26.5% (107.9 ± 18.5 g). Left ventricular ejection fraction (LVEF) had increased in most patients and decreased in only one. For patients with preoperatively impaired left ventricular function an increase of LVEF of 13.1 ± 3.1% was seen. CONCLUSION: Porcine stentless aortic valves provide excellent hemodynamic long-term results without significant rise of transvalvular pressure gradients or relevant insufficiencies until 14 years after implantation, leading to sustained decrease of left ventricular mass and improvement of left ventricular function.

Cerebroprotective effect of preoperative dual antiplatelet therapy in patients undergoing coronary bypass surgery.

OBJECTIVES: Reduction of cognitive function is a possible side effect after coronary artery surgery using cardiopulmonary bypass (CPB). We investigated the effect of single versus dual antiplatelet therapy on cognitive performance in patients undergoing coronary artery bypass grafting (CABG) with CPB. METHODS: 50 consecutive CABG patients with preoperative intake of aspirin were compared to 49 consecutive patients with aspirin and clopidogrel. Six neuropsychological subtests from the Syndrom Kurz Test and the Alzheimer's Disease Assessment Scale were performed preoperatively and on the third postoperative day. To assess the overall cognitive function and the degree of cognitive decline across all tests after surgery we combined the six test-scores by principal component analysis. RESULTS: Patients had a mean age of 66.1 ± 9.3 years, received a mean of 2.8 ± 1.0 bypasses within an average of 87 ± 31 minutes on cardiopulmonary bypass. These parameters as well as the preoperative combined neurocognitive score were not significantly different between the groups. After the operation there was a significant deterioration of the combined neuropsychological score in both groups (single: preop -0.2 ± 1.5 vs. postop -1.8 ± 1.7, p = 0.000 and dual: preop 0.2 ± 1.5 vs. postop -0.5 ± 2.1, p = 0.004). However, the patients operated under dual antiplatelet therapy showed a significant less decline of overall cognitive function compared to the single antiplatelet therapy patients (dual: 0.7 ± 1.5 vs single: 1.6 ± 1.6, p = 0.004). CONCLUSION: Dual antiplatelet therapy has a cerebroprotective effect in patients undergoing coronary artery bypass surgery. Compared to single antiplatelet therapy it reduces an early postoperative substantial decline of neuropsychological abilities.

Long-term follow-up after aortic valve replacement with Edwards Prima Plus stentless bioprostheses in patients younger than 60 years of age.

OBJECTIVES: The Edwards Prima Plus was one of the first stentless aortic valve bioprostheses, with larger orifice areas and improved hemodynamics compared to stented bioprostheses. The aim of the present single-center retrospective study was to assess the long-term results of the Edwards Prima Plus in patients 60 years old or younger. METHODS: From 1993 to 2001, 120 patients (99 men and 21 women) aged 60 years or younger underwent implantation of the Edwards Prima Plus. The indications were stenosis and/or insufficiency. Associated procedures were performed in 38 patients (31.7%). Of the patients, 39% had impaired left ventricular function. Follow-up data were acquired by telephone interview. Time-to event analyses were performed using the Kaplan-Meier method. Variables affecting survival and freedom from reoperation were evaluated using Cox regression analysis. The mean patient age at surgery was 53.1 ± 8.0 years. The follow-up data were 88.8% complete at a mean of 8.5 ± 4.5 years. The total follow-up was 1022.7 patient-years. RESULTS: At 10 and 15 years, the overall actuarial survival rate was 71.8% ± 4.4% and 48.8% ± 9.6%, respectively. Survival was significantly lower for patients with older age, aortic insufficiency as the surgical indication, and small prosthesis size (≤25 mm vs ≥27 mm). Reoperation was performed in 20 patients (16.7%), with a hospital mortality of 5%. At 10 and 14 years, the overall freedom from reoperation rate was 85.6% ± 3.7% and 65.2% ± 8.6%, respectively. Freedom from reoperation was significantly lower in patients with a small prosthesis size (≤25 mm) and insufficiency as the indication for surgery. CONCLUSIONS: In patients aged 60 years or younger, an Edwards Prima Plus can provide reliable long-term results with acceptable freedom-from-reoperation rates.

Stentless aortic valve replacement in the young patient: long-term results.

BACKGROUND: Stentless aortic valve replacement (SAVR) became a common surgical procedure to treat aortic valve disease, as it offers larger orifice area and improved hemodynamics. The aim of our single-centre retrospective study was to assess long term results of first generation stentless aortic valves in young patients, where mechanical prostheses are considered first line therapy. METHODS: From 1993 to 2001, 188 (149 male and 39 female) patients (≤60 years) underwent SAVR. Indications were in 63.3% stenosis or mixed lesions and in 36.7% isolated regurgitation. Mean age of patients at surgery was 53.1 ± 7.1 years. Associated procedures were performed in 60 patients (31.9%). Follow-up data were acquired through telephone interviews. Follow-up was 90.4% complete at a mean of 8.8 ± 4.7 years. Total follow-up was 1657.6 patient-years with a maximum of 17 years. RESULTS: Overall hospital mortality was 3.2% (2.5% for isolated SAVR). Overall actuarial survival-rate at 10/15 years and freedom from reoperation at 10/14 years were 73.0% ± 3.5%/ 55.8% ± 5.4% and 81.0% ± 3.4%/ 58.0% ± 7.5%, respectively. For isolated SAVR, actuarial survival at 10/15 years and freedom from reoperation at 10/14 years were 70.1% ± 4.4%/ 64.1% ± 4.8% and 83.1% ± 4.0%/ 52.9% ± 9.0%, respectively. Reoperation was performed in 42 patients (22.3%) due to structural valve deterioration and endocarditis. Age (≤50 years) and associated procedures did not significantly lower survival and freedom from reoperation, however, small prosthesis sizes (≤25 mm) did. CONCLUSION: In patients aged 60 and younger, SAVR provides reliable long-term results especially for larger aortic valves.

Effect of different pump heads for CPB on early cognitive outcome after coronary artery bypass surgery.

OBJECTIVES: Reduction of cognitive function is a possible side effect after coronary artery surgery using cardiopulmonary bypass (CPB). We investigated the effect of roller versus centrifugal pumps for CPB on cognitive performance in patients undergoing coronary artery bypass grafting (CABG). METHODS: 50 consecutive CABG patients operated with centrifugal pump were compared to 50 roller pump patients matched for age and duration of CPB. Six neuropsychological subtests from the Syndrom Kurz Test and the Alzheimer's Disease Assessment Scale were performed preoperatively and on the third postoperative day in a double blind fashion. To assess the overall cognitive function and the degree of cognitive decline across all tests after surgery we combined the six test-scores by principal component analysis. RESULTS: Patients with a mean age of 63.9±8.4 years received a mean of 3.0±0.9 bypasses within an average of 80.6±20.7 mins on CPB. These parameters as well as the preoperative combined neurocognitive score were not significantly different between the groups. After the operation there was a significant deterioration of the combined neuropsychological score in both groups (centrifugal: preop 0.41±2.49 vs.postop -2.86±2.70, p <0.0005 and roller: preop -0.41±2.35 vs. postop -2.73±3.16, p <0.0005). However, the patients operated with a centrifugal pump had a significantly greater decline of overall cognitive function compared to the roller pump patients(3.3±1.7 vs. 2.3±2.7, p = 0.04). CONCLUSION: Roller pumps have a less cerebro-damaging effect than centrifugal pumps since they lead to a smaller postoperative decline of neuropsychological abilities in coronary bypass patients.

Encouraging experience with intracardiac transplantation of unselected autologous bone marrow cells concomitant with coronary artery bypass surgery after myocardial infarction.

BACKGROUND: Chronic heart failure after myocardial infarction is still a serious problem without a fundamental therapy. Experimental transplantation of bone marrow cells (BMC) into infarcted myocardium resulted in regeneration and functional improvement. OBJECTIVE: Clinical investigation of safety and efficacy of intracardiac transplantation of unselected autologous BMC. METHOD: 22 patients scheduled for elective and isolated coronary artery bypass grafting (CABG) with a reduced LVEF due to myocardial infarction were included. Intraoperatively, sternal bone marrow blood was aspirated, and a sterile buffy coat was prepared and applicated. 19 age, LVEF and coronary disease matched patients served as controls. Heart function, geometry, and scar proportion were assessed by echocardiography and Gadolinium-MRI at the time of the operation and 6 months thereafter. RESULTS: Transplanted patients received a mean number of 360 × 106 BMC. We did not notice any significant differences in early or late complications in the transplant group as compared to controls. At six months follow up only the transplanted patients showed a significant improvement of NYHA classes from 2.7 to 1.5 and of LVEF from 36 to 43 %, (p < 0.05). Furthermore, only CABG concomitant with BMC-TX led to a significant reduction of left ventricular end diastolic diameter (LVEDD) from 59 to 54 mm and of scar proportion of the infarcted segments from 2.53 to 2.42, (p < 0.05). CONCLUSION: Intracardiac transplantation of unselected, autologous BMC is safe and feasible. In adjunct with coronary revascularization it leads to an improvement of ventricular geometry and function. Moreover, it reduces myocardial scar proportion and heart failure symptoms.

Assessment of mitral valve stenosis by helical MDCT: comparison with transthoracic doppler echocardiography and cardiac catheterization.

OBJECTIVE: We evaluated the precision of helical MDCT for the quantification of mitral valve stenosis (MVS) compared with transthoracic echocardiography (TTE) and cardiac catheterization. MATERIALS AND METHODS: A total of 28 patients with MVS of differing severity underwent an ECG-gated contrast-enhanced MDCT scan. The mitral valve area (MVA) was determined planimetrically by MDCT and was compared with Doppler TTE using the pressure half-time method and with cardiac catheterization using the Gorlin formula. RESULTS: Planimetry of the MVA with MDCT was feasible in all cases. The MVA on MDCT (1.88 ± 0.76 cm(2)) was significantly larger than that seen with TTE (1.74 ± 0.75 cm(2); p = 0.039) or cardiac catheterization (1.72 ± 0.67 cm(2); p = 0.037). The correlation between MDCT and TTE (r = 0.90; p < 0.001; limits of agreement, ± 0.65 cm(2)) and that between MDCT and cardiac catheterization (r = 0.86; p < 0.001; limits of agreement, ± 0.76 cm(2)) were good and similar to the correlation between TTE and cardiac catheterization (r = 0.88; p < 0.001; limits of agreement, ± 0.71 cm(2)). The best cutoff level for detecting moderate-to-severe stenosis at MDCT was an MVA of 1.70 cm(2), resulting in a sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 73%, 88%, 82%, 80%, and 83%, respectively, with two false-positive and three false-negative results. CONCLUSION: The MVA planimetrically determined by MDCT is systematically larger than those calculated by Doppler TTE and cardiac catheterization. However, because of a good correlation between methods and adjustment for the systematic bias, MDCT may allow reliable quantification of MVS and effectual discrimination among severity grades, although discrepancies between methods remain in individual cases.

Cerebroprotective effect of piracetam in patients undergoing open heart surgery.

OBJECTIVES: Reduction of cognitive function is a possible side effect after the use of cardiopulmonary bypass (CPB) during cardiac surgery. Since it has been proven that piracetam is cerebroprotective in patients undergoing coronary bypass surgery, we investigated the effects of piracetam on the cognitive performance of patients undergoing open heart surgery. METHODS: Patients scheduled for elective open heart surgery were randomized to the piracetam or placebo group in a double-blind study. Patients received 12 g of piracetam or placebo at the beginning of the operation. Six neuropsychological subtests from the Syndrom Kurz Test and the Alzheimer's Disease Assessment Scale were performed preoperatively and on day 3, postoperatively. To assess the overall cognitive function and the degree of cognitive decline across all tests after the surgery, we combined the six test-scores by principal component analysis. RESULTS: A total of 88 patients with a mean age of 67 years were enrolled into the study. The mean duration of CPB was 110 minutes. Preoperative clinical parameters and overall cognitive functions were not significantly different between the groups. The postoperative combined score of the neuropsychological tests showed deterioration of cognitive function in both groups (piracetam: preoperative 0.19 ± 0.97 vs. postoperative -0.97 ± 1.38, p <0.0005 and placebo: preoperative -0.14 ± 0.98 vs. postoperative -1.35 ± 1.23, p <0.0005). Patients taking piracetam did not perform better than those taking placebo, and both groups had the same decline of overall cognitive function (p = 0.955). CONCLUSION: Piracetam had no cerebroprotective effect in patients undergoing open heart surgery. Unlike the patients who underwent coronary surgery, piracetam did not reduce the early postoperative decline of neuropsychological abilities in heart valve patients.

Development and evaluation of a perfusion decellularization porcine heart model--generation of 3-dimensional myocardial neoscaffolds.

BACKGROUND: Reports about the generation of 3-dimensional neoscaffolds for myocardial tissue engineering are limited. The architecture provided by perfusion decellularization of whole hearts would support the production of human-sized 3-dimensional living tissues from an acellular matrix. The aim of this study was to evaluate the potential of a perfusion decellularization model for whole heart tissue engineering. METHODS AND RESULTS: Hearts were obtained from 12 German Landrace pigs from a selected abattoir. After preparation, the hearts were mounted and perfused on a modified Langendorff decellularization model specifically constructed for this reason. Decellularization was achieved by an ionic detergent-based perfusion protocol. The quality of the decellularization process was quantified by histology and fluorescence microscopy. Data regarding the presence of residual DNA within the decellularized hearts was measured with spectrophotometric quantification and compared to controls. After histological examination, all hearts lacked intracellular components but retained various types of collagen, proteoglycan and elastin. Quantitative DNA analysis demonstrated a significant reduction of DNA in decellularized hearts compared to controls (84.32±3.99 ng DNA/mg tissue vs. 470.13±18.77 ng DNA/mg tissue (P<0.05)). CONCLUSIONS: The modified Langendorff perfusion decellularization model described here is applicable for whole porcine hearts by removing cellular content and DNA. The resulting 3-dimensional matrix provides an interesting tool for further studies in the field of whole heart tissue engineering.

Overestimation of the operative risk by the EuroSCORE also in high-risk patients undergoing aortic valve replacement with a stentless biological prosthesis.

BACKGROUND: The EuroSCORE generally overestimates the risk of standard aortic valve replacement (AVR). The predictive value of this risk algorithm for high-risk patients undergoing stentless AVR is unclear; therefore, we compared the EuroSCORE prediction with our results in this patient population. METHODS: One hundred thirty-two patients with a logistic EuroSCORE of at least 10 (mean, 25) underwent primary isolated AVR with a stentless bioprosthesis between January 2004 and December 2007. Seventy-one patients (54%) were octogenarians or nonagenarians, 62 (47%) had a reduced left ventricular ejection fraction, and 46 (35%) had an extracardiac arteriopathy. RESULTS: Maximum/mean pressure gradients for the implanted valve prostheses were 19/11 mm Hg, and the mean regurgitation grade was 0.06. Stroke occurred in 3% of the patients, and a permanent pacemaker was required in 3%. The 30-day mortality rate was 8%. Another 5% of the patients died after the 30th postoperative day but within the same hospital admission. The predicted mortality was almost 100% greater than the observed mortality. CONCLUSION: We observed a mortality rate that was 50% lower than that predicted by the logistic EuroSCORE. Therefore, one should not hesitate to use stentless valves in high-risk patients because the EuroSCORE greatly overestimates their surgical risk.

Clinical experience with the ATS 3F stentless aortic bioprosthesis: five years' follow up.

BACKGROUND AND AIM OF THE STUDY: The ATS 3F aortic bioprosthesis is an equine pericardial stentless valve used for aortic valve replacement (AVR). The study aim was to determine the incidence of valve-related events during a five-year follow up period. METHODS: Between 2002 and 2003, a total of 35 patients (mean age 73 +/- 6 years; range 61-86 years) underwent AVR with the ATS 3F valve implanted in the subcoronary position, utilizing a single running suture technique. The mean valve size was 26.0 +/- 1.9 mm. Prior to surgery, all patients were in NYHA class III or IV. The hemodynamic performance of the valve was assessed after one, three, and five years by means of transthoracic echocardiography. Clinical outcome was evaluated by either physical examination or by telephone interviews with the primary care physicians. RESULTS: The total patient follow up was 123 patient-years. Four patients (11%) were lost to follow up. The overall survival was 86%, and none of the deaths was valve-related. Up to five years, no severe structural or non-structural valve dysfunction was identified in the followed patients. Freedom from severe adverse events (SAE) was 89%; the SAE included one permanent and three transient neuroembolic events, but echocardiographic examinations of these patients were unsuggestive for thrombotic depositions on the prosthetic valves. Freedom from endocarditis was 100%. Minimal paravalvular regurgitation was detected in four patients; this was of no clinical importance, and resulted in a 100% freedom from reoperation. The mean transvalvular pressure gradients were 12.9 +/- 6.3, 11.2 +/- 4.2, and 15.2 +/- 5.3 mmHg at one, three, and five years, respectively. The left ventricular mass and NHYA class were each improved significantly during the observation period. The left ventricular geometries showed also a trend towards improvement. CONCLUSION: The ATS 3F aortic valve prosthesis continues to perform with satisfactory hemodynamic results, comparable to those of other pericardial valves. With minimal SAE, the prosthesis demonstrated excellent intermediate-term clinical results and--to date--is proving to be durable.

Cerebroprotective effect of piracetam in patients undergoing coronary bypass burgery.

BACKGROUND: Reduction of cognitive function is a possible side effect after cardiac surgery using cardiopulmonary bypass. We investigated the cerebroprotective effect of piracetam on cognitive performance in patients undergoing coronary artery bypass surgery under cardiopulmonary bypass. MATERIAL/METHODS: Patients scheduled for elective, primary and isolated coronary bypass surgery were randomised either to piracetam or placebo group. The study was performed in a double blind fashion. Patients received either 12 g piracetam or placebo at the beginning of the operation. Six neuropsychological subtests from the Syndrom Kurz Test and the Alzheimer's Disease Assessment Scale were performed preoperatively and on the third postoperative day. To assess the overall cognitive function and the degree of cognitive decline across all tests after surgery we combined the six test-scores by principal component analysis. RESULTS: A total number of 120 patients were enrolled into the study. Preoperative overall cognitive function were not significantly different between the groups. The postoperative combined score of the neuropsychological tests showed a deterioration of cognitive function in both groups (placebo-pre: -0.06+/-0.99 vs placebo-post: -1.38+/-1.11; p<0.0005 and piracetam-pre: 0.06+/-1.02 vs piracetam-post: -0.65+/-0.93; p<0.0005). However, the piracetam patients performed significantly better compared to the placebo patients after the operation and had a less decline of overall cognitive function (p<0.0005). CONCLUSIONS: Piracetam has a cerebroprotective effect in patients undergoing coronary artery bypass surgery with the use of cardiopulmonary bypass. It reduces an early postoperative substantial decline of neuropsychological abilities.