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.

Surgical-transcatheter approach for endocarditis of a calcified aortic homograft.

Repeat aortic valve replacement (AVR) after freestanding homograft root replacement with reimplantation of the coronary arteries is challenging and risky, especially in patients with major homograft wall calcifications. Although new transcatheter techniques for AVR may offer an alternative in structurally degenerated homografts, they are not suitable to treat endocarditis. Here, the case is reported of successful treatment of bacterial endocarditis within a totally calcified homograft after aortic root replacement by combining conventional surgery and transcatheter techniques.

Extracellular matrix in deoxycholic acid decellularized aortic heart valves.

BACKGROUND: Only limited information is available regarding the influence of decellularization on the extracellular matrix in heart valves. Within the extracellular matrix proteoglycans (PG) play a central role in the structural organization and physical functioning of valves and in their capability of settling with endothelial and interstitial cells partially myofibroblasts. We have therefore estimated the effects of decellularization using deoxycholic acid on the structure of the extracellular matrix and PG´s in porcine aortic valves. MATERIAL/METHODS: Cupromeronic blue was used, alone or in combination with OsO4/thio-carbo-hydrazide/OsO4 for electron microscopic visualization. For PG and glycosaminoglycan (GAG) investigation a papain digestion was employed in combination with photometric determination using dimethylmethylene blue. RESULTS: The results indicate that deoxycholic acid affects the compartmentation of the PG-associated interstitial network not significantly. Compared to controls the PG-rich network was preserved even after deoxycholic acid treatment for 48 h. In parallel to electron microscopy immune assays (ELISA) showed smooth muscle cell -actin to be reduced to 0.96% ± 0.71 and total soluble protein to 6.68% ± 2.0 (n=3) of untreated controls. Protein loss corresponded well with the observations in electron micrographs of rupture and efflux of cell content. Further signs of lysis were irregular cell contours and loss of the basement membrane. CONCLUSIONS: Efficient cell-lysis without disintegration or loss of integrity of the interstitial PG network can be achieved by treatment of aortic valves with deoxycholic acid for 48h. This protocol might also be suitable for clinical use to optimize conditions for growth and autologous remodelling of valves.

Right ventricular outflow tract reconstruction with decellularized porcine xenografts in patients with congenital heart disease.

BACKGROUND AND AIM OF THE STUDY: Decellularized xenogeneic pulmonary valves have been introduced for right ventricular outflow tract (RVOT) reconstruction in congenital heart disease. In the present study, the intermediate-term results from three institutions were analyzed. METHODS: Between January 2006 and September 2008, a total of 61 patients (median age 7 years; range: 9 days to 50 years; median body weight 21 kg; range: 1.9-140 kg) underwent RVOT reconstruction with either the Matrix P (n = 9) or Matrix P Plus (n = 52) tissue-engineered conduit. Eighteen patients underwent surgery in infancy, and 31 patients had previously undergone one or more RVOT interventions or operations. RESULTS: The valve sizes ranged from 11 to 27mm. Five patients died during the hospital stay or within three months, from non-valve-related causes; hence, the early mortality was 8.2%. No deaths occurred during the follow up period. Reoperation due to valve failure became necessary in four patients; three patients underwent RVOT interventions due to distal anastomotic stenosis, and six reinterventions were performed distal to the valve due to hypoplastic branch pulmonary arteries. Patients with valve implantation during infancy showed a composite freedom from valve-related reoperation, catheter intervention or valve dysfunction (defined as dP(max) > 40 mmHg) of 87% at one and three years postoperatively. Both, computed tomography and magnetic resonance imaging studies demonstrated normal structural features, with no evidence of calcification. CONCLUSION: The Matrix P/Matrix Plus conduit represents a viable alternative for RVOT reconstruction in patients with congenital heart disease. The intermediate-term performance of the conduits was favorable compared to that of other currently available implants.

Noninvasive monitoring of cardiac function in a chronic ischemic heart failure model in the rat: assessment with tissue Doppler and non-Doppler 2D strain echocardiography.

OBJECTIVES: Feasibility of noninvasive monitoring of cardiac function after surgically induced ischemic cardiomyopathy with tissue Doppler and non-Doppler 2D strain echocardiography in rats. BACKGROUND: The optimal method for quantitative assessment of global and regional ventricular function in rats with chronic heart failure for research purposes remains unclear. METHODS: 20 rats underwent suture ligation of the left anterior descending coronary artery via a left thoracotomy to induce ischemic cardiomyopathy. Echocardiographic examination with estimation of left ventricular wall thickness, diameters, fractional shortening, ejection fraction, wall velocities as well as radial strain were performed before and 4 weeks after surgery. RESULTS: Mean LVEF decreased from 70 ± 6% to 40 ± 8% (p < 0.0001) one month after the operation. LVEDD increased from 7 ± 1 mm to 9 ± 1 mm (p < 0.0001), systolic anterior velocity decreased from 0.79 ± 0.25 cm/s to 0.18 ± 0.19 cm/s (p < 0.0001). Radial 2D strain was significantly reduced after myocardial infarction of the septal (18.2 ± 6.6% vs 7.0 ± 5.9%, p < 0.001), anteroseptal (17.3 ± 5.2% vs 4.6 ± 3.0%, p < 0.0001), anterior (18.9 ± 5.9% vs 5.6 ± 2.5%, p < 0.0001), lateral (21.4 ± 4.9% vs 8.1 ± 3.5%, p < 0.0001) as well as posterior myocardial segments (19.3 ± 5.2% vs 15.4 ± 5.5%, p < 0.01). Inferior segments (19.2 ± 7.9% vs 17.8 ± 7.9%, ns) did not change at all. CONCLUSION: It is feasible to assess dimensions, global function, and regional contractility with echocardiography in rats suffering from chronic heart failure after myocardial infarction. Particularly regional function can be exactly evaluated if tissue Doppler and 2D strain is used.

Inadequate cytoplasmatic calcium signals in alveolar macrophages after cardiac surgery.

OBJECTIVE AND DESIGN: Patients undergoing cardiac surgery have an elevated risk for pulmonary complications. A dysfunction of alveolar macrophages (AM) might promote postoperative infections. Therefore intracellular calcium [Ca(2+)](i) as an important second messenger in cellular signaling was assessed in AM. MATERIALS AND METHODS: Twelve patients undergoing elective coronary artery bypass graft surgery (CABG) were enrolled in this clinical trial. After anesthesia induction and 2 h after cardiopulomary bypass (CPB) declamping, the bronchoalveolar lavage (BAL) fluid was collected preoperatively from the right middle lobe and postoperatively from the left lingula of the lung. Cell subpopulations and [Ca(2+)](i) signals were assessed via flow cytometry. To express the changes of [Ca(2+)](i) signals the Fluo4/FuraRed-Ratio was used. RESULTS: After surgery the [Ca(2+)](i) baseline in unstimulated AMs were significantly reduced (p < 0.001). A significant signal reduction after fMLP (p = 0.021) and C5a (p = 0.028) stimulation was found in FSC high AMs after surgery, even though all populations showed a trend of less responsiveness. CONCLUSION: We suggest that the reduced [Ca(2+)](i) signaling in postoperative AMs is caused by a reduced coupling to membrane channels. These preliminary data suggest an inadequate [Ca(2+)](i) signal of AM after surgery, which may contribute to a local immune dysfunction in the lung.

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.

Clinical experience with expanded use of the Ross procedure: a paradigm shift?

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate the short-term survival and functional outcome after the Ross procedure, with expanded inclusion criteria. METHODS: A total of 91 patients (21 females, 70 males; mean age 57.3 +/- 13.1 years; range: 0.1-74 years) underwent aortic valve replacement (AVR) with a Ross procedure at the authors' institution during the year 2007. The underlying valve diseases were stenosis in 60 patients, regurgitation in 17, and a mixed lesion in 14. Seven patients suffered from acute infective endocarditis, and in five patients the Ross operation was a reoperative procedure. Forty-four patients (48%) underwent surgery in association with concomitant procedures, which included predominantly coronary artery bypass surgery, mitral valve repair or replacement, or procedures of the ascending aorta. RESULTS: The mean cardiopulmonary bypass and aortic cross-clamp times were 147 +/- 31 min (range: 87-246 min) and 124 +/- 26 min (range: 73-195 min), respectively. Hospital mortality was 2.2%. No patient died during the follow up period. The aortic gradient was decreased from 5.1 +/- 2 mmHg at discharge, to 3.2 +/- 1 mmHg during follow up (p < 0.05); at the same times, the mean gradient of the decellularized tissue-engineered pulmonary valve was 2.8 +/- 1 mmHg and 2.7 +/- 1 mmHg, respectively. An echocardiographic examination of neo-aortic valve competence at 12 months revealed no or trivial aortic valve regurgitation in 80 patients, and mild (grade 1+) regurgitation in nine patients. No patient required reoperation of the autograft during follow up. Two patients underwent reconstruction of the right ventricular outflow tract. At 12 months' follow up, all patients enjoyed normal social interactions, were in NYHA functional class I or II, and free from complications. CONCLUSION: The Ross procedure can be offered as an alternative to standard prosthetic AVR with an excellent short-term outcome. The former inclusion/exclusion criteria for this procedure should be re-evaluated.

Recellularization of decellularized mitral heart valves in juvenile pigs.

BACKGROUND AND AIM OF THE STUDY: Glutaraldehyde-preserved bioprosthetic heart valves are non-viable and have a limited durability because of calcification, tissue wear, and inflammation, especially in children. Decellularized porcine heart valves, when treated with deoxycholic acid (DOA), have exhibited complete recellularization and an absence of calcification when implanted into the pulmonary position in juvenile sheep. The study aim was to determine the degree of recellularization and calcification in DOA-treated heart valve prostheses in the mitral position in juvenile pigs. METHODS: A mitral heart valve prosthesis was implanted into each of 17 pigs, and subsequently explanted and fixed in formaldehyde after between five and 26 weeks. A gross pathologic assessment, high-resolution X-ray imaging and histological examination were then performed on each valve. RESULTS: Eight pigs survived the observational period. Five valves had only a slight fibrin deposition and calcification foci within the fibrin deposits. Three valves had severe thrombotic material deposits with disseminated calcification and valve stenosis, and one valve had infective endocarditis. A myofibroblast-like cell ingrowth was observed at different locations of the valve housing in all explanted heart valves, but ingrowth in the basal part of the cusp matrix was limited. In four valve prostheses, endothelial cells covered up to 10% of the cusp surface after six months. Inflammatory cells were observed in large numbers in those valves showing endocarditis and severe thrombosis, but in only limited numbers in the other valves. CONCLUSION: All valves showed the deposition of fibrin and platelet material, in three cases to a severe degree. A limited ingrowth of both endothelial and myofibroblast-like cells was observed in five valves in which calcification was limited to a few commissural foci. The non-endothelialized surface of the decellularized valves makes them very susceptible to platelet and fibrin deposition; however, slow revitalization seems possible.

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.

Covered perforated aortocoronary saphenous vein graft aneurysm.

We report a case of a 75-year-old man suffering from a covered perforated aneurysm of a saphenous bypass graft to the right coronary artery (RCA) constructed 22 years ago. Additional complete revascularization had been performed in 2001. A thoracic computed tomography scan for evaluation of fever of unknown origin had revealed a huge hematoma in front of the right heart. Coronary angiography showed open bypasses but an irregular-shaped aneurysm of the venous graft to the RCA right before the distal anastomosis. Occurrence of a new right-sided pleural effusion led to the emergent operation since rupture of the aneurysm and drainage into the pleura was likely. A massive precordial hematoma was found and the existence of the perforated aneurysm could be confirmed. After institution of cardiopulmonary bypass the graft was resected. Since the patient had a functioning bypass to the RIVP, there was no need for additional revascularization. The patient underwent an uneventful postoperative course.

Early outcome after surgery for active native and prosthetic aortic valve endocarditis.

BACKGROUND AND AIM OF THE STUDY: Today, the in-hospital mortality of patients treated surgically for active aortic native and prosthetic valve endocarditis remains high. The study aim was to identify the preoperative and intraoperative predictors of early outcome. METHODS: Between January 2004 and December 2006, 75 patients (57 males, 18 females; mean age 61.6 +/- 14.1 years) underwent surgery for active native valve (NVE) or prosthetic aortic valve endocarditis (PVE). RESULTS: Active aortic NVE was present in 49 patients (65.3%), and PVE in 26 (34.7%). Staphylococcus species were the most common infecting microorganisms in both groups, while 20 cases (26.7%) were culture-negative. Except for significantly higher preoperative renal failure (RF) in patients with PVE (p = 0.01), the clinical characteristics were equally distributed. Four patient subsets were identified based on the extent of the infectious process: (i) locally controlled NVE (38.7%); (ii) locally uncontrolled NVE (26.7%); (iii) locally controlled PVE (14.6%); and (iv) locally uncontrolled PVE (20%). Aortic valve replacement (AVR) was performed with a stentless bioprosthesis in 53 cases (70.7%), a mechanical prosthesis in eight (10.6%), and a Ross procedure in 14 (18.7%). Concomitant active mitral valve endocarditis was treated in 17 patients (22.7%). Associated procedures were performed in 14 cases (18.7%). The in-hospital mortality was 24% (n = 18). Female gender (p = 0.0147), preoperative septic or cardiogenic shock (p = 0.0275) and previous embolic events (p = 0.0129) were identified as independent predictors for in-hospital mortality. Eight late deaths occurred; the estimated overall actuarial survival was 66.6 +/- 5.6% at 12 months and 60.7 +/- 6.5% at 24 months. On Cox multiple regression, age > 70 years (p = 0.0113), preoperative RF (p = 0.0015) and mitral valve surgery due to concomitant infective endocarditis (p = 0.0363) were significant adverse predictors of late death. CONCLUSION: Surgery for active aortic valve infective endocarditis is associated with high operative mortality and morbidity. Failure of antibiotic therapy causing septic or cardiogenic shock and delayed referral to surgery may have a detrimental effect on early outcome. Surgical eradication of cardiac infections should always be associated with the treatment of extracardiac septic foci, which could maintain a septic state and adversely influence early outcome. Adhesion to surgical guidelines, together with a multidisciplinary approach, may have a major impact on the early prognosis of these high-risk patients.

Factors predicting the time until atrial fibrillation recurrence after concomitant left atrial ablation.

OBJECTIVE: Treatment of atrial fibrillation, a risk factor for morbidity and mortality, by left atrial ablation is a less complex procedure which is increasingly performed in conjunction with surgery for various heart diseases. Although restoration of sinus rhythm is effective initially, atrial fibrillation may recur. We investigated factors predicting the time until its recurrence. METHODS: Between January 2003 and December 2005, 162 consecutive patients (52.5% male, age 69+/-8.7 years) with permanent atrial fibrillation underwent concomitant left atrial ablation and isolated or combined mitral valve surgery (42.6%), isolated or combined aortic valve surgery (32.1%), and isolated or combined coronary artery bypass grafting (24.1%). Ablation was performed by microwave (n=93, 57.4%) or radiofrequency (n=69, 42.6%) technology. Follow-up was after 3, 6, 12 months and yearly thereafter. Predictive values of variables for postoperative atrial fibrillation were examined using techniques of univariate and multivariate survival analysis (proportional hazards regression). RESULTS: Eight patients died perioperatively and 13 during follow-up (not ablation related). Two patients were lost to follow-up. At last follow-up (19+/-11.3 months), 86 patients (62%) were in stable sinus rhythm, 73 (52%) without antiarrhythmic drugs, and 43 (31%) were in atrial fibrillation. Predictors for the time until recurrence of atrial fibrillation in a multivariate model were preoperative atrial fibrillation duration (hazard ratio 1.005, 95% confidence interval 1.003-1.007, p<0.001) and left atrial diameter (hazard ratio 1.056, 95% confidence interval 1.020-1.093, p=0.002). Overall, sinus rhythm conversion rate was 75% when preoperative atrial fibrillation duration was less than 2 years, but 42% in longer lasting atrial fibrillation with left atrial dilatation (>50mm). Age, gender, primary heart disease, history of thromboembolism or cardioversion, presence of concomitant diseases, EuroScore, left ventricular size and function, aortic cross-clamp time, ablation technology, and treatment with antiarrhythmic drugs did not predict rhythm outcome. CONCLUSIONS: Preoperative atrial fibrillation duration and left atrial diameter predict the time until atrial fibrillation recurrence after concomitant left atrial ablation, whereas age, type of primary cardiac surgery, ablation technology and antiarrhythmic therapy do not.

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.

Local glycoprotein IIb/IIIa receptor inhibitor delivery from the pump surface attenuates platelet adhesion in continuous flow ventricular assist devices.

Shear-induced platelet activation (SIPA) has been identified to induce platelet adhesion and thrombus formation in continuous flow left ventricular assist devices (LVAD). Platelet glycoprotein (GP) IIb/IIIa receptor inhibitors are effective to prevent SIPA. However, systemic GP IIb/IIIa receptor inhibitor application is associated with severe bleeding complications. The aim of the study was to evaluate (i) the feasibility of absorption and elution of the GP IIb/IIIa receptor blocker TAK-029 from the Ti6Al4V surface of the pump; and (ii) the effect of local GP IIb/IIIa receptor blocker delivery regarding platelet adhesion on the surface of a continuous flow VAD model. Saturating concentrations of TAK-029 were adsorbed on the surface of a centrifugal pump. Whole human blood was perfused in circulatory mock loops using untreated (control), albumin-coated, or TAK-029-coated pumps. Peripheral resistance of the circulatory systems were adjusted accordingly to generate 5 L flow per min with impeller rotational speeds of 3500 (high-shear group) and 1500 rpm (low-shear group), respectively. Platelet adhesions on the respective impellers were quantified by ELISA and scanning electron microscopy (SEM). TAK-029 elution and half-life time were determined by ELISA. Compared with control, albumin-coated pumps showed 64 and 20% less platelet adhesions in the high- and low-shear group, respectively. TAK-029 coated pumps reduced platelet adhesion by additional 33 and 65%, respectively, compared with the albumin group. Elution of TAK 029 was initially very rapid and continued slowly. The results show that it is possible to adsorb and elute a small molecular weight GP IIb/IIIa receptor blocker from the pump surface. This drug elution reduced platelet adhesion on the pump significantly. Further studies are necessary to find a suitable drug bonding that will prolong the antiplatelet effect and preclude any bleeding complication caused by this procedure.

Analysis of atrial fibrillatory activity from high-resolution surface electrocardiograms: Evaluation and application of a new system.

BACKGROUND: Algorithms of signal processing allow the estimation of atrial fibrillation (AF) activity from surface electrocardiograms (ECGs). OBJECTIVE: To evaluate a new commercially available ECG system for AF analysis from surface potentials. METHODS: Patients (n=52, mean [+/- SD] age of 68+/-9.6 years) with persistent AF (mean duration 44+/-52.2 months), referred for cardiac surgery, underwent high-gain, high-resolution ECG preoperatively. After QRST cancellation, the frequency content of AF was identified by fast Fourier transformation. Epicardial potentials were registered at the right atrial appendage, the right atrium (RA), the left atrium (LA) and the left atrial appendage intraoperatively (nine patients). RESULTS: Mean (+/- SD) fibrillatory rate (MFR) in lead V(1) (393+/-40.4 fibrillations/min [fpm]) correlated significantly with V(2) (391+/-43.3 fpm, r=0.976; P<0.05) and II (379+/-41.1 fpm, r=0.878; P<0.05), and was stable within an interval of 13.6+/-3.8 min (27 patients). In the right atrial appendage, RA, LA and left atrial appendage, the relative difference in MFR was small (5.6%, 6.6%, 6.8% and 5.7%, respectively, compared with V(1)). The mean peak frequency component at 75% of the maximum power was significantly smaller in the LA than in the RA (13+/-4.2 fpm versus 22+/-7.2 fpm, respectively; P<0.01), and in patients with high (more than 390 fpm) compared with low (390 fpm or fewer) fibrillatory activity (14+/-7.6 fpm versus 22+/-13.3 fpm, respectively; P<0.05). There was a nonsignificant trend to higher fibrillatory activity with longer AF duration. Other characteristics (age, sex, LA size, ejection fraction, type of heart disease and medication) were not associated with the MFR. CONCLUSIONS: Using the CardioLink system, AF analysis from surface ECG is reliable and equivalent to epicardial measurements. By noninvasive assessment of individual electrical remodelling, this system certainly supports clinical AF research.

Surgical ablation of atrial fibrillation in patients with congestive heart failure.

BACKGROUND: Congestive heart failure (CHF) and atrial fibrillation (AF), both of which cause morbidity and mortality, are mutually promoting diseases. We aimed to evaluate surgical AF ablation in CHF. METHODS AND RESULTS: Among 212 patients (age 69 +/- 8.8 years, 87% with persistent AF) undergoing concomitant left atrial (LA) ablation, 79 (37.3%) presented CHF (n = 62 with a left ventricular ejection fraction [LVEF] 0.31-0.45, n = 17 with an LVEF < or = 0.30). Patients with CHF were similar to controls regarding AF duration (61 +/- 65.1 months vs. 54 +/- 67.2 months, not significant [NS]), LA diameter (49 +/- 7.5 mm vs. 50 +/- 9.2 mm, NS), and heart rate (78 +/- 18.4 min(-1) vs. 81 +/- 21.3 min(-1), NS), but they required more circulatory support (17.7% vs. 1.5%, P < .001) and a longer intensive care unit stay (6 +/- 9.5 days vs. 4 +/- 10.5 days, P = .032). At follow-up after 13 +/- 7.3 months, 42 patients (66%) with CHF and 81 controls (74%, NS) were in sinus rhythm (SR) (55% and 64% without antiarrhythmic drugs, respectively, NS). Univariate and logistic regression analysis revealed that AF duration and LA diameter predicted rhythm outcome but not CHF. In patients with an LVEF of 0.30 or less, SR conversion significantly improved LVEF, New York Heart Association class, and Minnesota Living with Heart Failure score. Kaplan-Meier estimates suggested superior survival of patients with stable SR (100% vs. 73%, log-rank P < .05). CONCLUSIONS: If patients presenting with CHF and AF require cardiac surgery, concomitant AF ablation should be considered, especially if left ventricular function is severely impaired.

The Freedom SOLO valve: superior hemodynamic results with a new stentless pericardial valve for aortic valve replacement.

BACKGROUND AND AIM OF THE STUDY: The new Freedom SOLO aortic valve, as a modification of the Pericarbon Freedom stentless valve, requires only one suture line. The study aim was to compare both prostheses with regard to surgical convenience and early postoperative hemodynamics. METHODS: In this case-matched study, 90 patients underwent primary elective isolated or combined aortic valve replacement (AVR) between 2001 and 2004. The Freedom SOLO valve was implanted in 30 patients using a supra-annular, subcoronary technique with one continuous subcoronary suture line (group FS). For comparison, the Pericarbon Freedom valve was implanted in 30 patients using an interrupted suture (group PFI), and in 30 patients using a continuous suture line at the inflow site (group PFC). Patient hemodynamics at discharge were investigated by monitoring echocardiographic peak and mean gradients, and regurgitation. RESULTS: The mean extracorporeal circulation time (75.5+/-22.7 min in FS; 83.7+/-21.0 min in PFC versus 110.9+/-31.4 min in PFI) and cross-clamp time (56.0+/-18.6 min in FS; 62.2+/-16.2 min in PFC versus 87.7 +/-25.4 min in PFI) were significantly shorter with the continuous implantation techniques. Hemodynamics were most favorable for the Freedom SOLO valve as compared to either implantation technique of the Pericarbon Freedom valve (mean gradient 7.4+/-4.6 mmHg in FS versus 10.6+/-6.0 mmHg in PFC and 11.0+/-5.7 mmHg in PFI). There were no paravalvular leakages or transvalvular regurgitations. CONCLUSION: The Freedom SOLO stentless valve is easy to implant and demonstrates superior early postoperative hemodynamics. Due to the reduced cross-clamp time, it also offers an attractive option in isolated and combined AVR.

Avoiding early partial valve thrombosis of the Pericarbon Freedom stentless valve.

Pericardial stentless valve prostheses have shown excellent results in aortic valve replacement. However, due to flexibility of the prosthetic material, immobilization and subsequent partial valve thrombosis may occur in case of non-symmetric sinuses of Valsalva. This report details an implantation technique designed to prevent stress on the non-coronary cusp of pericardial stentless prostheses, thereby avoiding this problem.

In-vivo repopularization of a tissue-engineered heart valve in a human subject.

A 63-year-old male with a massively calcified aortic valve showed an active lifestyle. Therefore, valve replacement was completed using the Ross procedure. During postoperative echocardiographic control, a ventricular septal defect was noted which was closed surgically. During this reoperation, a biopsy sample was taken from the wall of the tissue-engineered heart valve which was used to reconstruct the right ventricular outflow tract. A persistent monolayer of endothelial cells and host recellularization of the deeper layer was demonstrated histologically. The postoperative course was uneventful, and the patient rapidly recovered. After six years, he remains in excellent health.