Improved outcome of chronic hepatitis B after heart transplantation by long-term antiviral therapy.

Chronic hepatitis B progresses to cirrhosis in the majority of immunosuppressed patients. The outcome of long-term antiviral therapy in HBV-infected organ transplant recipients is unknown. In 1996, we included 20 heart transplant (HT) recipients in a pilot trial to treat chronic hepatitis B with famciclovir. At that time, bridging fibrosis or cirrhosis was evident in 15 individuals (75%). From 1998 onwards, patients were switched to lamivudine in case of primary or secondary virological nonresponse to famciclovir. Adefovir or tenofovir became available at our centre for HT recipients in 2002. After 103 months, one patient was still on famciclovir showing a complete virological response. Sixteen patients were switched to lamivudine after 0.5-4 years of famciclovir therapy. Six of those showed a long-term response to lamivudine therapy lasting for up to 7 years. Lamivudine resistance developed in the remaining 10 patients (63%), in 4 of them successful rescue therapy (adefovir n = 3, tenofovir n = 1) could be initiated. Only one hepatocellular carcinoma developed, which was successfully treated by locoregional ablative therapy. Nine patients died (45%), with lamivudine-resistance-related liver failure as the cause of death in five cases. Significant improvement of Ishak fibrosis scores could be demonstrated in six of the seven patients with more than two sequential liver biopsies available. Long-term antiviral therapy of chronic hepatitis B can lead to regression of liver cirrhosis in patients after organ transplantation, unless viral resistance occurs. This study demonstrates the urgent need for further antivirals to overcome antiviral resistance.

Acute dissection of the ascending aorta: first results of emergency valve sparing aortic root reconstruction.

OBJECTIVE: Acute dissection of the ascending aorta requires immediate surgical intervention. In this study, we report our first results with valve sparing aortic root reconstruction removing all the diseased tissues. METHODS: From August 1995 to December 2000, 22 patients with acute aortic dissection of the ascending aorta (Stanford type A) underwent valve sparing aortic root reconstruction. Their ages ranged from 20 to 76 years (52+/-15, 68% males). Dissection was found in the ascending aorta (3 patients) or both in the ascending aorta and aortic arch (19 patients; 86%). Course and length of hospitalization, echocardiographic and clinical follow-up, complications and mortality were analysed. RESULTS: Mean cardiopulmonary bypass time was 212+/-56 min (134-352 min), mean aortic cross clamp time was 157+/-24 min (114-205 min). In patients undergoing additional arch replacement (n=19), circulatory arrest was 35+/-18 min (11-75 min). After reconstruction, intraoperative echocardiography showed aortic insufficiency (AI) grade 0 in 16 patients (84%) and grade 1 in three patients (16%). Stay in intensive care unit was 2.1+/-0.7 days, and postoperative hospitalization was 21+/-14.4 days. There were three perioperative deaths (14%). Mean post-operative follow-up was 18.4+/-18 months (0.4-65.4 month). One patient died 10 months postoperatively. At follow-up, no patient suffered AI grade 2 or higher, and no reoperation for aortic valve failure was necessary. All patients presented with a favorable exercise tolerance being in New York Heart Association functional class I or II. CONCLUSION: Valve sparing aortic root reconstruction in patients with type A dissection can be performed with acceptable intraoperative mortality and morbidity and excellent results during follow-up. The complete resection of the diseased aorta is particularly appealing.

Valve sparing aortic root reconstruction versus composite replacement -- perioperative course and early complications.

OBJECTIVE: In patients with aneurysm of the ascending aorta, dilatation of the sinotubular junction is the major cause of aortic valve regurgitation. Valve sparing aortic root replacement in patients without valvular structural defects offers a new form of treatment. The aim of this study was the assessment of the perioperative course and early complications of this method compared to composite replacement in a large single center cohort. METHODS: From 1992 to 1999, valve sparing replacement of the ascending aorta (recon) has been performed in 78 patients, while 269 patients underwent replacement by a composite graft (comp). A comparison of matched pairs (n=52) with respect to age, gender, presence of Marfan's syndrome, aortic dissection as well as date of surgery, was chosen. Aortic insufficiency was 2.8+/-0.7 for recon vs. 2.2+/-1.1 for comp preoperatively. Course and length of hospitalization, echocardiographic follow-up, complications, and mortality were compared at 1-year follow-up. RESULTS: There were no operative deaths. During follow-up, one patient (2%) died 5 months postoperatively (recon) vs. two patients (3.9%) in the comp group. Bypass-time (123+/-31 vs. 153+/-31 min, P<0.0001) and cross-clamp-time (82+/-22 vs. 120+/-23 min, P<0.0001) were significantly shorter in comp. Stay in ICU (1.9+/-1.6 for recon vs. 2.3+/-2.1 days for comp) and post-op hospitalization (18.3+/-5.7 vs. 21.2+/-11.1 days) were comparable. Improvement of NYHA-class was significant after both operations (recon 2.6+/-0.8 vs. 1.3+/-0.5 and for comp 2.4+/-0.6 vs. 1.5+/-0.7, both P<0.0001). One patient (1.9%) in the recon group had to be reoperated for valve failure. Thrombembolic or bleeding complications were observed in 6 patients (12%) in comp, zero in recon (P=0.027). CONCLUSION: Valve sparing aortic root reconstruction is feasible with low perioperative morbidity and mortality and good early results. Major advantages of recon are significant reduction of thrombembolic and anticoagulation related complications as opposed to longer cross-clamp and bypass times as well as a valve failure in one patient. Further follow-up is needed to confirm our data in a long-term perspective.

Aerosolized iloprost for severe pulmonary hypertension as a bridge to heart transplantation.

Preexisting pulmonary hypertension in pediatric patients is associated with poor outcome after cardiac transplantation because of donor right ventricular dysfunction. To avoid a combined heart-lung transplantation in a 17-year-old patient, we used an intensified pretreatment with intravenous prostacyclin and dobutamine combined with an inhalative therapy with the aerosolized prostacyclin-analog Iloprost. With this regimen, the patient was hemodynamically stabilized for the waiting period of 21 days after which an uneventful cardiac transplantation was performed.

Normalized quantification by real-time PCR of Epstein-Barr virus load in patients at risk for posttransplant lymphoproliferative disorders.

The load of Epstein-Barr virus (EBV) in peripheral blood mononuclear cells of transplant recipients represents a predictive parameter for posttransplant lymphoproliferative disorders (PTLD). The aim of our work was to develop a rapid and reliable PCR protocol for the quantification of cell-associated EBV DNA in transplant recipients. In contrast to previous studies, a protocol that facilitated quantification independent of photometric nucleic acid analysis was established. We took advantage of the real-time PCR technology which allows for single-tube coamplification of EBV and genomic C-reactive protein (CRP) DNA. EBV copy numbers were normalized by division by the amount of CRP DNA, with the quotient representing the actual amount of amplifiable genomic DNA per reaction. Coamplification of CRP DNA did not result in a diminished detection limit for EBV. By using the protocol without normalization, EBV copy numbers in 4 out of 10 PTLD patients were within the normal range determined with data for 114 transplant recipients that served as controls. After normalization, however, all of the PTLD patients had a higher viral load than the control population, indicating an increased sensitivity of the assay. Moreover, EBV copy numbers obtained for one patient by conventional quantification and suggestive of relapsing PTLD were within normal range after normalization. We conclude that normalization of PCR signals to coamplified genomic DNA allows a more accurate quantification of cell-bound EBV.

Tissue engineering of pulmonary heart valves on allogenic acellular matrix conduits: in vivo restoration of valve tissue.

BACKGROUND: Tissue engineering using in vitro-cultivated autologous vascular wall cells is a new approach to biological heart valve replacement. In the present study, we analyzed a new concept to process allogenic acellular matrix scaffolds of pulmonary heart valves after in vitro seeding with the use of autologous cells in a sheep model. METHODS AND RESULTS: Allogenic heart valve conduits were acellularized by a 48-hour trypsin/EDTA incubation to extract endothelial cells and myofibroblasts. The acellularization procedure resulted in an almost complete removal of cells. After that procedure, a static reseeding of the upper surface of the valve was performed sequentially with autologous myofibroblasts for 6 days and endothelial cells for 2 days, resulting in a patchy cellular restitution on the valve surface. The in vivo function was tested in a sheep model of orthotopic pulmonary valve conduit transplantation. Three of 4 unseeded control valves and 5 of 6 tissue-engineered valves showed normal function up to 3 months. Unseeded allogenic acellular control valves showed partial degeneration (2 of 4 valves) and no interstitial valve tissue reconstitution. Tissue-engineered valves showed complete histological restitution of valve tissue and confluent endothelial surface coverage in all cases. Immunohistological analysis revealed cellular reconstitution of endothelial cells (von Willebrand factor), myofibroblasts (alpha-actin), and matrix synthesis (procollagen I). There were histological signs of inflammatory reactions to subvalvar muscle leading to calcifications, but these were not found in valve and pulmonary artery tissue. CONCLUSIONS: The in vitro tissue-engineering approach using acellular matrix conduits leads to the in vivo reconstitution of viable heart valve tissue.

Myelodysplastic syndrome and acute myelogenous leukemia secondary to heart transplantation.

Myelodysplastic syndrome and acute myelogenous leukemia secondary to radiotherapy, radiation exposure, and chemotherapy is a well-documented malignant stem cell disorder. The incidence and natural course of myelodysplastic syndrome and acute myelogenous leukemia after organ transplantation remains less thoroughly investigated. In our institution, 631 heart transplantations have been performed between 1983 and 1998. We report five patients (age, 22-63 years) with myelodysplastic syndrome (MDS) (n=1) or acute myelogenous leukemia (AML) (n=4) occuring 4-8 years after transplantation. Immunosuppression consisted uniformly of a combination of prednisone, cyclosporine, and azathioprine. Successful cytogenetic analysis was performed in three patients, showing typical cytogenetic abnormalities in each case. The course of AML was uniformly fatal. One patient with MDS, refractory anemia with excess of blasts according to the FAB criteria, is alive with transfusion dependency 32 months after diagnosis. MDS and AML may occur during immunosuppression after heart transplantation. Treatment results are poor in this subgroup of patients with secondary leukemia.

[Long-term management after heart transplantation--an assessment of current status]. / Langzeitbetreuung nach Herztransplantation--eine Bestandsaufnahme.

Due to an improvement of results after heart transplantation, there is a continuously growing number of long-term surviving patients. Aimed at a characterization of established diagnostic and therapeutic protocols, the Working Group of Thoracic Organ Transplantation within the German Society of Cardiology performed a survey among all German heart transplantation centers. Based on the experience of 1,500 patients, the clinical relevance as well as approaches for prevention and treatment of rejection, infection, cardiac allograft vasculopathy, malignancy, hypertension, renal insufficiency, and quality of life were assessed by a questionnaire. As a result, a time dependency of expected complications could clearly be shown. While early after HTX acute rejection and infection episodes were judged as clinically important, later on cardiac allograft vasculopathy, malignancy, and renal insufficiency predominate as relevant complications. This spectrum was reflected by a differentiated diagnostic protocol (early after HTX more frequent diagnostic procedures for rejection and infection, later intensified examinations to identify cardiac allograft vascular disease and malignancy) as well as by different intensities of immunosuppression and concomittant medication. Regarding further improvement of survival rates and quality of life, future clinical and scientific activities should be focused on the prevention of late complications after heart transplantation.

Cardiac allograft vasculopathy--coronary interventions and surgical options.

Despite improved results early after heart transplantation (HTX) obstructive allograft vasculopathy still remains the leading cause of death late after HTX. Studies in the past, focused on angioplasty (PTCA), presented with disappointing results. Using intravascular ultrasound an extensive early recoil could be shown to be the major cause for re/rest-stenosis in dilated lesions. Stimulated by these observations, stent implantation was recently shown to be an effective therapeutical alternative in focal luminal obstruction in graft coronary arteries. Treatment of 41 patients in a single center experience (75 lesions, 85 stents) resulted in a success rate of 98%; no acute or subacute stent thromboses were observed (protocol with ASS and Ticlopidine). Control angiography revealed a 6-month restenosis rate of 14.1% defining stent implantation as the method of choice for relief of focal luminal obstruction. Only limited experience is available regarding the surgical approach with coronary artery bypass grafting. In selected patients (focal obstruction not suitable for interventional therapy, adequate peripheral vessels) it might represent a therapeutical alternative.

[Hybrid technique for myocardial revascularization: value of combined minimal invasive bypass technique (MIDCAB) with interventional therapy (PTCA)]. / Hybrid-Verfahren zur Myokardrevaskularisation: Stellenwert der Kombination von minimal-invasiver Bypasstechnik (MIDCAB) mit interventioneller Therapie (PTCA).

BACKGROUND: Minimally invasive direct coronary artery bypass (MIDCAB) grafting without cardiopulmonary bypass (CPB) through an anterolateral minithoracotomy has become a promising therapeutical option especially in multimorbid, elderly and reoperative patients with single vessel disease. However, this procedure precludes complete revascularization in multivessel disease because the minithoracotomy limits the surgical access either to anterior or lateral or posterior vessels of the beating heart. To expand the benefits of the MIDCAB concept to patients with multivessel disease, new interdisciplinary approaches have recently been introduced. METHODS: Since December 1996, 26 patients (21 male, 5 female, mean age 56.6 +/- 18.8 years) underwent a "hybrid" revascularization performed as a primary MIDCAB procedure for grafting of the left anterior descending artery (LAD) with the left internal mammary artery (LIMA) followed by staged angioplasty and stenting of additional coronary lesions. RESULTS: After MIDCAB grafting, the postoperative course was uneventful in all patients. Coronary re-angiography after a median of 7 days revealed patent and functioning LIMA grafts in all patients. Applying subsequent percutaneous transluminal coronary angioplasty (PTCA) and occasional stenting (n = 8), a total of 31 lesions were treated successfully. Procedure related complications did not occur. All patients remained angina-free and no stress electrocardiographic changes were recorded. CONCLUSION: Our preliminary results of a "hybrid" approach to myocardial revascularization suggest that this concept is a safe and effective approach of complete revascularization for selected patients with multivessel involvement. Especially elderly and reoperative patients with significant comorbidity may benefit from hybrid procedures avoiding cardiopulmonary bypass and midsternotomy.

Replacement of ascending aorta with aortic valve reimplantation: midterm results.

OBJECTIVE: Aneurysms of the aortic root lead to aortic valve incompetence due to dilatation of the sinotubular junction and annuloaortic ectasia. Reimplantation of the native, structurally intact aortic valve within a Dacron tube graft corrects annular ectasia as well as dilatation of sinotubular junction and aortic sinuses. Durability of this valve repair with respect to increased mechanical stress on valve cusps is discussed controversially and is yet unknown. METHODS: Since 7/93, replacement of the ascending aorta with repair of the aortic valve was performed in 48 patients (34 male, 14 female; 47+/-20 years) with aortic insufficiency and aneurysm of the aortic root. Fifteen patients (31%) had Marfan's syndrome and five patients (10%) had an aortic dissection type A (two acute, three chronic). In 11 patients (23%), concomitant replacement of the aortic arch was necessary utilizing elephant trunk technique in two patients. Additionally, one patient required mitral valve repair and two other patients coronary artery bypass grafts. Clinical and echocardiographic follow-up was performed in 6-12 month intervals for a cumulative study period of 100 patient years. RESULTS: There were no operative deaths. Two patients (4%) died 5 and 20 months postoperatively. One additional patient experienced a TIA within the first postoperative week. Three patients (6%) with an early postoperative aortic insufficiency (AI) > 1 required aortic valve replacement after 9, 11, and 14 months due to progressive AI. In these patients, distortion of the aortic root geometry led to valve incompetence. All other patients have no or mild aortic insufficiency. The repair now remains stable for up to 63 months (mean 25+/-18 months). Other valve related complications did not occur. CONCLUSIONS: Our results demonstrate that this type of aortic valve repair achieves excellent results in selected patients. Perfect coaptation of valve cusps during the repair with no or only trace AI at initial echocardiography seems to be essential for durability.

Different approaches for minimally invasive closure of atrial septal defects.

BACKGROUND: To improve the acceptance of cosmetic results after closure of atrial septal defects, anterior or lateral thoracotomies are preferred rather than median sternotomies. Along with the availability of minimally invasive techniques, a further reduction in incision length appeared feasible while preserving thoracic stability. METHODS: Various minimally invasive approaches differing in the type of incision and mode of cannulation have been applied under conditions of normothermic ventricular fibrillation. In technique 1 (n = 5), a right parasternal mini-incision was combined with a central aortic and bicaval cannulation. Technique 2 (n = 2) was composed of an anterior submammary mini-incision with femoral arterial and central bicaval cannulation. To optimize the surgical access, the transincisional cannulation of the superior vena cava was replaced by a percutaneous cervical cannulation (technique 3, n = 17). RESULTS: Effective atrial septal defect closure assessed by intraoperative echocardiography was achieved in all patients. Central neurologic complications were completely absent. Besides temporary atrial fibrillation in one case, no other cardiac complications occurred. There were no cases with complicated wound healing. CONCLUSIONS: Along with modified cannulation techniques and intraoperative echocardiography, minimally invasive techniques can be safely applied for atrial septal defect closure. Submammary incisions were highly accepted and allowed for adequate surgical exposure.

Ten year survival after heart transplantation: palliative procedure or successful long term treatment?

OBJECTIVE: To investigate the long term outcome and prognostic factors after heart transplantation. SETTING: University hospital. SUBJECTS: 120 heart transplant patients (98 male, 22 female; underlying disease: dilated cardiomyopathy in 69, coronary artery disease in 42, miscellaneous in nine) who had undergone heart transplantation between October 1984 and October 1987. Immunosuppressive treatment was comparable in all patients and rejection episodes were treated in a uniform manner. METHODS: Functional status, quality of life, and potential predictors for long term survival were investigated. RESULTS: Actuarial survival rates were 65% at five years and 48% at 10 years; 58 patients survived > 10 years. The major causes of death were cardiac allograft vasculopathy (39%), acute rejection (18%), infection (11%), and malignancy (11%). Long term survivors had good exercise tolerance assessed by the New York Heart Association classification: 47 (81%) in grade I/II; 11 (19%) in grade III/IV. Echocardiography showed good left ventricular function in 48 patients. On angiography, severe allograft vasculopathy was present in only 16 patients (28%). Renal function was only slightly impaired, with mean (SD) serum creatinine of 148.5 (84.9) micromol/l. Multiple potential predictors of long term survival were analysed but none was found useful. CONCLUSIONS: Heart transplantation represents a valuable form of treatment. Survival for more than 10 years with a good exercise tolerance and acceptable side effects from immunosuppression can be achieved in about 50% of patients.

Long-term outcome of chronic hepatitis B in heart transplant recipients.

BACKGROUND: Hepatitis B is common in organ transplant recipients. It adversely affects the prognosis after liver and kidney transplantation. The long-term outcome of hepatitis B virus (HBV) infection in heart transplant recipients has not been studied before. METHODS: Between July 1984 and June 1993, 436 patients underwent heart transplantation at the Hannover Medical School. A total of 345 patients survived for more than 1 year and were included in this study. Of these, 74 were found to be hepatitis B surface antigen (HBsAg)-positive during follow-up; 69 acquired HBV infection at known time points 25+/-17 months after transplantation, and 5 had already been infected before heart transplantation. Mean follow-up was 105 (range, 25-157) months. RESULTS: Patients developed significant alanine aminotransferase (ALT) elevations after HBV infection, which peaked and then remained above normal. Preinfection levels of ALT were 15.4+/-6.4 U/L, peak values were 71.2+/-47.2 U/L, and mean values after HBV infection were 28.9+/-14.6 U/L. All patients remained HBsAg-positive. Thirteen patients (18%) became HBeAg-negative during follow-up, 10 with negative quantitative HBV-DNA assays. Mean HBV-DNA levels in the remaining patients were 292+/-267 (range, 0-978) pg/ml. Thirty-four patients died during follow-up (45.9%) compared to 78/271 (28.8%) in the control group (P=0.008). Six of the HBsAg-positive patients (17.1%) died of liver failure 6.2-10.6 years (mean, 8.6) after transplantation. Histology of 25 HBsAg-positive patients more than 5 years after infection revealed severe fibrosis or cirrhosis in 14 (56%), mild fibrosis in 9 (36%), and chronic hepatitis without fibroproliferation in 2 (8%). CONCLUSIONS: Hepatitis B infection after heart transplantation leads to chronic liver disease in the majority of the affected patients, causing cirrhosis in more than 55% within the first decade after transplantation. Liver failure is a common cause of death in the infected group of patients. Active HBV vaccination is mandatory for all organ transplant candidates, in particular before heart transplantation.

[Aortic valve insufficiency in aneurysms of the ascending aorta: functional results following valve-sparing reconstruction]. / Aortenklappeninsuffizienz bei Aneurysmen der Aorta ascendens: funktionelle Ergebnisse nach klappenerhaltender Rekonstruktion.

BACKGROUND AND OBJECTIVE: Changes in geometry of the aortic root, especially a dilatation of the sinotubular junction, are the major causes of aortic valve regurgitation in ascending aortic aneurysm. In valves without structural defect, a valve sparing aortic root reconstruction may be a therapeutic option. Aim of this study was the assessment of functional results, in the early postoperative, and during follow-up, in a large patient cohort from one centre. PATIENTS AND METHODS: Between July 1993 and March 1998, a total of 48 valve sparing operations were performed at Hannover Medical School. Mean age of patients (34 males, 14 females) was 47.4 +/- 19 years. In a prospective design clinical, and echocardiographic examinations were performed pre-, intra and early postoperatively as well as 3.6 and then every 12 months during follow-up. Structural valve changes, systolic pressure gradients as well as the degree of diastolic regurgitation were evaluated. RESULTS: Aortic root reconstruction was successful in all patients; none died perioperatively. Extension of the underlying disease to the aortic arch was present in eleven, acute and chronic dissection of the ascending aorta (type A) in two and three patients, respectively. Echocardiographic follow-up over a mean period of 25.1 +/- 18.3 months (cumulatively 1204 months) revealed stable valve function in 41 patients without (n = 30) or with a minimal (n = 11) regurgitation. In three patients moderate valve regurgitation (grade 2) was observed, three patients (6.3%) had to be reoperated because of a progressive valve failure. Thromboembolic or bleeding complications were not observed. CONCLUSIONS: Valve sparing aortic root reconstruction is a promising alternative to the composite replacement of the ascending aorta. Low perioperative morbidity and mortality rates as well as favourable functional results were demonstrated. Long-term anticoagulation can be avoided. Long-term follow-up will be necessary to assess the definitive role of this new surgical approach.

Surgical treatment of Marfan patients with aneurysms and dissection of the proximal aorta.

BACKGROUND: The authors retrospectively analyzed early and late results of surgical treatment for 79 Marfan patients with aneurysms and dissection of the proximal aorta. METHODS: From September 1979 to February 1996, 79 patients with Marfan syndrome underwent aortic root replacement using composite grafts (n=68, Bentall-technique 63, button-technique 5), and ascending aortic replacement with a valve-sparing procedure (n=11). There were 12 patients (15.2%) who simultaneously received partial or total arch replacement. 55 patients (69.6%) were male, and 24 female (30.4%). The average age was 33.8 years. Forty-one patient (51.9%) had non-dissecting aneurysms while the remaining 38 patients suffered from either acute (24.0%) or chronic aortic dissection (24.0%). The aortic valve was involved in 97.5% of all cases. RESULTS: The total early mortality (< or =30 days) was 3.8%, 10.5% for acute aortic dissection and 2.4% for non-dissecting aneurysms. There were no early postoperative deaths in patients after valve-sparing operation and in those with chronic aortic dissection. The follow-up rate was 98.7%. During a mean follow-up of 68+/-25 months 10 patients (13.3%) died and cardiac complications were a common cause of the late deaths. There was no late mortality in the valve-sparing operations during a mean follow-up period of 8+/-6 months, however, 1 required valve replacement. 19 (25.3%) of the 75 patients surviving late have undergone 25 secondary operations on the cardiovascular system. Reoperations at aortic sites distant from the original were much more frequent after primary repair for acute and chronic dissection when compared to non-dissecting aneurysms (p<0.005). Actuarial survival rate of all patients with composite graft replacement including early deaths was 91.2% at 1 year, 84.4% at 5 years and 75.2% at 10 years. CONCLUSIONS: Composite graft insertion has become the gold standard for treating Marfan-patients with non-dissecting and dissecting aneurysms of the aortic root. Our early experience in 11 patients with valve-sparing procedures indicated that this,variant may be the better choice in selected patients.

Silicon carbide-coated stents: clinical experience in coronary lesions with increased thrombotic risk.

PURPOSE: To report the results of a prospective, nonrandomized, multicenter study of a semiconductor-coated stent in coronary lesions at high risk for stent thrombosis. METHODS: A balloon-expandable tantalum stent was coated with silicon carbide to enhance thromboresistance (Tensum). Patients were enrolled in an observational study that compared coronary stenting with the Tensum stent in patients at low risk for stent thrombosis against those with factors predisposing to local thrombosis (acute myocardial infarction, small vessel diameter, recanalized chronic total occlusion, saphenous vein bypass grafts, and coronary allograft vascular disease). RESULTS: In 294 patients with 364 coronary lesions, 111 patients with 142 lesions were assigned to the high-risk group. Overall, 406 Tensum stents were implanted (94% procedural success) using antiplatelet medication only after the procedure. The stent thrombosis rate (2.7% overall) in the high-risk group (3.6%) was not significantly different from that of the low-risk patients (2.1%). CONCLUSIONS: Silicon carbide coating on coronary stents may inhibit acute/subacute stent thrombosis even in patients at high risk. Randomized trials are underway for further evaluation of this promising coated stent.

Perioperative complications in combined aortic valve replacement and extraanatomic ascending-descending bypass.

BACKGROUND: In adult patients, the combination of severe aortic valve stenosis and coarctation is rare. Surgical options comprise either a two-stage approach with valve replacement and subsequent repair of the coarctation or a one-stage repair involving valve replacement and insertion of an extraanatomic bypass graft from the ascending to the descending aorta. METHODS: We report the cases of 2 adult patients with this combined lesion who underwent simultaneous aortic valve replacement and transpericardial bypass of the coarctation. RESULTS: Weaning from extracorporeal circulation and restoration of spontaneous circulation required resuscitative measures. By increasing mean arterial perfusion pressure using norepinephrine, the observed hemodynamic instability could be controlled effectively. CONCLUSIONS: Changes in the hemodynamics of the thoracic vascular bed resulting in coronary malperfusion are discussed to be the major cause of heart failure and life-threatening ventricular arrhythmias seen in our patients after aortic valve replacement and insertion of an ascending-descending aorta bypass graft. Awareness of the complications described is considered important for successful management of these high-risk patients.