Deposition of nonsarcomeric alpha-actinin in cardiomyocytes from patients with dilated cardiomyopathy or chronic pressure overload.

Nonsarcomeric alpha-actinin (ACTN-1)-positive clusters have been detected in human myocardium structurally jeopardized by dilated cardiomyopathy, hypertrophy due to aortic stenosis, or chronic hibernation, but have never been detected in normal tissue. To systematically investigate these clusters, immunohistochemistry, electron microscopy, Northern blot and Western blot were performed in human myocardium, isolated rat cardiomyocytes and rabbit smooth muscle cells. ACTN-1-positive clusters were localized in the perinuclear area of cardiomyocytes surrounded by rough endoplasmic reticulum. Quantification of structures containing ACTN-1 showed that it was present in up to 10% of all myocytes in 60% of aortic stenosis patients with severely reduced ejection fraction and in 70% of patients with dilated cardiomyopathy, exclusively in myocytes from hearts with structural degeneration and reduced function. Ultrastructurally, clusters of medium electron density corresponding to the confocal microscopic accumulations were observed in the same tissue samples. The messenger RNA of ACTN-1 was unchanged compared with controls, but a Western blot revealed that the protein was significantly elevated in failing hearts. Because membranes of the endoplasmic reticulum surround the clusters, it was concluded that in the presence of undisturbed transcription, a post-translational malfunction of ACTN-1 glycosylation might lead to storage of this protein. Autophagic and ischemic cell death were observed, but a possible toxic effect of this storage product was excluded because markers of cell death rarely colocalized with ACTN-1. The occurrence of ACTN-1-positive clusters, however, appears to be a useful marker for structural degeneration in failing myocardium.

Low-dose oral anticoagulation in patients with mechanical heart valve prostheses: final report from the early self-management anticoagulation trial II.

AIMS: In mechanical heart valve recipients, low-dose international normalized ratio (INR) self-management of oral anticoagulants can reduce the risk of developing thrombo-embolic events and improve long-term survival compared with INR control by a general practitioner. Here, we present data on the safety of low-dose INR self-management. METHODS AND RESULTS: In a prospective, randomized multi-centre trial, 1346 patients with a target INR range of 2.5-4.5 and 1327 patients with a target INR range of 1.8-2.8 for aortic valve recipients and an INR range of 2.5-3.5 for mitral or double valve recipients were followed up for 24 months. The incidence of thrombo-embolic events that required hospital admission was 0.37 and 0.19% per patient year in the conventional and low-dose groups, respectively (P = 0.79). No thrombo-embolic events occurred in the subgroups of patients with mitral or double valve replacement. The incidence of bleeding events that required hospital admission was 1.52 and 1.42%, respectively (P = 0.69). In the majority of patients with bleeding events, INR values were < 3.0. Mortality rate did not differ between the study groups. CONCLUSION: Data demonstrate that low-dose INR self-management does not increase the risk of thrombo-embolic events compared with conventional dose INR self-management. Even in patients with low INR target range, the risk of bleeding events is still higher than the risk of thrombo-embolism.

Low-dose international normalized ratio self-management: a promising tool to achieve low complication rates after mechanical heart valve replacement.

BACKGROUND: International normalized ratio (INR) self-management can significantly reduce INR fluctuations, bleeding, and thromboembolic events compared with INR control managed by general practitioners. However, even patients with INR self-management may have an increased risk of bleeding if their INR value is above 3.5. This study evaluated the compliance, clinical complications, and survival of patients after mechanical heart valve replacement with low-dose INR self-management compared with conventional-dose anticoagulation. METHODS: Group 1 (n = 908) received low-dose anticoagulation with a target INR range of 1.8 to 2.8 for aortic valve replacement and 2.5 to 3.5 for mitral or double valve replacement. Group 2 (n = 910) received conventional-dose anticoagulation with a target INR range of 2.5 to 4.5 for all heart valve prostheses. RESULTS: In groups 1 and 2, 76% and 75% of INR values, respectively, were in the target range. Results did not differ according to schooling and age. The rate of thromboembolic events per patient year was 0.18% in group 1 and 0.40% in group 2 (p = 0.210). The rate of bleeding complications was 0.74% for group 1 and 1.20% for group 2 (p = 0.502). In most patients with clinically relevant bleeding, these complications occurred although their measured INR values were below 3.5. The survival rate did not differ between the study groups (p = 0.495). CONCLUSIONS: Low-dose INR self-management is a promising tool to achieve low hemorrhagic complications without increasing the risk of thromboembolic complications. INR self-management is applicable for all patients in whom permanent anticoagulation therapy is indicated. Even INR values below 3.5 can bear the risk of bleeding complications.

Predictors of failure to cure atrial fibrillation with the mini-maze operation.

BACKGROUND: Maze-III is a complex surgical procedure designed to treat chronic atrial fibrillation. A reduction in the number of right and left atrial incisions could decrease the operative time. The aim of this study was to assess the results of a mini-maze operation and to define predictors of its failure. METHODS: Between 1995 and 2000, 72 patients (mean age 64 +/- 9 years) undergoing cardiac surgery had a concomitant mini-maze operation for symptomatic chronic atrial fibrillation. Three and 12 months post-operatively, heart rhythm and left atrial transport functions were assessed by electrophysiology, echocardiography, and magnetic resonance imaging. Multivariate analysis was performed to identify predictors of failure of the mini-maze operation. RESULTS: Operative mortality was 1.4% (1/72). Death during follow-up occurred in 5.6% of patients (4/71), in one due to chronic heart failure. After 1 year, 80% of patients (48/60) were either in sinus rhythm (n = 43; 72%) or had a pacemaker (n = 5; 8%) implanted due to sick sinus syndrome. Intermittent and chronic atrial fibrillation was found in 20% of patients (12/60). Preoperative duration of atrial fibrillation (p = 0.05), preoperative left atrial diameter (p = 0.001), preoperative right atrial diameter (p = 0.02), a reduced left ventricular ejection fraction (p = 0.03), an increased left ventricular end-diastolic diameter (p = 0.04), and the presence of mitral valve stenosis (p = 0.001) were found to be univariate predictors of failure of the mini-maze operation 1 year postoperatively. Multivariate analysis defined preoperative diagnosis of mitral valve stenosis (p = 0.005; OR 117.5), longer duration of preoperative atrial fibrillation (p = 0.01; OR 1.33), and increased preoperative left ventricular end-systolic diameter (p = 0.02; OR 1.2) as incremental independent risk factors for failure of the mini-maze operation to cure chronic atrial fibrillation. CONCLUSION: The mini-maze operation is a safe procedure with similar results to that of Cox's Maze-III operation. The less-invasive mini-maze operation could be applicable even to patients with severely reduced left ventricular function, in whom complex cardiac surgery has to be performed concomitantly as well as in those presenting severe comorbidities.

Long-term follow-up after the mini-maze procedure.

BACKGROUND: Atrial fibrillation (AF) is associated with significant morbidity and mortality. The standard to treat AF surgically is the Cox maze III procedure but owing to its complexity it is not performed on a regular basis. Meanwhile several maze variants have been developed but their long-term results are still not well known. METHODS: From November 1995 until May 2002 a mini-maze procedure was performed upon 77 patients aged 64 +/- 8.7 years with chronic symptomatic AF. Electrophysiological evaluation, magnetic resonance imaging, echocardiography and electrocardiographic evaluations were performed after 3 and 12 months. After a mean follow-up of 50 +/- 2.6 months a standard questionnaire was sent to all patients. RESULTS: Early and late mortality was 1.2% and 9.3% respectively. Actuarial survival was 91%, 90%, and 87% after 1, 3, and 5 years respectively. Left bundle branch block was an independent risk factor for late death (p = 0.02). Patients who were in sinus rhythm at follow-up had significantly better survival rate as compared with the patients still in AF. Seventy-one percent of patients were in sinus rhythm or paced by an atrial pacemaker. Predictors for restoration of sinus rhythm were absence of preoperative mitral insufficiency (p = 0.03) and larger left atrium (p = 0.04). The presence of preoperative tricuspid insufficiency (p = 0.03) and larger right atrium (p = 0.017) were predictors for postoperative pacemaker implantation. CONCLUSIONS: The mini-maze procedure can be carried out with satisfactory early and long-term results regarding mortality and restoration of sinus rhythm. Prophylactic implantation of biventricular pacemakers in patients with left bundle branch block may decrease late mortality. Every effort should be done to cure AF as it affects long-term survival.

Diffusion-weighted magnetic resonance imaging and neurobiochemical markers after aortic valve replacement: implications for future neuroprotective trials?

BACKGROUND AND PURPOSE: Cardiac surgery carries a high risk of neurological complications; therefore, these patients would be an appropriate target population for neuroprotective strategies. In this study, we evaluated postoperative diffusion-weighted imaging (DWI) as a potential surrogate marker for brain embolism and its relationship to neurobiochemical markers of brain injury. METHODS: Of a total of 45 consecutive patients undergoing aortic valve replacement, 37 completed preoperative and postoperative MRI. At the time of the MRI studies, serum S100beta and neuron-specific enolase concentrations were determined. Preexisting T2 and postoperative DWI lesion volumes were quantified. All patients had a blinded neurological examination before and after operation. RESULTS: New perioperative DWI lesions were present in 14 patients (38%), of whom only 3 developed focal neurological deficits. Eighteen small lesions were found in the white matter or vascular border zones in all but 2 patients with territorial stroke. The appearance of new DWI lesions correlated with age, pre-existing T2 lesion volume, and postoperative S100beta concentrations on days 2 to 4 after surgery. In a forward stepwise canonical discrimination model, only T2 lesion volume was selected as a relevant variable. CONCLUSIONS: The incidence of postoperative DWI lesions in aortic valve replacement is high, and a suitable marker for neuroprotective trials would be a reduction in the number of such lesions. The volume of preexisting T2 lesions is related to the development of perioperative DWI lesions.

Post-operative course of coronary artery bypass surgery patients who pre-donate autologous blood.

BACKGROUND: Pre-operative autologous blood donation is used to reduce the need of allogeneic blood in patients undergoing coronary bypass surgery operations, but it is not clear what impact the blood donation has on the post-operative course of these patients. METHODS: We studied the post-operative course of 210 patients who pre-donated autologous blood before their coronary bypass operation (donors) and of 67 patients who were eligible to pre-donate but did not (controls). RESULTS: The clinical variables and the technical operative parameters of the patients in the two groups were similar. There was no significant difference between the duration of assisted ventilation post-operatively (756 +/- 197 vs. 802 +/- 395 min; P=0.54) or length of stay in the intensive care unit (1.8 +/- 1.1 vs. 1.7 +/- 0.9 days; P=0.52) of the two groups. The number of autologous units of packed red cells and of fresh frozen plasma (FFP) received by the donors was significantly higher than the number of units of allogeneic packed red cells (1.5 +/- 0.9 vs. 0.3 +/- 0.9; P=0.001) and the units of homologous FFP received by the controls (2.3 +/- 0.8 vs. 0.6 +/- 1; P=0.001). CONCLUSIONS: We found no evidence that autologous blood donation exerted a negative influence on the post-operative course of patients undergoing coronary bypass surgery. Patients who pre-donated blood received no allogeneic blood products, but the number of autologous blood products received by donors was higher than the number of blood products received by patients who did not pre-donate.

Post-mitral valve repair systolic anterior motion produced by non-obstructive septal bulge.

OBJECTIVE: Systolic anterior motion (SAM) may rarely occur after mitral valve reconstruction due to different anatomic factors. Several techniques have been described to reduce the incidence of post-repair SAM, e.g. leaflet sliding plasty. However, SAM can still occur after these special procedures. We reviewed data of patients developing SAM with significant mitral regurgitation due to non-obstructive septal bulge. METHODS: During a 2-year period mitral valve repair was performed in 358 patients. Five of 358 (1.4%) patients with a mean age of 52+/-10.5 years developed post-repair SAM with severe mitral insufficiency due to non-obstructive septal bulge. Data of these patients were analyzed retrospectively and controlled after a mean follow-up of 18+/-2.7 months. RESULTS: Preoperative echocardiography showed end-diastolic septum diameter of 7, 10, 10, 11 and 15 mm. The ratio between end-diastolic septum diameter and free wall diameter was 1 in four patients and 1.25 in one patient. There was no left ventricular outflow tract obstruction (LVOT). Intraoperative data revealed large myxomatous anterior (four patients) and posterior (three patients) leaflets. Quadrangular resection of posterior leaflet was carried out in four patients and sliding plasty in one patient. Cause for post-repair mitral regurgitation was a non-obstructive septal bulge. During a second pump run septal bulge was resected. Mean aortic cross-clamp time and cardiopulmonary bypass time for this procedure was 15+/-1.4 and 28+/-3.1 min, respectively. Mitral regurgitation disappeared in all patients immediately after this procedure. The grade of mitral regurgitation at follow-up was 0-1 in all patients. One patient had subaortic gradient of 36 mmHg. CONCLUSIONS: If mitral regurgitation occurs after primary successful mitral repair, septum bulge should always be considered as the primary cause for SAM even there is no preoperative gradient in LVOT. Before performing time-consuming corrective operations to relieve SAM, a septum resection should be carried out during a short second pump run.

In vitro biocompatibility evaluation of the dynamic bubble trap.

The goal of this study was to evaluate the biocompatibility of the dynamic bubble trap (DBT) prior to the clinical trial. It was set up as an in vitro model, which simulates physiological conditions. Twenty runs were performed (ten with the DBT, ten without the DBT) at a blood flow of 3 l/min, each lasting 180 min. Fifteen blood parameters (hemogram, hemostasis, complement system, and cytokines) were measured at five time intervals. None of the tested parameters showed a statistically significant difference between the DBT and control group. The data assessed in this in vitro model show that the DBT has no adverse influence on hemocompatibility. It may be concluded that the DBT is a safe tool to be used in vivo.

Low-density lipoproteins induce the polar secretion of PAI-1 by endothelial cells in culture.

Patients with hypercholesterolemia and with coronary atherosclerosis have increased plasma levels of plasminogen activator inhibitor (PAI)-1. PAI-1 and low-density lipoproteins (LDL) are also present in the walls of atherosclerotic vessels, where they participate in the development and remodeling of the atherosclerotic plaques. We investigated the influence of LDL on the apical (luminal) and basolateral (subendothelial) secretion of PAI-1 by human umbilical vein endothelial cells in a two-compartment cell-culture model. Confluent cells were incubated with LDL either in the apical compartment or in the basal compartment. Cells incubated with culture medium served as controls. A significantly higher concentration of PAI-1 was found in both the apical (P = 0.025) and the basal compartment (P = 0.025) if cells were incubated with LDL on the basolateral side. In contrast, incubation of the cells with LDL apically resulted in an increased PAI-1 concentration only in the apical compartment (P = 0.028) and not in the basal compartment. Our findings indicate that the LDL particles that reach the subendothelial space can induce an increased release of PAI-1 by endothelial cells into the vessel lumen and also contribute to the release of PAI-1 into the subendothelial space and thus to the process of atherosclerotic plaque remodeling.

Mitral annuloplasty in patients with ischemic versus dilated cardiomyopathy.

OBJECTIVE: Mitral regurgitation is a frequent finding in patients with end-stage cardiomyopathy predicting poor survival. Conventional treatment consists medical treatment or cardiac transplantation. However, despite severely decreased left ventricular function, mitral annuloplasty may improve survival and reduce the need for allografts. METHODS: From January 1996 to July 2002, 121 patients with severe end-stage dilated (DCM) or ischemic cardiomyopathy (ICM), mitral regurgitation > or =2, and left ventricular ejection fraction < or =30% underwent mitral valve annuloplasty using a flexible posterior ring. DCM was diagnosed in 30 patients (25%), whereas ICM was found in 91 patients (75%). Concomitant tricuspid valve repair was performed in 14 (46.6%) patients in the DCM, and in 11 (12%) in the ICM group (P=0.0001), coronary artery bypass grafting in three (10%) in the DCM, and in 78 patients (86%) in the ICM group (P<0.00001). The mean follow-up time was 567+/-74 days in the DCM and 793+/-63 days in the ICM group (ns). RESULTS: Early mortality was 6.6% (8/121), and was equal for both groups. Improvement in NYHA class (DCM 3.3+0.1-1.8+/-0.16; ICM from 3.2+0.04 to 1.7+/-0.07) were equal between groups after 1 year. Seventeen (15%) late deaths occurred during the follow-up period. There was no difference in the 2-year actuarial survival between groups (DCM/ICM 0.93/0.85). Risk factors for mitral reconstruction failure, defined as regurgitation > or =2 after 1 year, were preoperative NYHA IV in the DCM group (P=0.03), a preoperative posterior infarction (P=0.025), decreased left ventricular function (P=0.043), larger ring size (P=0.026) and preoperative renal failure (P=0.05) in the ICM group. Risk factors for death were larger ring size (P=0.02) and an increased LVEDD (P=0.027) in the DCM group and the postoperative use of IABP (P=0.002), renal failure (P=0.001), and a larger preoperative LVESD (P=0.035) in the ICM group. CONCLUSION: Mitral reconstruction with a posterior annuloplasty using a flexible ring is effective in patients with severely depressed left ventricle function and has an acceptable operative mortality. Mid-term results are superior to medical treatment alone and comparable to cardiac transplantation.

Myocytes die by multiple mechanisms in failing human hearts.

We tested the hypothesis that myocyte loss in failing human hearts occurs by different mechanisms: apoptosis, oncosis, and autophagic cell death. Explanted hearts from 19 patients with idiopathic dilated cardiomyopathy (EF< or =20%) and 7 control hearts were analyzed. Myocyte apoptosis revealed by caspase-3 activation and TUNEL staining occurred at a rate of 0.002+/-0.0005% (P<0.05 versus control) and oncosis assessed by complement 9 labeling at 0.06+/-0.001% (P<0.05). Cellular degeneration including appearance of ubiquitin containing autophagic vacuoles and nuclear disintegration was present at the ultrastructural level. Nuclear and cytosolic ubiquitin/protein accumulations occurred at 0.08+/-0.004% (P<0.05). The ubiquitin-activating enzyme E1 and the ligase E3 were not different from control. In contrast, ubiquitin mRNA levels were 1.8-fold (P<0.02) elevated, and the conjugating enzyme E2 was 2.3-fold upregulated (P<0.005). The most important finding, however, is the 2.3-fold downregulation of the deubiquitination enzyme isopeptidase-T and the 1.5-fold reduction of the ubiquitin-fusion degradation system-1, which in conjunction with unchanged proteasomal subunit levels and proteasomal activity results in massive storage of ubiquitin/protein complexes and in autophagic cell death. A 2-fold decrease of cathepsin D might be an additional factor responsible for the accumulation of ubiquitin/protein conjugates. It is concluded that in human failing hearts apoptosis, oncosis, and autophagy act in parallel to varying degrees. A disturbed balance between a high rate of ubiquitination and inadequate degradation of ubiquitin/protein conjugates may contribute to autophagic cell death. Together, these different types of cell death play a significant role for myocyte disappearance and the development of contractile dysfunction in failing hearts.

Gap junction remodeling and altered connexin43 expression in the failing human heart.

Gap junctions (GJ) are important determinants of cardiac conduction and the evidence has recently emerged that altered distribution of these junctions and changes in the expression of their constituent connexins (Cx) may lead to abnormal coupling between cardiomyocytes and likely contribute to arrhythmogenesis. However, it is largely unknown whether changes in the expression and distribution of the major cardiac GJ protein, Cx43, is a general feature of diverse chronic myocardial diseases or is confined to some particular pathophysiological settings. In the present study, we therefore set out to investigate qualitatively and quantitatively the distribution and expression of Cx43 in normal human myocardium and in patients with dilated (DCM), ischemic (ICM), and inflammatory cardiomyopathies (MYO). Left ventricular tissue samples were obtained at the time of cardiac transplantation and investigated with immunoconfocal and electron microscopy. As compared with the control group, Cx43 labeling in myocytes bordering regions of healed myocardial infarction (ICM), small areas of replacement fibrosis (DCM) and myocardial inflammation (MYO) was found to be highly disrupted instead of being confined to the intercalated discs. In all groups, myocardium distant from these regions showed an apparently normal Cx43 distribution at the intercalated discs. Quantitative immunoconfocal analysis of Cx43 in the latter myocytes revealed that the Cx43 area per myocyte area or per myocyte volume is significantly decreased by respectively 30 and 55% in DCM, 23 and 48% in ICM, and by 21 and 40% in MYO as compared with normal human myocardium. In conclusion, focal disorganization of GJ distribution and down-regulation of Cx43 are typical features of myocardial remodeling that may play an important role in the development of an arrhythmogenic substrate in human cardiomyopathies.

Progression from compensated hypertrophy to failure in the pressure-overloaded human heart: structural deterioration and compensatory mechanisms.

BACKGROUND: The progression of compensated hypertrophy to heart failure (HF) is still debated. We investigated patients with isolated valvular aortic stenosis and differing degrees of left ventricular (LV) systolic dysfunction to test the hypothesis that structural remodeling, as well as cell death, contributes to the transition to HF. METHODS AND RESULTS: Structural alterations were studied in LV myectomies from 3 groups of patients (group 1: ejection fraction [EF] >50%, n=12; group 2: EF 30% to 50%, n=12; group 3: EF <30%, n=10) undergoing aortic valve replacement. Control patients were patients with mitral valve stenosis but normal LV (n=6). Myocyte hypertrophy was accompanied by increased nuclear DNA and Sc-35 (splicing factor) content. ACE and TGF-beta1 were upregulated correlating with fibrosis, which increased 2.3-, 2.2-, and 3.2-fold over control in the 3 groups. Myocyte degeneration increased 10, 22, and 32 times over control. A significant correlation exists between EF and myocyte degeneration or fibrosis. Ubiquitin-related autophagic cell death was 0.5 per thousand in control and group 1, 1.05 in group 2, and 6.05 per thousand in group 3. Death by oncosis was 0 per thousand in control, 3 per thousand in group 1, and increased to 5 per thousand (groups 2 and 3). Apoptosis was not detectable in control and group 3, but it was present at 0.02 per thousand in group 1 and 0.01 per thousand in group 2. Cardiomyocyte mitosis was never observed. CONCLUSIONS: These structure-function correlations confirm the hypothesis that transition to HF occurs by fibrosis and myocyte degeneration partially compensated by hypertrophy involving DNA synthesis and transcription. Cell loss, mainly by autophagy and oncosis, contributes significantly to the progression of LV systolic dysfunction.

Aneurysm formation after patch aortoplasty repair (Vossschulte): reoperation in adults with and without hypothermic circulatory arrest.

BACKGROUND: Aortic aneurysm formation is common after patch aortoplasty repair of coarctation of the aorta. Its incidence varies between 5% and 38%. The majority of patients show progressive aneurysmal dilation within 6 to 18 years and reoperation is necessary to avoid rupture of the aneurysm. METHODS: Ten patients were reoperated on for patch aneurysm formation. Femorofemoral cardiopulmonary bypass (CPB) with a heparinized system was used in all patients. Decision to initiate hypothermic circulatory arrest (HCA) was made intraoperatively. All patients received a Dacron graft replacement of the aneurysmatic thoracic aorta. RESULTS: HCA was initiated in 5 patients owing to extreme adhesions in vicinity to the aneurysm. There was no significant intergroup difference regarding time interval after first operation, age, operation time, and postoperative blood loss. Only minor neurologic events were present in 2 patients with cross-clamping the aorta. CONCLUSIONS: Patch aneurysms after Vossschulte aortoplasty can safely be operated on with femorofemoral CPB. Initiation of HCA is recommended to prevent rupture of the aneurysm during preparation and injury of adjacent nerves and vessels.