Short and midterm results of epi and endocardial cryoablation.

BACKGROUND: Cryoablation is a new surgical technique for the treatment of atrial fibrillation. Because long-term results are scarce, we report on our findings with this antiarrhythmic therapy. METHODS: Forty-three patients (men: 22; women: 21) with paroxysmal (20 patients) or permanent (23) atrial fibrillation underwent different cardiac procedures with simultaneous cryoablation from 2002 to 2007. Cryoablation was performed epicardially with the SurgiFrostTM Cryosurgical system in patients with closed-heart procedures and endocardially in patients with mitral valve surgery. Data were collected by reviewing charts of the patients. Follow-up data were obtained by phoning the general practitioners and/or cardiologists of the patients. RESULTS: The mean age of the patients was 66.2 ± 9.0 years. Fifteen different operations were performed, with coronary artery bypass grafting and mitral valve replacement occurring most frequently. Four patients (9.3%) died postoperatively, 22 were discharged with sinus rhythm (56.4%), and the others demonstrated atrial fibrillation (43.6%). A cardioversion performed on 9 patients postoperatively was successful in 5. All patients were treated with phenprocoumon and amiodarone for a minimum of 6 months postoperatively. Follow-up data were collected 26 ± 15 months after surgery. The number of patients with sinus rhythm had increased to 26 (66.7%), whereas 13 (33.3%) patients still suffered from atrial fibrillation. CONCLUSION: Cryoablation seems to be an effective tool in the treatment of atrial fibrillation.

Results and treatment strategy for patients undergoing emergent coronary artery bypass grafting.

BACKGROUND: Emergent coronary artery bypass grafting (CABG) remains a high-risk procedure in cardiac surgery. Therefore we performed this study to evaluate its current results. METHODS: From 2001 to 2007, fifty-seven patients with an acute coronary syndrome underwent an isolated CABG procedure emergently. Data were collected retrospectively from the patients' charts. RESULTS: The mean age of the patients, 45 males (79%) and 12 females (21%), was 64.5 ± 11.5 years. Operations were performed on 40 patients (70%) with cardiopulmonary bypass (CPB) and cardioplegic cardiac arrest and on 6 without CPB. Eleven patients (11%) underwent on-pump beating heart procedures (19%). The operating times (minutes) were duration of surgery 215.2 ± 64.2; duration of CPB 116.9 ± 51.5; and X-clamp time 57.3 ± 19.9. The mean number of grafts per patient was 2.95 ± 0.97. Postoperative durations of mechanical ventilation (hours), Intensive Care Unit stay (days), and normal ward stay (days) were 45.8 ± 75.3, 8.9 ± 23.1, and 9.6 ± 8.0, respectively. The total number of complications was 57, and postoperative confusion (29.8%), revision for bleeding (22.8%), and renal insufficiency (21%) occurred most frequently. Seven of the 57 patients died: 5 succumbed to multiorgan failures, 1 to cardiac decompensation, and 1 to bleeding complications. CONCLUSION: Emergent CABG is associated with an enhanced perioperative risk, and further developments are absolutely necessary to improve its results.

Alteration of matrix metalloproteinases in selective left ventricular adriamycin-induced cardiomyopathy in the pig.

INTRODUCTION: Anthracyclines are widely used in oncogenic therapy. Owing to their cardiotoxic side effects, their application is subdued to dose limitations. Many cardioprotective approaches have failed. This study examined the role of matrix metalloproteinases (MMP) in the remodeling process of extracellular matrix after treatment with doxorubicin (Adriamycin) as a toehold for a new therapeutic approach, for example, treatment with MMP inhibitors. METHODS: Severe heart failure was induced in 6 pigs by the repetitive intracoronary application of Adriamycin. Degree of dilatation and insufficiency were measured by echocardiography and hemodynamics. Before and after treatment, MMP activity (fluorogenic assay: MMP-1, MMP-2) and gene expression (reverse transcription-polymerase chain reaction [RT-PCR]: MMP-1, -2, -9; membrane type-1 matrix metalloproteinase, [MT1MMP]; tissue inhibitor of metalloproteinase 1 [TIMP-1]) were measured. Spatial distribution of MMP-1, MMP-2, and collagen were visualized in antibody-stained frozen sections. One-way analysis of variance was used for data analysis. RESULTS: Severe myocardial insufficiency (ejection fractions < 50% of baseline values) developed in all animals. No severe side effects were encountered. We found a strong activation of MMP-1 and MMP-2 in fluorogenic and PCR assays. RT-PCR revealed a significant activation of MMP-9 and MT1-MMP and a weaker induction of TIMP-1. Histology showed typical signs of myocardial fibrosis, with myocardial cell loss, collagen disorder, and vacuoles. CONCLUSION: We showed a strong transcriptional activation for several specific MMPs in Adriamycin-induced cardiac remodeling. Contrary to published data on myocardial infarction, early inhibitory therapy before myocardial injury is possible in Adriamycin-treated patients. Local application by our catheter-based system would additionally help to avoid systemic side effects.

Perioperative risk of redo aortic valve replacement.

BACKGROUND: To evaluate the perioperative risk of redo aortic valve replacement (AVR). MATERIALS AND METHODS: Sixty-three patients (53 males, 10 females) underwent redo AVR from 2001-2005. Forty-one bioprostheses had to be replaced for degeneration and/or paravalvular leakage, and 18 mechanical prostheses were changed because of thrombosis and/or paravalvular leakage. Four patients with a bicuspid aortic valve underwent a mechanical AVR after a primary reconstructive procedure. We compared the perioperative course of the redo AVR (group 2) with the primary procedure (group 1). RESULTS: Fifty-two patients received a mechanical prosthesis and eight a biological one. Three patients underwent a refixation of the prosthesis for a paravalvular leakage. The durations of surgery (261.7 +/- 49.5 min vs. 191.7 +/- 31.6 min), cardiopulmonary bypass (130.3 +/- 37.1 min vs. 101.3 +/- 28.4 min), and cross-clamping (80.4 +/- 23.4 min vs. 66.4 +/- 20.6 min) were significantly longer in group 2 than in group 1. Forty-three patients had an uneventful postoperative course. There were 28 (8) postoperative complications in group 2 (1): Need for pacemaker insertion: 8 vs. 2; reexploration for bleeding: 4 vs. 1; temporary renal insufficiency: 3 vs. 4; cerebral confusion: 5 vs. 0; low cardiac output syndrome: 4 vs. 0; wound infection: 2 vs. 1; intestinal ischemia: 1 vs. 0. Four patients expired after redo AVR: two resulting from multiorgan failure, one suffered from an intestinal ischemia requiring bowel resection, and one expired as a result of an aortic rupture during resuscitation. CONCLUSION: Conventional reoperative AVR is associated with an enhanced perioperative risk. Therefore these patients should be referred early for reoperation to avoid high-risk emergency operations with a significantly increased mortality.

Comparison of the Carpentier-Edwards Perimount and St. Jude Medical Epic bioprostheses for aortic valve replacement--a retrospective echocardiographic short-term study.

OBJECTIVE: Stented biological prostheses show different performance related to their design and ultrastructure. Therefore, we compared the Carpentier-Edwards Perimount (Edwards Lifesciences, Irvine, CA, USA) and the St. Jude Medical Epic (SJM Epic; St. Jude Medical Inc., St. Paul, MN, USA) prostheses with respect to their hemodynamic features. METHODS: Eighty-six patients underwent aortic valve replacement for severe aortic stenosis (50 patients), aortic regurgitation (seven patients), or mixed lesion (29 patients) with these randomly assigned bioprostheses (Perimount: 39 patients; SJM Epic: 47 patients). Following informed consent, patients were examined postoperatively (mean 9.7 +/- 4 months after surgery) with a detailed echocardiographic study, quality of life was determined by a standardized questionnaire. RESULTS: Comparing the indexed effective orifice area (0.77 cm(2)/m(2) vs. 0.64 cm(2)/m(2); p = 0.019), the mean pressure gradient (11.15 mmHg vs. 14.80 mmHg; p = 0.004) and the stroke-work loss (6.95% vs. 8.49%; p = 0.025), the Carpentier-Edwards Perimount demonstrated significantly better hemodynamic features than the SJM Epic prosthesis. These effects were more pronounced in the smaller prosthetic sizes. CONCLUSION: The Carpentier-Edwards Perimount prosthesis was less obstructive than the SJM Epic in echocardiographic controls. Patient-prosthesis mismatch as determined by indexed effective orifice area showed no impact on functional recovery.

Past, present, and future of long-term mechanical cardiac support in adults.

The growing number of heart failure patients and the scarcity of donor organs give rise to the development of mechanical circulatory support devices for a long-term support. After approximately 15 years of experience, these devices should be critically evaluated. The presented article gives an overview on the currently most often used mechanical circulatory support systems, describes the indications for implantation (bridge to cardiac transplantation, destination therapy, and bridge to recovery), the complications like bleeding, thromboembolic events, infections, and technical failures, and analyzes the costs of this therapy. Furthermore, alternative treatment options like cardiac transplantation, coronary artery bypass grafting, cardiac valve surgery, defibrillator implantation, multisite pacing, dynamic and passive cardiomyoplasty, partial left ventriculectomy (PLV), Myosplint implantation (Myocor, Maple Grove, MN, USA), stem cell therapy, and xenotransplantation are shortly presented, and the future of mechanical support devices is discussed. Despite a great number of patients benefitting from mechanical support devices, the treatment with these devices will only compete with other therapeutic strategies if the rates of complications and technical failures as well as the costs are significantly reduced. Furthermore, innovative therapies like biochemical influencing of the cardiac metabolism have a high potential and may play an important role in the future.

Selective left ventricular adriamycin-induced cardiomyopathy in the pig.

OBJECTIVE: The aim of this study was the development of an experimental cardiomyopathy induced with Adriamycin (Pharmacia & Upjohn, Erlangen, Germany) with selective toxic damage of the left ventricular myocardium that avoided an ischemic component. METHODS: An intracoronary catheter was implanted directly into the left main stem in pigs and connected to a percutaneous access port that was used for repetitive Adriamycin administration (3-5 x 25 mg weekly over a 1-hour period). Hemodynamic and echocardiographic variables were measured before Adriamycin administration, 1 week after, and at 4 weeks. Thereafter, all hearts were autopsied for detailed histologic examination. Statistical analysis was done by an analysis of variance for multiple parameters. RESULTS: All pigs had normal baseline cardiac function. Measurements after Adriamycin administration and 4 weeks later demonstrated a continued increase of the central venous pressure, pulmonary artery pressure, pulmonary wedge pressure, and pulmonary vascular resistance, whereas cardiac output, stroke volume index, and left ventricular stroke work index decreased. These results were supported by the echocardiographic data depicting an increase of left ventricular diameters and volumes, accompanied by a decrease of intraventricular and left ventricular posterior wall thickness as well as left ventricular ejection fraction. Right ventricular volumes and function did not change during the trial. The histologic examination of the hearts revealed a selective toxic damage of the left ventricular myocardium with multifocal necroses and advanced tissue reorganization. CONCLUSION: This animal model creates a selective left ventricular damage that avoids ischemic damage of the myocardium. Both aspects can improve research on Adriamycin-induced cardiomyopathy, especially preventive or therapeutic strategies.

Insufficiency of an aortic valve prosthesis due to tissue ingrowth: a case report.

Tissue ingrowth of a prosthetic heart valve usually leads to a stenosis. We report a rare case of a patient with a fixation of the prosthetic leaflet due to tissue ingrowth. This state caused a total prosthetic insufficiency. The therapy used to treat this prosthetic heart valve with tissue ingrowth is discussed in this report.

Treatment of right heart failure with a new microaxial blood pump.

Isolated postcardiotomy right ventricular failure is rare but associated with a high mortality. Therefore, new developments reducing this mortality are necessary. We report our first successful clinical use of a new paracardiac right ventricular microaxial blood pump which was developed for postcardiotomy right heart failure.

Doxorubicin in experimental and clinical heart failure.

Doxorubicin-induced heart failure is a rare but serious illness due to the well-known treatment difficulties. Prevention strategies have not demonstrated the expected success and unfortunately, this specific type of heart failure does not respond to the usual medical therapy as other kinds of heart failure. Therefore, surgical procedures may be necessary in some patients. Cardiac transplantation is performed in most cases but it requires the cure of the neoplastic disease. This usually requires a recurrence-free interval of several years which is associated with a high attrition rate in these patients due to their cardiac disease. Therefore, other conservative and surgical treatment concepts were developed during the last years. This review presents the most common procedures and discusses their efficacy as well as their clinical applicability.

In vivo experimental testing of a microaxial blood pump for right ventricular support.

The incidence of isolated right ventricular (RV) failure is rare in postcardiotomy patients, but high in patients undergoing implantation of a left ventricular assist device or cardiac transplantation. Therefore, we have developed a new microaxial flow device and report on our first in vivo animal trials. Six healthy adult female sheep weighing 80-90 kg underwent implantation of the microaxial blood pump for partial unloading of the right ventricle. This pump is a miniaturized rotary blood pump with a diameter of only 6.4 mm and a weight of 11 g. The inner volume of the pump is limited to 12 mL, and the inner artificial blood contacting surface is 65 cm(2). The pump consists of a rotor driven by an incorporated brushless direct current motor, the housing of the rotor, the inflow cage, the outflow cannula, and the driveline. At the maximum speed of 32,500 rotations/min, a flow of 6 L/min can be delivered. The inflow and outflow conduit were anastomosed to the right atrium and the main pulmonary artery, respectively. Hemodynamic and echocardiographic data as well as blood samples were measured over the whole test period of 7 days. The hearts and lungs as well as the pump were explanted for a thorough examination at the end of the trial. Systemic arterial blood pressures remained unchanged during the entire test period. RV cardiac output was diminished significantly as demonstrated by the echocardiographic studies. The number of platelets decreased perioperatively, but recovered within the test period. The free hemoglobin was not enhanced postoperatively indicating no significant hemolysis. Liver function was only slightly impaired due to operative reasons (increase in bilirubin on the first postoperative day but normalization within the test period). The pathologic examination revealed some clots at the inflow cage and fibrin depositions on the impeller as well as on the inner surface of the outflow graft without an impairment of pump function. Our results demonstrate that this newly developed microaxial blood pump is a promising device for RV support, but it cannot be driven without any anticoagulation.

Aortic valve endocarditis with Bartonella quintana - a rare entity.

Endocarditis caused by Bartonella species is difficult to diagnose and still remains a rare entity. Therefore, a young male patient undergoing aortic valve replacement for culture-negative endocarditis is reported in whom the diagnosis of a Bartonella quintana infection was made with a great delay postoperatively.

Experimental testing of a new left ventricular assist device--the microdiagonal blood pump.

All existing ventricular assist devices are associated with a considerable number of serious complications. This article reports on the first animal tests with a newly developed microdiagonal blood pump (MDP). Six adult female sheep weighing 80 to 90 kg underwent implantation of the microdiagonal blood pump. The inflow and outflow conduits were anastomosed to the left atrium and the descending aorta. Pump flow was adjusted to 2-3 L/minute. Hemodynamic and echocardiographic data, as well as blood samples, were measured over the entire test period of 7 days. All internal organs and the pump were explanted for thorough examination at the end of the trial. Mean arterial (range 88.5 +/- 13.1-103.7 +/- 10.7 mm Hg) and mean pulmonary arterial (18.3 +/- 2.7-21.6 +/- 20.5 mm Hg) pressures, as well as the pulmonary capillary wedge pressure (14.2 +/- 3.0 - 16.6 +/- 4.0 mm Hg), remained stable during the whole test period. Cardiac output (4.9 +/- 0.7 --> 3.2 +/- 0.5 L/minute) decreased postoperatively caused by partial unloading of the heart. Left ventricular end diastolic (4.1 +/- 0.5 --> 3.6 +/- 0.3 cm) and end systolic (3.2 +/- 0.4 --> 2.8 +/- 0.5 cm) diameters, as well as the ejection fraction (57 +/- 9 --> 42 +/- 5%), decreased after MDP implantation and did not change during the test period. Mean number of platelets (428 +/- 54 --> 286 +/- 66 x 10(3)/microL) and hemoglobin (9.8 +/- 1.3 --> 6.3 +/- 0.8 g/dL) decreased perioperatively because of surgical reasons and increased continuously in the postoperative course (platelet count and hemoglobin on day 7:441 +/- 74 x 10(3)/microL and 7.2 +/- 1.1 g/dL, respectively). Free hemoglobin was not enhanced in the postoperative course (mean value during the test period: 18.8 mmoL/L). Histologic examination of the organs did not demonstrate any infarctions of internal organs other than typical operative sequelae such as chronic pericarditis and some degree of atelectasis of the left lungs. These results demonstrate that the microdiagonal pump may be a promising alternative to the currently used ventricular assist devices, if long-term trials support these results.

A new right ventricular assist device for right ventricular support.

Right ventricular support by mechanical devices for postcardiotomy right heart failure is still associated with a high mortality. We report on the first use of a new paracardiac microaxial blood pump for postcardiotomy right heart failure in two patients undergoing emergency coronary artery bypass grafting (the first patient for a myocardial infarction complicated by a left ventricular wall rupture, the second patient for a dissection of the right coronary artery after an interventional procedure).

[Surgical therapy of end-stage heart failure]. / Chirurgische Therapie der chronischen Herzinsuffizienz]

Heart failure is still associated with a poor prognosis despite great advances in drug therapy, so that surgical procedures are necessary in patients with end-stage cardiac failure. Cardiac transplantation was the therapy of choice during the last decades, but due to its disadvantages and the increasing scarcity of donor organs other surgical procedures were developed. Multisite pacing improves quality of life, but a longterm survival benefit remains to be proved. Coronary artery bypass grafting and valve surgery demonstrated to improve quality of life and to increase long-term survival. Ventricular assist devices are effective in bridging up to 70% of patients to cardiac transplantation, but the number of complications must be reduced. Partial left ventriculectomy may be performed with results similar to those obtained of cardiac transplantation, but long-term results are not yet available. Dynamic cardiomyoplasty and Myosplint implantation were not successful, but it must be awaited, if passive cardiomyoplasty leads to better results. Xenotransplantation is under intense investigation, but cannot be used clinically until now due to the hurdles of rejection and transfer of infectious diseases. This work provides a summary of today's knowledge about surgical procedures for end-stage heart failure.

[Anomalous origin of the left coronary artery. Surgical therapy using a miniaturized heart-lung machine]. / Fehlabgang der linken aus der rechten Koronararterie. Chirurgische Therapie unter Verwendung einer miniaturisierten Herz-Lungen-Maschine.

Anomalies of the coronary arteries are rare, congenital heart diseases which often require surgical therapy. We report on a patient with an aberrant left coronary artery originating from the right coronary artery and discuss the operative procedure using a miniaturized heart-lung machine.

Partial left ventriculectomy in modified adriamycin-induced cardiomyopathy in the dog.

BACKGROUND: The purpose of this study was to evaluate modified adriamycin-induced cardiomyopathy in the dog for research on partial left ventriculectomy (PLV). METHODS: An intracoronary catheter was introduced into the left main stem via the first marginal branch in a retrograde fashion in 12 adult foxhound dogs. The catheter was connected to a percutaneous access port that was used for weekly adriamycin administration (10 mg over a 1-hour period on 5 occasions). Follow-up examinations (transthoracic echocardiography, hemodynamic parameters, cardiopulmonary status, neurohormones) were done before, 1 week after the last adriamycin administration, and then 6 weeks later. This protocol was performed in 6 dogs (control group: Group 1). The other 6 dogs underwent PLV 1 week after the last adriamycin administration (Group 2). After the last measurements, all dogs were killed with saturated potassium chloride under general anesthesia and the hearts were excised for histologic examination. All data were calculated as mean and standard error of the mean. Differences were calculated by the Wilcoxon signed-rank test for paired and unpaired data. p < 0.05 was considered statistically significant. RESULTS: One dog from each group died suddenly during adriamycin administration (probably due to ventricular arrhythmia). In addition, 1 dog from Group 2 suffered from a severe systemic inflammatory response syndrome after PLV and died 36 hours after surgery. Thus, 5 dogs from Group 1 and 4 from Group 2 underwent the entire study protocol. Adriamycin administration resulted in a severe dilated cardiomyopathy that was comparable in both groups (significant increase of central venous pressure, mean pulmonary artery pressure, pulmonary wedge pressure, left ventricular end-systolic and end-diastolic diameters, oxygen extraction, troponin I and anti-diuretic hormone, whereas cardiac output, ejection fraction and venous oxygen saturation decreased significantly). Deterioration of cardiac function continued after termination of adriamycin administration in Group 1 dogs, albeit not as progressively as during adriamycin administration. In contrast, cardiac function improved in Group 2 dogs after PLV, but did not reach baseline values. Cardiac index increased and oxygen extraction (p = 0.03) decreased, resulting in an enhanced venous oxygen saturation (p = 0.02). In particular, the distance of the papillary muscles at end diastole (p = 0.02) and at end systole (p = 0.02) at the mid-papillary level decreased significantly after PLV, resulting in reduced left ventricular diameter and volume (statistically significant for left ventricular end-systolic diameter and volume). All hearts had severe histologic alterations characteristic of adriamycin-induced toxicity, including cytoplasmic vacuolation, myocyte degeneration and increased fibrosis. CONCLUSION: Modified adriamycin-induced cardiomyopathy in the dog may be suitable for research on PLV.