Predictors of postoperative complications in octogenarians undergoing cardiac surgery.

OBJECTIVE: Aim of the study was to clarify the impact of different pre- and perioperative conditions on outcome in octogenarians undergoing cardiac surgery. METHODS: We retrospectively analyzed preoperative risk factors and intraoperative adverse events and studied in-hospital morbidity and mortality in 646 patients > or = 80 years of age (82.5 +/- 3.5 years) and in 6081 younger patients (70.3 +/- 3.4 years) who underwent cardiac surgery between 1/2001 and 12/2006. RESULTS: Preoperatively, octogenarians suffered significantly more from arterial hypertension, renal failure, previous neurological problems, unstable angina and NYHA class IV than younger subjects. The incidence of combined valve and coronary procedures and of urgent operations was also significantly higher in patients > or = 80 years (27.7 % vs. 18.2 %, P < 0.05, and 7.3 % vs. 4.2 %, P < 0.05, respectively). In-hospital mortality was higher (7.4 % vs. 3.7 %, P < 0.05), and average ICU and total in-hospital stay was longer in the older age group. Postoperative complications occurred in 15 % of patients > or = 80 years compared to 7.6 % of patients < or = 79 years ( P < 0.05). NYHA class IV, female sex and preoperative renal failure correlated with perioperative morbidity. Multivariate analysis could identify urgent procedures, redo surgery, mitral valve surgery and prolonged cross-clamping times as predictors of mortality. CONCLUSIONS: Cardiac surgery in octogenarians can be performed with an acceptable risk but an increased mortality and morbidity compared to younger patients. High-risk octogenarians, who require intensive perioperative management, should be identified to reduce the incidence of postoperative complications.

Cardiac valve replacement in patients with end-stage renal failure: impact of prosthesis type on the early postoperative course.

BACKGROUND: It is still unclear whether biological or mechanical valves should be preferred in patients on chronic dialysis therapy. PATIENTS AND METHODS: We retrospectively analyzed data from 104 patients (66.5 +/- 8.6 years) with end-stage renal failure (RF) who underwent aortic or mitral valve replacement between 2002 and 4/2008. Mechanical valves were implanted in 44 (42 %) patients and bioprostheses in 60 (58 %). The two groups were comparable with regard to preoperative data, age and incidence of additional CABG procedures. We studied in-hospital morbidity and mortality, major postoperative complications and length of ICU and hospital stay. Additionally, parameters predicting a poor outcome were analyzed with multivariate regression analysis. RESULTS: The overall hospital mortality was 12.5 % and did not differ between the two groups (mechanical: 13.6 %, biological: 11.7 %, n. s.). In the postoperative course, duration of ventilation and ICU stay were similar, whereas hospital stay was significantly longer for patients with mechanical prostheses (19.5 +/- 5.4 vs. 15.6 +/- 4.1 days, P < 0.05). Mechanical valve patients had a significantly higher rate of postoperative cerebrovascular incidents (18.2 vs. 8.3 %, P < 0.05) and bleeding complications (15.9 vs. 11.7 %, P < 0.05). Reoperation, obesity, left ventricular ejection fraction < 30 % and previous neurological complications were independent predictors of hospital mortality. CONCLUSIONS: Our results demonstrate that in patients with end-stage RF, the use of mechanical valves is associated with a significant risk of complications. Because of the poor overall survival of patients on dialysis, bioprosthesis degeneration will not be a limiting factor. Therefore, preference should be given to biological valves in these patients.

The impact of pre- and postoperative renal dysfunction on outcome of patients undergoing coronary artery bypass grafting (CABG).

OBJECTIVE: Acute changes in renal function after elective coronary bypass surgery represent a challenging clinical problem. In this study, we evaluated perioperative risk factors for the development of postoperative renal dysfunction (PRD), and the impact of such an event on the perioperative course. Additionally, we investigated the influence of preoperatively mildly increased serum creatinine on perioperative mortality and morbidity. METHODS: We retrospectively analyzed data of 2511 patients undergoing isolated CABG between 2004 and 2007 with a preoperative serum creatinine < or = 2.2 mg/dL. There were 592 patients with a preoperative serum creatinine of between 1.4 and 2.2 mg/dl (mild renal dysfunction group) and 1919 patients with a serum creatinine < 1.4 mg/dl. Perioperative risk factors for PRD were analyzed by multivariate regression analysis. RESULTS: Global in-hospital mortality was 3.1 %.The incidence of PRD was 6.2 %. Mortality for patients who had PRD was 7.8 vs. 2.9 % for patients who did not ( P < 0.05). PRD increased the length of hospital stay by 3.7 days (12.2 vs. 15.9; P < 0.05). Multivariate logistic regression identified the following variables as independent predictors of PRD: age, angina class III/IV, diabetes mellitus, prolonged cardiopulmonary bypass time, and preoperative serum creatinine. With regard to preoperative renal function, we found that operative mortality was higher in the mild renal dysfunction group (5.7 % vs. 2.5 %; P < 0.05). New dialysis/hemofiltration (5.1 % vs. 1.2 %; P < 0.05) and postoperative stroke (5.1 % vs. 1.6 %; P < 0.05) were also more common in these patients. CONCLUSIONS: Mild renal dysfunction preoperatively is an important predictor of outcome after CABG. In these patients, PRD dramatically increases mortality, morbidity and length of hospital stay.

Predictors and outcome of ICU readmission after cardiac surgery.

OBJECTIVE: Readmission to the intensive care unit (ICU) after cardiac surgery is associated with higher costs and may be correlated with an increased mortality. We wanted to evaluate predictors of ICU readmission and to analyze the outcome of those patients. METHODS: 3523 patients who underwent CABG and/or valve surgery between 2004 and 2007 were reviewed retrospectively. The reasons for readmission and the postoperative course were analyzed. Furthermore, perioperative risk factors for readmission were determined by multivariate regression analysis. RESULTS: Of the 3374 patients discharged from the ICU, 5.9 % (198) of patients required a second stay in the intensive care (group r). The readmission rate was 4.8 % following CABG and 8.9 % following valve +/- CABG ( P < 0.05). The mean interval from ICU discharge to readmission was 3.3 +/- 6.2 days. Of the patients who were not readmitted, 1.3 % died in hospital, compared to 14.4 % in group r ( P < 0.05). After readmission, the mean length of stay in the ICU and in hospital was 7.1 +/- 5.9 and 21.3 +/- 11.1 days (3.1 +/- 1.2 and 13.1 +/- 5.1 days for all other patients [ P < 0.05]). Main reasons for readmission were respiratory failure (59 %), cardiovascular instability (25 %), renal failure (6.5 %), cardiac tamponade/bleeding (6 %), gastrointestinal complications (2 %) and sepsis (1.5 %). Multivariate logistic regression analysis revealed that preoperative renal failure, mechanical ventilation > 24 h, reexploration for bleeding and low cardiac output state were independent predictors for readmission. CONCLUSIONS: Patients after valve/combined surgery are more likely to require readmission to the ICU. Respiratory complications were the most common reasons for readmission. To reduce the readmission rate, it is necessary to treat cardio-respiratory problems early, particularly in patients showing predictive risk factors.

Intraaortic balloon pumping in patients with right ventricular insufficiency after cardiac surgery: parameters to predict failure of IABP Support.

BACKGROUND: The indications for intra-aortic balloon pump (IABP) in the case of a failing right ventricle after operations with extracorporeal circulation (ECC) are still discussed controversially. We investigated the benefit of IABP in patients with a predominantly right ventricular dysfunction after ECC. Additionally, we wanted to identify early and easily available prognostic markers for outcome in all patients receiving IABP support. PATIENTS AND METHODS: Between 1/2004 and 1/2008, 4550 patients underwent cardiac surgical procedures with ECC, 223 of whom (4.9 %) had an IABP inserted intra- or postoperatively (group 1). 79 of these patients were treated intraoperatively with IABP for early postoperative low cardiac output syndrome (LCOS) characterized by predominantly right ventricular failure (RV group). Clinical data and hemodynamic variables were recorded perioperatively. Multiple potential markers of mortality and postoperative complications were analyzed statistically, especially with regard to their predictive ability. RESULTS: 68 % of all IABP patients were successfully weaned from IABP support and 63 % survived to hospital discharge. In the RV group, cardiac index (CI) and mean arterial pressure (MAP) increased (CI 1.8 +/- 0.2 to 2.8 +/- 0.2, MAP 53 +/- 10 to 73 +/- 8, P < 0.05) within 1 hour after IABP, whereas central venous pressure (CVP) and pulmonary artery wedge pressure (PAWP) decreased ( P < 0.05). 59 patients in the RV group (75 %) could be weaned from IABP successfully and 69 % survived to hospital discharge. Serum lactate of more than 11 mmol/L in the first 10 hours of IABP support predicted a 100 % mortality. A base deficit of more than 12 mmol/L, mean arterial pressure less than 55 mmHg, urine output of less than 50 ml/h for 2 hours, and dose of epinephrine or norepinephrine of more than 0.4 mg/kg/min were other highly predictive prognostic markers. Furthermore, multivariate analysis showed that patients with a left atrial pressure > 17 mmHg or a mixed venous saturation (SVO (2)) < 65 % had poor outcomes. CONCLUSIONS: In patients with IABP support for postcardiotomy cardiogenic shock, elevated serum lactate, elevated base deficit, hypotension, oliguria and large vasopressor doses are all predictors of mortality. In these patients, the use of another mechanical assist device should be considered in good time. Our study additionally shows that LCOS caused by predominantly right ventricular failure - particularly after CABG - may be an additional indication for IABP.

Intermediate coronary revascularization using the Deltastream blood pump: results from an experimental study.

BACKGROUND: Myocardial revascularization using a complete heart-lung machine may involve many problems, as do complete off-pump attempts. Thus, it was the aim of this study to evaluate the effects of intermediate on-pump/off-pump myocardial revascularization using the miniaturized Deltastream blood pump, on ischemia and hemolysis, in comparison with standard myocardial revascularization. METHODS: In a group of 8 mini-pigs, combined on-pump/off-pump myocardial revascularization was performed using the Deltastream blood pump as beating-heart support for the on-pump part of the operation (group A). Seven other animals served as controls and underwent standard myocardial revascularization with the same device as integrated pump of a complete heart-lung machine (group B). Blood samples for blood gas metabolism, creatine kinase (CK), troponin I, lactate dehydrogenase (LDH), and hydroxybutyrate dehydrogenase (HBDH) were taken before and after the entire operation. RESULTS: Comparing the baseline values, the increase of CK was more pronounced in group B than in group A (176.4-/+41.2 to 279.7-/+29 U/L vs. 274-/+142.7 to 288.1-/+118.6 U/L, respectively; p=0.0006). Increase of troponin I was significantly higher in group B than in group A (1-/+0.3 to 2.9-/+1 ng/mL vs. 1.1-/+0.9 to 3-/+3.8 ng/mL, respectively; p=0.002). LDH increase was also more pronounced in group B (231.7-/+54.3 to 299.9-/+39.8 U/L vs. 274.9-/+59.7 to 263.8-/+57.9 U/L, respectively; p=0.01). HBDH values increased significantly in group B after the operation (group A: 215.9-/+34.7 to 200-/+39.2 U/L vs. group B: 195.4-/+41.7 to 274.9-/+51.6 U/L; p=0.02). Hemodynamic measures and LDH values under luxation (group A: 1.9-/+0.6 U/L; B: 3.5-/+1 U/L,p=0.001) were also superior in the study group. CONCLUSION: The current set-up might be superior to conventional extracorporeal circulation and thus be an alternative for high-risk candidates to avoid the adverse events of a complete heart-lung machine, when they are scheduled for complete myocardial revascularization.

Blood pressure and heart rate immediately after termination of short-term ventricular fibrillation.

BACKGROUND: Implantable cardioverter/defibrillators (ICDs) can detect ventricular fibrillation (VF) and terminate it. For determining the optimal defibrillation threshold, ventricular fibrillation is repetitively induced and terminated with DC shocks. Depending on the protocol, several fibrillation/defibrillation sequences are mandatory before the final implantation of an ICD. This procedure provides an elegant human model of circulatory arrest and resuscitation. PATIENTS AND METHODS: In anesthetized 73 patients (15 females) of on the average 60+/-11 years, the end-expiratory pressure was set to zero. Left ventricular pressure (LVP) was monitored with a microtip-catheter, central venous pressure (CVP) through a cannula which was advanced into the superior V. cava. ECG was recorded. After testing, a monoexponential function was found to best fit the time courses of LVP, CVP and heart rate. Data are mean+/-S.D. RESULTS: After termination of circulatory arrest, peak LVP increased with a time constant tau of 9.2+/-4.2 beats, CVP decreased with tau=2.8+/-1.5 beats, and RR-intervals decreased with tau=4.3+/-3.5 beats. Correlations between prefibrillatory values and steady-state values after termination of fibrillation were high: peak LVP: r=0.78; CVP: r=0.95; RRI: r=0.82. SUMMARY: After DC termination of VF, the heart 'finds' relatively quickly a steady-state rhythm at the prefibrillatory level (22 beats), thereby normalizing CVP almost in parallel (14 beats). Peak LVP plateaus only after about 40 beats, although reasonable arterial pressures are reached within the first beats. Our data are limited to periods of ventricular fibrillation of no longer than 60s, which limits the generalisability to the setting of clinical cardiac arrest.

Inotropic, vasodilating and preconditioning actions of levosimendan in the heart.

BACKGROUND: Levosimendan improves ventricular function, induces vasodilation and induces myocardial preconditioning. We determined the external efficiency and assessed the effects on arrhythmias. METHODS: In isolated, blood-perfused rabbit hearts, levosimendan (0.75 micromol) or placebo was administered, while hemodynamics were recorded. After no-flow ischemia and reperfusion, data were recorded again. RESULTS: Placebo in normoxic hearts did not affect measurements, while levosimendan increased heart rate (+ 18 %) and improved coronary output (+ 52 %), stroke volume (+ 28 %), maximal left ventricular pressure (+ 30 %), maximal rate of pressure increase (+ 36 %), work (+ 68 %), minimal rate of pressure increase (+ 53 %), coronary blood flow (+ 41 %), coronary resistance (- 19 %) and external efficiency (33 %; P < 0.05). During reperfusion, hemodynamics in the levosimendan group were significantly better preserved compared with the placebo group. Early reperfusion arrhythmias were decreased (levosimendan group: 7 +/- 3 % vs. placebo group: 25 +/- 17 %; P < 0.05). CONCLUSIONS: Levosimendan does not impair diastole, dilates coronary vessels, induces pharmacological preconditioning, improves external efficiency and exerts antiarrhythmic properties during reperfusion. As this drug protects the heart from reperfusion injury, it seems well suited for treating dysfunctional hearts after cardiac surgery.

CABG-procedures in patients with pretreatment with the GPIIb/IIIa-receptor antagonist tirofiban (Aggrastat): modification of perioperative management?

In order to investigate the effects of tirofiban administration in cardiac surgery all patients undergoing coronary artery bypass grafting (CABG) which received this drug preoperatively between 1/2002 and 6/2005 (n=232) were studied. Three groups regarding the perioperative administration of antifibrinolytic drugs were compared: group A=controls (n=70), group B=aprotinin (n=110), group C=tranexamic acid (n=52) Furthermore we could differ the patients depending on the time when tirofiban was stopped (<2 h, 2-4 h, >4 h preoperatively). The postoperative blood loss was significantly higher in all tirofiban-patients (A-C) compared to a group of CABG-patients without tirofiban. The best results concerning blood loss, transfusion of red cell concentrates (rcc), fresh frozen plasma (ffp) and incidence of re-sternotomy could be found in patients with aprotinin. A further significant improvement could be seen in patients who received platelets, intraoperative hemofiltration and in which tirofiban was stopped >4 h preoperatively. We conclude that by early presurgical discontinuing of tirofiban-therapy and slight modifications of the perioperative management bleeding complications can significantly be reduced.

Reduction in beta-myosin heavy chains in stunned myocardium as assessed by nondenaturing gel electrophoresis.

Myosin plays a key role in the structure and function of cardiac muscle. Three myosin isoenzymes (V(1), V(2), and V(3)) with different ATPase activities have been identified in mammalian ventricles based on their heavy chain constituents. The relative amount of myosin isoenzymes changes under physiological and pathological conditions. Until now, myosin isoenzymes have frequently been determined using either tube gel (nondenaturing) polyacrylamide gel electrophoresis (PAGE), or gradient or uniform sodium dodecyl sulfate (denaturing) PAGE. Both methods have disadvantages, e.g., a long running time. We developed, therefore, a uniform, nondenaturing PAGE with slab minigel format for analyzing the myosin isoenzymes in normoxic and stunned rabbit hearts. In normoxic hearts of adult rabbits, V(3) predominated over V(1) (46 vs 41%). In turn, in the stunned hearts, V(1) predominated over V(3) (70 vs 30%), and the heterodimeric V(2) was not anymore detectable. This alteration appears to result from a selective loss of myosin heavy chain (MHC)-beta. In parallel, the biochemical markers troponin I and creatine kinase were increased in the stunned hearts. We suggest that alterations of myosin isoenzymes in stunned myocardium can be monitored with native PAGE. The present analysis of myosin isoenzyme appears thus as a new tool for evaluating defects in MHC dimer formation in postischemic hearts.

Intramyocardial implantation of CD133+ stem cells improved cardiac function without bypass surgery.

INTRODUCTION: Cell transplantation for myocardial regeneration has been shown to have beneficial effects on cardiac function after myocardial infarction. Most clinical studies of intramyocardial cell transplantation were performed in combination with coronary artery bypass grafting (CABG). The contribution of implanted stem cells could yet not be clearly distinguished from the effect of the CABG surgery. Our current phase 1 clinical study has focused on the safety and feasibility of CD133+-enriched stem cell transplantation without CABG and its potential beneficial effect on cardiac function. METHOD AND RESULTS: Ten patients with end-stage chronic ischemic cardiomyopathy (ejection fraction <22%) were enrolled in the study. Bone marrow (up to 380 mL) was harvested from the iliac crest. CD133+ cells were purified from bone marrow cells using the CliniMACS device with purities up to 99%. Autologous bone marrow CD133+ cells (1.5-9.7 X 106 cells) were injected into predefined regions. Cardiac functions prior to and 3, 6, and 9 months after cell transplantation were assessed by cardiac magnetic resonance imaging. Stem cell transplantation typically improved the heart function stage from New York Heart Association/Canadian Cardiovascular Society class III-IV to I-II. The mean preoperative and postoperative ventricular ejection fractions were 15.8 +/- 5% and 24.8 +/- 5%, respectively. CONCLUSION: CD133+ injection into ischemic myocardium was feasible and safe. Stem cell transplantation alone improved cardiac function in all patients. This technique might hold promise as an alternative to medical management in patients with severe ischemic heart failure who are ineligible for conventional revascularization.

Clinically applicable 7-Tesla magnetic resonance visualization of transplanted human adult stem cells labeled with CliniMACS nanoparticles.

BACKGROUND: Intra-myocardial transplantation of bone marrow derived cells is currently under clinical evaluation as a therapy for heart failure. A major limitation of all clinical studies for myocardial restoration through cell transfer is the inability to track the fate of the transplanted cells. We present a clinically applicable technique using advanced ultra high-field 7-Tesla (7T) magnetic resonance imaging (MRI) of nanoparticle-labeled transplanted human EPCs in porcine ischemic hearts. METHODS: CD133 positive cells were isolated from bone marrow by magnetic bead selection. Positive cells (5 - 8 x 10 (6) cells) were transplanted into porcine ischemic myocardium (n = 8). Control animals (n = 3) received a medium injection. MRI on a 7T scanner was performed to demonstrate the distribution of the EPCs. RESULTS: CD133+ cells were identified on gradient echo images (T(1)-weighted) within the myocardium 4 weeks after transplantation. CONCLUSIONS: Magnetically labeled EPCs transplanted for therapeutic neovascularization or reduction of infarct size in myocardial ischemia can be visualized by MRI at high-field strengths.

Predictive risk factors in double-valve replacement (AVR and MVR) compared to isolated aortic valve replacement.

BACKGROUND: The operative risk of combined aortic and mitral surgery is still between 5 and 13 %, whereas isolated AVR normally causes complications in less than 4 % of all patients. Thus, it was the aim of the study to compare both procedures and to evaluate risk stratification in our patient cohort. PATIENTS AND METHODS: The inhospital mortality and complication rates were analyzed in both groups over a period of 4 years. There were 396 patients with isolated AVR, and 98 patients with AVR and MVR. For both groups, we investigated 16 possible risk factors for perioperative death or severe complications, such as low cardiac output syndrome (LCOS). The risk factors were analyzed by univariate analysis, and factors with P < 0.01 were entered into a multivariate analysis. RESULTS: There were 11/396 perioperative deaths in patients with AVR (2.8 %) compared to 5/98 (5.1 %) in DVR. The incidence of major complications was 5.3 % in AVR vs. 11.2 % in DVR. As risk factors ( P < 0.05) for death, we found in AVR: former cardiac surgery, aortic stenosis, and pulmonary arterial pressure > 55 mmHg. In patients with DVR, we additionally found: left atrial pressure (LAP) > 20 mmHg and creatinine > 2 mg/dl. Risk factors for severe complications in AVR were: former cardiac surgery and creatinine > 2 mg/dl, in cases of DVR, additionally: tricuspid valve disease (TVD) and LAP > 20 mmHg. CONCLUSIONS: Our analysis of risk factors shows that in patients with DVR preoperative parameters, which sometimes are estimated to be unimportant, may cause an adverse outcome. The operation should be carried out before reaching advanced or even end-stage heart failure, and more attention should be paid to an individual perioperative concept and optimized myocardial protection in such patients.

Comparison of a beta-blocker and an If current inhibitor in rabbits with myocardial infarction.

AIM: We compared protective effects of a ss-adrenoceptor blocker (metoprolol; Met) and a If current (Ivabradine; Iva) in a rabbit model of myocardial infarction. METHODS: Experiments were performed on 44 adult New-Zealand-White (NZW) rabbits. The effects of either metoprolol or ivabradine were assessed 15 min after experimental occlusion of a coronary artery (CAO), 28 days after CAO (drug gavage), and in vitro hearts (Langendorff apparatus). The results were compared with sham and placebo hearts. RESULTS: Metoprolol (0.25 mg/kg) slightly reduced heart rate and left ventricular systolic function. Ivabradine (0.25 mg/kg) reduced heart rate significantly (P<0.05) (18% vs control). Both drugs provided advantages over placebo: mortality was significantly (P<0.01)smaller (6/13 Pla animals died, 2/10 Met animals, and 3/11 Iva animals), left ventricular function was better preserved after 28 days (external power; Pla; Met; Iva=56%; 76%; 74%), and dilatation (BNP) was reduced (P<0.05). In the Pla group, the ST segment was significantly (P<0.05) elevated by 0.35 mV after CAO and exhibited in 50% of the animals Q waves after 28 days, while after ivabradine or metoprolol, ST displacement and Q waves had disappeared. The uneconomic myosin isoenzyme V3 predominated in Met hearts and Iva hearts (V3/V1: 63/37% and 62/38%), while it was further increased in Pla hearts (78/21%). External efficiency was lowest in Pla hearts (1.00+/-0.50 a.u.; P<0.05) and was significantly higher both in Met hearts (4.0+/-1.8 a.u.) and in Iva hearts (3.3+/-1.6 a.u.). CONCLUSIONS: Met and Iva seem suited for the treatment of chronic myocardial infarction.

Decompression sickness following breath-hold diving.

Despite convincing evidence of a relationship between breath-hold diving and decompression sickness (DCS), the causal connection is only slowly being accepted. Only the more recent textbooks have acknowledged the risks of repetitive breath-hold diving. We compare four groups of breath-hold divers: (1) Japanese and Korean amas and other divers from the Pacific area, (2) instructors at naval training facilities, (3) spear fishers, and (4) free-dive athletes. While the number of amas is likely decreasing, and Scandinavian Navy training facilities recorded only a few accidents, the number of spear fishers suffering accidents is on the rise, in particular during championships or using scooters. Finally, national and international associations (e.g., International Association of Free Drives [IAFD] or Association Internationale pour Le Developpment De L'Apnee [AIDA]) promote free-diving championships including deep diving categories such as constant weight, variable weight, and no limit. A number of free-diving athletes, training for or participating in competitions, are increasingly accident prone as the world record is presently set at a depth of 171 m. This review presents data found after searching Medline and ISI Web of Science and using appropriate Internet search engines (e.g., Google). We report some 90 cases in which DCS occurred after repetitive breath-hold dives. Even today, the risk of suffering from DCS after repetitive breath-hold diving is often not acknowledged. We strongly suggest that breath-hold divers and their advisors and physicians be made aware of the possibility of DCS and of the appropriate therapeutic measures to be taken when DCS is suspected. Because the risk of suffering from DCS increases depending on depth, bottom time, rate of ascent, and duration of surface intervals, some approaches to assess the risks are presented. Regrettably, none of these approaches is widely accepted. We propose therefore the development of easily manageable algorithms for the prevention of those avoidable accidents.

Autologous transplantation of CD133+ BM-derived stem cells as a therapeutic option for dilatative cardiomyopathy.

We report the case of a 58-year-old man with end-stage non-ischemic cardiomyopathy. Baseline transthoracic echocardiography (TTE) and cardiac magnetic resonance (cMRI) revealed a markedly depressed left ventricle systolic function. He underwent autologous CD133+ BM-derived cell transplantation through a minimally invasive approach. During surgery 19 x 10(6) BM-derived stem cells were injected by the transepimyocardial route. Six months after the operation TTE and cMRI showed a clear improvement in left ventricular contractility.

Intraaortic balloon pump counterpulsation after implantation of infrarenal and thoracoabdominal aortic protheses.

Highly complex vascular surgery interventions have nowadays become possible due to sophisticated operative techniques and modern intra- and postoperative anesthesiological strategies. Accordingly, the number of high risk vascular surgery interventions rises continuously and thus, the number of secondary complications after high risk interventions increases as well and requires likewise extraordinary treatment concepts. We report of a 68-year old patient who 6 months previously was operated on a ruptured abdominal aneurysm, before he was admitted to our institution for the treatment of a type IIIb (Crawford classification) thoracoabdominal aneurysm. Intraoperatively we implanted a 26 mm Dacron prosthesis which was anastomosed with the previously existing infrarenal graft. Postoperatively the patient suffered from a hemodynamically significant myocardial infarction and acute coronary catheter intervention was necessary. However, circulatory stability could not be reestablished by interventional measures and we therefore decided to implant the intraaortic balloon pump despite the presence of two synthetic aortic grafts. However, the chance of success of such a manoeuver as well as the effectiveness of intraprosthetic counterpulsation was unclear and our literature research undertaken to predict the risk of such a manouver was unsatisfactory. We therefore want to report this case and compile the literature dealing with perceptions and complications of intraaortic counterpulsation after the implantation of synthetic aortic prostheses, since such a treatment option comes to an increased clinical application in comparable constellations.

Ventricular constraint in dilated cardiomyopathy: a new, compliant textile mesh exerts prophylactic and therapeutic properties.

BACKGROUND: Dilated cardiomyopathy is associated with a progressive decrease in cardiac function, leading to end-stage heart failure. We aimed to stop this process by mechanically constraining the heart with a new, compliant textile mesh. METHODS: In 16 male Munich minipigs (50 +/- 7 kg), dilated cardiomyopathy with congestive heart failure was induced through 4 weeks of rapid ventricular pacing (220 beats/min). In the early-mesh group (n = 8), a polyvinylidene fluoride mesh was positioned around both ventricles before pacing was started. In the other group (n = 8), experimental dilated cardiomyopathy through rapid pacing was induced (no mesh). After mesh grafting, rapid pacing was continued (late mesh). RESULTS: Rapid pacing in the no-mesh group (control group) significantly decreased both systolic (cardiac output, peak systolic pressure, and the derivative of pressure increase [dP/dt(max)]) and diastolic (minimum rate of pressure rise [dP/dt(min)] and left ventricular end-diastolic pressure) variables, whereas these variables remained almost unchanged in the early-mesh group. In the late-mesh group the passive-elastic constraint not only prevented further deterioration but even exerted reverse remodeling to some extent (dP/dt(max) and left ventricular end-diastolic pressure, P < .05). CONCLUSIONS: Ventricular constraint with the new mesh seems to be a prophylactic and therapeutic option in cardiac insufficiency caused by ventricular dilation. This passive-elastic cardioplasty induced reverse remodeling of dilated hearts and significantly improved diastolic and systolic ventricular function.

Hemodynamic performance and clinical consequences of aortic valve replacement with 21-mm sized pericardial bioprostheses.

BACKGROUND: Aortic valve replacement (AVR) with a 21-mm sized bioprothesis is still discussed controversially. Since better results have been reported for pericardial valves, the aim of the current study was to analyze the hemodynamic performance as well as clinical parameters in our patients and to compare pericardial and standard porcine valves in particular. METHODS: 342 patients underwent AVR with a bioprosthesis between 1987 and 2000. A 21 mm prosthesis was used in 39 patients (group S), while 303 patients received at least a 23-mm sized valve (group L). Group S was further divided into 19 patients with a pericardial valve (group S1) and 20 patients with a standard porcine valve (group S2). The hemodynamic and clinical parameters were studied in all three groups. RESULTS: The peak and mean transprosthetic gradients were significantly lower in the pericardial group than in the porcine group, particularly between patients with 21 mm valves (peak/mean: S1: 24 +/- 9/20.8 +/- 6.5 mm Hg vs. S2: 38 +/- 15/33 +/- 9 mm Hg, p < 0.05) at discharge. We could also observe that the peak transprosthetic gradient 7 days postoperatively was not significantly higher in patients with a 21 mm pericardial valve compared to group L patients. Comparing clinical parameters, we found significantly more cerebral ischemic events, a prolonged mechanical ventilation, a higher mortality and a longer stay in hospital in the group S2 compared to the group S1. CONCLUSION: The current study shows that pericardial valves perform well, particularly in patients with small aortic roots. Postoperative hemodynamics and clinical results were better than for comparable standard porcine valves. As the outcome of patients with a 21 mm pericardial valve was no worse than that in patients with bigger valves, enlarging procedures for the aortic root are not necessary in the majority of these patients.

Does adenosine pharmacologically precondition human myocardium during coronary bypass surgery?

AIM: Adenosine (Ado) triggers ischemic preconditioning. We investigated whether Ado provides additional myocardial protection in patients during intermittent aortic cross-clamping (IAC) bypass surgery. METHODS: The placebo group was made of 15 male of 66+/-8 years while the Ado group was made of 19 male of 65+/-10 years. The patients of the Ado group had a 3-vessel heart disease and were treated with elective surgery. With the aortic cross-clamping, Ado or vehicle were infused over 10 min at systemic pressure together with sufficient blood via the aortic root. Blood samples before anaesthesia and onset of ECC, 1 hour after end of surgery, and on day 1 and 2 post-surgery to assess CK-MB and troponin I were performed. Hemodynamic measures (heart rate, left ventricular pressure, max/min pressure rise, central venous pressure) before installation and 15 min after completion of the coronary artery bypass. Different ECGs for electrophysiological analyses were performed. RESULTS: Hemodynamic and laboratory measures revealed no significant advantages of either protocol. Mortality rate was zero in both groups. CONCLUSIONS: The comparable outcome is likely due to cardioprotection provided by both IAC bypass surgery and hypothermia, which might obscure beneficial effects of pharmacological preconditioning in patients with good left ventricular function (ejection fraction >50%). As the benefit might have been marginal, it may well become apparent in a larger study on patients with more severe left ventricular dysfunction.