Diffusion-weighted magnetic resonance imaging for the detection of ischemic brain lesions in coronary artery bypass graft surgery: relation to extracorporeal circulation and heparinization.

AIM: Cognitive decline is a well recognized complication after on-pump coronary artery bypass graft (CABG) surgery. We investigated whether the design of extracorporeal circulation (ECC) and the extent of perioperative heparinization have an impact on neurological dysfunction. METHODS: Sixty-three CABG surgery patients were randomly perfused with an uncoated ECC-set (group A) or with two different heparin-coated ECC-sets (groups B and C). In groups A and B, systemic heparin was given in doses of 400 IU/kg body weight, whereas group C received 150 IU/kg body weight. ECC sets in group C included a diagonal pump and low priming as opposed to roller pumps in groups A and B. Furthermore, in group C blood contact to surfaces other than endothelium and heparin coated material was eliminated. Brain lesions were detected by diffusion-weighted magnetic resonance imaging (DWI). Neurological complications were assessed clinically until discharge (manifest motoric, sensitive or cognitive disturbance). Biochemical coagulation and inflammation parameters were measured pre-, peri-, and postoperatively. RESULTS: No major neurological events were observed in either group until discharge. DWIs showed 61 new lesions in 19 of 45 patients who terminated all MRI study procedures. Number and volume of the lesions did not differ between groups (P>0.05). Biochemical and inflammatory parameters showed the expected time courses and variations between groups. CONCLUSION: Ischemic brain lesions are frequently observed in CABG surgery patients but are neither associated with clinically relevant neurological complications nor with ECC set-up and intraoperative heparin dosage. DWI may help in the development of new surgical strategies to reduce postoperative brain damage.

Effect of vitamin D supplementation on testosterone levels in men.

The male reproductive tract has been identified as a target tissue for vitamin D, and previous data suggest an association of 25-hydroxyvitamin D [25(OH)D] with testosterone levels in men. We therefore aimed to evaluate whether vitamin D supplementation influences testosterone levels in men. Healthy overweight men undergoing a weight reduction program who participated in a randomized controlled trial were analyzed for testosterone levels. The entire study included 200 nondiabetic subjects, of whom 165 participants (54 men) completed the trial. Participants received either 83 µg (3,332 IU) vitamin D daily for 1 year (n = 31) or placebo (n =2 3). Initial 25(OH)D concentrations were in the deficiency range (< 50 nmol/l) and testosterone values were at the lower end of the reference range (9.09-55.28 nmol/l for males aged 20-49 years) in both groups. Mean circulating 25(OH)D concentrations increased significantly by 53.5 nmol/l in the vitamin D group, but remained almost constant in the placebo group. Compared to baseline values, a significant increase in total testosterone levels (from 10.7 ± 3.9 nmol/l to 13.4 ± 4.7 nmol/l; p < 0.001), bioactive testosterone (from 5.21 ± 1.87 nmol/l to 6.25 ± 2.01 nmol/l; p = 0.001), and free testosterone levels (from 0.222 ± 0.080 nmol/l to 0.267 ± 0.087 nmol/l; p = 0.001) were observed in the vitamin D supplemented group. By contrast, there was no significant change in any testosterone measure in the placebo group. Our results suggest that vitamin D supplementation might increase testosterone levels. Further randomized controlled trials are warranted to confirm this hypothesis.

Heparin-coated extracorporeal circulation in combination with low dose systemic heparinization reduces early postoperative blood loss in cardiac surgery.

AIM: According to a recently performed meta-analysis, heparin-bonded circuits do not reduce blood loss in cardiac surgery patients compared to nonheparin-bonded circuits within the first 24 h postoperatively. We investigated the effects of heparin-coated circuits in combination with a reduced systemic heparin dose on early postoperative blood loss (first 12 h), platelet function, and postoperative complications. METHODS: Patients who underwent their first coronary artery bypass graft surgery were included in a randomized prospective study. Group A (n=149) was perfused with an uncoated extracorporeal circulation (ECC)-set and groups B (n=152) and C (n=149) with heparin-coated ECC-sets. In groups A and B, conventional dose systemic heparin was given, whereas group C received low dose systemic heparin. Blood loss was assessed within the first 12 h postoperatively. Moreover, biochemical parameters of pro-coagulant activity and immunological function were measured. RESULTS: None of the pro-coagulant activity markers and immunological parameters measured differed preoperatively or postoperatively between study groups. However, intraoperative platelet counts and maximal intraoperative concentrations of platelet factor 4, ss-thromboglobulin, and poly-morpho-nuclear (PMN)-elastase were lowest in group C, whereas group C also had the highest concentrations of thrombin-antithrombin complex (P<0.018-0.001). Blood loss within the first 12 h postoperatively was 457 +/- 204 mL in group A, 431 +/- 178 mL in group B, and 382 +/- 188 mL in group C (P<0.01). Complication rates and 30-day mortality did not differ between study groups. CONCLUSION: The combined use of heparin-coated circuits and low dose systemic heparinization is able to reduce early postoperative blood loss without enhancing the risk of complications.

Initial experience with the medtronic ADVANTAGE valve prosthesis in the mitral position--clinical outcome and analysis of complications.

OBJECTIVE: The Medtronic ADVANTAGE prosthetic heart valve is a bileaflet mechanical heart valve which has two main design modifications. The prosthesis has an enlarged central orifice to improve blood flow characteristics and an asymmetric butterfly pivot recess with expanded outflow component designed to enhance the blood flow washing through the pivot region. This report summarizes the initial experience with 55 patients who underwent isolated mitral valve replacement. METHODS: We prospectively followed 55 patients undergoing mitral valve replacement with the Medtronic ADVANTAGE prosthesis in a single center study. All patients were operated on via a median sternotomy and a left atrial approach. RESULTS: The age of the patients at implant ranged from 42 years to 77 years with a mean of 61.8 years. Forty-five percent of the patients were male. Seventy-five percent of the patients were in NYHA functional class III or IV prior to valve replacement. The diameters of the implanted prostheses were as follows: 25 mm in 2 patients, 27 mm in 12 patients, 29 mm in 20 patients, and 31 mm in 21 patients. Coronary artery bypass grafting was performed with valve replacement in 16.4 % of patients and additional tricuspid repair in 10.9 %. After one year, 97.6 % and after two years 100 % of the included patients were in NYHA functional class I or II. All patients had Coumadin (warfarin) therapy postoperatively with a target INR range of 2.5 to 3.5, or 3.0 to 4.0. There were 4 thromboembolic events (7.3 %) in the early period and 2 late events (2.6 %). Episodes of valve thrombosis were not seen during the follow-up, which consisted of 76.5 patient years. The hemodynamic performance was favorable and within clinically acceptable ranges. The incidence of valve-related mortality and morbidity in this preliminary study was extremely low, indicating good clinical results comparable to those reported for other bileaflet valves. CONCLUSION: The ADVANTAGE valve is a safe and effective option for mitral valve replacement with a very low incidence of valve-related complications.

Aortico-left ventricular tunnel, an unusual congenital cardiac anomaly in adult: application of a new operative technique.

Aortico-left ventricular tunnel is a rare congenital cardiac anomaly. A 45-year-old man was referred to our clinic with unstable angina pectoris. The patient had an aortico-left ventricular tunnel that had been operated on 15 years before and that now showed a recurrence. We performed a new surgical technique, including closure of orifices of the tunnel by resection of the aorta at the left coronary ostium, reconstruction of the aorta with patch plasty, and formation of a neo-left main branch by applying a saphenous magna vein patch at the noncoronary cusp. In this technique, the possibility of aortic regurgitation caused by stretching and distortion of the aortic ring and leaflets by primary suture closure of tunnel is eliminated. The postoperative 2-D colored Doppler echocardiography and cardiac MRI showed an excellent result of the procedure. Coronary flow could be restored, and thus anginal symptoms disappeared.

INR self-management permits lower anticoagulation levels after mechanical heart valve replacement.

BACKGROUND: The Early Self Controlled Anticoagulation Trial (ESCAT I) showed that anticoagulation self-management after mechanical heart valve replacement decreased complication rates by maintaining INR levels closer to the target range than International Normalized Ratio (INR) home doctor management. The therapeutic range for the INR in that study was between 2.5 and 4.5 for all positions of prosthetic valves. ESCAT II should find out whether lowering the target range for INR self-management would further reduce complication rates. METHODS: ESCAT II is a prospective controlled randomized (valves: St. Jude Medical Standard or Medtronic Hall, treatment: conventional/low-dose) multicenter study with 3,300 patients. We present interim results of 1,818 patients. 908 were categorized as having a low-dose target range, which was INR 1.8 to 2.8 for prostheses in aortic position and 2.5 to 3.5 for prostheses in mitral position or in combined valve replacement. The control group (conventional group) with 910 patients aimed at an INR of 2.5 to 4.5 for all valve positions. RESULTS: In the conventional group, 74% of INR values measured were within the therapeutic range. In the low-dose group, 72% of the values were within that range. The linearized thromboembolism rate (% per patient year) was 0.21% for both groups. The bleeding complication rate was 0.56% in the low-dose regimen group versus 0.91% in the conventional group. CONCLUSIONS: Early onset INR self-management under oral anticoagulation after mechanical heart valve replacement enables patients to keep within a lower and smaller INR target range. The reduced anticoagulation level resulted in fewer grade III bleeding complications without increasing thromboembolic event rates.

INR self-management following mechanical heart valve replacement.

INR self-management can reduce severe thromboembolic and hemorrhagic complications following mechanical heart valve replacement. Beginning anticoagulation therapy immediately in the postoperative period further reduces anticoagulant-induced complications. Data were collected from the first 600 surviving patients (from a total study sample of 1200 patients) who completed follow-up of at least 2 years. Patients were randomly divided into a self-management group and a control group. INR self-management reduced severe hemorrhagic and thromboembolic complications (P=0.018). Nearly 80% of INR values recorded by patients themselves, regardless of educational level, were within the target therapeutic range of INR 2.5-4.5, compared with 62% of INR values monitored by family practitioners. Only 8.3% of patients trained in self-management immediately after surgery were unable to continue with INR self-management. The results differed slightly between patient groups with different levels of education. We conclude that all patients for whom anticoagulation is indicated are candidates for INR self-management regardless of education level.

Mitroflow pericardial valve prosthesis in the aortic position: an analysis of long-term outcome and prognostic factors.

BACKGROUND AND AIM OF THE STUDY: Pericardial valves combine optimal hemodynamic properties with limited durability. To describe the long-term performance of Mitroflow pericardial valves in the aortic position, outcome and risk factors up to 12 years after implantation were analyzed. METHODS: A retrospective study, based on follow up of 1,029 patients who received 1,044 Mitroflow pericardial valves in the aortic position between February 1985 and December 1996, was performed. Follow up was 98.2% complete. Average follow up was 3.79 years. Mean patient age was 75.2+/-6.5 years (range: 27.9-90.9 years). At surgery, 86.3% of patients were aged over 70 years. Among patients, 482 (46.8%) had concomitant operations. RESULTS: Results (+/- SE) are given for evident and possible (in parentheses) valve-related events; the latter included all reported postoperative strokes and sudden deaths. Actuarial event-free rates after 5 and 10 years respectively were: structural valve deterioration: 99.2+/-0.5% and 77.6+/-4.4%; non-structural valve deterioration: 99.7+/-0.2% and 99.7+/-1.2%; valve-related complications: 95.7+/-0.9% and 73.5+/-4.0% (5 years 90.1+/-1.2%, 10 years 57.0+/-4.3%); endocarditis: 96.6+/-0.8% and 92.6+/-1.6%; explantation: 98.6+/-0.5% and 80.1+/-3.9%; cerebrovascular accident 95.2+/-0.9% and 82.5+/-3.5%; embolism 99.9+/-0.1% and 99.9+/-0.5%; bleeding 99.8+/-0.2% and 99.8+/-1.3%; overall mortality 69.9+/-1.8% and 35.3+/-3.0%; valve-related death 97.5 +/-1.1% and 95.1+/-4.2% (5 years 91.9+/-1.4%, 10 years 76.1+/-3.2%). The 30-day mortality rate was 4.1%. Patients aged 70 years or more with valve diameters of < or =23 mm showed 10-year freedom rates of 85.8+/-4.6% for structural valve degeneration and 95.1+/-1.2% for evident valve-related death. The detailed risk factor analysis showed results that were in accordance with clinical experience. CONCLUSION: Long-term results with Mitroflow pericardial valves in the aortic position compare well with those for other widely used bioprostheses, especially in patients aged > or =70 years and with small aortic root diameters (< or =23 mm).

Long-term results after myectomy in 64 patients with hypertrophic obstructive cardiomyopathy (HOCM). Morphological and hemodynamic aspects.

BACKGROUND: The aim of this study was to observe the changes in left-ventricular morphology, the improvement in hemodynamics and the survival curves (according to Kaplan-Meier) of patients following transaortic myectomy. METHODS: From November 1985 to August 1997, transaortic myectomy according to Morrow's proposal was carried out at the Heart Center NRW in Bad Oeynhausen in 64 patients with isolated HOCM. At the time of operation, the patient group included 33 women and 31 men aged between 14 and 76 years (mean 52.56 years). A hemodynamically relevant aortic stenosis was excluded in all patients. Sixty-three patients (98.4%) were evaluated in total over a mean observation period of 4.6 years (4 months to 12 years). One patient lost touch with our hospital RESULTS: The clinical symptoms according to NYHA grade could be improved postoperatively from 3.4 +/- 0.33 to 1.36 +/- 0.6 (p < 0.001). The echocardiographic preoperative pressure gradient between the left ventricle and the aorta was 73.2 +/- 14.8 mmHg at rest and 139.6 +/- 21.2 mmHg after provocation by ventricular premature beats (VPBs). Postoperatively, the gradient was reduced significantly: 13.56 +/- 2.7 mmHg at rest and 23.3 +/- 10.7 mmHg after VPBs, respectively (p < 0.001). Perioperative complications occurred in 12 patients including 1 early death due to low-output syndrome, corresponding to an early mortality rate of 1.6%. Four patients died within a postoperative period of 1 year to 9.5 years, none of them due to cardiac causes, 2 due to non-cardiac causes and 1 of unknown causes. In 2 patients a recurrent HOCM occurred at 7 and 10 years after the myectomy and they were treated by catheter intervention with the alcohol induced septal infarction. CONCLUSIONS: Based on the 12-year survival rate of 76.640% in our study, transaortal myectomy according to Morrow represents a safe and reliable form of therapy, with relatively low perioperative mortality and complication rates, also in the long-term

Results of heart transplantation in patients with preexisting malignancies.

Twenty patients with end-stage heart failure and preexisting malignancies underwent heart transplantation at a single center, with a neoplasm-free interval before the procedure of 0 to 240 months. Twelve patients were long-term survivors (2 to 72 months); there were 2 early and 6 late deaths, thus justifying heart transplantation in patients with preexisting malignancies in individual cases.

Heart transplantation at the Heart Center North Rhine-Westphalia in Bad Oeynhausen -- 1995 report.

Since March 1989, 713 heart transplants were performed at our center, limited only by donor availability. The induction of immunosuppression was based on double-drug therapy (CsA + Aza) without the use of mono- or polyclonal antibodies. Whenever possible, maintenance immunosuppression was based on CsA and Aza without steroids. Monitoring in adult patients was based on endomyocardial biopsies only during the first 12 months. In the pediatric patient group, only noninvasive diagnostic procedures were performed. The current 1- and 5-year survival rates for heart transplant patients are 80% and 75%, respectively.

Heart transplantation at the Heart Center North Rhine-Westphalia.

Since 1989, 427 heart transplants were performed at our center, limited only by donor availability, not by moderating donor criteria. Therefore, an increasing number of possible recipients was bridged with mechanical circulatory support systems. Immunosuppression was based on double-drug therapy (CsA, Aza) without steroid maintenance if possible and without mono- or polyclonal antibody prophylaxis. Monitoring adult transplant patients was based on endomyocardial biopsies only during the first 12 months posttransplant. In the pediatric group, only noninvasive diagnostic procedures were performed. Our present 1- and 3-year survival rates for heart transplant patients are 85% and 78%, respectively. We believe that only centers performing approximately 1,000 routine open-heart surgery procedures per year should be allowed to perform heart transplantation, with a minimum of 25 procedures per year (5). Our goal is to start our heart-lung and lung transplant programs in the near future. Our research interests are mainly in the field of postoperative monitoring, induction of immune tolerance, and in establishing a method to determine an individual immunosuppression protocol for each patient (6).