Gender and career in cardiology-a cross-sectional study.

BACKGROUND: The proportion of women as leading physicians in cardiology in university medicine has stagnated and the share of women in senior positions in cardiology is low compared with other medical specialist fields. Here, we analyze the typical barriers for women as doctors in cardiology and point to issues that make the discipline less attractive for both genders. METHODS: In a cross-sectional study, a standardized online questionnaire was sent to 3873 members of the German Cardiac Society (DGK). Answers from 567 (278 women, 289 men) were analyzed, using comparisons between groups, correlation analyses, and tests of normal distribution. RESULTS: For 47.4% of respondents (52.0%, of women; 42.8%, of men; p = 0.049), training had lasted longer than anticipated. Average monthly gross income (full-time work) differed significantly between women and men as specialists (p = 0.004) and assistant doctors (p = 0.030). Of women, 32.1% had experienced sexual harassment in the workplace. The main arguments against a career in university medicine were an extremely competitive working climate (66.7% of women, 63.2% of men), lack of work-life balance (66.7% women, 55.3% men), and excessive workload (57.8% women, 62.5% men). As strategies to increase job attractiveness, both mentioned measures to improve the work-life balance, and the flexibility of working times and improved financial provision. Women asked for gender balance at management level (76.3% vs. 32.9% of men) and opportunities for sharing management tasks (82.4% vs. 57.9%). Flatter hierarchies were requested by more men (67.1 vs. 54.8%). CONCLUSION: Further development of the work culture in cardiology seems necessary. In order to increase the attractiveness of the field overall and to provide equal opportunities in cardiology, more targeted support should be provided to young doctors and more flexibility introduced into work.

Real-world outcomes of endovascular treatment in a non-selected population with peripheral artery disease - prospective study with 2-year follow-up.

Background: The study aimed to evaluate the outcomes of percutaneous transluminal angioplasty (PTA) in lower-extremity peripheral artery disease (PAD) patients. Patients and methods: A multi-centre, observational study was performed with 32 German and Austrian centres contributing data to the PTA registry. Data of 1,781 patients with lower-leg and pelvic PAD who were suitable for endovascular PTA treatment were contributed from participating centres. Data from 1,533 patients are reported here (1,055 male and 478 female). This study did not have exclusion criteria. Quality of life (QOL) questionnaire (EQ-5D) scores, Rutherford classification, mortality, patency rate and details of major adverse cardiovascular events were collected at 6-, 12-, 18-, and 24-month follow ups. Results: PTA with/without stenting achieved 90.3 %, 86.5 %, 82.7 %, and 71.9 % technical success (recanalisation achieving ≥ 70 % patency, no evidence of embolisation, recoiling or dissection) in iliac, femoral, popliteal, and below-the-knee arteries, respectively. Procedural/postprocedural complications occurred in 142 (9.3 %, 1 death) and 74 (4.8 %) patients. QOL, mobility, self-care, activity, and pain/discomfort scores improved (p < 0.01), anxiety/depression was insignificantly improved. During follow-up, 409 (26.7 %) patients were hospitalised for PAD, 281 (18.3 %) required reintervention, and 145 (9.5 %) died or needed amputation (n = 49; 3.2 %). Multivariate analysis demonstrated poorer outcomes in patients with comorbidities. Conclusions: PTA with/without stenting is effective, safe, and widely applicable, with few complications. It improves QOL, but not anxiety/depression.

PEACE I all-comers registry: patency evaluation after implantation of the 4-French Pulsar-18 self-expanding nitinol stent in femoropopliteal lesions.

PURPOSE: To evaluate the 1-year patency of the 4-F Pulsar-18 self-expanding nitinol stent for treatment of femoropopliteal occlusive disease in a national, prospective, multicenter, all-comers registry. METHODS: Between January and June 2012, the German PEACE I all-comers prospective registry enrolled 148 patients with symptomatic femoropopliteal lesions (Rutherford category 2-5) undergoing recanalization and implantation of the Pulsar-18 SE nitinol stent at 6 clinical centers. Thirty patients did not have the 12-month follow-up visit (18 declined reevaluation, 5 withdrew consent, and 7 died), leaving 118 patients (64 men; mean 71.9±9.6 age years) for the 1-year evaluation. The average lesion length was 111.5±71.4 mm, and 38 of the 118 lesions were classified as TASC II D. More than half the lesions (67, 56.7%) were chronic total occlusions (CTO). The popliteal segment was involved in 22 (18.7%) lesions. The mean stented length was 122.7±64.5 mm. Routine follow-up included duplex ultrasound at 6 and 12 months. Outcome measures were primary patency and no clinically driven target lesion revascularization (TLR) within 12 months. RESULTS: The overall primary patency rates after 6 and 12 months were 87.4% and 79.5%, respectively; in the popliteal segments, the rate was 71.4% after 12 months. The overall freedom from TLR was 93.2% after 6 months and 81% after 12 months. Ankle-brachial index, pain-free walking distance, and Rutherford category all improved significantly (p<0.0001) after 6 and 12 months. The primary patency rates in patients with diabetes (p=1.0) and those with renal insufficiency (p=0.8) were not significantly lower compared to the overall rate. There was no significant difference (p=0.67) in restenosis rate for recanalization of CTOs compared to non-CTO lesions. CONCLUSIONS: In this all-comers registry, the use of the Pulsar-18 self-expanding nitinol stent in femoropopliteal lesions averaging 111.5 mm long showed promising primary patency and freedom from TLR after 6 and 12 months. Diabetes had no negative impact on patency. Primary patency in the popliteal segments was acceptable at 12 months.

German multicenter real-world registry of stenting for superficial femoral artery disease: clinical results and predictive factors for revascularization.

PURPOSE: To investigate nitinol stent treatment of superficial femoral artery (SFA) lesions and the impact of different risk factors on the need for clinically driven target lesion revascularization (TLR) in a large, real-world population of claudicants. METHODS: Patients presenting with symptomatic SFA stenosis >70% were consecutively enrolled in the 13-center MARIS prospective registry (ClinicalTrials.gov identifier NCT01067885). There was no restriction on lesion length, thus leading to the inclusion of a real-world as well as high-risk patient cohort. The 998 participating patients (657 men; mean age 67.4±9.2 years) had 1050 lesions treated with the same nitinol stent type. The mean lesion length was 9.5±9.6 cm (range 0.5-44; median 8.0); more than a third of the lesions (450, 42.9%) were total occlusions. The primary endpoint was the need for clinically driven target lesion revascularization (TLR) at 12 months. RESULTS: Acute technical success was achieved in 1042 (99.2%) lesions. Restenosis occurred in 187 (23.7%) and reocclusion in 79 (10.0%) lesions at 12 months. The primary endpoint of TLR at 12 months was reached by 136 (17.2%) patients. The periprocedural complication rate was 5.4%. Independent predictors of TLR were female gender [odds ratio (OR) 0.5, 95% confidence interval (CI) 0.3 to 0.7, p<0.001] and lesion length >20 cm vs. 10 cm (OR 2.7, 95% CI 1.1 to 6.6, p=0.029) and 10-20 cm vs. 10 cm (OR 1.9, 95% CI 1.0 to 4.1, p=0.047). CONCLUSION: Stent implantation in the SFA is safe and associated with favorable acute and midterm results in a real-world setting. Lesion length and female gender were identified as independent risk factors for TLR.

GDF5 and BMP2 inhibit apoptosis via activation of BMPR2 and subsequent stabilization of XIAP.

GDF5 and BMP2, members of the TGF-beta superfamily of growth factors, are known to regulate apoptosis in different cell types either positively or negatively. We wanted to investigate the effects of GDF5 and BMP2 on vascular smooth muscle cells and mouse embryonic fibroblasts and disclose the mechanism by which GDF5 and BMP2 might exert anti-apoptotic effects. The effect of GDF5 and BMP2 on proliferation and/or programmed cells death was assessed in isolated human vascular smooth muscle cells and mouse embryonic fibroblasts. We demonstrate that GDF5 and BMP2 prevent apoptosis induced by serum starvation in mouse embryonic fibroblasts but not in smooth muscle cells via the BMP receptor 2 (BMPR2), which is often mutated in hereditary cases of primary pulmonary hypertension. GDF5 and BMP2 stimulate the interaction of BMPR-2 with XIAP thereby reducing the ubiquitination of XIAP, which results in enhanced protein stability. The increased concentration of XIAP counteracts apoptosis by binding and inactivating activated caspases. We conclude that the inhibition of apoptosis in mouse embryonic fibroblasts by BMP2 and GDF5 does not depend on more complex signal transduction pathways such as smad and MAPK signaling but on direct stabilization of XIAP by BMPR2.

Effect of insulin and glucose infusion on myocardial infarction size in uraemic rats.

The post myocardial infarction (MI) mortality rate is high in renal patients. One possible explanation is the reduced ischemia tolerance caused by uraemia. Previous investigations showed larger MI size in uraemic rats when compared with sham-operated controls. To explore a possible link between uraemic insulin resistance syndrome and MI size in uraemia, we studied an intervention model with administration of insulin and glucose during acute MI in subtotally nephrectomized (SNX) rats and sham-operated controls. In 16 SNX rats and 16 sham-operated controls, the left coronary artery was ligated for 60 min, followed by reperfusion for 90 min. To visualize the perfused myocardium, lissamine-green ink was injected. The nonperfused area (lissamine exclusion) and the area of total infarction (TTC stain) were assessed in sections of the left ventricle (LV) using image analysis. While eight SNX rats and eight sham-operated controls were treated with a placebo during the procedure, the other animals received an insulin bolus of 85 mU/kg and then a continuous insulin infusion of 8 mU/kg per minute. Blood glucose levels were clamped to baseline levels with an infusion of 25% glucose. Insulin receptor substrates (IRS-1 and IRS-2) and glucose transporter (GLUT 4) were studied by western blot in another seven SNX and seven sham-operated controls without further intervention. The infarcted area, given as a proportion of the nonperfused risk area, was not different in sham-operated controls treated with a hyperinsulinaemic clamp versus untreated (0.55 +/- 0.07 vs. 0.51 +/- 0.13, p = 0.477). The eight SNX animals treated with the hyperinsulinaemic clamp utilized significantly less glucose to stabilize baseline glucose levels when compared with the sham-operated controls (5,637 vs. 3,207 microl Glc 25%, p = 0.007). The infarcted area was significantly lower in SNX rats treated with the hyperinsulinaemic clamp compared to non-treated SNX animals (0.56 +/- 0.06 vs. 0.79 +/- 0.09, p < 0.001). SNX rats with the insulin clamp had the same infarcted area size as sham-operated controls (0.56 +/- 0.06 vs. 0.51 +/- 0.13, p = 0.357). Western blotting did not show any change in the expression of GLUT 4 and IRS-1/IRS-2 in SNX animals when compared with sham-operated controls. The size of MI in uraemic rats is significantly reduced by a glucose/insulin infusion. The results suggest an insulin resistance in uraemic rats with similar benefits of glucose/insulin application during acute MI, as found in diabetic individuals. Further analysis did not reveal a down regulation in GLUT 4 and IRS-1/IRS-2.

Transcatheter closure of patent foramen ovale with radiofrequency: acute and intermediate term results in 144 patients.

AIMS: Currently available devices for transcatheter closure of patent foramen ovale (PFO) which rely on a permanent implant have limitations, including late complications. The study objective was to evaluate the safety, feasibility, and effectiveness of the PFx Closure System, the first transcatheter technique for PFO closure without an implantable device. METHODS AND RESULTS: A prospective study of 144 patients was conducted at nine clinical sites from October 2005 through August 2007. All patients had a history of cryptogenic stroke, transient ischemic attack, migraines, or decompression illness. The mean balloon stretched diameter of the PFO was 7.9 +/- 2.5 mm. Technical success (successful application of radiofrequency energy) was achieved in 130 patients. One patient required a transfusion as a result of blood loss during the procedure. There were no other major procedural complications. There were no recurrent strokes, deaths, conduction abnormalities, or perforations following the procedure. At a mean follow-up of 6 months, successful closure was achieved in 79 patients (55%). In PFOs with balloon sized or stretched diameters less than 8 mm, the closure rate was 72% (53/74). CONCLUSION: This study demonstrates that transcatheter closure of a PFO without a permanent implant is technically feasible and safe. Further technique and device modifications are required to achieve higher closure rates.

Treatment of iatrogenic femoral pseudoaneurysm by ultrasound-guided compression therapy and thrombin injection.

Development of an arterial pseudoaneurysm is a common complication following cardiac catheterization. We analyzed data from 6,300 patients who received left heart catheterization at our institution. One day after the procedure, approximately 10% of the patients were examined with duplex sonography. In 204 patients (3.0%), a pseudoaneurysm of the femoral artery was diagnosed. All patients underwent compression therapy. Thereby, 159 of the pseudoaneurysms could be treated successfully. The remaining 45 pseudoaneurysms had a maximal diameter of more than 1.5 cm. Forty-two patients underwent ultrasound and biopsy-line-guided thrombin injection without complications. This strategy resulted in a successful occlusion in 41 cases. Pseudoaneurysms smaller than 2 cm can be treated with compression therapy. Larger pseudoaneurysms can be occluded by thrombin injection using ultrasound guidance. Patients with a pseudoaneurysm with a wide "neck" should be treated surgically, because the risk of an arterial occlusion following thrombin injection cannot be excluded.

Plasma membrane-associated nucleoside diphosphate kinase (nm23) in the heart is regulated by beta-adrenergic signaling.

1. Receptor-independent activation of heterotrimeric G proteins by plasma membrane-associated nucleoside diphosphate kinase (NDPK) has been demonstrated in vivo, and elevated levels of NDPK were found in purified sarcolemmal membranes of patients with end-stage heart failure. 2. Among 22 consecutive patients with chronic heart failure who underwent cardiac transplantation, those treated with a beta-blocker (n=8) had a 65% lower NDPK content and activity in the cardiac sarcolemma, compared to patients with similar base line characteristics who had no beta-blocker therapy (n=14). 3. The lower NDPK was associated with a reduced NDPK-dependent, Gi-mediated inhibition of adenylyl cyclase activity, as assessed by in vitro measurement of adenylyl cyclase activity in the presence of GDP or its kinase-resistant analog guanosine 5'-O-(2-thio)diphosphate (GDPbetaS). 4. We further tested whether treatment with a beta-adrenergic agonist would induce an increase in sarcolemmal NDPK. Rats treated with isoproterenol developed myocardial hypertrophy, and NDPK in the sarcolemma rose by 60% during 14 days of treatment. The beta-blocker propranolol prevented both effects. When hypertrophy was induced with thyroid hormone, NDPK did not increase. 5. In conclusion, chronic activation of beta-adrenergic receptors increases the binding of NDPK to cardiac sarcolemma, where it may activate heterotrimeric G proteins.

Transcatheter implantation of the MONARC coronary sinus device for mitral regurgitation: 1-year results from the EVOLUTION phase I study (Clinical Evaluation of the Edwards Lifesciences Percutaneous Mitral Annuloplasty System for the Treatment of Mitral Regurgitation).

OBJECTIVES: This study sought to assess the safety and efficacy of transcatheter valve annuloplasty in patients with mitral regurgitation (MR). BACKGROUND: Mitral regurgitation is associated with a worsened prognosis in patients with dilated cardiomyopathy. Surgical mitral annuloplasty reduces the septal-lateral dimension of the mitral annulus resulting in improved leaflet coaptation with a reduction in regurgitation. Percutaneous annuloplasty with the MONARC device (Edwards Lifesciences, Irvine, California) implanted within the coronary sinus is designed to reduce mitral regurgitation through a similar mechanism. METHODS: A total of 72 patients with MR grade ≥ 2 were enrolled at 8 participating centers in 4 countries. Clinical evaluation and transthoracic echocardiography were performed at baseline and at 3, 6, and 12 months. Multislice cardiac computed tomography and coronary angiography were performed at baseline and 3 months. RESULTS: The MONARC device was implanted in 59 of 72 patients (82%). The primary safety end point (freedom from death, tamponade, or myocardial infarction at 30 days) was met in 91% of patients at 30 days and in 82% at 1 year. Computed tomography imaging documented passage of the great cardiac vein over an obtuse marginal artery in 55% of patients and was associated with angiographic coronary artery compression in 15 patients and myocardial infarction in 2 patients (3.4%). At 12 months, a reduction in MR by ≥ 1 grade was observed in 50.0% of 22 implanted patients with matched echocardiograms and in 85.7% of 7 patients with baseline MR grade ≥ 3. CONCLUSIONS: Implantation of the MONARC device in the coronary sinus is feasible and may reduce MR. However, coronary artery compression may occur in patients in whom the great cardiac vein passes over a coronary artery, necessitating strategies in future studies to avoid this occurrence.

Significance of close surveillance of patients with peripheral arterial disease.

BACKGROUND: Peripheral arterial disease (PAD) indicates generalized atherosclerosis but is still underdiagnosed and undertreated. METHODS: Data were collected from patients with PAD from the Department of Cardiology and Angiology, University of Heidelberg, Germany. The prevalence of cardiovascular risk factors and medication were documented. RESULTS: Atherogenic risk factors, cardiovascular disease, and cerebrovascular disease were highly prevalent. By continuous care at the university clinic, in addition to family medicine treatment, the use of platelet inhibitors, antihypertensives, and lipid-lowering therapy was increased. Ankle-brachial index and walking distance improved. CONCLUSION: Long-term treatment at the university clinic had positive effects on atherogenic risk factors. The regular use of secondary preventive medication was improved. Still, this patient population remained undertreated and showed a high incidence of vascular event rates and a need for vascular interventions. This study implies the importance of both specialists and general practitioners in the care of these individuals.

Abdominal aortic aneurysm repair in cardiac high risk patients--medication, surgery or stent?

With increasing age of the general population, a higher awareness of the disease, better screening methods and the option of less invasive therapeutical strategies, the incidence of abdominal aortic aneurysms (AAA) is rising steadily. Since AAA is a disease of the elderly patient with generalized atherosclerosis, there is a high coincidence with other vascular morbidities. Especially the presence of coronary artery disease and concomitant left ventricular dysfunction proves many of those patients to be cardiac high risk patients with respect to an operative approach. On the other hand, a high coincidence of severe peripheral arterial occlusive disease might hamper the endovascular approach and endovascular therapy might carry a high risk for these patients as well. Therefore, it is of utmost importance to consider how and when cardiac high risk patients with AAA should be treated. In this review therefore special aspects such as the choice of medical treatment, the need of preoperative coronary revascularization and the situation in old patients are discussed in detail.

Nitinol stent implantation in TASC A and B superficial femoral artery lesions: the Femoral Artery Conformexx Trial (FACT).

PURPOSE: To investigate the impact of nitinol stenting of superficial femoral artery (SFA) lesions with a maximum length of 10 cm (TASC-II A or B) on 1-year outcomes compared to a historical study cohort from the Femoral Artery Stent Trial (FAST). METHODS: Between January 2004 and August 2005, 6 study sites enrolled 110 symptomatic patients (75 men; mean age 68+/-9 years) with a single de novo >70% SFA lesion <10 cm long treated with the self-expanding nitinol Conformexx stent. The primary study endpoint was binary restenosis determined by duplex ultrasound at 12 months. Secondary 12-month endpoints were target lesion revascularization (TLR), ankle-brachial index (ABI), mean Rutherford category, >1-class change in Rutherford category, and major adverse events. Data were analyzed according to the intention-to-treat principle and according to the actual treatment received ("on treatment" analysis). Outcomes were compared to the historical balloon angioplasty (BA) arm and the Luminexx 3 stent arm of the randomized FAST study. RESULTS: Technical success was achieved in 106 (96%) patients; at 1 year, the primary endpoint of ultrasound-assessed binary restenosis was reached in 14 (23.3%) of 60 patients (95% CI 13.4% to 36%). This restenosis rate was lower versus the historical BA (38.6%, p=0.057) or Luminexx 3 stent controls (31.7%, p=0.284) from FAST. The clinically driven TLR was 7.4% (7 of 94 clinically controlled patients), which was also lower compared to 18.3% (p=0.098) and 14.9% (p=0.267) for the historical BA and Luminexx 3 stent groups, respectively. The mean Rutherford category was reduced from 2.75+/-0.79 to 0.94+/-1.38 (p<0.0001); 85.1% were improved by at least 1 Rutherford category. The ABI increased from 0.62+/-0.15 to 0.85+/-0.20 (p<0.0001). CONCLUSION: This study of patients with SFA lesions documented favorable outcomes using nitinol stents in TASC-II A or B lesions after 1 year. The study was underpowered to prove superiority of the Conformexx nitinol stent design compared to historical balloon only or Luminexx 3 stent groups.

Myocardial preconditioning and remote renal preconditioning--identifying a protective factor using proteomic methods?

It is still unknown whether remote ischemic preconditioning is mediated by a humoral or a neurogenic mechanism from the preconditioning to the preconditioned tissue. The purpose of the following study was to identify a possible humoral trigger of ischemic myocardial preconditioning and remote renal preconditioning. Open chest rats were subjected to a coronary artery occlusion period of 45 min followed by 2 h of reperfusion (Control animals; n = 6). The coronary preconditioned group (IPC, n = 6) was subjected to a preceding preconditioning period of 5 min coronary artery occlusion followed by 5 min of reperfusion, repeated three times. The renal preconditioned group (IPR, n = 6) was subjected to a preceding renal artery occlusion period of 10 min followed by 20 min of reperfusion. Area at risk (AAR) and infarcted area (IA) were determined at the end of each protocol. Blood samples were taken at the end of the preconditioning protocols from parallel experiments for proteomic analysis using two-dimensional gel electrophoresis (2-DE), matrix assisted laser desorption and ionization-time of flight-mass spectrometry (MALDI-TOF-MS), and liquid chromatography-electrospray ionization-tandem mass spectrometry (nanoLC-ESI-MS/MS). IA/AAR was 87.8 +/- 10.7% in the control group. IPC and IPR significantly reduced IA/AAR (58.2 +/- 9.3% and 56.9 +/- 9.0%, p < 0.001). Proteomic analyses detected four protein spots which were either up- (n = 3) or down-regulated in the preconditioned groups vs. the control group. The three up-regulated protein spots were identified as albumin fragments, whereas the down-regulated spot was identified as liver regeneration-related protein (LRRG03). Interestingly, albumin modification by brief ischemia has been recently shown and evaluated for the clinical diagnosis of sublethal myocardial ischemia. However, no differentially abundant proteins which possess a known signaling function could be found. Hence, though there is a differential protein expression in blood following IPC and IPR, our data are not in favor of a humoral mediator of remote preconditioning with a molecular weight of more than 8 kDa. Our results rather suggest either a neurogenic pathway or a mediator smaller than 8 kDa.

Patent foramen ovale using the Premere device: the results of the CLOSEUP trial.

OBJECTIVES: The CLOSEUP trial was conducted to determine the safety and effectiveness of the Premere closure device in closure of patent foramen ovale (PFO). BACKGROUND: PFO is a relatively common congenital condition, associated with cryptogenic stroke and migraine with aura. The Premere device is specifically designed to close PFO of variable size and length, with right and left anchor arms connected by a flexible tether. The device has an open architecture, a low profile, and a small surface area on the left atrial side which may discourage thrombus formation. METHODS: Patients between 18 and 65 years of age who had a cryptogenic ischemic stroke or a transient ischemic attack and a PFO underwent percutaneous PFO closure using the Premere device. RESULTS: Of the 73 enrolled patients, six patients had atrial anatomy not appropriate for the Premere; 27 patients received the 15 mm and 40 patients received the 20 mm device. Implantation was successful in all patients. At 6 months of follow-up, 86% of patients had no shunt that could be provoked with Valsalva as assessed during contrast echocardiography. Closure rates were better with the 20 mm versus the 15 mm device, and three patients with residual shunt had atrial septal aneurysms at baseline. One patient had transient atrial fibrillation which resolved by 3 months. There were no instances of thrombus, death, or stroke. CONCLUSIONS: These data demonstrate that the Premere device can safely and effectively close PFO. Additional studies should be undertaken to demonstrate the effectiveness of PFO closure in reducing thrombo-embolic events such as stroke.

Sepiapterin reduces postischemic injury in the rat heart.

A reduced availability of tetrahydrobiopterin (BH4), an essential cofactor for NO-synthesis, is causally involved in the development of endothelial dysfunction associated with ischemia/reperfusion. We, therefore, investigated the effect of sepiapterin, a substrate for BH4 synthesis, on postischemic injury in myocardial infarction and myocardial stunning. In rats, myocardial stunning was induced by repetitive ischemia (5 x 10-min ligature of the left coronary artery, 5 x 20-min reperfusion) and myocardial infarction by 50-min ligature and 60-min reperfusion. Myocardial blood flow was determined by H2-clearance, regional myocardial function by pulsed Doppler and infarct size by tetrazolium staining. Myeloperoxidase (MPO) activity was measured as a marker of neutrophil extravasation. cGMP was determined in rat serum as an indicator of increased NO synthesis. In animals treated with sepiapterin, regional myocardial function was significantly improved in both myocardial stunning and infarction and infarct size was significantly reduced. MPO activity decreased with sepiapterin treatment in both models. The systemic level of cGMP was reduced both following myocardial stunning and myocardial infarction in the control group. Pretreatment with sepiapterin induced a significant increase of cGMP level at the end of the protocol in both models. Substitution of sepiapterin reduces postischemic injury both in myocardial stunning and infarction apparently by ameliorating the availability of NO, thereby attenuating the activation of neutrophils in ischemia/reperfusion.

ACE inhibitors and statins acutely improve endothelial dysfunction of human coronary arterioles.

Long-term treatment with angiotensin-converting enzyme (ACE) inhibitors as well as angiotensin II type 1 (AT(1)) receptor antagonists and statins reduces cardiovascular mortality in patients with coronary artery disease as well as chronic heart failure. Little is known about the acute effects of these compounds on vascular reactivity of coronary resistance vessels. Coronary arterioles were obtained from patients undergoing coronary bypass operation (atherosclerosis group) or valve replacement (control group). Responses to endothelium-dependent agonists (histamine, serotonin, and acetylcholine) as well as to the endothelium-independent agonist sodium nitroprusside (SNP) were investigated under baseline conditions and after incubation (15 min) with lisinopril (ACE inhibitor), candesartan (AT(1) receptor antagonist), or fluvastatin. In atherosclerotic vessels, vasorelaxation was significantly reduced to all endothelium-dependent agonists but not, however, to SNP (77 +/- 8, -24 +/- 16, -46 +/- 24, and 98 +/- 8% relaxation for histamine, serotonin, acetylcholine, and SNP, respectively). Lisinopril and fluvastatin but not candesartan significantly improved the responses to the endothelium-dependent agonists (lisinopril: 94 +/- 4, 17 +/- 22, and -20 +/- 13%; fluvastatin: 96 +/- 8, 23 +/- 21, and -25 +/- 18% relaxation for histamine, serotonin, and acetylcholine, respectively). The effect of lisinopril was prevented by pretreatment with a bradykinin antagonist (HOE-130) and dichloroisocoumarine, an inhibitor of kinine-forming enzymes. Pretreatment with a nitric oxide (NO) synthase inhibitor abolished the improvement of endothelial function by lisinopril and fluvastatin. Vascular reactivity in the control group was not influenced by any of the pharmacological interventions. The data demonstrate that in atherosclerosis, endothelium-dependent relaxation of coronary resistance arteries is severely compromised. The impairment can acutely be reversed by ACE inhibitors and statins via increasing the availability of NO.

Increased infarct size in uremic rats: reduced ischemia tolerance?

In patients with renal failure, myocardial infarction (MI) is more frequent and the rate of death from acute MI is very high. It has been argued that ischemia tolerance of the heart is reduced in uremia, but direct evidence for this hypothesis has not been provided. It was the purpose of this study (1) to ligate the left coronary artery and to measure the nonperfused area (risk area: total infarction plus penumbra) as well as the area of total infarction in subtotally nephrectomized (SNX) rats compared with sham-operated pair-fed control rats and (2) to examine the effects of potential confounders such as BP, sympathetic overactivity, and salt retention. The left coronary artery was ligated for 60 min, followed by reperfusion for 90 min. For visualizing perfused myocardium, lissamine green ink was injected. The nonperfused area (lissamine exclusion) and the area of total infarction (triphenyltetrazolium chloride stain) were assessed in sections of the left ventricle using image analysis. Groups of SNX rats also received: antihypertensive treatment (nadolol plus hydralazine); moxonidine; high salt diet or low salt diet (1.58% versus 0.015%). In surviving animals, the nonperfused area at risk (as the proportion of total left ventricular area), presumably determined by the geometry of vascular supply, was similar in sham-operated and SNX animals (0.38 +/- 0.13 versus 0.45 +/- 0.09; NS). In contrast, the infarcted area, given as a proportion of the nonperfused risk area, was significantly (P < 0.003) higher in SNX (0.68 +/- 0.09) compared with sham-operated (0.51 +/- 0.11) rats and was not altered by any of the above interventions. The finding that a greater proportion of nonperfused myocardium undergoes total necrosis is consistent with the hypothesis of reduced ischemia tolerance of the heart in renal failure. The findings could explain the high rate of death from MI in patients with impaired renal function.