The effects of angiotensin receptor neprilysin inhibition by sacubitril/valsartan on adipose tissue transcriptome and protein expression in obese hypertensive patients.

Increased activation of the renin-angiotensin system is involved in the onset and progression of cardiometabolic diseases, while natriuretic peptides (NP) may exert protective effects. We have recently demonstrated that sacubitril/valsartan (LCZ696), a first-in-class angiotensin receptor neprilysin inhibitor, which blocks the angiotensin II type-1 receptor and augments natriuretic peptide levels, improved peripheral insulin sensitivity in obese hypertensive patients. Here, we investigated the effects of sacubitril/valsartan (400 mg QD) treatment for 8 weeks on the abdominal subcutaneous adipose tissue (AT) phenotype compared to the metabolically neutral comparator amlodipine (10 mg QD) in 70 obese hypertensive patients. Abdominal subcutaneous AT biopsies were collected before and after intervention to determine the AT transcriptome and expression of proteins involved in lipolysis, NP signaling and mitochondrial oxidative metabolism. Both sacubitril/valsartan and amlodipine treatment did not significantly induce AT transcriptional changes in pathways related to lipolysis, NP signaling and oxidative metabolism. Furthermore, protein expression of adipose triglyceride lipase (ATGL) (Ptime*group = 0.195), hormone-sensitive lipase (HSL) (Ptime*group = 0.458), HSL-ser660 phosphorylation (Ptime*group = 0.340), NP receptor-A (NPRA) (Ptime*group = 0.829) and OXPHOS complexes (Ptime*group = 0.964) remained unchanged. In conclusion, sacubitril/valsartan treatment for 8 weeks did not alter the abdominal subcutaneous AT transcriptome and expression of proteins involved in lipolysis, NP signaling and oxidative metabolism in obese hypertensive patients.

Improved Insulin Sensitivity With Angiotensin Receptor Neprilysin Inhibition in Individuals With Obesity and Hypertension.

Natriuretic peptide (NP) deficiency and sustained renin-angiotensin system activation are associated with impaired oxidative metabolism and predispose to type-2 diabetes. We hypothesized that sacubitril/valsartan (LCZ696), which augments NP through neprilysin inhibition while blocking angiotensin II type-1 (AT1 )-receptors, improves insulin sensitivity, lipid mobilization, and oxidation. After 8 weeks of treatment of obese patients with hypertension, sacubitril/valsartan 400 mg q.d., but not amlodipine 10 mg q.d., was associated with a significant increase from baseline in the insulin sensitivity index (hyperinsulinemic-euglycemic clamp), and tended to be higher in patients treated with sacubitril/valsartan compared to amlodipine. Abdominal adipose tissue interstitial glycerol concentrations increased with sacubitril/valsartan, but decreased with amlodipine. Whole-body lipolysis and substrate oxidation did not change with either treatment. Results confirm that sacubitril/valsartan treatment leads to a metabolic benefit in the study population and supports the relevance of neprilysin inhibition along with AT1 -receptor blockade in the regulation of human glucose and lipid metabolism.

Pharmacokinetics and pharmacodynamics of various glucagon dosages at different blood glucose levels.

AIMS: To evaluate the pharmacokinetics and pharmacodynamics of different doses of glucagon administered subcutaneously (s.c.) at different blood glucose levels. METHODS: This study was an open-label, randomized, three-period, cross-over experiment in 6 patients with type 1 diabetes. During each of the three periods, different blood glucose levels were established in four consecutive steps (8, 6, 4 and 2.8 mmol/l) and glucagon was given at each blood glucose level in doses from 0.11 to 0.44 mg and 0.33, 0.66 and 1 mg at the lowest glucose concentration. RESULTS: Maximum glucagon concentration and area under the curve increased with increasing glucagon dose. Maximum glucagon concentration was reached after 10-20 min. Glucagon raised blood glucose in a dose-dependent manner at different baseline blood glucose levels. The median glucose excursion ranged from 2.6 to 6.2 mmol/l. Time to maximum glucose concentration was dose-dependent for the glucagon doses at 2.8 mmol/l, with median values from 40 to 80 min. CONCLUSIONS: Glucagon administered s.c. produces a stable pharmacokinetic and pharmacodynamic response at lower doses than the usual rescue dose and across a range of hypo- to hyperglycaemic blood glucose levels. This supports the use of small glucagon doses in the artificial pancreas to correct and prevent hypoglycaemia.

Relevance of hemostasis on restenosis in clinically stable patients undergoing elective PTCA.

BACKGROUND: Secondary coronary thrombus formation is considered to be co-factor in the pathogenesis of restenosis after percutaneous transluminal coronary angioplasty (PTCA). Therefore systemic factors indicating a hypercoagulable disease state may be relevant for the process of coronary renarrowing. Even though experimental data suggest that in particular thrombin may be of major relevance for restenosis induced by mechanical injury, only little clinical data has been presented so far. METHODS AND RESULTS: In 60 consecutive patients, who had been clinical stable for at least 2 months, and who underwent elective and primarily successful PTCA, follow-up films were evaluated by means of quantitative coronary angiography in respect to a categorical and a continuous definition of restenosis, luminal narrowing >50% and late luminal loss respectively. Of the chosen laboratory variables prothrombin fragment 1+2 (1.3+/-0.5 vs. 0.9+/-0.4 mmol/l, p<0.001) red blood cell aggregation at low shear stress (13.5+/-2.9 vs. 11.6+/-2.8 units, p<0.05), and plasminogen-activator inhibitor (3.7+/-1.8 vs. 5.3+/-3.2 U/ml p<0.05) differentiated between patients with (n=18) and without restenosis (n=42). Late luminal loss correlated positively with prothrombin fragment 1+2 (r=0.41, p<0.001), plasminogen-activator inhibitor (r= -0.28, p<0.05) and plasmin-alpha2-antiplasmin complex (r=0.39, p<0.01). CONCLUSIONS: A hypercoagulable disease state and in particular thrombin generation characterize a high-risk group prone for restenosis in clinically stable coronary artery disease.

[Cyanosis and dyspnoea in orthostasis]. / Zyanose und Luftnot in Orthostase.

HISTORY AND CLINICAL FINDINGS: A 69-year-old female patient was admitted to a hospital for severe dyspnoea. It was conspicuous that shortness of breath and cyanosis only occurred in upright and completely disappeared in the supine position. This finding was objectified by pulse oximetry which demonstrated a decrease of arterial oyxgen saturation from 96 % in the supine to 86 % in the upright position. INVESTIGATIONS: After exclusion of other diseases the diagnosis of platypnoe- orthodeoxia syndrome as a result of a patent foramen ovale (PFO) was established. TREATMENT AND COURSE: Cardiac catheterization in the upright and the supine position documented a high-grade right-to-left shunt of 31 % proportionally to systemic circulatory volume in the upright position with subsequent critical reduction of pulmonary perfusion to 1.4 l/min/m (2) (reference value > 2.2 l/min/m (2)) as the cause of dyspnoea. Catheter-based occlusion of the PFO was chosen as causal treatment modality. After that arterial oxygen saturation remained constant at 95 % in the supine and upright position and symptoms improved. CONCLUSIONS: Platypnoe-othodeoxia syndrome is a very rare syndrome but it can be substantiated by pathognomonic case history, clinical examination and simple machine-aided examinations. With a causative PFO a causal and save therapy is available.

A distinct "side population" of cells with high drug efflux capacity in human tumor cells.

A subset of stem cells, termed the "side population" (SP), has been identified in several tissues in mammalian species. These cells maintain a high efflux capability for antimitotic drugs. We have investigated whether functionally equivalent stem cells also may be detected in human cancers. We initially examined primary tumor cells from 23 patients with neuroblastoma and cell lines derived from a range of other tumors. A distinct SP was found in neuroblastoma cells from 15 of 23 patients (65%). The SP was capable of sustained expansion ex vivo and showed evidence for asymmetric division, generating both SP and non-SP progeny. These cells also expressed high levels of ABCG2 and ABCA3 transporter genes and had a greater capacity to expel cytotoxic drugs, such as mitoxantrone, resulting in better survival. A SP also was detected in breast cancer, lung cancer, and glioblastoma cell lines, suggesting that this phenotype defines a class of cancer stem cells with inherently high resistance to chemotherapeutic agents that should be targeted during the treatment of malignant disease.

Morphological differences of the internal thoracic artery in patients with and without coronary artery disease--evaluation by duplex-scanning.

OBJECTIVE: The internal thoracic artery is an established arterial graft for myocardial revascularisation, especially of the left anterior descending artery because of a higher patency rate compared to venous grafts. It has never been investigated, whether there are morphological differences in this vessel between patients with or without coronary artery disease or if they are comparable to morphological changes in the common carotid artery. METHODS: We investigated the internal thoracic artery and the common carotid artery of 24 patients (12 with coronary artery disease, 12 without coronary artery disease) with an ultrasonic system on both sides. The intima-media thickness and the diameter of both vessels were estimated. RESULTS: The intima-media-thickness of the internal thoracic artery was comparable in all patients, independent of the presence of a coronary artery disease (0.51+/-0.11 mm with coronary artery disease, 0.50+/-0.17 mm without coronary artery disease, P>0.05). Compared with this the intima-media-thickness of the common carotid artery was thicker in patients with coronary artery disease (0.84+/-0.13 mm with coronary artery disease, 0.73+/-0.07 mm without coronary artery disease, P< or or =0.014). There was no correlation between the thickness of the internal thoracic artery and the common carotid artery (r=0.018, P>0.05). CONCLUSIONS: It could be demonstrated for the first with non-invasive ultrasound, that the intima-media-complex of the internal thoracic artery is protected of the influence of arteriosclerosis. There are no morphological differences like the intima-media-thickness of the common carotid artery. The proven protective mechanism underlines the widespread use of the internal thoracic artery as a coronary artery bypass graft.

Vineberg graft: flow reserve of bilateral implantation after 27 years.

We report a patient who underwent bilateral internal thoracic artery implantation into the myocardium known as a Vineberg procedure 27 years ago. Coronary angiography and Doppler echocardiography revealed patent grafts with total occlusion of all native coronary arteries. We measured flow velocities at rest and under stress conditions with noninvasive ultrasonic Doppler echocardiography. The flow patterns in both grafts were biphasic as in native coronary arteries. Under stress conditions no increase in flow was detectable as a marker of end-stage coronary artery disease with refractory angina pectoris.

In vitro bleeding test with PFA-100-aspects of controlling individual acetylsalicylic acid induced platelet inhibition in patients with cardiovascular disease.

OBJECTIVES: This study investigated the usefulness and practicability of a platelet function analyzer (PFA-100(TM), DADE-Behring, Germany) to determine individual platelet inhibition in patients treated with acetylsalicylic acid (ASA). BACKGROUND: Patients with coronary artery disease (CAD) routinely and during angioplasty (PTCA) receive standard doses of ASA to avoid acute coronary syndromes and abrupt vessel closures without information of the individual efficacy of platelet inhibition. METHODS: With the PFA-100(TM) a standardized bleeding time is measured. Whole-blood anticoagulated with 3.2% sodium citrate is aspirated through a capillary ( solidus in circle 200 microm) and through an aperture ( solidus in circle 147 microm). The time until occlusion of the aperture (closure time, CT) by a stable platelet plug induced by shear stress, collagen and epinephrine (COLL/EPI-CT) or shear stress, collagen and adenosine 5'-diphosphate (COLL/ADP-CT) is determined. To examine the usefulness of the PFA-100(TM) as a rapid bedside test and the individual effect of ASA, closure time was measured in healthy individuals (n=17), in patients with stable CAD (n=19) and in patients undergoing PTCA (n=8). RESULTS: Patients with stable CAD and regular medication with 100 mg ASA per day for at least 3 month showed shorter COLL/ADP-CT in comparison to healthy individuals who took only one single dose of 100 mg ASA. Of the patients with CAD 63% had a COLL/EPI-CT within normal range suggesting a low or no response to ASA. Also only 50% of the patients undergoing PTCA reached the expected COLL/EPI-CT>300 s after an additive single dose of 500 mg ASA intravenously. Neither heparin, phenprocoumon, sex nor different blood sampling methods seem to influence the measurements relevantly. CONCLUSIONS: This pilot study indicates that with the PFA-100(TM) test device a simple and quick measurement of an in vitro bleeding time is possible. It is able to detect an increase in the bleeding time after a single dose of ASA 100 mg in healthy subjects, reflecting a sensitive detection of ASA induced changes in platelet inhibition respective activation. Differences in the individual response to ASA could be observed in healthy subjects, patients with stable CAD and patients undergoing PTCA. Further studies should validate the PFA-100(TM) with standard methods to determine ASA response in patients with cardiovascular disease and investigate implications for treatment and outcome in this patient group.

Successful weaning from milrinone of a patient with severe congestive heart failure using carvedilol.

Congestive heart failure is a major and growing health care concern worldwide, and mortality in patients with severe heart failure is high. Few options are available to patients with New York Heart Association class IV heart failure refractory to oral medical therapy. Over the last 15-20 years milrinone, a phosphodiesterase-III inhibitor, has been used occasionally to treat patients with acute heart failure and as a bridge to heart transplantation and, more recently, has been used intermittently or continuously on an outpatient basis. We report a patient with severe, chronic congestive heart failure, whom we treated successfully with continuous milrinone infusions as an outpatient. We were able to wean him of the milrinone after successful up-titration of carvedilol. Nine months after discontinuation of milrinone the patient remains stable in New York Heart Association class I on high dose carvedilol. Research is required to validate the possibility that patients with severe heart failure may be successfully weaned from milrinone using carvedilol and achieve significant improvement of their functional status and quality of life. This may prove to be an effective strategy for the treatment of selected patients with severe, chronic congestive heart failure. (c)2001 by CHF, Inc.

Non-invasive assessment of graft patency using transcutaneous Doppler echocardiography for the validation of functional improvement after PTCA of the LAD via internal thoracic artery graft.

Percutaneous transluminal coronary angioplasty (PTCA) of a native coronary artery via internal thoracic artery (ITA) graft after bypass surgery is a relatively rare procedure. Our current study evaluates the flow velocity patterns of the graft before and after PTCA. After intervention the mean diastolic flow velocity increased under rest and stress conditions. In addition, the graft patency was proved not before control angiography after 6 months. It could be verified that the measurement of flow velocity patterns under rest and stress conditions is a useful non-invasive procedure for monitoring long-term patency and PTCA-results of this vessel.

[New antithrombotic therapy approaches in coronary heart disease--prospects for gene therapy]. / Neue antithrombotische Therapieansätze bei koronarer Herzerkrankung--Perspektiven einer Gentherapie.

Despite considerable progress, pharmacological therapies have not provided a complete solution for common cardiovascular problems, including recurrent thrombosis, restenosis, and vein graft deterioration. Optimal drug dosage, reproducing plasma concentrations achieved in animal studies establishing proof-of-principle, would often be too toxic to administer. Local gene therapy aims at overexpressing proteins that regulate the cell cycle of vascular smooth muscle cells, inhibit vascular smooth muscle cell migration, endow the endothelium with enhanced vasoprotective properties. Alternatively, some approaches tend to suppress gene expression of proteins believed to promote vascular smooth muscle cell proliferation and migration. In sharp contrast to drug treatments, local gene therapy limits expression of the beneficial agent to the injured vascular site, where it can extend the presence of this agent to weeks and, with some gene vectors, to many months. This review summarizes and discusses antithrombotic gene therapy approaches for the prevention of restenosis and late thrombosis after catheter-based revascularizations.

The emerging clinical potential of cardiovascular gene therapy.

Despite considerable progress, pharmacological therapies have not provided a complete solution for common cardiovascular problems, including recurrent thrombosis, restenosis, and vein graft deterioration. Optimal drug dosage, reproducing plasma concentrations achieved in animal studies establishing proof-of-principle, would often be too toxic to administer, especially when given over prolonged periods of time. Local gene therapy aims at overexpressing proteins that: (1) regulate the cell cycle of VSMC; (2) inhibit VSMC migration; (3) endow the endothelium with its vasoprotective properties; and (4) stimulate growth of endothelium and angiogenesis. Alternatively, some approaches tend to suppress gene expression of proteins believed to promote VSMC proliferation and migration. In sharp contrast to drug treatments, local gene therapy limits expression of the beneficial agent to the injured vascular site, and there, it can extend the presence of this agent to weeks and, with some gene vectors, to many months. The clinical potential of this approach has led to the initiation of trials that currently evaluate gene therapy approaches to the attenuation of peripheral and myocardial ischaemia and the prevention of vein graft disease.

[PTCA of the LAD via the internal thoracic artery graft with Doppler ultrasonic control of the results: a case report and review of the literature]. / RIVA-PTCA via Arteria-thoracica-interna-Bypass mit dopplersonographischer Erfolgskontrolle--Eine Kasuistik mit Literaturübersicht.

The report presents a transluminal angioplasty (PTCA) of a severe stenosis of the left anterior descending artery (LAD) behind the anastomosis; the internal thoracic artery (ITA) graft was used as a conduit. Before and after the PTCA the changing of velocity flow patterns under rest and stress conditions with a handgrip-maneuver were measured with a noninvasive transthoracic ultrasound Doppler system. The mean diastolic velocity, which represent coronary perfusion through the ITA graft, increased after successful PTCA at rest and under stress conditions. An additional increasing of the mean diastolic velocity at rest and under stress conditions was seen after six months before the catheterization proposing no signs of restenosis. For this reason the vessel could be classified prospectively patient. This could be confirmed during coronary angiography. We also present a review of the published reports concerning PTCA of ITA grafts and PTCA of the native vessel using the ITA as a conduit. In this review 286 cardiac interventions on 273 patients with a primary rate of success of 87% could be counted, the documented rate of restenosis was 30%, and the rate of complication was approximately 1%. The PTCA in ITA grafts or of the native vessel via ITA grafts, respectively, represent an alternative to reoperation. The ultrasound-duplex measurements are gaining an increasing significance for the noninvasive patency rate and post-interventional monitoring of the long-term PTCA result. With the augmentation of the ITA as a coronary bypass and expected increase of post-operative interventions, a noninvasive tool is necessary.

[Internal thoracic artery bypass--basic principles of Doppler ultrasound for pre- and postoperative diagnosis]. / Arteria thoracica interna-Bypass--Grundlagen der Dopplersonographie für die prä- und postoperative Diagnostik.

During the last 25 years the internal thoracic artery has become a well established conduit for coronary revascularization. Next to angiography, duplex-sonography is increasingly used as a non-invasive imaging procedure for the evaluation of this graft vessel. Preoperative investigation in 117 patients has yielded a high level of agreement between angiography and duplex-sonography. While the preoperative flow-pattern is dominated by systolic flow as it is typical for vessels supplying skeletal muscle, the postoperative findings show an adaptation to the coronary vascular bed as the diastolic flow increases. These non-invasive measurements are well matched with invasive intravascular recordings. Coronary angiography and duplex-sonography of the internal thoracic artery yielded comparable findings in respect to the procedural result. Considering the increasing use of the internal thoracic artery in coronary artery bypass surgery, this non-invasive method should gain increasing relevance.

[Assessment of the anti-ischemic effect in patients with therapy refractory angina pectoris in end-stage coronary heart disease--results of chronic intermittent urokinase therapy]. / Antiischämischer Wirkungsnachweis bei Patienten mit therapierefraktärer Angina pectoris im Endstadium der koronaren Herzkrankheit--Ergebnisse zur chronisch-intermittierenden Urokinasetherapie.

Patients with refractory angina pectoris and end-stage coronary artery disease represent an increasing clinical problem. Numbers of these patients will increase in the future for improved survival due to effective secondary prevention of coronary artery disease. Next to the evaluation of clinical symptoms non-invasive objective parameters of myocardial ischemia are of major relevance before initiation of alternative treatment modalities and for verification of antiischemic effectiveness. Based on our own experience it can be shown that in these patients testing which is mainly based on the patients physical exercise capacity is only of limited value due to the early occurrence of clinical symptoms. Furthermore diffuse perfusion abnormalities reduce the sensitivity of electrocardiographic and scintigraphic detection of ischemic changes. In contrast indirect measures of ischemia relating to the systolic or diastolic function of the left ventricle like doppler-echocardiography and radionuclide ventriculography seem to be promising approaches. This is confirmed by the results from the application of long-term intermittent urokinase therapy. Long-term intermittent urokinase therapy leads to an absolute enhancement of myocardial perfusion, which makes this approach superior to other medical interventions which are mainly based on a reduction of cardiac work-load.

[Diastolic function parameters and atrial arrhythmias in patients with arterial hypertension]. / Diastolische Funktionsparameter und atriale Rhythmusstörungen bei Patienten mit arterieller Hypertonie.

OBJECTIVE: To investigate in patients with arterial hypertension (HT) the extent of left ventricular (LV) hypertrophy and diastolic function in relation to atrial arrhythmias. PATIENTS AND METHODS: In 112 hypertensive patients (40 women, 72 men; mean age 50 +/- 6.6 years) with a mean systolic blood pressure for the cohort of 170 +/- 5 mmHg, their first invasive coronary angiography was performed between July 1995 and October 1997 because of angina pectoris and/or an abnormal stress electrocardiogram. After excluding coronary heart disease LV dimensions and diastolic function were measured by echocardiography; in 59 of the 112 patients LV hypertrophy was demonstrated. In addition, long-term blood pressure monitoring, exercise and long-term electrocardiography, late-potential analysis and measurement of heart rate variability were undertaken. The control group consisted of 51 patients without arterial hypertension after exclusion of coronary heart disease. RESULTS: Even in the hypertensive patients without LV hypertrophy diastolic LV function and ergometric exercise capacity were reduced. The risk of LV arrhythmias was significantly higher in patients with LV hypertrophy than those without and in the control group, as measured by the complexity of atrial arrhythmias (P < 0.001), the incidence of abnormal late potentials (P < 0.001) and reduction in heart rate variability (29.3 +/- 5.3 ms vs 47.8 +/- 12.1 ms vs 60.7 +/- 6.6 ms; P < 0.001). There were similar results regarding severe complex atrial arrhythmias (38.5 vs 15.0 vs 0%; P < 0.001). The incidence of atrial arrhythmias correlated with the LV diameter (r = 0.68, P < 0.001), LV morphological dimensions and diastolic function (isovolumetric relaxation time r = 0.44, P < 0.001) and the ratio of early to late diastolic inflow (r = 0.46; P < 0.001). CONCLUSIONS: Hypertensive patients have a higher risk of atrial and ventricular arrhythmias, depending on the degree of LV hypertrophy. But atrial arrhythmias, in contrary to ventricular arrhythmias, are also closely related to abnormalities in LV diastolic function.