Hemodynamic and neurohumoral effects of continuous infusion of levosimendan in patients with congestive heart failure.

OBJECTIVES: We sought to define the therapeutic dose range of levosimendan in patients with New York Heart Association class II-IV heart failure of ischemic origin. BACKGROUND: Levosimendan is a calcium sensitizer for treatment of acute decompensated heart failure. METHODS: A double-blind, placebo-controlled, randomized, multicenter, parallel-group study included 151 adult patients. Levosimendan was given as a 10-min intravenous bolus of 3, 6, 12, 24 or 36 microg/kg, followed by a 24-h infusion of 0.05, 0.1, 0.2, 0.4 or 0.6 microg/kg/min, respectively. Dobutamine, for comparative purposes, was given as an open-label infusion (6 microg/kg/min). The primary efficacy variable was the proportion of patients achieving in each treatment group at least one of the following: 1) a > or =15% increase in stroke volume (SV) at 23 h to 24 h; 2) a > or =25% decrease in pulmonary capillary wedge pressure (PCWP) (and > or =4 mm Hg) at 23 h to 24 h; 3) a > or =40% increase in cardiac output (CO) (with change in heart rate [HR] <20%); 4) a > or =50% decrease in PCWP during two consecutive measurements. RESULTS: The response rate to levosimendan ranged from 50% at the lowest dose to 88% at the highest dose (compared with placebo 14%, dobutamine 70%). A dose-response relationship was demonstrated for levosimendan on increases in CO and SV, and reductions in PCWP during the infusion (for all, p< or =0.001). Headache (9%), nausea (5%) and hypotension (5%) were the most frequently reported adverse events at higher dosages. CONCLUSIONS: Dosing of levosimendan with a 10-min bolus of 6 to 24 microg/kg followed by an infusion of 0.05 to 0.2 microg/kg/min is well tolerated and leads to favorable hemodynamic effects.

Exercise hemodynamics and catecholamine metabolism after catechol-O-methyltransferase inhibition with nitecapone.

The effect of catechol-O-methyltransferase inhibition with nitecapone (OR-462) on the hemodynamic responses to exercise and catecholamine metabolism was studied in 10 healthy male volunteers (aged 19 to 26 years). Nitecapone, a new specific and selective catechol-O-methyltransferase inhibitor, was given at increasing single oral doses up to 100 mg. Nitecapone did not influence resting or exercise heart rate, blood pressure, systolic time intervals, or plasma catecholamine levels. It altered the metabolic profile of catecholamines as shown by (1) an increase of 140% in the plasma concentration of the monoamine oxidase-dependent metabolite 3,4-dihydroxyphenylethyleneglycol (p less than 0.001), (2) a decrease of 27% in the plasma concentration of its methylation product 3-methoxy-4-hydroxyphenylethyleneglycol (p less than 0.05), and (3) a 25% reduction in the urinary excretion of the methylated metabolites 3-methoxy-4-hydroxymandelic acid and homovanillic acid (p less than 0.05). Nitecapone was well tolerated and seemed to be hemodynamically safe in humans.

Myocardial efficiency during calcium sensitization with levosimendan: a noninvasive study with positron emission tomography and echocardiography in healthy volunteers.

Dynamic positron emission tomography (PET) with [11C]acetate allows noninvasive assessment of myocardial oxygen consumption. In combination with echocardiography, PET enables determination of cardiac efficiency (defined as useful cardiac work per unit of oxygen consumption). We used this approach to compare the effects of levosimendan, a Ca(2+)-dependent calcium sensitizer, with dobutamine and sodium nitroprusside in healthy male volunteers. The effects of levosimendan on k(mono), an index of oxygen consumption, and cardiac efficiency were neutral, whereas the hemodynamic profile was consistent with balanced inotropism and vasodilatation. Dobutamine enhanced cardiac efficiency at the expense of increased oxygen requirement, but the effects of nitroprusside on k(mono) and cardiac efficiency were neutral. This study shows the feasibility of PET in phase 1 pharmacodynamic studies and suggests potential energetical advantages of calcium sensitization with levosimendan.

Myocardial efficiency during levosimendan infusion in congestive heart failure.

AIMS: Levosimendan, a novel calcium-dependent calcium sensitizer of the myocardial contractile proteins, also enhances diastolic relaxation and induces peripheral vasodilation by opening potassium channels. To assess the combined energetical effects of levosimendan infusion in vivo, we performed positron emission tomography in patients with decompensated chronic heart failure. METHODS AND RESULTS: Eight hospitalized patients with New York Heart Association functional class III or IV heart failure received levosimendan or placebo intravenously in a randomized double-blind cross-over study. During steady-state, dynamic positron emission tomography with [11C]acetate was used to assess myocardial oxygen consumption and [15O]H2O to measure myocardial blood flow. Cardiac performance and dimensions were assessed by pulmonary artery catheterization and echocardiography. Compared with healthy volunteers, myocardial oxygen consumption during placebo was elevated in the right ventricle but comparable in the left ventricle. During administration of levosimendan, cardiac output increased by 32% (P = .002) mainly because of higher stroke volume. Coronary, pulmonary, and systemic vascular resistance values were significantly reduced. Mean myocardial blood flow increased from 0.76 to 1.02 mL/min/g (P = .033). Levosimendan was neutral on myocardial oxygen consumption and left ventricular efficiency, but it improved right ventricular mechanical efficiency by 24% (P = .012). CONCLUSIONS: Levosimendan has an energetically favorable short-term profile in the treatment of congestive heart failure. It enhances cardiac output without oxygen wasting, particularly by improving efficiency in the right ventricle.

Soluble and membrane-bound catechol-O-methyltransferase in normal and malignant mammary gland.

The levels of 26 kDa-soluble (S) and 30 kDa-membrane-bound (MB) catechol-O-methyltransferase (COMT) polypeptides were determined in paired samples from normal and neoplastic breast tissue of 32 patients with breast cancer. Immunohistochemical staining showed that the COMT reaction in normal mammary tissue was restricted to the epithelial cells in the ducti and lobuli, whereas in the tumors a strong reaction was also seen in the malignant cells. The amounts of COMT proteins in tumors could not be correlated with various clinical or pathological parameters. Quantitative immunoblotting analysis revealed that the total amount of COMT proteins in tumors was more than 50% higher than in respective normal samples in 26 out of 32 patients. Five cases showed less than a 50% difference and in one case less COMT was detected in the tumor. In most cases the amount of both S- and MB-COMT forms was increased. The average amount of total COMT was 178 +/- 57 pg/microg total protein in normal tissue and 566 +/- 94 pg/microg total protein in tumor. Respective values for S-COMT were 137 +/- 52 pg/microg total protein in normal tissue and 369 +/- 62 pg/microg total protein in tumor and for MB-COMT 41 +/- 10 and 197 +/- 41 pg/microg total protein, respectively. Analysis of COMT-specific transcripts suggested that the COMT enzyme level in tumors is determined in some cases by transcriptional and in some cases by post-transcriptional mechanisms.

Anti-anginal therapy and quality of life. A comparison of the effects of transdermal nitroglycerin and long-acting oral nitrates.

A total of 112 male patients with severe effort-induced angina pectoris (New York Heart Association functional classes II and III) participated in a randomized open trial consisting of a 6 month phase with 3 month treatment cross-overs. The aim of the study was to compare the effect of transdermal nitroglycerin (TN) patches and long-acting oral nitrates (LAON) on quality of life (QL). During the cross-over period 30 patients (20 on TN and 10 on LAON) withdrew from the study, over half of them within the first month. Although the results should be interpreted with some caution, they showed that improvement in QL was present for both treatments but greater during the transdermal therapy (unadjusted p = 0.07, adjusted p = 0.03). Anginal attacks were associated with improved QL scores, and fewer attacks occurred on TN (p = 0.06). Improvement in QL was most pronounced in patients whose recorded duration of angina was less than 8 years.

The effect of flaxseed supplementation in processed foods on serum fatty acids and enterolactone.

OBJECTIVE: The purpose was to study the effects of flaxseed supplementation as a part of daily diet on serum lipids, fatty acids and plasma enterolactone. DESIGN: Eighty volunteers participated in this clinical nutrition study which was carried out in a controlled, double-blind and cross-over manner. The subjects were randomized to diet sequences AB or BA. Diet A meals contained 1.3 g/100 g ground flaxseed and 5 g/100 g flaxseed oil. Also 3-4 g/100 of inulin and wheat fiber was added. AB diet with non-supplemented foods served as control. Test subjects were on both diets for 4 weeks separated by a 4-week wash-out period. Fifteen test subjects continued an open part of the study for 4 additional months. INTERVENTIONS: The dietary intake, basic blood values, serum lipids, fatty acids and enterolactone were measured at baseline, after both intervention periods and during the open study, at baseline and after 2 and 4 months. Serum thiocyanate and blood cadmium were controlled after both intervention periods. RESULTS: The percentage of flaxseed supplemented test food out of total dietary intake was 20% of energy. The test food contained significantly higher amounts of fiber, polyunsaturated fatty acids (PUFAs) and especially alpha-linolenic acid than the control food. No significant changes were observed in the basic laboratory values or in blood lipids. There was a significant increase in serum alpha-linolenic acid, eicosapentaenoic acid and docosapentaenoic acid. Serum enterolactone concentration was doubled during flaxseed supplementation. Serum thiocyanate and blood cadmium values did not exceed reference values and there was no difference between the diets. CONCLUSIONS: In this study we were able to show that, by adding ground flaxseed and flaxseed oil to one or two daily meals, it is possible to obtain significant effects on serum levels of enterolactone and alpha-linolenic acid. SPONSORSHIP: The study was sponsored by the National Technology Agency of Finland (Tekes).

Assessment of cardiac performance: short- and medium-term variability of impedance cardiography at rest and during dynamic exercise.

Short- and medium-term variability of impedance cardiography at rest and during exercise at a heart rate of 155-160 beats/min were assessed in 12 healthy men aged 21-28 years. Two consecutive measurements within 1 min were performed 4 times at 2-hour intervals on 2 days 14 days apart. Ejection fraction was the most reproducible of all impedance cardiography parameters, the CV ranging from 3.3-5.9%. The short-term reproducibility of cardiac output and stroke volume at rest was good, the between-repeats coefficient of variation (CV) being 4-6%. The reproducibility weakened with longer time span (between-day CV being about 12%) and higher heart rates (exercise). However, even the between-day reproducibility at rest was as good as that of heart rate. Between-day CV during exercise were about 20%.

Sucralfate effervescent tablet: treatment of peptic ulcer disease and change in serum aluminium concentration.

In a single-centre randomised clinical trial, a new effervescent formulation of sucralfate was compared with the granular formulation of the drug in the treatment of peptic ulcer. The effervescent tablet had not been previously administered to human subjects. Fifty patients with endoscopically verified duodenal (40) and gastric (10) ulcers were treated with 2.0 g sucralfate twice daily, given either as a granular formulation or effervescent tablet. Control endoscopies were performed at weeks 4 and 8 and again at week 12 if gastric ulcers had not healed earlier. The healing rates in the effervescent tablet group were 71% (15/21) and 86% (18/21) after 4 and 8 weeks. In this group one gastric ulcer had to be treated for a further 4 weeks and had not healed at week 12. The corresponding rates in the sucralfate granulate group were 95% (18/19) after 4 and 8 weeks. Serum aluminium concentrations were measured simultaneously before and after treatment. The aluminium concentration almost doubled in both treatment groups during dosing with sucralfate. This effect has not been described previously in the course of therapy with sucralfate in patients with peptic ulcer disease and should be borne in mind when considering treatment with this drug.

Safety of levosimendan and other calcium sensitizers.

Levosimendan belongs to a new group of heart failure drugs, the calcium sensitizers. Because these compounds are not yet available for clinical use, the adverse drug events (ADEs) during levosimendan treatment cannot be predicted in detail. To evaluate the tolerability of levosimendan in human subjects, ADEs, safety laboratory values before and after treatment, and ambulatory ECG findings have been collected from several phase I and phase II clinical studies. By June 1994, approximately 200 subjects had received levosimendan. The most common ADE seen in healthy volunteers is headache, reported by some 40% of subjects in oral dosing but only 10% in i.v. dosing. The incidence of headache does not correlate well with the total daily dose of the drug. However, the controlled release formulations tested appear to cause vasodilatory symptoms more frequently than i.v. or rapid release oral formulations. The other typical vasodilatory ADEs seen in healthy volunteers are nausea, palpitation, and dizziness. Symptomatic hypotension is rarely encountered. It appears that heart failure patients tolerate the vasodilatory actions of the drug better than healthy volunteers. Only individual cases of headache, vertigo, and flushing have been reported, and injection site irritation has been the most commonly reported ADE (with an incidence <5%). However, because the longest administration of the i.v. infusion has been only 24 h, the duration of exposure to the drug is too short to allow any definitive conclusions to be drawn. All patients who have received levosimendan have been monitored with an ambulatory ECG. Even though some increase in heart rate is seen with high doses of the drug, there are thus far no signs of an increased incidence of ventricular tachyarrhythmias, nor have there been any noteworthy changes in the clinical laboratory safety tests. The experience with levosimendan is limited thus far and long-term data are lacking. It can be concluded, however, that at least in i.v. dosing the drug is devoid of ADEs with significant medical seriousness.

The effects of the COMT inhibitor nitecapone for one week on exercise haemodynamics and catecholamine disposition.

We have studied resting and exercise haemodynamics and catecholamine disposition after catechol-O-methyl-transferase (COMT) inhibition with nitecapone 100 mg t.d.s. for 7 days in 15 healthy men (aged 21 to 28 y) in a placebo-controlled, cross-over study. Nitecapone did not alter resting or exercise heart rates, blood pressure, or plasma catecholamine concentrations, but it altered the metabolic profile of endogenous catecholamines, as shown by: (1) a fall in the concentrations of the COMT-dependent metabolite 3-methoxy-4-hydroxy-phenylglycol (MHPG) by 22% (P < 0.01), (2) increases in plasma concentrations of the monoamine oxidase-dependent metabolites 3,4-dihydroxyphenylglycol (DHPG) by up to 90% (P < 0.001) and 3,4-dihydroxyphenylacetic acid (DOPAC) by 67% (P < 0.05), (3) a three-fold increase in the concentration of circulating conjugated adrenaline (P < 0.001).

The effects of the COMT inhibitor entacapone on haemodynamics and peripheral catecholamine metabolism during exercise.

1. Catechol-O-methyltransferase (COMT) inhibition might be assumed to potentiate the effects of circulating catecholamines, particularly under conditions of enhanced catecholamine release. 2. The purpose of the present study was to establish whether the novel COMT inhibitor, entacapone, changes haemodynamic responses and catecholamine metabolism during exercise. 3. Entacapone was given orally to 12 healthy male subjects (age 23-30 years) in increasing single doses from 0 mg (control day) to 200 mg. A submaximal exercise test was performed on a bicycle ergometer, and blood pressure, heart rate and ECG were recorded. The concentrations of noradrenaline, adrenaline, DHPG (3,4-dihydroxyphenylglycol), MHPG (3-methoxy-4-hydroxyphenyl-glycol) and, DOPAC (3,4-dihydroxyphenylacetic acid) in plasma were determined. 4. Entacapone did not influence haemodynamics or ECG at rest or during exercise. 5. Entacapone did not influence plasma catecholamine levels, either at rest or during exercise. However, it altered the metabolic profile of catecholamines, which was shown by increases in the plasma concentrations of the monoamine oxidase-dependent metabolites DHPG (by up to 100%) and DOPAC (by up to 53%), and by a decrease of the COMT-dependent metabolite MHPG (by up to 29%).

Electrophysiologic effects of a calcium sensitizer inotrope levosimendan administered intravenously in patients with normal cardiac function.

Provocation of fatal cardiac arrhythmias has limited the use of inotropic agents as heart failure therapy. Calcium sensitization of the myofilaments might increase inotropy without influencing cardiac electrophysiology unless modified by ancillary properties of the drugs. Electrophysiologic effects of a calcium sensitizer inotrope levosimendan were examined in short-term intravenous administration in humans. Variables were determined in 10 patients with normal cardiac function during a preceding control phase and levosimendan infusion yielding a high therapeutic concentration of 110 (+/-22) microg/L. Levosimendan increased heart rate by 9 beats/min (p < 0.01) on average and shortened the sinus node recovery time and AH interval. At the tested cycle lengths, levosimendan shortened the effective refractory periods in the atrioventricular node by 40-63 ms (p < 0.05), in the atrium by 22-33 ms (p < 0.001), and in the ventricle by 5-9 ms (p < 0.005) on average. Levosimendan increased ventricular monophasic action potential duration by 9-17 ms at 50% (p < 0.001) and by 5-15 ms (p = 0.07) at 90% levels of repolarization on average. The QT interval during spontaneous rhythm and atrial pacing remained unchanged although increased slightly when corrected to sinus rate (p < 0.001). The observations indicate that levosimendan in short-term administration facilitates impulse formation and conduction in cardiac slow-response tissue, enhances recovery of excitability in the myocardium, and may delay ventricular repolarization. The effects on the ventricle were not substantial, and therefore the likelihood of provoking serious cardiac arrhythmias is not estimated to be high.

Haemodynamic dose-efficacy of levosimendan in healthy volunteers.

Levosimendan is a new calcium-sensitiser intended for the treatment of congestive heart failure. The results of preclinical studies indicate it has positive inotropic and vasodilator effects. In the open study reported here up to 5 mg levosimendan and vehicle were administered to 8 healthy male volunteers at one- to 2-week intervals. Efficacy was evaluated using M-mode echocardiography, and by measuring systolic time intervals, recording ECG and measuring blood pressure. For almost all haemodynamic parameters except heart rate (HR) the maximum effect was seen 10 or 20 min after drug infusion. Effects 10 min after infusion of drug and vehicle were compared. HR was significantly increased 10 min only after infusion of 5 mg: significant increases were seen 60 min after infusions of 2, 3 and 5 mg (4, 8 and 17 beats.min-1, respectively). Diastolic blood pressure was significantly lower after doses of 1 mg or more. The decrease after 5 mg was 17 mmHg. Systolic blood pressure tended to increase. Fractional shortening (FS) and ejection fraction (EF) increased significantly after doses of 1 mg and higher. EF 10 min after infusion of vehicle was 54%. It increased to 73% after 5 mg. Decreases in electromechanical systole (QS2i) 10 min after 2, 3 and 5 mg were significant. There were no clinically significant adverse events or changes in laboratory safety values. The changes in QS2i, FS, EF and blood pressure indicate that levosimendan has positive inotropic and vasodilator effects in healthy subjects.

Studies on psychomotoric effects and pharmacokinetic interactions of the new calcium sensitizing drug levosimendan and ethanol.

Levosimendan (CAS 141505-33-1) is a calcium sensitizing drug intended for the treatment of congestive heart failure. In animal experiments levosimendan has potentiated the sedative effects of ethanol. Due to poor water solubility of the compound, ethanol is used as a diluent in the intravenous formulation. In this study the possible interactions between levosimendan and ethanol in human have been studied. Twelve healthy male volunteers were included in this double-blind, randomized, cross-over study. The study consisted of three treatment periods: levosimendan 1 mg intravenously, levosimendan combined with ethanol orally and ethanol 0.8 g/kg alone. Blood samples for determination of levosimendan and ethanol concentrations were collected for 8 h after the dosing. To observe possible pharmacodynamic interactions psychomotoric tests were made before drug administration and 1h, 2h, 3h and 6h thereafter. These tests included Digit symbol substitution test, Maddox wing, Critical Flicker fusion and VAS-test for subjective assessment of performance status. Plasma levosimendan concentrations were not changed by the concomitant ethanol administration. Ethanol did not alter the pharmacokinetics of levosimendan except the volume of distribution of central compartment which was decreased. Levosimendan did neither affect elimination of ethanol. Levosimendan did not potentiate the psychomotoric effects of ethanol neither did it have any psychomotoric effects itself. In conclusion, levosimendan is not likely to have any psychomotoric adverse effects or any clinically significant interactions with ethanol.

Effects of a new calcium sensitizer, levosimendan, on haemodynamics, coronary blood flow and myocardial substrate utilization early after coronary artery bypass grafting.

AIMS: The aim of the study was to evaluate the effects on systemic and coronary haemodynamics and myocardial substrate utilization of a new calcium sensitizer, levosimendan, after coronary artery bypass grafting. METHODS AND RESULTS: Twenty-three low-risk patients were included in this randomized and double-blind study. They received placebo (n = 8), 8 (n = 8) or 24 (n = 7) micrograms.kg-1 of levosimendan after coronary artery bypass operation. Systemic and coronary sinus haemodynamics with thermodilution and myocardial substrate utilization were measured. The heart rate increased 11 beats.min-1 after the higher dose (P < 0.05). Cardiac output increased by 0.7 and 1.61.min-1 (P < 0.05 for both) after 8 and 24 micrograms.kg-1 of levosimendan, respectively. Systemic and pulmonary vascular resistance decreased significantly after both doses. Coronary sinus blood flow increased by 28 and 42 ml/(P = 0.054 for the combined effect) after the lower and higher dose, respectively. Myocardial oxygen consumption or substrate extractions did not change statistically significantly. CONCLUSION: Despite improved cardiac performance, levosimendan did not increase myocardial oxygen consumption or change myocardial substrate utilization. Thus levosimendan has the potential to treat low cardiac output states after cardiopulmonary bypass surgery.