Utility value estimates in cardiovascular disease and the effect of changing elicitation methods: a systematic literature review.

OBJECTIVE: Identify the most recent utility value estimates for cardiovascular disease (CVD) via systematic literature review (SLR) and explore trends in utility elicitation methods in the last 6 years. METHODS: This SLR was updated on January 25, 2018, and identified studies reporting utilities for myocardial infarction (MI), stroke, angina, peripheral artery disease (PAD), and any-cause revascularization by searching Embase, PubMed, Health Technology Assessment Database, and grey literature. RESULTS: A total of 375 studies reported CVD utilities (pre-2013 vs post-2013: MI, 38 vs 32; stroke, 86 vs 113; stable angina, 8 vs 9; undefined/unstable angina, 23 vs 8; PAD, 29 vs 13; revascularization, 54 vs 40). Median average utilities for MI, stroke, and revascularization increased over time (pre-2013 vs post-2013: MI, 0.71 vs 0.79; stroke, 0.63 vs 0.64; revascularization, 0.76 vs 0.81); angina and PAD showed a decrease in median values over time (stable angina, 0.83 vs 0.72; undefined/unstable angina, 0.70 vs 0.69; PAD, 0.76 vs 0.71). The proportion of utility estimates from trials increased across health states (pre-2013 vs post-2013: 22.5% vs 37.2%), as did the proportion of trials using the EuroQol Five Dimensions Questionnaire (EQ-5D; pre-2013 vs post-2013: 73.8% vs 91.4%). Use of methods such as the standard gamble, time trade-off, and Health Utilities Index has declined. CONCLUSIONS: Health state utilities for cardiovascular health states have changed in the last 6 years, likely due to changes in the types of studies conducted, the patient populations evaluated, and possibly changing utility elicitation methods. The EQ-5D has been used more frequently.

Pharmacological Actions of Hydrogen Sulfide Donors on Sympathetic Neurotransmission in the Bovine Anterior Uvea, In Vitro.

In the present study, we investigated the effect of three different sources of hydrogen sulfide (H2S) on sympathetic neurotransmission from isolated superfused bovine iris-ciliary bodies. The three agents under consideration were: ACS67, a hybrid of latanoprost and a H2S-donating moiety; L-cysteine, a substrate for endogenous production of H2S and GYY 4137, a slow donor of H2S. We also examined the contribution of prostaglandins to the pharmacological actions of the H2S donors on release of [(3)H]-norepinephrine ([(3)H]NE) triggered by electrical field stimulation. ACS67, L-cysteine and GYY 4137 caused a concentration-dependent inhibition of electrically-evoked [(3)H]NE release from isolated bovine iris-ciliary bodies without affecting basal [(3)H]NE efflux. The cyclooxygenase inhibitor, flurbiprofen enhanced the inhibitory action of ACS67 and L-cysteine on stimulated [(3)H]NE release. Both aminooxyacetic acid, an inhibitor of cystathionine-ß-synthase and glibenclamide, a KATP channel blocker reversed the inhibition of evoked NE release induced by the H2S donors. We conclude that H2S donors can inhibit sympathetic neurotransmission from isolated bovine iris-ciliary bodies, an effect partially dependent on the in situ production of H2S and prostanoids, and is mediated by an action on KATP channels.

Inhibitory action of novel hydrogen sulfide donors on bovine isolated posterior ciliary arteries.

In the present study, we investigate the inhibitory effect of novel H2S donors, AP67 and AP72 on isolated bovine posterior ciliary arteries (PCAs) under conditions of tone induced by an adrenoceptor agonist. Furthermore, we examined the possible mechanisms underlying the AP67- and AP72-induced relaxations. Isolated bovine PCA were set up for measurement of isometric tension in organ baths containing oxygenated Krebs solution. The relaxant action of H2S donors was studied on phenylephrine-induced tone in the absence or presence of enzyme inhibitors for the following pathways: cyclooxygenase (COX); H2S; nitric oxide and the ATP-sensitive K(+) (KATP) channel. The H2S donors, NaSH (1 nM - 10 µM), AP67 (1 nM - 10 µM) and AP72 (10 nM - 1 µM) elicited a concentration-dependent relaxation of phenylephrine-induced tone in isolated bovine PCA. While the COX inhibitor, flurbiprofen (3 µM) blocked significantly (p < 0.05) the inhibitory response elicited by AP67, it had no effect on relaxations induced by NaSH and AP72. Both aminooxyacetic acid (30 µM) and propargylglycine (1 mM), enzyme inhibitors of H2S biosynthesis caused significant (p < 0.05) rightward shifts in the concentration-response curve to AP67 and AP72. Furthermore, the KATP channel antagonist, glibenclamide (300 µM) and the NO synthase inhibitor, l-NAME (100 µM) significantly attenuated (p < 0.05) the relaxation effect induced by AP67 and AP72 on PCA. We conclude that H2S donors can relax pre-contracted isolated bovine PCA, an effect dependent on endogenous production of H2S. The inhibitory action of only AP67 on pre-contracted PCA may involve the production of inhibitory endogenous prostanoids. Furthermore, the observed inhibitory action of H2S donors on PCA may depend on the endogenous biosynthesis of NO and by an action of KATP channels.

Pharmacological actions of the slow release hydrogen sulfide donor GYY4137 on phenylephrine-induced tone in isolated bovine ciliary artery.

Hydrogen sulfide (H2S), a colorless gas characterized by its pungent odor of rotten eggs has been reported to elicit relaxation effects on basal and pre-contracted non-ocular smooth muscles of several mammalian species. In the present study, we investigated the pharmacological actions of a H2S donor, GYY4137 on isolated bovine posterior ciliary artery after contraction with the adrenergic receptor agonist, phenylephrine. Furthermore, we studied the underlying mechanism of inhibitory action of GYY4137 on the posterior ciliary arteries. Isolated bovine posterior ciliary arteries were mounted in oxygenated organ baths and changes in isometric tension were measured with a Grass FT03 transducer connected to a recorder using a Grass Polyview Software. The relaxant actions of GYY4137 on phenylephrine pre-contracted arteries were observed in the absence and presence of an inhibitor of cyclo-oxygenase, flurbiprofen. Furthermore, the inhibitory effects of GYY4137 were studied in the absence or presence of inhibitors/activators of biosynthetic enzymes for H2S and nitric oxide production, as well as specific ion channel blockers. In the concentration range, 100 nM to 100 µM, GYY4137 elicited a concentration-dependant relaxation of phenylephrine-induced tone in isolated posterior ciliary arteries, with IC50 value of 13.4 ± 1.9 µM (n = 6). The cyclo-oxygenase inhibitor, flurbiprofen, significantly (p < 0.01) enhanced the relaxation induced by GYY4137 yielding IC50 value of 0.13 ± 0.08 µM (n = 6). Both the inhibitors of cystathionine ß-synthase (aminooxyacetic acid, AOAA, 30 µM) and cystathionine γ-lyase (propargylglycine, PAG, 1 mM) caused significant (p < 0.05) rightward shifts in the concentration-response curve to GYY4137. Furthermore, the KATP channel antagonist, glibenclamide (100 µM) significantly (p < 0.01) attenuated the relaxant action induced by GYY4137 on bovine ciliary artery. Conversely, the activator of cystathionine ß-synthase, SAM (100 µM) and an inhibitor of nitric oxide synthase, L-NAME (100 µM) had no significant effect on relaxations induced by GYY4137. We conclude that the inhibitory action of GYY4137 on isolated bovine ciliary artery is dependent upon the endogenous production of both prostanoids and H2S. Furthermore, the observed vascular smooth muscle relaxation induced by GYY4137 is mediated, at least in part, by KATP channels.

A Systematic Literature Review of the Relationship between Serum Ferritin and Outcomes in Myelodysplastic Syndromes.

Anemia is the most common form of cytopenia in patients with myelodysplastic syndromes (MDS), who require chronic red blood cell transfusions and may present high serum ferritin (SF) levels as a result of iron overload. To better understand the potential effects of high SF levels, we conducted a systematic literature review (SLR) to identify evidence on the relationship between SF levels and clinical, economic, or humanistic outcomes in adult patients with MDS. Of 267 references identified, 21 were included. No studies assessing SF levels and their relationship with humanistic or economic outcomes were identified. Increased SF levels were an indicator of worse overall survival and other worsened outcomes; however, the association was not consistently significant. SF levels were a significant prognostic factor for relapse incidence of MDS and showed a significant positive correlation with number of blood units transfused but were not associated with progression to acute myeloid leukemia or the time to transformation. Higher SF levels were also an indicator of a lower likelihood of leukemia-free survival, relapse-free survival, and event-free survival. The SLR suggests that SF levels are associated with clinical outcomes in MDS, with higher levels correlated with number of blood units transfused, frequently indicating worse outcomes.

Relationship between Serum Ferritin and Outcomes in ß-Thalassemia: A Systematic Literature Review.

Among the difficulties of living with ß-thalassemia, patients frequently require blood transfusions and experience iron overload. As serum ferritin (SF) provides an indication of potential iron overload, we conducted a systematic literature review (SLR) to assess whether SF levels are associated with clinical and economic burden and patient-reported outcomes (PROs). The SLR was conducted on 23 April 2020 and followed by analysis of the literature. Dual-screening was performed at the title, abstract, and full-text levels using predefined inclusion and exclusion criteria. Ten studies identified by the SLR were eligible for inclusion in the analysis. Seven studies were conducted in Europe, and most were prospective or retrospective in design. The patient populations had a median age of 20.7-42.6 years, with a percentage of men of 38-80%. Sparse data were found on the correlation between SF levels and mortality, and hepatic, skeletal, and cardiac complications; however, in general, higher SF levels were associated with worsened outcomes. The bulk of the evidence reported on the significant association between higher SF levels and endocrine dysfunction in its many presentations, including a 14-fold increase in the risk of diabetes for patients with persistently elevated SF levels. No studies reporting data on PROs or economic burden were identified by the SLR. SF levels provide another option for prognostic assessment to predict a range of clinical outcomes in patients with ß-thalassemia.

An indirect treatment comparison of the efficacy of patisiran and tafamidis for the treatment of hereditary transthyretin-mediated amyloidosis with polyneuropathy.

BACKGROUND: Hereditary transthyretin-mediated amyloidosis (hATTR amyloidosis) is a progressive, life-threatening disease. Until recently, tafamidis was the only approved pharmacotherapy. Patisiran significantly improved polyneuropathy and quality of life (QoL) in the phase III APOLLO trial. In the absence of direct comparisons, this analysis aimed to evaluate the comparative efficacy of tafamidis and patisiran in hATTR amyloidosis with polyneuropathy. RESEARCH DESIGN AND METHODS: Randomized controlled trial evidence for tafamidis was identified by systematic literature review. Indirect treatment comparisons were performed using the standard pairwise Bucher method for endpoints used in both APOLLO and the tafamidis Fx-005 trial: change from baseline in Neuropathy Impairment Score-lower limbs (NIS-LL), Norfolk QoL-Diabetic Neuropathy questionnaire (QoL-DN), NIS-LL response, and mBMI vs. placebo. Inter-trial population differences were assessed by sensitivity analysis. RESULTS: The base-case analysis (FAP Stage 1 APOLLO patients vs. intent-to-treat Fx-005 population) suggested patisiran had a greater treatment effect vs. tafamidis for all endpoints, with significant improvements in mean change in NIS-LL (-5.49) and QoL-DN (-13.10) from baseline to Month 18. Similar trends were observed in all sensitivity analyses. CONCLUSIONS: In the absence of direct comparisons, this analysis suggests patisiran has a greater treatment effect than tafamidis in patients with hATTR amyloidosis with polyneuropathy.

Interaction between hydrogen sulfide, nitric oxide, and carbon monoxide pathways in the bovine isolated retina.

PURPOSE: Nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S) are physiologically relevant gaseous neurotransmitters that are endogenously produced in mammalian tissues. In the present study, we investigated the possibility that NO and CO can regulate the endogenous levels of H2S in bovine isolated neural retina. METHODS: Isolated bovine neural retina were homogenized and tissue homogenates were treated with a NO synthase inhibitor, NO donor, heme oxygenase-1 inhibitor, and/donor. H2S concentrations in bovine retinal homogenates were measured using a well-established colorimetric assay. RESULTS: L-NAME (300 nM-500 µM) caused a concentration-dependent decrease in basal endogenous levels of H2S by 86.2%. On the other hand, SNP (10-300 µM) elicited a concentration-related increase in H2S levels from 18.3 nM/mg of protein to 65.7 nM/mg of protein. ZnPP-IX (300 nM-10 µM) caused a concentration-dependent increase in the endogenous production of H2S whereas hemin (300 nM-20 µM) attenuated the basal levels of H2S. CONCLUSION: We conclude that changes in the biosynthesis and availability of both NO and CO can interfere with the pathway/s involved in the production of H2S in the retina. The demonstrated ability of NO, CO and H2S to interact in the mammalian retina affirms a physiological/pharmacological role for these gaseous mediators in the eye.

Effect of Hydrogen Sulfide Donors on Intraocular Pressure in Rabbits.

PURPOSE: In this study, we investigated the effect of a slow-releasing hydrogen sulfide (H2S) donor, GYY 4137, on intraocular pressure (IOP) in normotensive rabbits. Furthermore, we compared the IOP-lowering action of GYY 4137 with those elicited by other H2S-producing compounds, l-cysteine and ACS67 (a hybrid compound of latanoprost with an H2S-releasing moiety). METHODS: IOP was measured in New Zealand normotensive male albino rabbits using a pneumatonometer (model 30 classic; Reichert Ophthalmic Instruments, Depew, NY). At 0 h, 50 µL of test compounds were applied topically to 1 eye of each animal, while the contralateral eye received the same quantity of vehicle (saline). IOP was measured hourly until baseline IOP readings were attained and animal eyes monitored for potential side effects (i.e., tearing, hyperemia). RESULTS: GYY 4137 (0.1%-2%) produced a dose-dependent decrease in IOP reaching a maximum of 27.8% ± 3.14% (n = 5) after 6 h. Interestingly, a significant contralateral effect was observed in vehicle-treated controls eyes at all doses tested. l-cysteine (5%) and ACS67 (0.005%) also elicited a significant (P < 0.01) decrease in IOP that achieved a maximum of 28.84% ± 1.53% (n = 5) and 23.27% ± 0.51% (n = 5), respectively, after 3 h. All 3 H2S-producing compounds also caused a significant contralateral effect in vehicle-treated control eyes. CONCLUSION: We conclude that GYY 4137 and other H2S-producing donors can reduce IOP in normotensive rabbits. However, the profile of IOP-lowering action of GYY 4137 was different from the other H2S donors affirming its ability to act as a slow-releasing gas donor.

Lipid peroxidation: pathophysiological and pharmacological implications in the eye.

Oxygen-derived free radicals such as hydroxyl and hydroperoxyl species have been shown to oxidize phospholipids and other membrane lipid components leading to lipid peroxidation. In the eye, lipid peroxidation has been reported to play an important role in degenerative ocular diseases (age-related macular degeneration, cataract, glaucoma, diabetic retinopathy). Indeed, ocular tissues are prone to damage from reactive oxygen species due to stress from constant exposure of the eye to sunlight, atmospheric oxygen and environmental chemicals. Furthermore, free radical catalyzed peroxidation of long chain polyunsaturated acids (LCPUFAs) such as arachidonic acid and docosahexaenoic acid leads to generation of LCPUFA metabolites including isoprostanes and neuroprostanes that may further exert pharmacological/toxicological actions in ocular tissues. Evidence from literature supports the presence of endogenous defense mechanisms against reactive oxygen species in the eye, thereby presenting new avenues for the prevention and treatment of ocular degeneration. Hydrogen peroxide (H2O2) and synthetic peroxides can exert pharmacological and toxicological effects on tissues of the anterior uvea of several mammalian species. There is evidence suggesting that the retina, especially retinal ganglion cells can exhibit unique characteristics of antioxidant defense mechanisms. In the posterior segment of the eye, H2O2 and synthetic peroxides produce an inhibitory action on glutamate release (using [(3)H]-D-aspartate as a marker), in vitro and on the endogenous glutamate and glycine concentrations in vivo. In addition to peroxides, isoprostanes can elicit both excitatory and inhibitory effects on norepinephrine (NE) release from sympathetic nerves in isolated mammalian iris ciliary bodies. Whereas isoprostanes attenuate dopamine release from mammalian neural retina, in vitro, these novel arachidonic acid metabolites exhibit a biphasic regulatory effect on glutamate release from retina and can regulate amino acid neurotransmitter metabolism without inducing cell death in the retina. Furthermore, there appears to be an inhibitory role for neuroprostanes in the release of excitatory amino acid neurotransmitters in mammalian retina. The ability of peroxides and metabolites of LCPUFA to alter the integrity of neurotransmitter pools provides new potential target sites and pathways for the treatment of degenerative ocular diseases.

Hydrogen sulfide: role in ion channel and transporter modulation in the eye.

Hydrogen sulfide (H(2)S), a colorless gas with a characteristic smell of rotten eggs, has been portrayed for decades as a toxic environmental pollutant. Since evidence of its basal production in mammalian tissues a decade ago, H(2)S has attracted substantial interest as a potential inorganic gaseous mediator with biological importance in cellular functions. Current research suggests that, next to its counterparts nitric oxide and carbon monoxide, H(2)S is an important multifunctional signaling molecule with pivotal regulatory roles in various physiological and pathophysiological processes as diverse as learning and memory, modulation of synaptic activities, cell survival, inflammation, and maintenance of vascular tone in the central nervous and cardiovascular systems. In contrast, there are few reports of a regulatory role of H(2)S in the eye. Accumulating reports on the pharmacological role of H(2)S in ocular tissues indicate the existence of a functional trans-sulfuration pathway and a potential physiological role for H(2)S as a gaseous neuromodulator in the eye. Thus, understanding the role of H(2)S in vision-related processes is imperative to our expanding knowledge of this molecule as a gaseous mediator in ocular tissues. This review aims to provide a comprehensive and current understanding of the potential role of H(2)S as a signaling molecule in the eye. This objective is achieved by discussing the involvement of H(2)S in the regulation of (1) ion channels such as calcium (L-type, T-type, and intracellular stores), potassium (K(ATP) and small conductance channels) and chloride channels, (2) glutamate transporters such as EAAT1/GLAST and the L-cystine/glutamate antiporter. The role of H(2)S as an important mediator in cellular functions and physiological processes that are triggered by its interaction with ion channels/transporters in the eye will also be discussed.