Primary mitral valve regurgitation scheduled for cardiac surgery: no longer need for coronary angiography? A clinical retrospective & HTA analysis

Introduction

In patients (pts) undergoing cardiac surgery for primary mitral regurgitation (PMR), coronary angiography (CA) is always scheduled shortly before surgery to rule out significant coronary artery disease (CAD), despite this population is often young and with relatively low risk for CAD. Computed Tomography Coronary Angiography (CTCA) could be an alternative approach to evaluate coronary arteries, at least ruling out significant CAD in selected pts, due to its high negative predictive value.

Purpose

A safer, more appropriate and efficient clinical and diagnostic pathway for patients undergoing cardiac surgery for PMR by stratifying patients prior cardiac surgery according to pretest probability score (PTP) and therefore shifting imaging of epicardial coronary arteries from invasive to noninvasive in specific patients subsets.

Methods

A retrospective analysis (Jan 2014–Dec 2020) was carried out through the extraction of 7343 electronic medical records of pts who underwent cardiac valve surgery. In 1556 pts with PMR (1195 with no-CAD and 361 with CAD) a PTP was retrospectively calculated according to Genders, 2012, to stratify their risk of CAD.

A Decision oriented Health Technology Assessment (DoHTA) and a cost analysis were also performed to support the analysis results. A survey was distributed to a team of experts with a multidisciplinary background to analyze the most significant evaluation areas (Economic Aspects, Clinical Effectiveness, Safety, Innovation) and the sub-criteria related to them.

Following the Core Model Eunethta as a guideline, a Rapid Report HTA has been drawn up to identify the best solution.

Results

Patients characteristics are listed in Picture 1. Pts with normal coronary arteries showed a PTP low-to intermediate while pts with high PTP had CAD and therefore had a real pretest need for a CA (average 11 percent ± 9 in noCAD group vs 20 percent ± 14 in the CAD group). In two thirds of PMR population coronary angiography could have been avoided according to a PTP score <15 percent.

The cost analysis results were significantly lower in CTCA (1,315.00 EUR vs 180.00 EUR, CA vs CTCA respectively), The Decision Oriented HTA conducted by a multidisciplinary team showed a relevant preference for the new pathway (Picture 2) with a score of 70.23 percent of preference among the Team.

Conclusions

This new pathway, already proposed for selected pts in ESC guidelines on valve diseases (class IIA, LOE C) could be always adopted in PMR pts with low-to intermediate PTP score undergoing cardiac surgery. It could improve workflow efficiency and reduce LOS, and last but not least, avoid an invasive test, reduce radiation exposure and AKI risk in in a relatively young population

The DoHTA provided a more effective and efficient support to the decision-making process.

Funding Acknowledgement

Type of funding sources: None. Picture 1. Patients characteristics (noCAD-CAD)Picture 2. HTA Score CTCA vs CA

Observed concentrations of amikacin and gentamycin in the setting of burn patients with gram-negative bacterial infections: Preliminary data from a prospective study

AIM OF THE STUDY

Critically ill populations often have shown subtherapeutic aminoglycosides' concentrations mostly because of unavoidable changes in drug volume distribution and clearance. We present a real life prospective study evaluating plasma concentrations for once-daily dosing for amikacin and gentamycin among a population of severe burn adults.

METHODS

We conducted a real life prospective study on the plasma observed concentrations of amikacin and gentamycin among severe burn patients, using aminoglycoside as combination therapy. Antibiotics were prescribed at the standard doses of 15-20mg/kg/day for amikacin and 3-5mg/kg/day for gentamycin.

RESULTS

Eight patients (4 in amikacin and 4 in gentamycin groups, respectively) were enrolled in the study. All subjects were admitted for severe burns. The most common site of infection was bloodstream (5; 62.5%) and pneumonia (4; 50%). Pseudomonas aeruginosa, followed by Klebsiella pneumoniae and multi-drug resistant Acinetobacter baumannii were the most prevalent agents isolated. Amikacin and gentamycin never achieved the target peak concentration of 60mg/L and 30mg/L: in our study C_max, for amikacin, was 33.1±15.6mg/L (SD), while for gentamycin was 14.3mg/L±9. C_max and total body surface area have shown a strong negative correlation with borderline statistical significance (amikacin: ρ=0.922, P=0.078; gentamycin: ρ=0.937, P=0.063). At the standard dosage, the pharmacokinetic/pharmacodynamic (PK/PD) target of C_max>8×highest MIC was reached for 8 (53.3%) out of 15 isolated pathogens.

CONCLUSIONS

The present study found that, in a population of septic burn patients, standard doses of gentamycin and amikacin most often lead to plasma concentrations under the PK/PD target.

Epidemiology, prevalence and risk factors for infections in burn patients: results from a regional burn centre's analysis

Burn patients are at high risk of infections due to severe impairment of immunity and loss of skin barrier function. We aimed to describe the epidemiology, incidence and risk factors for infection in a cohort of burns patients. Two hundred patients were retrospectively enrolled and subdivided into infected (N = 81) and uninfected groups (N = 119). The cumulative prevalence of infections was 27% on day 7 and 43.8% on day 28. Skin and soft tissue infections (32%) were the most frequent. Carbapenem-resistant Acinetobacter baumannii (28%), Pseudomonas aeruginosa (26%) and methicillin-resistant Staphylococcus aureus (25%) infections were most prevalent. An indwelling central venous catheter (CVC; sub-hazard ratio [SHR] 7.41, 95% confidence interval [CI] 3.78-14.62) and revised Baux score (RBS; SHR 2.08, 95% CI 0.98-4.42) were associated with higher incremental infection rate while surgical treatment resulted in a protective factor (SHR 0.45, 95% CI 0.29-0.75). RBS may be useful to stratify the infection risk: a strict collaboration between surgeons and infectious disease specialists is needed to implement source control and antimicrobial surveillance.

Synthesis of new 1,2,3-benzotriazin-4-one-arylpiperazine derivatives as 5-HT1A serotonin receptor ligands

A series of novel 1,2,3-benzotriazin-4-one derivatives was prepared and evaluated as ligands for 5-HT receptors. Radioligand binding assays proved that the majority of the novel compounds behaved as good to excellent ligands at the 5-HT1A receptor, some of which were selective with respect 5-HT2A and 5-HT2C receptors. Six analogues (1a, 2a, 2b, 2c, 2e and 2i) were selected and further evaluated for their binding affinities on D1, D2 dopaminergic and alpha1-, alpha2-adrenergic receptors. A o-OCH3 derivative (2e) bound at 5-HT1A sites with subnanomolar affinity (IC50 = 0.059 nM) and shows high selectivity over all considered receptors and may offer a new lead for the development of therapeutically efficacious agents.

Novel potent and selective central 5-HT3 receptor ligands provided with different intrinsic efficacy. 2. Molecular basis of the intrinsic efficacy of arylpiperazine derivatives at the central 5-HT3 receptors

Novel 5-HT3 receptor ligands were designed and synthesized with the aim of obtaining deeper insight into the molecular basis of the intrinsic efficacy of arylpiperazines interacting with the central 5-HT3 receptor. The newly synthesized compounds and some previously published compounds belonging to the same class of heteroarylpiperazines were tested for their potential ability to displace [3H]granisetron from rat cortical membranes. These 5-HT3 receptor binding studies revealed subnanomolar affinity in several of the compounds under study. The most active ligands were quipazine derivatives bearing a phenyl group in the 4-position and various oxygenated alkyl side chains in the 3-position of the quinoline nucleus. Qualitative and theoretical quantitative structure-affinity relationship studies were carried out, and the interaction model for the 5-HT3 ligands related to quipazine with their receptor, proposed in part 1 of the present work, was updated to incorporate the latest data. The potential 5-HT3 agonist/antagonist activity of 12 selected compounds was assessed in vitro on the 5-HT3 receptor-dependent [14C]guanidinium uptake in NG 108-15 cells. Their intrinsic efficacy ranged from the 5-HT3 full agonist properties of compounds 7a and 8h, i to those of partial agonists 10a,d and antagonists 8b,d,e, and 9c, d,h,i. The comparison between these functional data and those relative to the previously described compounds suggested that in this class of 5-HT3 ligands the intrinsic efficacy is modulated in a rather subtle manner by the steric features of the heteroaryl moiety.

Novel potent and selective central 5-HT3 receptor ligands provided with different intrinsic efficacy. 1. Mapping the central 5-HT3 receptor binding site by arylpiperazine derivatives

Synthesis and pharmacological evaluation of a series of condensed quinoline and pyridine derivatives bearing a N-methylpiperazine moiety attached to the 2-position of the quinoline or pyridine nucleus are described. 5-HT receptor binding studies revealed subnanomolar affinity for the 5-HT3 receptor subtype in some of the compounds under study. The most active compound (5b) displayed a Ki value about 1 order of magnitude higher than that of quipazine along with a higher selectivity. The potential 5-HT3 agonist/antagonist activity of four selected compounds was assessed in vitro on 5-HT3 receptor-dependent [14C]guanidinium uptake in NG 108-15 cells. Compound 5j acted as a 5-HT3 agonist in this assay with an EC50 value close to that reported for quipazine, while 5b was a partial agonist with an EC50 value of about 0.25 nM, and compound 5c possessed antagonist properties with an IC50 value (approximately 8 nM) in the same range as those of previously characterized 5-HT3 receptor antagonists. Qualitative and quantitative structure-affinity relationship studies carried out by making use of theoretical molecular descriptors allowed to elucidate the role of the main pharmacophoric components and to develop a model for the interaction of the 5-HT3 ligands related to quipazine with their receptor.

Molecular basis of peripheral vs central benzodiazepine receptor selectivity in a new class of peripheral benzodiazepine receptor ligands related to alpidem

Alpidem (1), the anxiolytic imidazopyridine, has nanomolar binding affinity for both the central benzodiazepine receptor (CBR) and the peripheral benzodiazepine receptor (PBR). A novel class of PBR ligands related to alpidem has been designed by comparing the interaction models of alpidem with PBR and CBR. Several compounds in this class have shown high selectivity for PBR vs CBR, and the selectivity has been discussed in terms of interaction models. The binding behavior of the three selected compounds was extensively studied by competition and saturation assays, and the results suggest that they are capable of recognizing two sites labeled by [3H]PK11195. The molecular structure of one of the most active compounds (4e) has been determined by X-ray diffraction and compared with that of alpidem. Molecular modeling studies suggest that the bioactive conformation of 4e is likely to be very similar to the conformation found in the crystal.

Cardiovascular characterization of pyrrolo[2,1-d][1,5]benzothiazepine derivatives binding selectively to the peripheral-type benzodiazepine receptor (PBR): from dual PBR affinity and calcium antagonist activity to novel and selective calcium entry blockers

The synthesis and cardiovascular characterization of a series of novel pyrrolo[2,1-d][1,5]-benzothiazepine derivatives (54-68) are described. Selective peripheral-type benzodiazepine receptor (PBR) ligands, such as PK 11195 and Ro 5-4864, have recently been found to possess low but significant inhibitory activity of L-type calcium channels, and this property is implicated in the cardiovascular effects observed with these compounds. In functional studies both PK 11195 (1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxa mide) and Ro 5-4864 (4'-chlorodiazepam) did not display selectivity between cardiac and vascular tissue. Therefore, several 7-(acyloxy)-6-arylpyrrolo[2,1-d][1,5]benzothiazepines, potent and selective peripheral-type benzodiazepine receptor ligands recently developed by us (3, 7-20), were subjected to calcium channel receptor binding assay. Some of these compounds showed an unexpected potency in displacing the binding of [3H]nitrendipine from L-type calcium channels, much higher than that reported for PK 11195 and Ro 5-4864 and equal to or higher than that of reference calcium antagonists such as verapamil and (+)-cis-diltiazem. Specifically, in rat cortex homogenate, our prototypic PBR ligand 7-acetoxy-6-(p-methoxyphenyl)pyrrolo[2,1-d][1,5]benzothiazepine (3) showed an IC50 equal to 0.13 nM for inhibition of [3H]nitrendipine binding. Furthermore, in functional studies this compound displayed a clear-cut selectivity for cardiac over vascular tissue. Comparison of calcium antagonist activity on guinea pig aorta strips with the negative inotropic activity, determined by using isolated guinea pig left atria, revealed that 3 displayed higher selectivity than the reference (+)-cis-diltiazem. Thus, the pyrrolobenzothiazepine 3 might represent a new tool for characterizing the relationship between the PBR and cardiac function. Furthermore, we have also investigated the structural dependence of binding to PBR and L-type calcium channels, and this study allowed us to identify a new class of potent calcium channel blockers selective for cardiac over vascular tissue, with no affinity for PBR. A number of structure-activity relationship trends have been identified, and a possible explanation is advanced in order to account for the observed differences in selectivity. Three structural features, namely, (i) the saturation of the C(6)-C(7) double bond, with a consequent higher molecular flexibility, (ii) the presence of a substituent in the benzofused ring, and (iii) a basic side chain at C-10 of the pyrrolobenzothiazepine ring system, were found to be responsible for potent L-type calcium channel antagonism and clear-cut selectivity for cardiac over vascular tissue. Among the synthesized compounds the pyrrolobenzothiazepine 62 was found to be the most promising selective calcium channel blocker. Additionally, the molecular structure determination of the key intermediate 48 by X-ray diffraction, molecular modeling, and NMR analysis is reported.

Pyrrolo[2,1-c][1,4]benzothiazines: synthesis, structure-activity relationships, molecular modeling studies, and cardiovascular activity

The synthesis and pharmacological evaluation of a series of pyrrolo[1,4]benzothiazine derivatives are described. These compounds, related to diltiazem, have been shown to be representative of a novel series of calcium channel antagonists. The IC50S for inhibition of [3H]nitrendipine binding calculated by radioreceptor assay on rat cortex and rat heart homogenates showed that some of the described compounds possess an affinity equal to or higher than those of the reference calcium antagonists verapamil and cis-(+)-diltiazem. Furthermore, the alteration of the benzothiazepinone system of diltiazem to the pyrrolo[1,4]benzothiazine system of the title compounds resulted in a clear-cut selectivity for cardiac over vascular tissue, as shown in functional studies. In fact comparison of calcium antagonist activity on guinea pig aorta strips with the negative inotropic activity, determined by using an isolated guinea pig left atrium, revealed that the compounds examined displayed higher selectivity than the reference standard, within a wide variation of data. A number of structure-activity relationship trends have been identified, and possible explanation is advanced in order to account for the observed differences in selectivity. Prerequisite for in vitro calcium channel-blocking activity is the presence of two pharmacophores, namely, the substitution at C-4 and the substitution on the pyrrole ring. Two of the tested compounds, 8b and 28a, were identified as potent calcium antagonists selective for cardiac over vascular tissue.

Effect of acetaminophen on glutathione levels in rat testis and lung

Glutathione (GSH) levels in rat testis and lung after oral administration (3 g/kg) of acetaminophen (APAP) were studied. At the administered dose APAP is present in each organ and influences the GSH levels. APAP value of 114 micrograms/g was obtained in testis at 6 hr (peak time); in the lung the Cmax was 92 mu/g at 8 hr and this value lasted several hours longer than that in testis. GSH levels are also affected differently in the organs studied after APAP administration; the lungs seem to be the primary organ undergoing the depleting action of APAP. This process could not only cause toxicity, but also predispose those organs to the action of toxic compounds responsible for specific pathologies.

Pyrazolo[4,3-c]quinolines, synthesis and specific inhibition of benzodiazepine receptor binding. Note II

Two new series of 2-arylpyrazolo[4,3-c]quinolin-3-ones (6,8-difluoro- and 7,9-dichloro-derivatives) have been synthesized and tested for their ability to displace [3H]flunitrazepam from rat brain membranes. Several compounds possess comparable and sometimes higher affinity for central benzodiazepine receptors than that of diazepam. Some selected compounds were also tested in vivo in the anti-pentylenetetrazol test; some anticonvulsant activity resulted for the 6,8-difluoroderivatives only.

Pyrazolo [4,3-c] quinolines synthesis and specific inhibition of benzodiazepine receptor binding (Note I)

A series of 2-arylpyrazolo[4,3-c] quinolin-3-one derivatives, bearing different substituents in the two aromatic rings, were prepared and tested for their ability to displace [3H] flunitrazepam from rat brain membranes. Some compounds have shown an affinity for receptors comparable and sometimes higher than that of CGS series.