Role of Phosphodiesterases in Biology and Pathology 2.0.

Phosphodiesterases (PDEs) are ubiquitous enzymes that hydrolyse cAMP and cGMP second messengers temporally, spatially, and integratedly according to their expression and compartmentalization inside the cell [...].

Aortopathy and aortic valve surgery in patients with bicuspid aortic valve with and without raphe.

AIM: To evaluate the association between raphe in bicuspid aortic valve (BAV) patients and valve dysfunction, aortopathy and aortic valve surgery in the REBECCA registry [REgistro della valvola aortica Bicuspide della Società Italiana di ECocardiografia e CArdiovascular Imaging (SIECVI)]. METHODS: Prevalence of aortic valve dysfunction and aortopathy was investigated in BAV patients with and without raphe. Aortic valve dysfunction (regurgitation or stenosis) was categorized as mild, moderate and severe. Aortopathy was defined as annulus ≥14 mm/m2; root ≥20 mm/m2; sinotubular junction ≥16 mm/m2; ascending aorta ≥17 mm/m2, and classified in Type A, isolated ascending aorta dilatation; Type B, aortic root and ascending aorta dilatation; and Type C, isolated aortic root dilatation. RESULTS: Overall, 695 patients with BAV were enrolled; 520 (74.8%) with raphe and 175 (25.2%) without raphe. BAV patients with raphe presented more frequently with moderate or severe aortic stenosis than BAV patients without raphe (183 [35.2%] vs 34 [19.4%], p < 0.001). A higher prevalence of aortopathy, particularly Type B, was observed in patients with vs without raphe. At multivariable analysis, raphe was a predictor of aortic valve surgery at three-year follow-up (odds ratio 2.19, 95% confidence interval 1.08-4.44, p < 0.001). CONCLUSIONS: Patients with BAV and raphe have a higher prevalence of significant aortic stenosis, aortopathy, especially Type B, and a higher risk of undergoing aortic valve surgery at three-year follow-up.

Transthyretin cardiac amyloidosis in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement: experience of a single center.

BACKGROUND: Even if prevalent among patients with severe aortic stenosis (AS), the clinical suspicion for transthyretin cardiac amyloidosis (ATTR-CA) remains difficult in this subset. We report our single center experience on ATTR-CA detection among TAVR candidates to provide insights on the prevalence and clinical features of dual pathology as compared to lone AS. METHODS: Consecutive severe AS patients undergoing transcatheter aortic valve replacement (TAVR) evaluation at a single center were prospectively included. Those with suspected ATTR-CA based on clinical assessment underwent 99m Tc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) bone scintigraphy. The RAISE score, a novel screening tool with high sensitivity for ATTR-CA in AS, was retrospectively calculated to rule-out ATTR-CA in the remaining patients. Patients were categorized as follow: "ATTR-CA+": patients with confirmed ATTR-CA at DPD bone scintigraphy; "ATTR-CA-": patients with negative DPD bone scintigraphy or a negative RAISE score; "ATTR-CA indeterminate": patients not undergoing ATTR-CA assessment with a positive RAISE score. The characteristics of ATTR-CA+ and ATTR-CA- patients were compared. RESULTS: Of 107 included patients, ATTR-CA suspicion was posed in 13 patients and confirmed in six. Patients were categorized as follow: 6 (5.6%) ATTR-CA+, 79 (73.8%) ATTR-CA-, 22 (20.6%) ATTR-CA indeterminate. Excluding ATTR-CA indeterminate patients, the prevalence of ATTR-CA was 7.1% (95% CI 2.6-14.7%). As compared to ATTR-CA - patients, ATTR-CA + patients were older, had higher procedural risk and more extensive myocardial and renal damage. They had higher left ventricle mass index and lower ECG voltages, translating into a lower voltage to mass ratio. Moreover, we describe for the first time bifascicular block as an ECG feature highly specific of patients with dual pathology (50.0% vs. 2.7%, P<0.001). Of note, pericardial effusion was rarely found in patients with lone AS (16.7% vs. 1.2%, P=0.027). No difference in procedural outcomes was observed between groups. CONCLUSIONS: Among severe AS patients, ATTR-CA is prevalent and presents with phenotypic features that may aid to differentiate it from lone AS. A clinical approach based on routine search of amyloidosis features might lead to selective DPD bone scintigraphy with a satisfactory positive predictive value.

Defects in AMPAR trafficking and microglia activation underlie socio-cognitive deficits associated to decreased expression of phosphodiesterase 2 a.

Phosphodiesterase 2 A (PDE2A) is an enzyme involved in the homeostasis of cAMP and cGMP and is the most highly expressed PDE in human brain regions critical for socio-cognitive behavior. In cerebral cortex and hippocampus, PDE2A expression level is upregulated in Fmr1-KO mice, a model of the Fragile X Syndrome (FXS), the most common form of inherited intellectual disability (ID) and autism spectrum disorder (ASD). Indeed, PDE2A translation is negatively modulated by FMRP, whose functional absence causes FXS. While the pharmacological inhibition of PDE2A has been associated to its pro-cognitive role in normal animals and in models of ID and ASD, homozygous PDE2A mutations have been identified in patients affected by ID, ASD and epilepsy. To clarify this apparent paradox about the role of PDE2A in brain development, we characterized here Pde2a+/- mice (homozygote animals being not viable) at the behavioral, cellular, molecular and electrophysiological levels. Pde2a+/- females display a milder form of the disorder with reduced cognitive performance in adulthood, conversely males show severe socio-cognitive deficits throughout their life. In males, these phenotypes are associated with microglia activation, elevated glutathione levels and increased externalization of Glutamate receptor (GluR1) in CA1, producing reduced mGluR-dependent Long-term Depression. Overall, our results reveal molecular targets of the PDE2A-dependent pathway underlying socio-cognitive performance. These results clarify the mechanism of action of pro-cognitive drugs based on PDE2A inactivation, which have been shown to be promising therapeutic approaches for Alzheimer's disease, schizophrenia, FXS as well as other forms of ASD.

Structural Characterization of Murine Phosphodiesterase 5 Isoforms and Involvement of Cysteine Residues in Supramolecular Assembly.

Phosphodiesterases (PDEs) are a superfamily of evolutionarily conserved cyclic nucleotide (cAMP/cGMP)-hydrolyzing enzymes, components of transduction pathways regulating crucial aspects of cell life. Within this family, the cGMP-dependent PDE5 is the major hydrolyzing enzyme in many mammalian tissues, where it regulates a number of cellular and tissular processes. Using Kluyveromyces lactis as a model organism, the murine PDE5A1, A2 and A3 isoforms were successfully expressed and studied, evidencing, for the first time, a distinct role of each isoform in the control, modulation and maintenance of the cellular redox metabolism. Moreover, we demonstrated that the short N-terminal peptide is responsible for the tetrameric assembly of MmPDE5A1 and for the mitochondrial localization of MmPDE5A2. We also analyzed MmPDE5A1, A2 and A3 using small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), structural mass spectrometry (MS) and polyacrylamide gel electrophoresis in their native conditions (native-PAGE) and in the presence of redox agents. These analyses pointed towards the role of a few specific cysteines in the isoforms' oligomeric assembly and the loss of enzymatic activity when modified.

Cellular Redox Metabolism Is Modulated by the Distinct Localization of Cyclic Nucleotide Phosphodiesterase 5A Isoforms.

3'-5' cyclic nucleotide phosphodiesterases (PDEs) are a family of evolutionarily conserved cAMP and/or cGMP hydrolyzing enzymes, components of transduction pathways regulating crucial aspects of cell life. Among them, cGMP-specific PDE5-being a regulator of vascular smooth muscle contraction-is the molecular target of several drugs used to treat erectile dysfunction and pulmonary hypertension. Production of full-length murine PDE5A isoforms in the milk-yeast Kluyveromyces lactis showed that the quaternary assembly of MmPDE5A1 is a mixture of dimers and tetramers, while MmPDE5A2 and MmPDE5A3 only assembled as dimers. We showed that the N-terminal peptide is responsible for the tetramer assembly of MmPDE5A1, while that of the MmPDE5A2 is responsible for its mitochondrial localization. Overexpression of the three isoforms alters at different levels the cAMP/cGMP equilibrium as well as the NAD(P)+/NAD(P)H balance and induces a metabolic switch from oxidative to fermentative. In particular, the mitochondrial localization of MmPDE5A2 unveiled the existence of a cAMP-cGMP signaling cascade in this organelle, for which we propose a metabolic model that could explain the role of PDE5 in some cardiomyopathies and some of the side effects of its inhibitors.

Italian Real-Life Experience of Patients with Hereditary Transthyretin Amyloidosis Treated with Patisiran.

Hereditary transthyretin amyloidosis (ATTRv) is a multisystemic, rare, inherited, progressive and adult-onset disease, affecting the sensorimotor nerves, heart, autonomic function and other organs. The actual scenario of pharmaceutical approaches for ATTRv amyloidosis includes five main groups: TTR stabilizers, TTR mRNA silencers, TTR fibril disruptors, inhibitor of TTR fibril seeding and gene therapy. Patisiran is a small, double-stranded interfering RNA encapsulated in a lipid nanoparticle, able to penetrate into hepatocytes, where it selectively targets TTR mRNA, reducing TTR production. We report and discuss 9 cases of different patients with ATTRv amyloidosis successfully managed with patisiran in the real clinical practice. Literature data, as well as the above presented case reports, show that this drug is effective and safe in improving both neurological and cardiovascular symptoms of ATTRv amyloidosis, and to maintain a good QoL, independently form the stage of the disease and the involved mutation. Recent studies correlated improved functional and biochemical outcomes with a regression of amyloid burden, especially at the cardiac level. Today, patisiran can be considered a valid therapeutic option for the management of patients with ATTRv amyloidosis and polyneuropathy and cardiovascular symptoms.

Phosphodiesterase 2A inhibition corrects the aberrant behavioral traits observed in genetic and environmental preclinical models of Autism Spectrum Disorder.

Pharmacological inhibition of phosphodiesterase 2A (PDE2A), which catalyzes the hydrolysis of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), has recently been proposed as a novel therapeutic tool for Fragile X Syndrome (FXS), the leading monogenic cause of Autism Spectrum Disorder (ASD). Here, we investigated the role of PDE2A in ASD pathogenesis using two rat models that reflect one of either the genetic or environmental factors involved in the human disease: the genetic Fmr1-Δexon 8 rat model and the environmental rat model based on prenatal exposure to valproic acid (VPA, 500 mg/kg). Prior to behavioral testing, the offspring was treated with the PDE2A inhibitor BAY607550 (0.05 mg/kg at infancy, 0.1 mg/kg at adolescence and adulthood). Socio-communicative symptoms were assessed in both models through the ultrasonic vocalization test at infancy and three-chamber test at adolescence and adulthood, while cognitive impairments were assessed by the novel object recognition test in Fmr1-Δexon 8 rats (adolescence and adulthood) and by the inhibitory avoidance test in VPA-exposed rats (adulthood). PDE2A enzymatic activity in VPA-exposed infant rats was also assessed. In line with the increased PDE2A enzymatic activity previously observed in the brain of Fmr1-KO animals, we found an altered upstream regulation of PDE2A activity in the brain of VPA-exposed rats at an early developmental age (p < 0.05). Pharmacological inhibition of PDE2A normalized the communicative (p < 0.01, p < 0.05), social (p < 0.001, p < 0.05), and cognitive impairment (p < 0.001) displayed by both Fmr1-Δexon 8 and VPA-exposed rats. Altogether, these data highlight a key role of PDE2A in brain development and point to PDE2A inhibition as a promising pharmacological approach for the deficits common to both FXS and ASD.

Phosphodiesterase 5a Signalling in Skeletal Muscle Pathophysiology.

Phosphodiesterase 5A (PDE5A) is involved in cGMP hydrolysis, regulating many physiological processes. Increased activity of PDE5A has been found in several pathological conditions, and the pharmacological inhibition of PDE5 has been demonstrated to have several therapeutic applications. We have identified the presence of three different Pde5a isoforms in cardiomyocytes, and we have found that the expression of specific Pde5a isoforms may have a causal role in the onset of pathological responses in these cells. In our previous study, we demonstrated that PDE5A inhibition could ameliorate muscular dystrophy by acting at different levels, as assessed by the altered genomic response of muscular cells following treatment with the PDE5A inhibitor tadalafil. Thus, considering the importance of PDE5A in various pathophysiological conditions, we further investigated the regulation of this enzyme. Here, we analysed the expression of Pde5a isoforms in the pathophysiology of skeletal muscle. We found that skeletal muscle tissues and myogenic cells express Pde5a1 and Pde5a2 isoforms, and we observed an increased expression of Pde5a1 in damaged skeletal muscles, while Pde5a2 levels remained unchanged. We also cloned and characterized the promoters that control the transcription of Pde5a isoforms, investigating which of the transcription factors predicted by bioinformatics analysis could be involved in their modulation. In conclusion, we found an overexpression of Pde5a1 in compromised muscle and identified an involvement of MyoD and Runx1 in Pde5a1 transcriptional activity.

Myocardial longitudinal strain as the first herald of cardiac impairment in very early iron overload state: an echocardiography and biosusceptometry study on beta-thalassemia patients.

BACKGROUND: Heart diseases due to iron overload are still the main cause of mortality in patients affected by beta-thalassemia. Detection of cardiac iron overload in pre-clinical stage allows tailoring of chelation therapy and follow-up strategies. Echocardiographic longitudinal strain analysis may be a useful tool for early detection of cardiac functional impairment iron-related. METHODS: We examined 58 patients with beta-thalassemia on regular blood transfusion and iron chelation, without overt cardiac disease who had recent Biosusceptometry SQUID to quantify liver iron concentration and cardiac assessment by CMR T2*. RESULTS: Average global longitudinal strain (GLS) was able to identify abnormal (<20 ms) cardiac T2* values with 96% specificity and negative predictive value of 92% (AUC 0.84, P=0.01). Apical 4-ch GLS may help identify early longitudinal impairment associated with severe liver iron overload with 96% specificity and negative predictive value of 92% (AUC 0.84, P=0.02). Patients with severe liver iron overload had lower average Global Longitudinal Strain values compared to other patients (P-value =0.005). CONCLUSION: GLS was a sensitive marker to detect both myocardial and liver iron overload in a population that is still free from cardiac symptoms. Thus, strain echocardiography may be a useful tool for early detection of iron overload in Beta-thalassemia.

Reshaping of Italian Echocardiographic Laboratories Activities during the Second Wave of COVID-19 Pandemic and Expectations for the Post-Pandemic Era.

BACKGROUND: Cardiology divisions reshaped their activities during the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to analyze the organization of echocardiographic laboratories and echocardiography practice during the second wave of the COVID-19 pandemic in Italy, and the expectations for the post-COVID era. METHODS: We analyzed two different time periods: the month of November during the second wave of the COVID-19 pandemic (2020) and the identical month during 2019 (November 2019). RESULTS: During the second wave of the COVID-19 pandemic, the hospital activity was partially reduced in 42 (60%) and wholly interrupted in 3 (4%) echocardiographic laboratories, whereas outpatient echocardiographic activity was partially reduced in 41 (59%) and completely interrupted in 7 (10%) laboratories. We observed an important change in the organization of activities in the echocardiography laboratory which reduced the operator-risk and improved self-protection of operators by using appropriate personal protection equipment. Operators wore FFP2 in 58 centers (83%) during trans-thoracic echocardiography (TTE), in 65 centers (93%) during transesophageal echocardiography (TEE) and 63 centers (90%) during stress echocardiography. The second wave caused a significant reduction in number of echocardiographic exams, compared to November 2019 (from 513 ± 539 to 341 ± 299 exams per center, -34%, p < 0.001). On average, there was a significant increase in the outpatient waiting list for elective echocardiographic exams (from 32.0 ± 28.1 to 45.5 ± 44.9 days, +41%, p < 0.001), with a reduction of in-hospital waiting list (2.9 ± 2.4 to 2.4 ± 2.0 days, -17%, p < 0.001). We observed a large diffusion of point-of-care cardiac ultrasound (88%), with a significant increase of lung ultrasound usage in 30 centers (43%) during 2019, extended to all centers in 2020. Carbon dioxide production by examination is an indicator of the environmental impact of technology (100-fold less with echocardiography compared to other cardiac imaging techniques). It was ignored in 2019 by 100% of centers, and currently it is considered potentially crucial for decision-making in cardiac imaging by 65 centers (93%). CONCLUSIONS: In one year, major changes occurred in echocardiography practice and culture. The examination structure changed with extensive usage of point-of-care cardiac ultrasound and with lung ultrasound embedded by default in the TTE examination, as well as the COVID-19 testing.

Wild-Type and Mutant FUS Expression Reduce Proliferation and Neuronal Differentiation Properties of Neural Stem Progenitor Cells.

Nervous system development involves proliferation and cell specification of progenitor cells into neurons and glial cells. Unveiling how this complex process is orchestrated under physiological conditions and deciphering the molecular and cellular changes leading to neurological diseases is mandatory. To date, great efforts have been aimed at identifying gene mutations associated with many neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). Mutations in the RNA/DNA binding protein Fused in Sarcoma/Translocated in Liposarcoma (FUS/TLS) have been associated with motor neuron degeneration in rodents and humans. Furthermore, increased levels of the wild-type protein can promote neuronal cell death. Despite the well-established causal link between FUS mutations and ALS, its role in neural cells remains elusive. In order to shed new light on FUS functions we studied its role in the control of neural stem progenitor cell (NSPC) properties. Here, we report that human wild-type Fused in Sarcoma (WT FUS), exogenously expressed in mouse embryonic spinal cord-derived NSPCs, was localized in the nucleus, caused cell cycle arrest in G1 phase by affecting cell cycle regulator expression, and strongly reduced neuronal differentiation. Furthermore, the expression of the human mutant form of FUS (P525L-FUS), associated with early-onset ALS, drives the cells preferentially towards a glial lineage, strongly reducing the number of developing neurons. These results provide insight into the involvement of FUS in NSPC proliferation and differentiation into neurons and glia.

Phosphodiesterase 4D Depletion/Inhibition Exerts Anti-Oncogenic Properties in Hepatocellular Carcinoma.

Isoform D of type 4 phosphodiesterase (PDE4D) has recently been associated with several human cancer types with the exception of human hepatocellular carcinoma (HCC). Here we explored the role of PDE4D in HCC. We found that PDE4D gene/protein were over-expressed in different samples of human HCCs compared to normal livers. Accordingly, HCC cells showed higher PDE4D activity than non-tumorigenic cells, accompanied by over-expression of the PDE4D isoform. Silencing of PDE4D gene and pharmacological inhibition of protein activity by the specific inhibitor Gebr-7b reduced cell proliferation and increased apoptosis in HCC cells, with a decreased fraction of cells in S phase and a differential modulation of key regulators of cell cycle and apoptosis. PDE4D silencing/inhibition also affected the gene expression of several cancer-related genes, such as the pro-oncogenic insulin growth factor (IGF2), which is down-regulated. Finally, gene expression data, available in the CancerLivER data base, confirm that PDE4D over-expression in human HCCs correlated with an increased expression of IGF2, suggesting a new possible molecular network that requires further investigations. In conclusion, intracellular depletion/inhibition of PDE4D prevents the growth of HCC cells, displaying anti-oncogenic effects. PDE4D may thus represent a new biomarker for diagnosis and a potential adjuvant target for HCC therapy.

Transjugular intrahepatic portosystemic shunt in refractory ascites: clinical impact of left ventricular diastolic dysfunction.

BACKGROUND AND AIMS: Left ventricular diastolic dysfunction (LVDD) in cirrhotics are associated with circulatory dysfunction, hepatorenal syndrome (HRS) and heart failure in stressful conditions. Transjugular intrahepatic portosystemic shunt (TIPS) exacerbates the hyperdynamic circulation and challenges cardiac function. We evaluated the incidence and the impact of LVDD in cirrhotic candidates to TIPS for refractory ascites. METHODS: Among 135 patients who underwent TIPS for refractory ascites, 63 cases (child B/C 53/10, Na-model for end-stage liver disease 16.5 ± 0.9) who had 2D-transthoracic-echocardiography with tissue-Doppler-imaging pre-TIPS were retrospectively analysed (group A); in 23 cases cardiac and hormonal assessment before and after TIPS was available. 41 cirrhotics without refractory ascites treated by banding ligation for variceal re-bleeding were used as controls (group B). RESULTS: The prevalence of LVDD was higher in group A (59%; 22% with grade ≥2) as compared to group B (35%; 7% with grade ≥2) (P < 0.01 and P < 0.03). A lack of clinical response to TIPS occurred in 10 patients, all with LVDD (P < 0.03 vs. no LVDD) and in patients with grade ≥2 LVDD mostly (P < 0.02 vs. grade 1). Central venous pressure >20 mmHg after TIPS and left ventricular end-diastolic volume at basal were predictors of no response to TIPS (P = 0.01 and P = 0.004, respectively), which was an independent predictor of death. Elevated levels of NT-proBNP 3 days after TIPS were associated with advanced cardiac dysfunction (P = 0.005). CONCLUSION: NT-proBNP and careful LVDD investigation are useful to better select patients and to predict clinical response and mortality after TIPS.

Phosphodiesterases Expression during Murine Cardiac Development.

3'-5' cyclic nucleotide phosphodiesterases (PDEs) are a large family of enzymes playing a fundamental role in the control of intracellular levels of cAMP and cGMP. Emerging evidence suggested an important role of phosphodiesterases in heart formation, but little is known about the expression of phosphodiesterases during cardiac development. In the present study, the pattern of expression and enzymatic activity of phosphodiesterases was investigated at different stages of heart formation. C57BL/6 mice were mated and embryos were collected from 14.5 to 18.5 days of development. Data obtained by qRT-PCR and Western blot analysis showed that seven different isoforms are expressed during heart development, and PDE1C, PDE2A, PDE4D, PDE5A and PDE8A are modulated from E14.5 to E18.5. In heart homogenates, the total cAMP and cGMP hydrolytic activity is constant at the evaluated times, and PDE4 accounts for the majority of the cAMP hydrolyzing ability and PDE2A accounts for cGMP hydrolysis. This study showed that a subset of PDEs is expressed in developing mice heart and some of them are modulated to maintain constant nucleotide phosphodiesterase activity in embryonic and fetal heart.

A2A Receptor Dysregulation in Dystonia DYT1 Knock-Out Mice.

We aimed to investigate A2A receptors in the basal ganglia of a DYT1 mouse model of dystonia. A2A was studied in control Tor1a+/+ and Tor1a+/- knock-out mice. A2A expression was assessed by anti-A2A antibody immunofluorescence and Western blotting. The co-localization of A2A was studied in striatal cholinergic interneurons identified by anti-choline-acetyltransferase (ChAT) antibody. A2A mRNA and cyclic adenosine monophosphate (cAMP) contents were also assessed. In Tor1a+/+, Western blotting detected an A2A 45 kDa band, which was stronger in the striatum and the globus pallidus than in the entopeduncular nucleus. Moreover, in Tor1a+/+, immunofluorescence showed A2A roundish aggregates, 0.3-0.4 µm in diameter, denser in the neuropil of the striatum and the globus pallidus than in the entopeduncular nucleus. In Tor1a+/-, A2A Western blotting expression and immunofluorescence aggregates appeared either increased in the striatum and the globus pallidus, or reduced in the entopeduncular nucleus. Moreover, in Tor1a+/-, A2A aggregates appeared increased in number on ChAT positive interneurons compared to Tor1a+/+. Finally, in Tor1a+/-, an increased content of cAMP signal was detected in the striatum, while significant levels of A2A mRNA were neo-expressed in the globus pallidus. In Tor1a+/-, opposite changes of A2A receptors' expression in the striatal-pallidal complex and the entopeduncular nucleus suggest that the pathophysiology of dystonia is critically dependent on a composite functional imbalance of the indirect over the direct pathway in basal ganglia.

Phosphodiesterase Inhibitors: Could They Be Beneficial for the Treatment of COVID-19?

In March 2020, the World Health Organization declared the severe acute respiratory syndrome corona virus 2 (SARS-CoV2) infection to be a pandemic disease. SARS-CoV2 was first identified in China and, despite the restrictive measures adopted, the epidemic has spread globally, becoming a pandemic in a very short time. Though there is growing knowledge of the SARS-CoV2 infection and its clinical manifestations, an effective cure to limit its acute symptoms and its severe complications has not yet been found. Given the worldwide health and economic emergency issues accompanying this pandemic, there is an absolute urgency to identify effective treatments and reduce the post infection outcomes. In this context, phosphodiesterases (PDEs), evolutionarily conserved cyclic nucleotide (cAMP/cGMP) hydrolyzing enzymes, could emerge as new potential targets. Given their extended distribution and modulating role in nearly all organs and cellular environments, a large number of drugs (PDE inhibitors) have been developed to control the specific functions of each PDE family. These PDE inhibitors have already been used in the treatment of pathologies that show clinical signs and symptoms completely or partially overlapping with post-COVID-19 conditions (e.g., thrombosis, inflammation, fibrosis), while new PDE-selective or pan-selective inhibitors are currently under study. This review discusses the state of the art of the different pathologies currently treated with phosphodiesterase inhibitors, highlighting the numerous similarities with the disorders linked to SARS-CoV2 infection, to support the hypothesis that PDE inhibitors, alone or in combination with other drugs, could be beneficial for the treatment of COVID-19.

Vascular Damage - Coronary Artery Disease.

Cardiovascular complications during chemotherapy and radiotherapy are becoming an increasing problem because many patients with cancer are treated with agents that exert significant vascular toxicity. Coronary heart disease in patients with cancer presents particular challenges, which directly impact the management of both the coronary disease and malignancy. Several chemotherapeutic agents have been shown to trigger ischemic heart disease, and as it has happened for myocardial cardiotoxicity, more attention should be dedicated to improving early recognition and prevention of cardiac vascular toxicity. Cardiac imaging could facilitate early detection of vascular toxicity, but a thorough risk stratification should always be performed to identify patients at higher risk of vascular impairment.

In the midst of a dangerous intersection with unclear therapeutic strategies: a challenging case of severe aortic stenosis.

BACKGROUND: One out of seven patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) may be affected by transthyretin cardiac amyloidosis (ATTR-CA), mostly presenting with low-flow low-gradient AS with mildly reduced ejection fraction. The complex interaction of these two pathologies poses specific diagnostic and management challenges. The prognostic implications of this clinical intersection are not defined yet. Moreover, whether TAVR may have a prognostic benefit in ATTR-CA patients with symptomatic severe AS remains unclear, posing doubts on the best management strategy in this increasingly recognized subset of patients. CLINICAL CASE: We present a case of an 87-year old man with low-flow low-gradient severe AS, for whom a diagnosis of ATTR-CA was suspected based on clinical and echocardiographic criteria specific to coexisting AS and ATTR-CA. The diagnosis was eventually confirmed by positive bone tracer scintigraphy imaging. Following in-depth Heart team discussion, integrating frailty and prognostic information from combined cardiomyopathy states, a decision was made to manage the patient's severe AS conservatively. CONCLUSION: In the presented case, we deemed the natural history of ATTR-CA amyloidosis to negatively affect both the patient' prognosis and procedural risk, adversing TAVR indication despite symptomatic severe AS. No clear evidence is currently available to guide decision making in this setting, advocating for prospective studies to clarify if TAVR may have a prognostic benefit in ATTR-CA - and which ATTR-CA - patients.

Management of antithrombotic therapy in gray areas of venous thromboembolism: a Delphi consensus panel.

For some years now, direct-acting oral anticoagulants (DOACs) have entered the clinical practice for stroke prevention in non-valvular atrial fibrillation (NVAF) or for prevention and treatment of venous thromboembolism (VTE). However, there is uncertainty on DOACs' use in some clinical scenarios that are not fully explored by clinical trials, but commonly encountered in the real world. We report a Delphi Consensus on DOAC use in VTE patients. The consensus dealt with seven main topics: (1) clinical superiority of DOACs compared to VKAs; (2) therapeutic options for patients with intermediate risk PE; (3) therapeutic management of patients with deep vein thrombosis (DVT); (4) DOACs' role in oncological patients with VTE; (5) role of the reversal agent; (6) safety of low doses of DOACs in VTE patients; (7) DOACs long-term therapy (more than 12 months) in VTE patients; Forty-six physicians (cardiologists, internists, angiologists, oncologists, hematologists, and geriatricians) from Italy expressed their level of agreement on each statement by using a five-point Likert scale (1: strongly disagree, 2: disagree, 3: somewhat agree, 4: agree, 5: strongly agree). Votes 1-2 were considered as disagreement, while votes 3-5 as agreement. For each statement an agreement of ≥ 66% among the respondents was considered consensus. A brief discussion about the results for each topic is also reported.