Blockage of the adenosine A2B receptor prevents cardiac fibroblasts overgrowth in rats with pulmonary arterial hypertension.

Sustained pressure overload and fibrosis of the right ventricle (RV) are the leading causes of mortality in pulmonary arterial hypertension (PAH). Although the role of adenosine in PAH has been attributed to the control of pulmonary vascular tone, cardiac reserve, and inflammatory processes, the involvement of the nucleoside in RV remodelling remains poorly understood. Conflicting results exist on targeting the low-affinity adenosine A2B receptor (A2BAR) for the treatment of PAH mostly because it displays dual roles in acute vs. chronic lung diseases. Herein, we investigated the role of the A2BAR in the viability/proliferation and collagen production by cardiac fibroblasts (CFs) isolated from RVs of rats with monocrotaline (MCT)-induced PAH. CFs from MCT-treated rats display higher cell viability/proliferation capacity and overexpress A2BAR compared to the cells from healthy littermates. The enzymatically stable adenosine analogue, 5'-N-ethylcarboxamidoadenosine (NECA, 1-30 µM), concentration-dependently increased growth, and type I collagen production by CFs originated from control and PAH rats, but its effects were more prominent in cells from rats with PAH. Blockage of the A2BAR with PSB603 (100 nM), but not of the A2AAR with SCH442416 (100 nM), attenuated the proliferative effect of NECA in CFs from PAH rats. The A2AAR agonist, CGS21680 (3 and 10 nM), was virtually devoid of effect. Overall, data suggest that adenosine signalling via A2BAR may contribute to RV overgrowth secondary to PAH. Therefore, blockage of the A2AAR may be a valuable therapeutic alternative to mitigate cardiac remodelling and prevent right heart failure in PAH patients.

Same-day discharge after elective percutaneous closure of patent foramen ovale.

Percutaneous closure of the patent foramen ovale (PFO) is increasingly performed in specific patients with cryptogenic stroke or clinical evidence of a paradoxical embolism. This study was performed to determine the safety of same-day discharge (SDD) following such procedures. This is a prospective, observational study of patients undergoing elective percutaneous PFO closure in a single tertiary center in Portugal between January 2020 and July 2023. AmplatzerTM devices (St. Jude Medical, St. Paul, MN, USA) and NobblestichTM EL (HeartStitch, Inc., Fountain Valley, CA, USA) were used. After 6 months, the following events were looked at: post-procedural paroxysmal atrial fibrillation, stroke, unplanned cardiac re-hospitalization, urgent cardiac surgery, major vascular complications, pericardial effusions, device embolization, and death. We studied 122 consecutive patients (52% female, 68; 48±12 years old) who had elective percutaneous closure with success and no complications. Forty-nine (40%) had SDD. AmplatzerTM devices were used more frequently in the SDD group, while NobblestichTM EL was more common in the overnight group. During the overnight group's follow-up period, there was one non-cardiovascular death; there were no further events. SDD after elective percutaneous closure of PFO was shown to be a safe and successful patient management method, including NobblestichTM, which we describe for the first time. Our results prove the safety of this same-day discharge strategy. We hypothesize that in the near future, in selected cases, PFO closure might become an ambulatory procedure.

Resolving the Ionotropic P2X4 Receptor Mystery Points Towards a New Therapeutic Target for Cardiovascular Diseases.

Adenosine triphosphate (ATP) is a primordial versatile autacoid that changes its role from an intracellular energy saver to a signaling molecule once released to the extracellular milieu. Extracellular ATP and its adenosine metabolite are the main activators of the P2 and P1 purinoceptor families, respectively. Mounting evidence suggests that the ionotropic P2X4 receptor (P2X4R) plays pivotal roles in the regulation of the cardiovascular system, yet further therapeutic advances have been hampered by the lack of selective P2X4R agonists. In this review, we provide the state of the art of the P2X4R activity in the cardiovascular system. We also discuss the role of P2X4R activation in kidney and lungs vis a vis their interplay to control cardiovascular functions and dysfunctions, including putative adverse effects emerging from P2X4R activation. Gathering this information may prompt further development of selective P2X4R agonists and its translation to the clinical practice.

Rheumatoid Arthritis and Pericardial Effusion - A Unique Major Manifestation.

Introduction: Pericardial effusion is common in the setting of rheumatoid arthritis (RA); however, it is rarely its first manifestation. Case description: An 82-year-old male presented with abdominal pain, vomiting and fever. Blood analysis revealed elevated systemic inflammatory markers, and an abdominal computed tomography scan revealed non-specific alveolar condensation of the right pulmonary base and pericardial effusion subsequently quantified as medium size by transthoracic echocardiography. A large aetiological panel was requested, with the autoimmunity study revealing high levels of rheumatoid factor (RF) and anti-citrullinated cyclic peptide (anti-CCP) antibodies. Since the patient did not present articular involvement, the initial hypothesis was pericardial effusion due to pneumonia and no specific treatment for RA was started. At follow-up, the pericardial effusion recurred and a pericardiocentesis was performed. The pericardial fluid analysis was sterile, and no malignant cells were identified. A new serological study confirmed high levels of RF and anti-CCP antibodies, and immunomodulatory treatment was initiated. After one year, the pericardial effusion recurred due to non-compliance with immunomodulatory therapy. A surgical pleuro-pericardial window was performed, and the cytological study of the pericardial patch revealed submesothelial thickening and foci of perivascular lymphocytic infiltrate. The patient remained asymptomatic. Discussion: After exclusion of a large spectrum of infectious and non-infectious causes and the relapse after suspension of immunomodulatory treatment, the most probable aetiology for the pericardial effusion remains RA. Conclusion: Pericardial syndromes can be the first manifestation of AR even in the absence of articular symptoms and this disease must be considered in the aetiological investigation. LEARNING POINTS: The occurrence of pericardial effusion in the setting of rheumatoid arthritis (RA) is a usual finding but this form of extra-articular manifestation is possibly the first and only presentation of the disease.In the case of recurrent pericardial effusion, the diagnosis of RA must be considered in the aetiological investigation even in the absence of more common manifestations of the disease.

Pulmonary Artery Aneurysm Associated with Sarcoidosis in a 75-year-old with Heart Failure: The Challenges of Diagnosis and Management.

Introduction: Pulmonary artery aneurysm (PAA) is a rare abnormality of pulmonary vasculature. It can be idiopathic or secondary to various pathologies, frequently with multiple factors leading to its formation. We report the case of a man with concomitant sarcoidosis and PAA. Case description: A 75-year-old male with a diagnosis of pulmonary sarcoidosis was referred to the Cardiology department due to heart failure with reduced left ventricular ejection fraction (LVEF). The transthoracic echocardiogram revealed mildly reduced LVEF, aortic root and pulmonary artery (PA) dilatation, and no signs of pulmonary hypertension (PH). Cardiac magnetic resonance imaging was performed, revealing mild left ventricular dilation, LVEF of 40%, main PA dilation (43 mm) and a pattern of late gadolinium enhancement suggestive of cardiac sarcoidosis. At follow-up, a thoracic computed tomography (CT) angiography scan revealed ascending aorta ectasia and giant main PA aneurysm (60 mm). A right heart catheterisation was performed, and a mean PA pressure of 34 mmHg was obtained. Given the clinical context, the patient was considered to have PH due to lung disease and left heart disease, and PAA was possible due to vascular granulomatous involvement by sarcoidosis. Conclusion: PAA is a rare finding and mostly occurs in the setting of PH. Sarcoidosis is a granulomatous disease that mostly affects the lungs, but the sarcoid involvement of great vessels has been described. In this clinical case, the probable cause for the PA fragility leading to aneurysm formation remains sarcoid vascular infiltration, regarding the discrepancy between the PA dimensions and mildly elevated PA pressure. LEARNING POINTS: Pulmonary artery aneurysm is a rare abnormality of pulmonary vasculature that can be idiopathic or a consequence of pulmonary hypertension, congenital heart disease, infection, vasculitis or collagenopathies.Due to the low incidence of this disease, there are no guidelines for its diagnosis, management or follow-up, and treatment is based on the underlying aetiology, aneurysm dimensions and occurrence of symptoms.Sarcoidosis is a multisystem disorder of unknown aetiology characterised by non-caseating granulomas that mostly involve the lungs, but can also affect skin, eyes, and lymph nodes. Sarcoid involvement of great vessels has been rarely described.

Triple-Valve Infective Endocarditis: A Case with Unusual Features.

Infective endocarditis is a condition associated with high morbidity and mortality, usually with univalvular involvement. We describe the case of a 76-year-old woman with triple-valve endocarditis due to Streptococcus gallolyticus, complicated by perivalvular suppurative lesions, acute heart failure and acute kidney injury. Unfortunately, the patient died despite antibiotic therapy and emergent surgery. This case highlights uncommon triple-valve involvement in the absence of risk factors, posing a diagnostic and therapeutic challenge. LEARNING POINTS: Native triple-valve endocarditis is extremely rare, especially in the absence of predisposing conditions.Streptococcus gallolyticus has been associated with endocarditis as well colonic and hepatobiliary pathology, so gastrointestinal endoscopy is important as bacteraemia frequently precedes gastrointestinal symptoms, allowing prompt diagnosis.In multivalvular involvement, early surgery is often required, and timely recognition and treatment before complications develop may be decisive for prognosis.

Pharmacological Tuning of Adenosine Signal Nuances Underlying Heart Failure With Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) roughly represents half of the cardiac failure events in developed countries. The proposed 'systemic microvascular paradigm' has been used to explain HFpHF presentation heterogeneity. The lack of effective treatments with few evidence-based therapeutic recommendations makes HFpEF one of the greatest unmet clinical necessities worldwide. The endogenous levels of the purine nucleoside, adenosine, increase significantly following cardiovascular events. Adenosine exerts cardioprotective, neuromodulatory, and immunosuppressive effects by activating plasma membrane-bound P1 receptors that are widely expressed in the cardiovascular system. Its proven benefits have been demonstrated in preclinical animal tests. Here, we provide a comprehensive and up-to-date critical review about the main therapeutic advantages of tuning adenosine signalling pathways in HFpEF, without discounting their side effects and how these can be seized.

Echocardiographic Assessment of Right Ventriculo-arterial Coupling: Clinical Correlates and Prognostic Impact in Heart Failure Patients Undergoing Cardiac Resynchronization Therapy.

BACKGROUND: Right ventriculo-arterial coupling (RV-PA) can be estimated by echocardiography using the ratio between tricuspid annular plane systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP) and it has prognostic value in the general heart failure (HF) population. We aimed to study the clinical correlates and prognostic value of RV-PA in HF patients undergoing cardiac resynchronization therapy (CRT). METHODS: We retrospectively studied 70 HF patients undergoing CRT implantation. RESULTS: RV-PA coupling was estimated by TAPSE/PASP ratio using baseline echocardiography. Non-response to CRT was defined as improvement of left ventricular ejection fraction < 5% in a follow-up echo 6-12 months after CRT. Those with lower TAPSE/PASP ratios (worse RV-PA coupling) had higher NT-proBNP concentrations and increased E/e' ratio. TAPSE/PASP ratio and PASP, but not TAPSE, predicted nonresponse to CRT with TAPSE/PASP ratio showing the best discriminative ability with a sensitivity of 76% and specificity of 71%. Among these parameters, PASP independently predicted all-cause mortality. CONCLUSIONS: RV-PA coupling estimated by TAPSE/PASP ratio was associated with established prognostic markers in HF. It numerically outperformed PASP and TAPSE in predicting the response to CRT. Our data suggest that this simple and widely available echocardiographic parameter conveys significant pathophysiological and prognostic meaning in HF patients undergoing CRT.

The Ionotropic P2X4 Receptor has Unique Properties in the Heart by Mediating the Negative Chronotropic Effect of ATP While Increasing the Ventricular Inotropy.

Background: Mounting evidence indicate that reducing the sinoatrial node (SAN) activity may be a useful therapeutic strategy to control of heart failure. Purines, like ATP and its metabolite adenosine, consistently reduce the SAN spontaneous activity leading to negative cardiac chronotropy, with variable effects on the force of myocardial contraction (inotropy). Apart from adenosine A1 receptors, the human SAN expresses high levels of ATP-sensitive ionotropic P2X4 receptors (P2X4R), yet their cardiac role is unexplored. Methods: Here, we investigated the activity of P2 purinoceptors on isolated spontaneously beating atria (chronotropy) and on 2 Hz-paced right ventricular (RV, inotropy) strips from Wistar rats. Results: ATP (pEC 50 = 4.05) and its stable analogue ATPγS (pEC 50 = 4.69) concentration-dependently reduced atrial chronotropy. Inhibition of ATP breakdown into adenosine by NTPDases with POM-1 failed to modify ATP-induced negative chronotropy. The effect of ATP on atrial rate was attenuated by a broad-spectrum P2 antagonist, PPADS, as well as by 5-BDBD, which selectively blocks the P2X4R subtype; however, no effect was observed upon blocking the A1 receptor with DPCPX. The P2X4R positive allosteric modulator, ivermectin, increased the negative chronotropic response of ATP. Likewise, CTP, a P2X agonist that does not generate adenosine, replicated the P2X4R-mediated negative chronotropism of ATP. Inhibition of the Na+/Ca2+ exchanger (NCX) with KB-R7943 and ORM-10103, but not blockage of the HCN channel with ZD7288, mimicked the effect of the P2X4R blocker, 5-BDBD. In paced RV strips, ATP caused a mild negative inotropic effect, which magnitude was 2 to 3-fold increased by 5-BDBD and KB-R7943. Immunofluorescence confocal microscopy studies confirm that cardiomyocytes of the rat SAN and RV co-express P2X4R and NCX1 proteins. Conclusions: Data suggest that activation of ATP-sensitive P2X4R slows down heart rate by reducing the SAN activity while increasing the magnitude of ventricular contractions. The mechanism underlying the dual effect of ATP in the heart may involve inhibition of intracellular Ca2+-extrusion by bolstering NCX function in the reverse mode. Thus, targeting the P2X4R activation may create novel well-tolerated heart-rate lowering drugs with potential benefits in patients with deteriorated ventricular function.

Is the adenosine A2B 'biased' receptor a valuable target for the treatment of pulmonary arterial hypertension?

Pulmonary arterial hypertension (PAH) is a maladaptive disorder characterized by increased pulmonary vascular resistance leading to right ventricular failure and death. Adenosine released by injured tissues, such as the lung and heart, influences tissue remodeling through the activation of adenosine receptors. Evidence regarding activation of the low-affinity A2BAR by adenosine points towards pivotal roles of this receptor in processes associated with both acute and chronic lung diseases. Conflicting results exist concerning the beneficial or detrimental roles of the A2B 'biased' receptor in right ventricular failure secondary to PAH. In this review, we discuss the pros and cons of manipulating A2BARs as a putative therapeutic target in PAH.

Ion Fluxes through KCa2 (SK) and Cav1 (L-type) Channels Contribute to Chronoselectivity of Adenosine A1 Receptor-Mediated Actions in Spontaneously Beating Rat Atria.

Impulse generation in supraventricular tissue is inhibited by adenosine and acetylcholine via the activation of A1 and M2 receptors coupled to inwardly rectifying GIRK/KIR3.1/3.4 channels, respectively. Unlike M2 receptors, bradycardia produced by A1 receptors activation predominates over negative inotropy. Such difference suggests that other ion currents may contribute to adenosine chronoselectivity. In isolated spontaneously beating rat atria, blockade of KCa2/SK channels with apamin and Cav1 (L-type) channels with nifedipine or verapamil, sensitized atria to the negative inotropic action of the A1 agonist, R-PIA, without affecting the nucleoside negative chronotropy. Patch-clamp experiments in the whole-cell configuration mode demonstrate that adenosine, via A1 receptors, activates the inwardly-rectifying GIRK/KIR3.1/KIR3.4 current resulting in hyperpolarization of atrial cardiomyocytes, which may slow down heart rate. Conversely, the nucleoside inactivates a small conductance Ca(2+)-activated KCa2/SK outward current, which eventually reduces the repolarizing force and thereby prolong action potentials duration and Ca(2+) influx into cardiomyocytes. Immunolocalization studies showed that differences in A1 receptors distribution between the sinoatrial node and surrounding cardiomyocytes do not afford a rationale for adenosine chronoselectivity. Immunolabelling of KIR3.1, KCa2.2, KCa2.3, and Cav1 was also observed throughout the right atrium. Functional data indicate that while both A1 and M2 receptors favor the opening of GIRK/KIR3.1/3.4 channels modulating atrial chronotropy, A1 receptors may additionally restrain KCa2/SK activation thereby compensating atrial inotropic depression by increasing the time available for Ca(2+) influx through Cav1 (L-type) channels.