Pulmonary hypertension in chronic heart failure

Riociguat for the treatment of pulmonary hypertension: a safety evaluation

INTRODUCTION

The development of pulmonary hypertension (PH) has multifactorial underlying pathophysiological causes and can be classified into five groups. While three different classes of therapeutic drugs are licensed for the treatment of pulmonary arterial hypertension (PAH, WHO group 1), specific medical therapies are lacking for other forms of PH, such as PH due to left heart disease. In 2013 riociguat, a first-in class soluble guanylate cyclase stimulator, has also become available for the treatment of PAH. Riociguat was further introduced as the first approved pharmacotherapy for the treatment of patients with chronic thromboembolic PH (WHO group 4, CTEPH). Despite these advances in therapeutic options for patients with PH, none of these agents have been approved for the treatment of PH due to left heart disease. Areas covered: We aim to give an overview of the pathophysiology of PH, pharmacodynamics and pharmacokinetic properties, safety and efficacy of riociguat, including adverse events, contraindications and drug interactions. Expert opinion: Considering the increasingly broad indications for riociguat in patients with PH, substantial knowledge of data and properties on safety and efficacy of riociguat are becoming more and more important for physicians prescribing riociguat to PH patients.

Riociguat: Mode of Action and Clinical Development in Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are progressive and debilitating diseases characterized by gradual obstruction of the pulmonary vasculature, leading to elevated pulmonary artery pressure (PAP) and increased pulmonary vascular resistance (PVR). If untreated, they can result in death due to right-sided heart failure. Riociguat is a novel soluble guanylate cyclase (sGC) stimulator that is approved for the treatment of PAH and CTEPH. We describe in detail the role of the nitric oxide-sGC-cyclic guanosine monophosphate (cGMP) signaling pathway in the pathogenesis of PAH and CTEPH and the mode of action of riociguat. We also review the preclinical data associated with the development of riociguat, along with the efficacy and safety data of riociguat from initial clinical trials and pivotal phase III randomized clinical trials in PAH and CTEPH.

Riociguat for pulmonary hypertension

Pulmonary hypertension, an elevation of the mean pulmonary artery pressure ≥25 mmHg, ultimately leads to premature death due to right ventricular dysfunction. Ten treatments from three classes of drugs are licensed for the management of pulmonary arterial hypertension. These treatments have improved exercise capacity but median survival is still poor. Additionally there are no licensed therapies for the other groups of pulmonary hypertension. Riociguat is a novel drug that stimulates soluble guanylate cyclase independently of nitric oxide and in synergy with nitric oxide. This review summarises the available evidence for riociguat in the treatment across all groups of pulmonary hypertension with a focus on pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension.

Pulmonary arterial hypertension associated with IgG4-related disease

A 22-year-old woman with generalized lymphadenopathy and symmetrical swelling of the lacrimal and submandibular glands was diagnosed with IgG4-related disease. Biopsy specimens of the lips, lymph nodes, gastrointestinal tract and bronchus showed IgG4-positive plasma cell infiltration. Echocardiography and right heart catheterization revealed a high mean pulmonary arterial pressure. The patient was treated with 50 mg of prednisolone daily and rapidly improved. This is the first reported case of pulmonary arterial hypertension associated with IgG4-related disease.

TNM-like classification: a new proposed method for heart failure staging

Heart Failure (HF) is an acute or chronic syndrome, that causes a lot of damaging effects to every system. The involvement of different systems is variably related to age and others comorbidities. The severity of organ damage is often proportional to the duration of heart failure. The typology of HF and the duration determine which organs will be affected and vice versa the severity of organ damage supplies precious information about prognosis and outcome of patients with heart failure. Moreover, a classification based not only on symptomatic and syndromic typical features of heart failure, but also on functional data of each system, could allow us to apply the most appropriate therapies, to obtain a more accurate prognosis, and to employ necessary and not redundant human and financial resources. With an eye on the TNM staging used in oncology, we drawn up a classification that will consider the different involvement of organs such as lungs, kidneys, and liver in addition to psychological pattern and quality of life in HF patients. For all these reasons, it is our intention to propose a valid and more specific classification available for the clinical staging of HF that takes into account pathophysiological and structural changes that can remark prognosis and management of HF.

Differentiating pulmonary arterial and pulmonary venous hypertension and the implications for therapy

Pulmonary arterial and pulmonary venous hypertension develop from distinctly different etiologies. Pulmonary arterial hypertension (PAH), or Group 1 pulmonary hypertension (PH), is a precapillary PH that arises idiopathically or as the result of a divergent array of causes, including connective tissue disease. Pulmonary venous hypertension (PVH), or Group 2 PH, primarily manifests as a postcapillary PH in the setting of left heart failure or valvular disease. A subset of PVH patients, however, develop a reactive precapillary component of PH that mimics PAH. These patients can be misdiagnosed as having Group 1 PH by 2-dimensional echocardiography and are sometimes treated as such, which leads to exacerbation of heart failure. Therefore, 2-dimensional or Doppler echocardiography alone cannot be used to differentiate between these two classifications of PH. This highlights the need for right heart catheterization in the clinical assessment and diagnostic work-up of PH. The combination of imaging and invasive hemodynamic assessment by right heart catheterization provides the best diagnostic approach to ensure proper delineation of pulmonary arterial and pulmonary venous hypertension, and in turn leads to appropriate treatment.

Cardiorenal syndrome: biomarkers linking kidney damage with heart failure

All the vital organs of the body share information by virtue of various biological mediators. Primary pathology of a major organ can lead to dysfunction of the other. Cardiorenal syndrome is an important example of such organ crosstalk. Primary dysfunction of the heart or kidney can lead to injury of the other organ. As molecular injury occurs prior to clinical dysfunction, effective interventions can be planned if one can detect this organ dysfunction at an earlier stage by virtue of some biological markers. Such biomarkers can be substances in urine, serum, imaging maneuvers or any other quantifiable parameters. Some currently available biomarkers are not sensitive enough to provide timely diagnosis of the disorder. An important research priority is the development of newer biomarkers or a panel of biomarkers for the early diagnosis of organ dysfunction, as well as nature of injury, guidance for therapeutic interventions and prognosis. Many newer biomarkers have been studied for both heart and kidney dysfunction. This article focuses on newer biomarkers for the cardiorenal syndrome.