Editorial: The Right Heart: A Key Target for Cardiovascular Medicine

Maria Concetta Pastore^1*Simona Sperlongano²Paolo Calabrò²Matteo Cameli¹

• ¹Department of Medical Biotechnologies, Division of Cardiology, University of Siena, Siena, Italy
• ²Universita degli Studi della Campania Luigi Vanvitelli Dipartimento di Scienze Mediche Traslazionali, Naples, Italy

After been neglected for decades, the evaluation of the right ventricle (RV) has gained increasing interest among clinicians and researchers due to the proved strong evidence highlighting its importance for prognosis [1] in different clinical conditions, such as heart failure, valvular heart disease, pulmonary hypertension [2][3][4][5]. Although not the primary affected chamber in many pathological conditions, its involvement may be considered a marker of disease severity and transition to poor prognosis [6]. Moreover, new interventional techniques focused on the right heart and valves have been developed with significant improvement in quality of life [7]. This article collection aimed at increasing scientific awareness on the right heart highlighting the pivotal role of all its structures, that often must be considered not only as a "collateral" but as the main target for diagnostics, risk stratification and therapy.The research focus on RV structural and functional impairment has led to the identification of new parameters to optimize the evaluation of this chamber, since its evaluation with common imaging modalities is sometimes limited [8]. One of the emerging imaging modalities for the assessment of RV structure and function is 3D echocardiography [9], which offers a more comprehensive quantification of RV dimensions, with volumes comparable to cardiac magnetic resonance, and is gaining feasibility parallel to the development of new automatic tools for the calculation. Memis H et al. provided good results on the reproducibility of 3D echocardiography among experts and nonexpert operator after a brief training to evaluate RV in patients with decompensated heart failure, which remains one of the main fields of application of RV assessment.However, 3D echocardiography may sometimes be challenging in patients with pulmonary illness or poorly cooperative. Speckle tracking echocardiography [10][11][12][13][14] has been studied for long and validated over multicenter studies for standardization of acquisition and reference values [15]. It offers a quick tool and sensitive parameters for RV function estimation, allowing both early diagnosis in subtle RV impairment and accurate prognostic assessment, particularly in pulmonary primary and secondary hypertension. Kaddoussi R et al. showed how free-wall RV strain was useful in detecting subtle myocardial involvement in chronic obstructive pulmonary disease, despite normal basic echocardiographic parameters and left ventricular strain. Also, they found an association that RV strain was associated with a higher risk of hospitalizations for acute exacerbation in one-year follow up (55% vs. 25% in patients with impaired vs.normal RV strain; p = 0.024). In these patients the main target is to detect early signs of cor pulmonale in order to provide early therapy.The same is for patients with chronic thromboembolic pulmonary hypertension, a rare but severe cause of pulmonary hypertension (classified as "group 4"), which poses patients at high risks of decompensation and fatal events. Simeone B et al., in two articles published in this collection, provided overview on the diagnostic algorithm and therapeutic strategies available for these patients, focusing on multidisciplinary evaluation and collaboration to optimize and personalize the treatment of these patients.On the other hand, some author claim that the use of imaging may be preceded by biomarkers for diagnosis. Huiling C et al. conducted a research in rats undergoing surgical pulmonary artery banding with consequent RV remodelling to search for differentially-expressed micro-RNAs(miRNAs), which were then validated on a cohort of 100 patients with either adaptive RV pressure overload (20), maladaptive RV pressure overload (20); left heart failure (20), left ventricular hypertrophy (19) and 21 controls, identifying circulating miRNA-486 as a marker of of RV maladaptation in PH patients, not significantly different from B-type natriuretic peptide (BNP), and that it was associated with tricuspid annular plane systolic excursion/systolic pulmonary artery pressure (TAPSE/sPAP) ratio and BNP.As previously mentioned, the RV acquires a fundamental role for prognostic assessment in different clinical conditions, among which cardiac surgery, for left heart disease as well, since the preexistence of RV dysfunction [16] or the development of considerable postoperative RV dysfunction entails a poor prognosis in patients undergoing cardiac surgery, and may condition the therapeutic choices. In fact, scientific community is moving towards the research of reliable prognostic markers in these patients. Watanabe R et al. proposed QRS duration acquired by a bipolar pacing catether in the RV as a perioperative monitoring parameter for RV function in patients undergoing robotic mitral valve surgery, since they observed a prolongation of this parameter during robotic mitral valve repair, an association right ventricular fractional area change (RVFAC), and that prolonged postoperative QRSRV duration was the only significant parameter associated with a longer intensive care unit stay after surgery. Last but not least, primary or acquired isolated right heart disease should not be forgotten since, although rare, they may cause fatal consequences. Particularly, in cyanotic disease one of the main causes include RV structure involvement, as depicted in the case report of Cui Y et al. showing an infant with cyanosis and profound tricuspid regurgitation after high-altitude exposure due to spontaneous chordae tendineae rupture and tricuspid valve prolapse, initially misdiagnosed and promptly solved with cardiac surgery.The panorama of diagnostic and therapeutic research regarding the right heart is continuously growing, the hope is that this Research Topic will shed light to the importance of the right heart evaluation, provide new practical information for the management of these patients and food for thought for future research in that field.