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Right heart failure (RHF) is a clinical syndrome in which symptoms and signs are caused by dysfunction and/or overload of the right heart structures, predominantly the right ventricle (RV), resulting in systemic venous hypertension, peripheral oedema and finally, the impaired ability of the right heart to provide tissue perfusion. Pathogenesis of RHF includes the incompetence of the right heart to maintain systemic venous pressure sufficiently low to guarantee an optimal venous return and to preserve renal function. Virtually, all myocardial diseases involving the left heart may be responsible for RHF. This may result from coronary artery disease, hypertension, valvular heart disease, cardiomyopathies and myocarditis. The most prominent clinical signs of RHF comprise swelling of the neck veins with an elevation of jugular venous pressure and ankle oedema. As the situation worsens, fluid accumulation becomes generalised with extensive oedema of the legs, congestive hepatomegaly and eventually ascites. Diagnosis of RHF requires the presence of signs of elevated right atrial and venous pressures, including dilation of neck veins, with at least one of the following criteria: (1) compromised RV function; (2) pulmonary hypertension; (3) peripheral oedema and congestive hepatomegaly. Early recognition of RHF and identifying the underlying aetiology as well as triggering factors are crucial to treating patients and possibly reversing the clinical manifestations effectively and improving prognosis.

In patients with systemic sclerosis, a ratio between forced vital capacity (FVC) and diffusing capacity of carbon monoxide (DLCO, FCV%/DLCO%) >1.5 might be a predictor of pulmonary hypertension (PH). The aim of this study is, therefore, to evaluate whether this index can be used in patients with PH, regardless of etiology. 83 consecutive outpatients with suspected PH at non-invasive work-up underwent spirometry and DLCO test before right heart catheterization (RHC); FVC%/DLCO% ratio was then calculated and compared with mean pulmonary-artery-pressure (mPAP) and mortality at 5-year follow-up. Significant correlations between FVC%/DLCO% and PAsP and mPAP levels were found (p < 0.05). After ROC curve analysis and definition of best cut-off values for PAsP and FVC%/DLCO%, increased mPAP values at RHC were observed comparing subjects with both PAsP and FVC%/DLCO% values below cut off values (-/-), either PAsP or FVC%/DLCO% above cut off values (±), or both above (+/+) (p < 0.05). Poorer survival rates are observed at follow-up with higher FVC%/DLCO% values (0% for <1, 17.4% for 1-3, 33.3% for >3, p < 0.05), when comparing subjects with either increased PAsP and FVC%/DLCO% values or both with those with lower (log-rank p < 0.05). Even in subjects with mPAP at RHC >25 mmHg, increased FVC%/DLCO% values predicted a worse outcome (p < 0.05). FVC%/DLCO% values are related to mPAP in subjects with suspected PH, and may further stratify the risk of mortality in addition to PAP.