Utility of FVC/DLCO ratio to stratify the risk of mortality in unselected subjects with pulmonary hypertension

Abstract

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.

Incidence and Patterns of Interstitial Lung Disease and Their Clinical Impact on Mortality in Patients with Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: Korean Single-Centre Observational Study

“…It is expected that a longer follow-up period would likely show a proportion of patients with ILD after AAV diagnosis above 49.1%. The higher occurrence rate of ILD among MPO-ANCA-positive patients than that in PR3-ANCA-positive patients was consistent with the findings of previous studies, which also support the effect of the short follow-up period on the low frequency of ILD in this study [ 14 ]. The 2022 classification criteria for MPA recently proposed by the American College of Rheumatology and the European Alliance of Associations for Rheumatology assigned the highest score of +6 to the item of “MPO-ANCA positivity” and a score of +3 to a newly added item of “fibrosis or ILD on chest imaging.” It can be said that the results of the present study are in the same context as the background in which these scores are assigned in the new criteria for MPA [ 15 ].…”

“…The third explanation is the similar FVC and DLCO between the two groups. A previous study reported an increased mortality rate with an increasing FVC/DLCO ratio because a decrease in DLCO was more closely related to an increase in all-cause mortality through the development of pulmonary hypertension [ 14 ]. However, in this study, the differences were not statistically significant: patients with AAV without the UIP pattern had a lower median DLCO than patients with the UIP pattern (68.0% vs. 74.0%), and the FVC/DLCO ratio was slightly higher in patients with AAV without the UIP pattern than in those without (1.25 vs. 1.11).…”

Efficacy and Safety of Nintedanib in Patients with Connective Tissue Disease-Interstitial Lung Disease (CTD-ILD): A Real-World Single Center Experience

“…The initial measurements of FVC and FEV1 were in L, and the initial measurements of DLco were in mL/min/mmHg. Additionally, we recorded FVC%/DLco% ratio measurements before and after nintedanib treatment, as a result >1.5 might be a predictor of pulmonary arterial hypertension [ 38 ]. Other data that was documented includes the follow-up month (defined as the month that the patient individually repeated pulmonary function tests after the treatment initiation and was different for every patient); the C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR) before and after the treatment; adverse effects; and concomitant treatment with steroids and disease-modifying drugs.…”

Sarcoidosis associated pulmonary hypertension: an update

“…Significant moderate to strong correlations between predicted DLCO < 60% and elevated PA systolic pressure has been shown in retrospective studies [9,32]. The FVC/ DLCO ratio > 1.6 has been shown to significantly correlate with PA pressure in other conditions that have co-existent pulmonary hypertension and pulmonary fibrosis; [33] however, robust evidence for the clinical application of this ratio in SAPH is lacking. The six-minute walk distance (6MWD) is another useful screening test in assessing patients suspected to have SAPH.…”