1. Prognostic value of pulmonary diffusing capacity for carbon monoxide and ventilation–perfusion SPECT findings in pulmonary arterial hypertension.
- Author
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Mohammad, Milan, Hartmann, Jacob P., Carlsen, Jørn, Greve, Anders M., Berg, Ronan M. G., and Mortensen, Jann
- Subjects
PULMONARY arterial hypertension ,CARBON monoxide ,PROGNOSIS ,SINGLE-photon emission computed tomography ,PULMONARY function tests - Abstract
Reduced pulmonary diffusing capacity for carbon monoxide (DLCO) can be observed in pulmonary arterial hypertension (PAH) and associates with increased mortality. However, the prognostic value of DLCO when corrected for haemoglobin (DLCOc), an independent modifier of DLCO, remains understudied. Additionally, the prognostic role of ventilation (V)–perfusion (Q) emission computed tomography (V/Q SPECT) findings in patients with PAH, which may concurrently be performed to rule out chronic thromboembolic pulmonary hypertension, is uncertain. A retrospective cohort study was conducted on 152 patients with PAH referred to a tertiary hospital for evaluation from January 2011 to January 2020. Lung function tests, clinical data and V/Q SPECT were ascertained. Cox regression analysis was performed to evaluate the association between DLCOc, DLCO and V/Q SPECT defects at referral with all‐cause mortality. In equally adjusted Cox regression analysis, each percentage increase in DLCOc % predicted (%pred) (hazard ratio (HR) 0.97; 95% CI: 0.94–0.99) and DLCO%pred (HR 0.97; 95% CI: 0.94–0.99) was similarly associated with all‐cause mortality. There was no detectable difference in area under the curve for prediction of all‐cause mortality by DLCOc%pred and DLCO%pred (C‐index 0.71 and 0.72, respectively, P = 0.85 for difference). None of the defects noted on V/Q SPECT were significantly associated with mortality, but mismatched defects were associated with lower values of DLCOc%pred and DLCO%pred. DLCOc%pred and DLCO%pred perform equally as prognostic markers in PAH, supporting the use of either metric when available for prognostic stratification. What is the central question of this study?Does haemoglobin correction of the pulmonary diffusing capacity for carbon monoxide improve prognostic stratification in patients with pulmonary arterial hypertension (PAH)?What is the main finding and its importance?In PAH, the pulmonary diffusing capacity for carbon monoxide predicts all‐cause mortality equally well regardless of whether it is haemoglobin‐corrected or not. Either metric can therefore be used for the diagnostic workup of these patients. Ancillary findings on ventilation–perfusion emission computed tomography concurrently performed to rule out chronic thromboembolic pulmonary hypertension did not inform prognosis further. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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