Morten Nissen Melsom

Global Lung Function Initiative 2012 reference equations for spirometry in the Norwegian population

We studied the fit of the Global Lung Function Initiative (GLI) all-age reference values to Norwegians, compared them with currently used references (European Community for Steel and Coal (ECSC) and Zapletal) and estimated the prevalence of obstructive lung disease. Spirometry data collected in 30 239 subjects (51.7% females) aged 12–90 years in three population-based studies were converted to z-scores. We studied healthy non-smokers comprising 2438 adults (57.4% females) aged 20–90 years and 8725 (47.7% female) adolescents aged 12–19 years. The GLI-2012 prediction equations fitted the Norwegian data satisfactorily. Median±sd z-scores were respectively 0.02±1.03, 0.01±1.04 and −0.04±0.91 for forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC in males, and −0.01±1.02, 0.07±0.97 and −0.21±0.82 in females. The ECSC and Zapletal references significantly underestimated FEV1 and FVC. Stricter criteria of obstruction (FEV1/FVC GLI-2012 LLN. Corresponding comparison regarding myocardial infarction showed a four-fold higher risk for women. The GLI-2012 reference values fit the Norwegian data satisfactorily and are recommended for use in Norway. Correspondingly, the FEV1/FVC GLI-2012 LLN identifies higher risk of obstructive characteristics than FEV1/FVC <0.7. GLI-2012 all-age reference values for spirometric indices fit Norwegians aged 12–85 years http://ow.ly/WP9D3034svA

Assessment of Right Ventricular Afterload in COPD

Abstract Background: We aimed to study whether pulmonary hypertension (PH) and elevated pulmonary vascular resistance (PVR) could be predicted by conventional echo Doppler and novel tissue Doppler imaging (TDI) in a population of chronic obstructive pulmonary disease (COPD) free of LV disease and co-morbidities.Methods: Echocardiography and right heart catheterization was performed in 100 outpatients with COPD. By echocardiography the time-integral of the TDI index, right ventricular systolic velocity (RVSmVTI) and pulmonary acceleration-time (PAAcT) were measured and adjusted for heart rate. The COPD patients were randomly divided in a derivation (n = 50) and a validation cohort (n = 50). Results: PH (mean pulmonary artery pressure (mPAP) ≥ 25mmHg) and elevated PVR ≥ 2Wood unit (WU) were predicted by satisfactory area under the curve for RVSmVTI of 0.93 and 0.93 and for PAAcT of 0.96 and 0.96, respectively. Both echo indices were 100% feasible, contrasting 84% feasibility for parameters relying on contrast enhanced tricuspid-regurgitation. RVSmVTI and PAAcT showed best correlations to invasive measured mPAP, but less so to PVR. PAAcT was accurate in 90- and 78% and RVSmVTI in 90- and 84% in the calculation of mPAP and PVR, respectively. Conclusions: Heart rate adjusted-PAAcT and RVSmVTI are simple and reproducible methods that correlate well with pulmonary artery pressure and PVR and showed high accuracy in detecting PH and increased PVR in patients with COPD. Taken into account the high feasibility of these two echo indices, they should be considered in the echocardiographic assessment of COPD patients.

Cardiopulmonary exercise test and PaO 2 in evaluation of pulmonary hypertension in COPD

Background Exercise tolerance decreases as COPD progresses. Pulmonary hypertension (PH) is common in COPD and may reduce performance further. COPD patients with and without PH could potentially be identified by cardiopulmonary exercise test (CPET). However, results from previous studies are diverging, and a unified conclusion is missing. We hypothesized that CPET combined with arterial blood gases is useful to discriminate between COPD outpatients with and without PH. Methods In total, 93 COPD patients were prospectively included. Pulmonary function tests, right heart catheterization, and CPET with blood gases were performed. The patients were divided, by mean pulmonary artery pressure, into COPD-noPH (<25 mmHg) and COPD-PH (≥25 mmHg) groups. Linear mixed models (LMMs) were fitted to estimate differences when repeated measurements during the course of exercise were considered and adjusted for gender, age, and airway obstruction. Results Ventilatory and/or hypoxemic limitation was the dominant cause of exercise termination. In LMM analyses, significant differences between COPD-noPH and COPD-PH were observed for PaO2, SaO2, PaCO2, ventilation, respiratory frequency, and heart rate. PaO2 <61 mmHg (8.1 kPa) during unloaded pedaling, the only load level achieved by all the patients, predicted PH with a sensitivity of 86% and a specificity of 78%. Conclusion During CPET, low exercise performance and PaO2 strongly indicated PH in COPD patients.