Ricerc@Sapienza

International registries have identified the NYHA/WHO functional class as the fundamental prognostic factor for risk stratification in Pulmonary Arterial Hypertension (PAH).
Indeed, which class a clinician decides to assign a patient to will depend on the clinicians interpretation of what construes "ordinary physical activity" and "slight" and "marked" limitations. The widely accepted criteria of the NYHA/WHO classification, when have been subjected to the systematic validity testing demonstrated low reproducibility and low discrimination. However, simple modifications to this scale, by introducing more objective measures, such as direct measurement of oxygen consumption, may increase reproducibility while maintaining the strong prognostic relevance. The aim of the present study is to make a reliable, reproducible assessment of functional capacity in a PAH derivation cohort relative to "ordinary physical activity" to standardize daily activities according to the expected METS (metabolic equivalent) required for each specific class.
Ordinary activities considered will be measured by oxygen consumption with K5 Wearable Metabolic Technology and used to classify the patients in the four ranks. This will allow us to build an Ordinary Activity Metabolic Scale. For every given "ordinary physical activity" provided for NYHA/WHO classification, the measured METS from the derivation cohort will be reported.
To test the hypothesis that such a standardized NYHA/WHO functional assessment will improve the prediction of clinical worsening, we will evaluate both the new standardized NYHA/WHO classification and the commonly used one in a validation cohort of 150 PAH patients from 3 different referral centers. The prognostic relevance of the two NYHA/WHO classification methods will be compared by the c-statistic.
We believe that our Ordinary Activity Metabolic Scale for PAH patients may represent an acceptable tradeoff between precision and complexity.