RT Journal Article
SR Electronic
T1 Usefulness of NT-proBNP dosage during the follow-up of PAH: Comparison with 6MWD
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P2387
VO 44
IS Suppl 58
A1 Giuseppe Paciocco
A1 Silvia Gamberini
A1 Luca Novelli
A1 Ausiliatrice Lucenti
A1 Antonella Vincenzi
A1 Alberto Pesci
YR 2014
UL http://erj.ersjournals.com/content/44/Suppl_58/P2387.abstract
AB INTRODUCTION: Pulmonary Arterial Hypertension (PAH) is a rare disease with poor prognosis that needs early diagnosis and aggressive therapy. 6-min walk distance (6MWD) has been diffusely used for clinical follow-up and therapy response. Serum NT-proBNP has been recently used to assess right ventricular dysfunction.PURPOSE: To analyze association between NT-proBNP and 6MWD and their distribution in different World Health Organization (WHO) functional class.METHODS: We followed 34 patients (pts) affected by group 1 PAH with a median follow-up of 31 months (m) (min. 1 – max 69 m) for a total of 431 visits. At each visit, all pts were clinically evaluated into WHO status and prospectively performed at same daily-time 6MWD, preceded by NT-proBNP dosage not more than 10 minutes before walking.RESULTS: Pearson correlation index between NT-proBNP and 6MWD resulted -0.60 (p<0.05). Using a recognized cut-off of 380m on 6MWD as value to define a good prognosis, we evaluated statistical power of 1400pg/mL as a cut-off for NT-proBNP. Out of the 75 visits with NT-proBNP>1400pg/mL, 93% of the 6MWT were ≤380m; only 56% of pts with NT-proBNP≤1400pg/mL walked >380m, probably due to physical confounding factors (age, sex weight, etc). During follow-up period, no pts in WHO I-II had NT-proBNP>1400pg/mL, while 15% of pts in WHO class I-II walked <380 m.CONCLUSION: If performed together, NT-proBNP and 6MWT had an inverse correlation. These results may suggest low clinical utility of follow-up 6MWT in pts with NT-proBNP>1400pg/mL, highlighted by their compromised functional class (WHO III-IV). A cut-off of 380m at 6MWT was not able to define a correct WHO status, whereas NT-proBNP>1400pg/mL may exclude pts in WHO I-II.