Role of NT-proBNP and 6MWD in Chronic Thromboembolic Pulmonary Hypertension

Respir Med. 2007 Nov;101(11):2254-62. doi: 10.1016/j.rmed.2007.06.027. Epub 2007 Aug 13.

Abstract

Background: This study aims to evaluate the role of NT-proBNP and six minute walking distance (6MWD) in the pre- and post-operative assessment of subjects undergoing pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH).

Methods: Subjects undergoing PEA between August 2004 and July 2006 were assessed at baseline and 3 months post-operatively with resting haemodynamics, NT-proBNP and 6MWD.

Results: A number of 111 subjects underwent surgery, of which 102 were included. 15 subjects died before their 3 month assessment. Non-survivors had significantly worse preoperative NT-proBNP and 6MWD (4728 pg/mL vs 1863 pg/mL, p=0.001, 182.4 m vs 263.5 m, p=0.001). Taking pre-operative cut-off values of 1200 pg/mL for NT-proBNP and 345 m for 6MWD, both tests had high negative predictive value for predicting mortality (97.3% and 100%, respectively). Amongst survivors, peri-operative changes in NT-proBNP and 6MWD correlated with changes in total pulmonary resistance (TPR) (r=0.49, p<0.001 and r=-0.46, p<0.001). Post-operatively, both NT-proBNP and 6MWD also correlated with mPAP (r=0.65, p<0.001 and r=-0.50, p<0.001) and PVR (r=0.63, p<0.001 and r=-0.47, p<0.001). The ability of NT-proBNP to predict persistent pulmonary hypertension was significantly confounded by age, but not gender, BMI or renal function.

Conclusions: Pre-operative evaluation with NT-proBNP and 6MWD helps risk-stratify patients prior to PEA. Post-operatively, both markers correlate with changes in disease burden and right ventricular function. These results suggest that both NT-proBNP and 6MWD offer effective 'bedside' tools for the long term follow up of patients with CTEPH.

Publication types

  • Evaluation Study

MeSH terms

  • Aged
  • Chronic Disease
  • Endarterectomy
  • Exercise Tolerance
  • Female
  • Hemodynamics
  • Humans
  • Hypertension, Pulmonary / blood
  • Hypertension, Pulmonary / etiology*
  • Male
  • Natriuretic Peptide, Brain / blood*
  • Patient Selection
  • Peptide Fragments / blood*
  • Postoperative Period
  • Predictive Value of Tests
  • Pulmonary Artery / physiopathology*
  • Pulmonary Embolism / complications
  • Pulmonary Embolism / physiopathology*
  • Pulmonary Embolism / surgery
  • Time Factors
  • Ventricular Dysfunction, Right / blood
  • Ventricular Dysfunction, Right / etiology
  • Ventricular Pressure

Substances

  • Peptide Fragments
  • pro-brain natriuretic peptide (1-76)
  • Natriuretic Peptide, Brain