title: Utility of BNP in differentiating constrictive pericarditis from restrictive cardiomyopathy in patients with renal insufficiency.
abstract: BACKGROUND
  Differentiating between constrictive pericarditis (CP) and restrictive cardiomyopathy (RCMP) is difficult because of similar clinical and hemodynamic presentation. Brain natriuretic peptide (BNP) has been reported a useful noninvasive biomarker to differentiate CP from RCMP; however, its utility in patients with renal insufficiency has not been evaluated.
  
  
  RESULTS
  Consecutive patients with suspected CP or RCMP were enrolled. All but 7 patients underwent transseptal catheterization. BNP, renal function, and comorbid conditions were recorded at the time of the procedure. Renal function was estimated using the Cockcroft-Gault formula. Descriptive statistics, Student t-test, and Mann-Whitney U test were performed; P < .05 was significant. Twenty-two patients had hemodynamically or surgically proven CP or RC. In patients with CP, 9 had at least Stage II kidney disease (GFR <90 mL/min, mean 58) and 8 had normal or Stage I kidney disease (GFR >90 mL/min, mean 118). BNP was higher in patients with CP and renal insufficiency versus those with CP and normal renal function (433 versus 116 pg/mL; P = .016). BNP in patients with CP and normal renal function was lower than in patients with RC (116 versus 728 pg/mL; P = .005).
  
  
  CONCLUSIONS
  BNP has reduced clinical utility in renal insufficiency to differentiate CP from RCMP.
authors.affiliation: Loyola University Medical Center, Department of Medicine, Division of Cardiology, Maywood, Illinois 60153, USA.
authors.forename: Proddutur R
authors.initials: PR
authors.lastname: Reddy
authors.forename: Robert S
authors.initials: RS
authors.lastname: Dieter
authors.forename: Pranab
authors.initials: P
authors.lastname: Das
authors.forename: Lowell H
authors.initials: LH
authors.lastname: Steen
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Lewis
authors.forename: Ferdinand S
authors.initials: FS
authors.lastname: Leya
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D015415:Biomarkers / Q000097:blood; D002313:Cardiomyopathy, Restrictive / Q000097:blood* / Q000175:diagnosis; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010494:Pericarditis, Constrictive / Q000097:blood* / Q000175:diagnosis; D051437:Renal Insufficiency / Q000097:blood* / Q000175:diagnosis
chemical_list: D015415:Biomarkers; D020097:Natriuretic Peptide, Brain