title: Diagnostic accuracy of NT-proBNP ratio (BNP-R) for early diagnosis of tachycardia-mediated cardiomyopathy: a pilot study.
abstract: BACKGROUND
  When heart failure and tachycardia occur simultaneously, a useful diagnostic tool for early discrimination of patients with benign tachycardia-mediated cardiomyopathy (TMC) versus major structural heart disease (MSHD) is not available. Such a tool is required to prevent unnecessary and wearing diagnostics in patients with reversible TMC. Moreover, it could lead to early additional diagnostics and therapeutic approaches in patients with MSHD.
  
  
  METHODS
  A total of 387 consecutive patients with supraventricular arrhythmia underwent assessment at a single center. Of these patients, 40 fulfilled the inclusion criteria with a resting heart rate ≥100 bpm and an impaired left ventricular ejection fraction <40%. In all patients, successful electrical cardioversion was performed. At baseline, day 1 and weekly for 4 weeks, levels of NT-proBNP and echocardiographic parameters were evaluated. An NT-proBNP ratio (BNP-R) was calculated as a quotient of baseline NT-proBNP/follow-up NT-proBNP. After 4 weeks, cardiac catheterization was performed to identify patients with a final diagnosis of TMC versus MSHD.
  
  
  RESULTS
  Initial NT-proBNP concentrations were elevated and consecutively decreased after cardioversion in all patients. Multivariate regression and ROC analysis revealed that BNP-R discriminated between patients with TMC versus MSHD independent and superior to all other variables. The area under the ROC curve for BNP-R to detect TMC was 0.90 (95% CI 0.79-1.00; p < 0.001) after 1 week and 0.995 (95% CI 0.99-1.00; p < 0.0001) after 4 weeks. One week after cardioversion already, a BNP-R cutoff ≥2.3 was useful for TMC diagnosis indicated by an accuracy of 90%, sensitivity of 84% and specificity of 95%.
  
  
  CONCLUSIONS
  BNP-R was found to be highly accurate for the early diagnosis of TMC.
authors.affiliation: Department of Internal Medicine III, University of Cologne, Germany.
authors.forename: Amir M
authors.initials: AM
authors.lastname: Nia
authors.forename: Natig
authors.initials: N
authors.lastname: Gassanov
authors.forename: Kristina M
authors.initials: KM
authors.lastname: Dahlem
authors.forename: Evren
authors.initials: E
authors.lastname: Caglayan
authors.forename: Martin
authors.initials: M
authors.lastname: Hellmich
authors.forename: Erland
authors.initials: E
authors.lastname: Erdmann
authors.forename: Fikret
authors.initials: F
authors.lastname: Er
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D006328:Cardiac Catheterization; D009202:Cardiomyopathies / Q000097:blood / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D042241:Early Diagnosis; D015150:Echocardiography, Doppler; D004554:Electric Countershock; D005080:Exercise Test; D005260:Female; D005858:Germany; D006333:Heart Failure / Q000097:blood / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D006339:Heart Rate; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D010865:Pilot Projects; D011237:Predictive Value of Tests; D012372:ROC Curve; D020127:Recovery of Function; D013318:Stroke Volume; D013617:Tachycardia, Supraventricular / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain