title: Plasma B-type natriuretic peptide levels are poorly related to the occurrence of ischemia or ventricular arrhythmias during symptom-limited exercise in low-risk patients.
abstract: BACKGROUND
  The usefulness of B-type natriuretic peptide (BNP) as a marker of ischemia is controversial. BNP levels have predicted arrhythmias in various settings, but it is unknown whether they are related to exercise-induced ischemic ventricular arrhythmias.
  
  
  METHODS
  We analyzed in 63 patients (64 ±14 years, 65% male, 62% with known coronary disease) undergoing exercise stress single-photon emission computed tomography (SPECT) the association between plasma BNP values (before and 15 min after exercise) and the occurrence of ischemia or ventricular arrhythmias during the test.
  
  
  RESULTS
  Exercise test (8.1 ±2.7 min, 7.4 ±8.1 metabolic equivalents, 82 ±12% of maximal predicted heart rate) induced reversible perfusion defects in 23 (36%) patients. Eight (13%) patients presented significant arrhythmias (≥ 7 ventricular premature complexes/min, couplets, or non-sustained ventricular tachycardia during exercise or in the first minute of recovery). Median baseline BNP levels were 17.5 (12.4-66.4) pg/ml in patients developing scintigraphic ischemia and 45.6 (13.2-107.4) pg/ml in those without ischemia (p = 0.137). The BNP levels increased after exercise (34.4 (15.3-65.4)% increment over baseline, p < 0.001), but the magnitude of this increase was not related to SPECT positivity (35.7 (18.8-65.4)% vs. 27.9 (5.6-64.0)% in patients with and without ischemia, respectively, p = 0.304). No significant association was found between BNP values (at baseline or their change during the test) and ventricular arrhythmias.
  
  
  CONCLUSIONS
  Plasma BNP values - at baseline or after exercise - were not associated with myocardial ischemia or with ventricular arrhythmia during exercise SPECT. These results highlight the limited usefulness of this biomarker to assess acute ischemia.
authors.affiliation: Servicio de Cardiología, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Andreu
authors.initials: A
authors.lastname: Porta
authors.affiliation: Servicio de Cardiología, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Barrabés
authors.affiliation: Servicio de Cardiología, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Candell-Riera
authors.affiliation: Servicio de Cardiología, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Agulló
authors.affiliation: Servicio de Medicina Nuclear, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Aguadé-Bruix
authors.affiliation: Servicio de Medicina Nuclear, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Gustavo
authors.initials: G
authors.lastname: de León
authors.affiliation: Servicio de Cardiología, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Figueras
authors.affiliation: Servicio de Cardiología, Hospital Universitari Vall d'Hebron, VHIR, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Garcia-Dorado
keywords: biomarkers; exercise stress test; ischemia; natriuretic peptides