title: Insights into the change in brain natriuretic peptide after ST-elevation myocardial infarction (STEMI): why should it be better than baseline?
abstract: While baseline N-terminal brain natriuretic peptide (NT-proBNP) is useful in the prognosis of acute ST-elevation myocardial infarction (STEMI), it is unclear whether a relationship exists between serial NT-proBNP, reperfusion success, and prognosis. We prospectively defined a NT-proBNP analysis in the WEST (Which Early ST-elevation myocardial infarction Therapy) trial that enrolled 304 acute STEMI patients. NT-proBNP (pg/mL) was measured at baseline prior to treatment (n=258) and 72 to 96 h (n=247) and 30 days (n=221) after treatment (Delta NT-proBNP=72 h value - the baseline NT-proBNP). Reperfusion success was measured by ST-segment resolution at 180 min, infarct size by peak creatine kinase (CK) during the first 24 h, and QRS score at discharge (QRSd). The primary endpoint was a 30 day clinical composite. The ability of either baseline NT-proBNP or Delta NT-proBNP to predict the primary endpoint was compared using single-variable logistic regression and the c-statistic. Median (interquartile range) NT-proBNP in pg/mL was 87 (39-316) at baseline, 864 (338-1857) at 72 h, and 585 (264-1212) at 30 days. ST resolution was inversely correlated with Delta NT-proBNP (r=-0.23, p=0.002) and 30 day NT-proBNP (30 day NT-proBNP 1016, 828, and 397 for <30%, 30%-70%, >or=70% STR, respectively, p<0.001). Infarct size was correlated with Delta NT-proBNP by CK (r=0.41, p<0.001) and QRSd (r=0.31, p<0.001); the 30 day NT-proBNP relationship was similar for CK (r=0.48, p<0.001) and QRSd (p=0.003). The baseline NT-proBNP was associated with an increased 30-day composite endpoint (Q1, 19%; Q2, 20%; Q3, 15%; Q4, 38%; p=0.03 for trend) as was Delta NT-proBNP (Q1, 16%; Q2, 18%; Q3, 19%; Q4, 37%; p=0.009 for trend). The c-statistic for baseline, 72 to 96 h, and Delta NT-proBNP was 0.59, 0.61, and 0.62 for the 30-day composite and 0.64, 0.62, and 0.62 for the 90-day composite, respectively. Delta NT-proBNP clearly predicts short-term adverse cardiac events and is superior to baseline NT-proBNP, but similar to the 72 to 96 h NT-proBNP in predicting clinical events after STEMI. This likely reflects the variability in NT-proBNP at presentation and the ability to integrate subsequent important physiologic sequelae of STEMI such as reperfusion and infarct size.
authors.affiliation: 2C2 Cardiology UAH, University of Alberta, 8440-112 Street, Edmonton, AB T6G 2B7, Canada. justin.ezekowitz@ualberta.ca
authors.forename: Justin A
authors.initials: JA
authors.lastname: Ezekowitz
authors.forename: Pierre
authors.initials: P
authors.lastname: Théroux
authors.forename: Robert
authors.initials: R
authors.lastname: Welsh
authors.forename: Iqbal
authors.initials: I
authors.lastname: Bata
authors.forename: John
authors.initials: J
authors.lastname: Webb
authors.forename: Paul W
authors.initials: PW
authors.lastname: Armstrong
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D003326:Coronary Circulation; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D015425:Myocardial Reperfusion / Q000379:methods*; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D016017:Odds Ratio; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012107:Research Design; D018570:Risk Assessment; D000077785:Tenecteplase; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D005343:Fibrinolytic Agents; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D002097:C-Reactive Protein; D010959:Tissue Plasminogen Activator; D000077785:Tenecteplase