Prognostic Value of Serial B-Type Natriuretic Peptide Testing During

ORIGINAL CONTRIBUTION

Prognostic Value of Serial B-Type Natriuretic Peptide Testing During Follow-up of Patients With Unstable Coronary Artery Disease David A. Morrow, MD, MPH James A. de Lemos, MD Michael A. Blazing, MD Marc S. Sabatine, MD, MPH Sabina A. Murphy, MPH Petr Jarolim, MD, PhD Harvey D. White, DSc Keith A. A. Fox, MB, ChB Robert M. Califf, MD Eugene Braunwald, MD for the A to Z Investigators

B

- TYPE NATRIURETIC PEPTIDE (BNP) is released from cardiac myocytes in response to increased wall stress,1 and is elevated in settings in which myocardial ischemia occurs. B-type natriuretic peptide is released during ischemia provoked by exercise testing2 and after acute myocardial infarction (MI), with some patients exhibiting a late increase, possibly related to adverse remodeling.3-6 When measured at the time of presentation, up to 7 days after onset of acute coronary syndrome (ACS), blood concentrations of BNP and N-amino terminal fragment of the prohormone BNP (NT-proBNP) are strongly associated with the short-term and long-term risk of death and new congestive heart failure (CHF).4,7-17 These data have led to approval for use of BNP and NTproBNP levels for risk stratification in ACS,18 and to the proposal that serial determinations during follow-up may be

Context Elevated concentrations of B-type natriuretic peptide (BNP) at presentation in patients with acute coronary syndrome (ACS) are associated with long-term mortality. Few data exist regarding serial assessment of BNP levels during follow-up. Objective To determine whether concentrations of BNP at study entry (prior to hospital discharge for ACS) and at outpatient follow-up at 4 months and 12 months are associated with subsequent clinical outcomes. Design, Setting, and Patients Prospective observational substudy of 4497 patients with non–ST-elevation or ST-elevation ACS who were enrolled in phase Z of the A to Z trial, which was conducted in 41 countries at 322 acute care hospitals between 1999 and 2003. Main Outcome Measure Death from any cause or new onset of congestive heart failure (CHF) through 2 years. Results Levels of BNP were available in 4266 patients at study entry (prior to hospital discharge), 3618 patients at 4 months, and 2966 patients at 12 months. During follow-up there were 230 deaths and 163 incident cases of CHF. Adjusting for age, sex, index event, renal function, hypertension, prior heart failure, and diabetes, elevated levels of BNP (⬎80 pg/mL) were associated with subsequent death or new CHF when measured at study entry (111 [21%] vs 246 [7%]; adjusted hazard ratio [HR], 2.5; 95% confidence interval [CI], 2.0-3.3), at 4 months (34 [19%] vs 125 [4%]; adjusted HR, 3.9; 95% CI, 2.6-6.0), and at 12 months (19 [11%] vs 37 [1%]; adjusted HR, 4.7; 95% CI, 2.5-8.9). Patients with newly elevated levels of BNP at 4 months were at increased risk of death or new CHF (10 [15%] vs 105 [3%]); HR, 4.5; 95% CI, 2.3-8.6). Patients with elevated levels of BNP at study entry and with BNP levels lower than 80 pg/mL at 4 months tended to have only modestly increased risk (HR, 1.7; 95% CI, 1.0-2.9) compared with patients with BNP levels lower than 80 pg/mL at both visits. Conclusions Serial determinations of BNP levels during outpatient follow-up after ACS predict the risk of death or new CHF. Changes in BNP levels over time are associated with long-term clinical outcomes and may provide a basis for enhanced clinical decision making in patients after onset of ACS. Clinical Trials Registration ClinicalTrials.gov Identifier: NCT00251576 www.jama.com

JAMA. 2005;294:2866-2871 Author Affiliations: Cardiovascular Division and Department of Medicine (Drs Morrow, Sabatine, and Braunwald and Ms Murphy) and Department of Pathology (Dr Jarolim), Brigham and Women’s Hospital and Harvard Medical School, Boston, Mass; Donald W. Reynolds Cardiovascular Clinical Research Center, University of Texas Southwestern Medical Center, Dallas (Dr de Lemos); Duke Clinical Research Institute, Duke University Medical Center,

2866 JAMA, December 14, 2005—Vol 294, No. 22 (Reprinted)

Durham, NC (Drs Blazing and Califf ); Green Lane Cardiovascular Research Unit, Auckland City Hospital, Auckland, New Zealand (Dr White); and Royal Infirmary of Edinburgh, Edinburgh, Scotland (Dr Fox). Corresponding Author: David A. Morrow, MD, MPH, Cardiovascular Division, Brigham and Women’s Hospital, 75 Francis St, Boston, MA 02115 (dmorrow @partners.org).

©2005 American Medical Association. All rights reserved.

Downloaded from www.jama.com at Medical Library of the PLA, on August 22, 2007

SERIAL B-TYPE NATRIURETIC PEPTIDE IN PATIENTS WITH ACS

useful both for additional prognostic assessment as well as monitoring response to therapy.19 However, few studies have evaluated serial measurements of BNP during extended follow-up of patients after ACS. Therefore, we investigated the prognostic value of BNP and changes in its concentration in patients with ACS prior to hospital discharge (study entry), at 4 months, and at 12 months in the A to Z trial. METHODS Study Population

Between 1999 and 2003, patients with non–ST-elevation or ST-elevation ACS were enrolled in phase Z of the A to Z trial and followed up for a median of 2 years. The study design, entry criteria, and primary results have been published previously.20,21 In phase Z, an early intensive statin strategy was compared with a less aggressive statin strategy in patients with ACS that was stabilized after initial presentation. The protocol was approved by the ethics committee at each of the 322 acute care hospitals and written informed consent was provided by all 4497 participants. All participants in phase Z who had plasma samples available for measurement of BNP were eligible for this substudy. Exclusion criteria for the A to Z trial relevant to this substudy included age older than 80 years, renal dysfunction (serum creatinine level ⬎2.0 mg/dL [⬎176.8 µmol/L]), acute pulmonary edema requiring intubation, or plans for coronary revascularization. BNP Testing

Samples of EDTA-anticoagulated plasma were obtained prior to randomization into phase Z (median [range] of 84 [62107] hours after symptom onset) and at outpatient follow-up at 4 months and 12 months and were shipped on ice overnight in plastic tubes for storage. Aliquots were then shipped on dry ice to the TIMI Biomarker Laboratory at Brigham and Women’s Hospital (Boston, Mass) where they were analyzed by batch. B-type natriuretic peptide was measured using the ADVIA Centaur (Bayer HealthCare Diagnostics, Tarry-

town, NY).22,23 All testing was performed by personnel blinded to clinical outcomes and treatment allocation. Statistical Methods

The prespecified primary end point for this substudy was the composite of death from any cause or new onset of CHF (requiring admission or initiation of medications). The major secondary end point was death from any cause. The concentration of BNP at each time point was described by the median (25th and 75th percentiles). The results of BNP testing were considered as a dichotomous variable using a prespecified level of 80 pg/mL based on prior research on ACS.10,11,24 Baseline characteristics were compared using the Wilcoxon rank sum test for continuous variables and the ␹2 test for categorical variables. Event rates for clinical outcomes were determined using the Kaplan-Meier method and compared using the log-rank test. Multivariable analyses of the association between BNP levels and clinical outcomes were performed using the Cox proportional hazards regression model to adjust for the effects of other major clinical predictors of mortality (age, sex, index event [non–ST-elevation vs STelevation ACS], deviation in STsegment depression, creatinine clearance at the time of the visit, hypertension at study entry, history of CHF, and diabetes). Creatinine clearance was estimated using the Cockroft-Gault formula. The proportional hazards assumption was validated. Assessment of an expanded model in the subset of patients with data available for C-reactive protein (study entry [baseline] and at 4 months), local troponin level from the index event, glucose level, and treatment with blockers of the reninangiotensin-aldosterone pathway and ␤-blockers revealed no significant confounding (⬍10% change in the adjusted hazard ratio [HR]), with the exception of the assessment of BNP level and C-reactive protein at entry to phase Z (reported in “Results”). Formal testing for an interaction with prior CHF revealed none (at each time point, P⬎.20 for interaction).

©2005 American Medical Association. All rights reserved.

Testing was performed for an association between the concentration of BNP at 4 months and at 12 months with subsequent clinical outcome by timeto-event (landmark) analysis beginning at the time of sampling and including all patients with an available BNP result from the relevant visit. Confirmatory analyses excluding patients with nonfatal ischemic and CHF events prior to the visit also were performed to eliminate possible confounding by recent cardiac events resulting in an increase in BNP level. All analyses were performed by the Thrombolysis in Myocardial Infarction study group using STATA Intercooled software version 8.2 (STATA Corp, College Station, Tex). P⬍.05 (2-tailed) was considered to indicate statistical significance. RESULTS Changes in BNP Level During Long-term Follow-up After ACS

The distribution of BNP concentrations at each visit are reported in TABLE 1. There were no significant differences between the study population and patients with missing BNP values at outpatient follow-up at 4 months and 12 months with respect to variables associated with BNP (age, presentation with ST-elevation, history of CHF, creatinine clearance). However, there was a greater proportion of women with missing plasma samples at 4 months (missing vs nonmissing: 31% vs 23%; P=.001) and at 12 months (28% vs 23%; P =.002). Among the 3493 patients with measurements at baseline and at 4 months, 473 (13.5%) had BNP concentrations higher than 80 pg/mL at baseline; of these 473 patients, 140 (29.6%) had levels that remained elevated at 4 months, while the remainder (n = 333; 70.4%) had levels that were lower than 80 pg/mL. There were 77 (2.5%) patients who had a newly elevated concentration of BNP at 4 months. Among the 2901 patients with plasma samples at 4 months and at 12 months, 173 (6.0%) had levels of BNP that were higher than 80 pg/mL at 4 months; of these 173 patients, 85

(Reprinted) JAMA, December 14, 2005—Vol 294, No. 22

Downloaded from www.jama.com at Medical Library of the PLA, on August 22, 2007

2867

SERIAL B-TYPE NATRIURETIC PEPTIDE IN PATIENTS WITH ACS

Table 1. Univariate Associations With Elevated Levels of B-Type Natriuretic Peptide (BNP)* Study Entry†

4 mo‡

Level of BNP, pg/mL

Demographics Age, median (range), y㛳 Women Risk factors Hypertension Smoking Diabetes

12 mo§

Level of BNP, pg/mL

Level of BNP, pg/mL

ⱕ80 (n = 3657)

⬎80 (n = 609)

P Value

ⱕ80 (n = 3396)

⬎80 (n = 222)

P Value

ⱕ80 (n = 2748)

⬎80 (n = 218)

P Value

60 (52-69)

65 (55-72)

⬍.001

60 (52-68)

67 (60-74)

⬍.001

60 (52-68)

68.5 (62-73)

⬍.001

⬍.001

867 (23.7)

172 (28.2)

.02

761 (22.4)

73 (32.9)

1798 (49.2) 1493 (40.9) 748 (20.5)

337 (55.3) 231 (37.9) 154 (25.3)

.005 1642 (48.4) .17 1424 (42.0) .007 672 (19.8)

137 (61.7) 55 (24.8) 65 (29.3)

615 (22.4)

69 (31.7)

.002

⬍.001 1317 (47.9) ⬍.001 1135 (41.3) .001 510 (18.6)

136 (62.4) 59 (27.1) 74 (33.9)

⬍.001 ⬍.001 ⬍.001

Prior CHF 170 (4.7) 42 (6.9) .02 152 (4.5) 23 (10.4) ⬍.001 117 (4.3) 27 (12.4) ⬍.001 Presenting characteristics STEMI 1304 (35.7) 398 (65.4) ⬍.001 1289 (38.0) 143 (64.4) ⬍.001 1022 (37.2) 127 (58.3) ⬍.001 Creatinine 76.8 (61.6-94.4) 66.8 (52.1-86.4) ⬍.001 76.8 (61.7-94.1) 61.0 (47.9-76.4) ⬍.001 76.7 (62.2-93.1) 61.4 (50.1-76.2) ⬍.001 clearance, median (range), mL/min㛳 Abbreviations: CHF, congestive heart failure; STEMI, ST-elevation myocardial infarction. SI converstion factor: To convert creatinine clearance to mL/s, multiply by 0.0167. *Values are expressed as number (percentage) unless otherwise indicated. †The median (range) BNP level was 11.5 (5-45) pg/mL. ‡The median (range) BNP level was 5.2 (5-23) pg/mL. §The median (range) BNP level was 11.2 (5-30) pg/mL. 㛳The range is the 25th and 75th percentile.

Table 2. Risk of Death or Congestive Heart Failure (Kaplan-Meier Estimated Rates) Stratified by B-Type Natriuretic Peptide (BNP) Results* No. (%) of Patients Risk of Death or CHF BNP Threshold and Time Point 20 pg/mL Baseline 4 mo 12 mo 40 pg/mL Baseline 4 mo 12 mo 80 pg/mL Baseline 4 mo 12 mo 160 pg/mL Baseline 4 mo 12 mo

BNP Level ⬎Threshold

BNP Level ⱕThreshold

BNP Level ⬎Threshold

Adjusted HR (95% CI)

1741 (41) 1027 (29) 1021 (35)

158 (6.5) 88 (3.3) 24 (1.1)

199 (12.7) 71 (8.1) 32 (3.8)

1.6 (1.3-2.0) 2.0 (1.4-2.8) 2.0 (1.1-3.6)

1149 (27) 540 (15) 535 (18)

198 (6.6) 105 (3.4) 30 (1.2)

159 (15.6) 54 (12.0) 26 (5.7)

1.9 (1.5-2.4) 2.9 (2.0-4.3) 3.0 (1.7-5.5)

609 (14) 219 (6) 215 (7)

246 (7.0) 125 (3.7) 37 (1.4)

111 (21.0) 34 (19.4) 19 (10.7)

2.5 (2.0-3.3) 3.9 (2.6-6.0) 4.7 (2.5-8.9)

216 (5) 76 (2) 62 (2)

297 (7.7) 140 (4.0) 46 (1.7)

60 (32.2) 19 (33.1) 10 (17.9)

3.2 (2.3-4.3) 5.4 (3.2-9.1) 5.7 (2.5-13.0)

Abbreviations: CHF, congestive heart failure; CI, confidence interval; HR, hazard ratio. *The additional prognostic information obtained from a BNP result was maximal (using the likelihood ratio test in the adjusted model) at 80 pg/mL for each of the time points.

(49%) had levels that remained elevated at 12 months. At 12 months, 125 (4.6%) patients had a newly elevated concentration of BNP.

Relationship Between BNP Level and Clinical Outcome

During 2 years of follow-up, there were 230 deaths and 163 cases of incident

2868 JAMA, December 14, 2005—Vol 294, No. 22 (Reprinted)

CHF (TABLE 2). Patients with a BNP level higher than 80 pg/mL at entry to phase Z were at significantly higher risk of death or new CHF through 2 years. After adjustment for other clinical predictors, a baseline BNP level higher than 80 pg/mL was associated with a 2-fold higher long-term risk of death (adjusted HR, 2.1; 95% confidence interval [CI], 1.5-3.0) and death or new CHF (adjusted HR, 2.5; 95% CI, 2.0-3.3). Addition of C-reactive protein to the model for those with data available partially attenuated the relationship with death or new CHF (adjusted HR, 1.9; 95% CI, 1.5-2.5). B-type natriurectic peptide was not associated with the risk of MI (47 [8.4%] vs 243 [6.9%]; adjusted HR, 1.2; 95% CI, 0.9-1.7) or readmission for ACS (36 [.07%] vs 167 [4.7%]; adjusted HR, 1.1; 95% CI, 0.7-1.7). Stratification by index presentation (STelevation vs non–ST-elevation ACS) revealed no heterogeneity with regard to the relationship between BNP level and death (P=.32 for interaction) or the risk of death or new CHF (P = .55 for interaction). When measured at 4 months, BNP level remained strongly associated with

©2005 American Medical Association. All rights reserved.

Downloaded from www.jama.com at Medical Library of the PLA, on August 22, 2007

SERIAL B-TYPE NATRIURETIC PEPTIDE IN PATIENTS WITH ACS

Figure 1. Cumulative Incidence of Subsequent Death and Death or New or Worsening Congestive Heart Failure Through 2 Years of Follow-up Death

Death or Congestive Heart Failure

20

20 Month 4 B-Type Natriuretic Peptide, pg/mL >80 ≤80

18 16

16 14

Percentage

Percentage

14

18

12 10 8 6

10 8 Log-Rank P < .001

6

Log-Rank P < .001

4

12

4

2

2

0

120

240

360

480

600

0

120

Days After Month 4 Visit

214 3324

203 3187

subsequent survival (adjusted HR, 3.6; 95% CI, 2.2-6.2), as well as the risk of death or new CHF (adjusted HR, 3.9; 95% CI, 2.6-6.0; F IGURE 1). Moreover, when patients with CHF or ischemic events that might contribute to increases in BNP level prior to outpatient follow-up at 4 months were excluded, an elevated level of BNP remained associated with a significantly higher risk of death (adjusted HR, 3.0; 95% CI, 1.7-5.6) and death or new CHF (adjusted HR, 3.5; 95% CI, 2.2-5.6). Results at outpatient follow-up at 12 months were similar with respect to survival (adjusted HR, 3.9; 95% CI, 1.98.5) and death or new CHF (adjusted HR, 4.7; 95% CI, 2.5-8.9). The absolute and relative risk relationships for BNP level applied at a range of possible decision limits at each time point appear in Table 2. Value of Serial Determination of BNP Level

Patients with a persistently elevated level of BNP were at highest risk of death or new CHF (FIGURE 2). Notably, compared with patients who had BNP levels that were lower than 80 pg/mL at both visits, patients who had a BNP level lower than 80 pg/mL at baseline but presented with an elevated BNP level at 4 months had a 4-fold higher risk of death or new CHF

168 2868

111 2481

55 1801

219 3377

360

480

600

209 3310

194 3166

158 2846

102 2460

52 1789

Figure 2. Cumulative Incidence of Subsequent Death or New or Worsening Congestive Heart Failure Death or Congestive Heart Failure, %

No. at Risk According to Month 4 B-Type Natriuretic Peptide, pg/mL >80 219 ≤80 3377

240

Days After Month 4 Visit

B-Type Natriuretic Peptide Levels Baseline-Month 4 High-High Low-High High-Low Low-Low

22 20 18 16 14 12 10 8 6 4 2 0

120

240

360

480

600

Days After Month 4 Visit No. at Risk High-High

137

128

121

91

59

35

Low-High

77

77

70

65

43

17

High-Low

330

322

292

225

161

97

Low-Low

2929

2877

2777

2539

2232

1649

Each group is labeled by the B-type natriuretic peptide (BNP) levels at baseline and month 4. For example, the group with BNP higher than 80 pg/mL at both visits is labeled as “high-high” and the group with elevated BNP at baseline and BNP of 80 pg/mL or lower at follow-up is labeled as “high-low.” Log-rank P values compared with those with BNP of 80 pg/mL or lower at both visits are P⬍.001 for the “high-high” group; P⬍.001 for the “low-high” group; and P = .05 for the “high-low” group.

(HR, 4.5; 95% CI, 2.3-8.6). In contrast, patients with elevated BNP levels at baseline who returned with BNP levels lower than 80 pg/mL at 4 months tended to have only a modestly increased risk compared with patients with BNP levels lower than 80 pg/mL at both visits (HR, 1.7; 95% CI, 1.02.9). These observations were not altered by excluding patients with inter-

©2005 American Medical Association. All rights reserved.

current ischemic or CHF events between visits. Similarly, compared with patients who had BNP levels lower than 80 pg/mL at 12 months (death or new CHF, n=2592; 1.4%), patients with either persistently (n = 85; 16.0% [P⬍.001]) or newly (n = 125; 8.2% [P⬍.001]) elevated levels of BNP at 12 months were at increased risk of death or new CHF.

(Reprinted) JAMA, December 14, 2005—Vol 294, No. 22

Downloaded from www.jama.com at Medical Library of the PLA, on August 22, 2007

2869

SERIAL B-TYPE NATRIURETIC PEPTIDE IN PATIENTS WITH ACS

No difference in the concentration of BNP or change in BNP level was observed at 4 months or 12 months between the randomized statin groups in phase Z. COMMENT This evaluation of BNP levels obtained early and during long-term follow-up after presentation in patients with ACS supports the value of serial determinations of BNP concentration for refining risk assessment and providing data to create a secondary prevention strategy in this population. Serial Determination of BNP Level in Patients With ACS

Emerging evidence suggests that ascertainment of changes in BNP level over time may be useful in risk assessment, as well as for monitoring and directing therapy in patients with CHF, and has stimulated interest in whether a similar approach may be valuable in patients with ACS.19 A study of 1791 ACS patients showed that persistent or new increases in NT-proBNP levels at 72 hours were associated with significantly higher risk of subsequent cardiovascular events through 30 days.17 Lindahl et al25 found that levels of NTproBNP declined substantially over time following onset of ACS and identified left ventricular dysfunction as a major predictor of persistent elevation of NTproBNP level. Notably, while they found that NT-proBNP level was associated with mortality when tested at 6 weeks to 6 months after presentation, these investigators did not detect a relationship between changes in NTproBNP concentration and clinical outcome. Our observations indicate that the achieved concentration of BNP during ambulatory follow-up after recent ACS is predictive of long-term clinical outcomes and that changes in the results of BNP testing are associated with subsequent survival without CHF. These findings have important clinical implications for the care of patients with ACS. Unlike traditional biomarkers used for risk stratification

(cardiac troponin and creatine kinaseMB), BNP has potential clinical applications both during the acute phase and for monitoring the longitudinal course after ACS. While we found no influence of the intensity of statin therapy on the levels of BNP, other treatments, such as angiotensin II receptor blockers and ␤-blockers, have been shown to lower levels of natriuretic peptides in patients with CHF26 and to improve clinical outcomes in high-risk patients with atherosclerotic vascular disease.27,28 Contemporary Application of BNP Level for Risk Stratification in Patients With ACS

Formal guidelines regarding the use of BNP level as a biomarker for risk stratification in patients with ischemic heart disease are under development.29 By virtue of its robust sample size, almost equal to the aggregate of previously available data for measurement of BNP levels in ACS (approximately 4300 patients), this study adds to the cumulative evidence for the prognostic value of BNP concentration measured during the initial hospitalization,29 and points toward novel applications for monitoring and guiding therapy. Nevertheless, recommendations for routine measurement of BNP levels in patients with ACS are not likely to emerge unless additional criteria are satisfied. Foremost, data supporting the benefit of specific therapeutic interventions to modify the risk associated with neurohormonal activation must be available before determination of BNP concentration is integrated into standard risk assessment strategies. At present, it seems reasonable to selectively apply BNP and NT-proBNP testing in patients for whom a more complete assessment of the absolute risk of death and/or CHF is desired by the clinician. Limitations

We studied the use of BNP levels for risk assessment in patients with a high clinical probability of ACS. The results re-

2870 JAMA, December 14, 2005—Vol 294, No. 22 (Reprinted)

garding in-hospital testing of BNP concentration may not apply to patients presenting with chest pain and low probability of ACS. Levels of BNP are increased in a variety of other conditions,30 and thus must be integrated with findings from the clinical examination to arrive at an overall diagnostic and prognostic assessment. Moreover, patients enrolled in the A to Z trial did not have significant renal insufficiency and were younger than 80 years. Application of the specific decision limits evaluated in this study may not be appropriate for patients with more advanced age or renal dysfunction. The analysis at each time point was by necessity limited to survivors with available samples that may have some impact on the generalizability of the findings. CONCLUSIONS Serial determination of BNP concentration prior to hospital discharge and during outpatient follow-up of patients with ACS provides significant independent prognostic information with respect to the risk of death or new heart failure. Changes in BNP level over time are associated with long-term clinical outcome and may provide a basis for enhanced clinical decision making in patients recovering from ACS. Author Contributions: Dr Morrow had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Morrow, de Lemos, Blazing, Murphy, White, Fox, Califf, Braunwald. Acquisition of data: de Lemos, Jarolim. Analysis and interpretation of data: Morrow, de Lemos, Sabatine, Murphy, White, Fox, Califf, Braunwald. Drafting of the manuscript: Morrow. Critical revision of the manuscript for important intellectual content: Morrow, de Lemos, Blazing, Sabatine, Murphy, Jarolim, White, Fox, Califf, Braunwald. Statistical analysis: Morrow, Sabatine, Murphy. Obtained funding: Morrow, Califf, Braunwald. Administrative, technical, or material support: de Lemos, Blazing, Jarolim, Califf, Braunwald. Study supervision: Morrow, de Lemos, Jarolim, Braunwald. Financial Disclosures: Dr Morrow has received research grant support administered via Brigham and Women’s Hospital from Bayer Healthcare Diagnostics, Beckman Coulter, Biosite, Dade Behring, Merck, and Roche Diagnostics. Dr Morrow has received honoraria for educational presentations from Bayer Healthcare Diagnostics, Beckman Coulter, and Dade Behring. Dr de Lemos has received research grants from Biosite and Roche and honoraria and consulting fees

©2005 American Medical Association. All rights reserved.

Downloaded from www.jama.com at Medical Library of the PLA, on August 22, 2007

SERIAL B-TYPE NATRIURETIC PEPTIDE IN PATIENTS WITH ACS for speaking from Biosite and Roche. Dr Blazing has received honoraria from Merck and Pfizer. Funding/Support: This study was supported by Merck and Co and Bayer Healthcare Diagnostics Division. Role of the Sponsor: Staff from Merck assisted in monitoring the progress and conduct of the A to Z trial. Bayer Healthcare provided reagents for B-type natriuretic peptide testing. The sponsors were not involved in the biomarker testing, analysis, or interpretation of the data, or in preparation of the manuscript for this substudy. Medical specialists employed by the sponsors reviewed the manuscript prior to submission.

REFERENCES 1. de Lemos JA, McGuire DK, Drazner MH. B-type natriuretic peptide in cardiovascular disease. Lancet. 2003;362:316-322. 2. Sabatine MS, Morrow DA, de Lemos JA, et al. Acute changes in circulating natriuretic peptide levels in relation to myocardial ischemia. J Am Coll Cardiol. 2004; 44:1988-1995. 3. Arakawa N, Nakamura M, Aoki H, Hiramori K. Relationship between plasma level of brain natriuretic peptide and myocardial infarct size. Cardiology. 1994;85: 334-340. 4. Talwar S, Squire IB, Downie PF, et al. Profile of plasma N-terminal proBNP following acute myocardial infarction: correlation with left ventricular systolic dysfunction. Eur Heart J. 2000;21:15141521. 5. Morita E, Yasue H, Yoshimura M, et al. Increased plasma levels of brain natriuretic peptide in patients with acute myocardial infarction. Circulation. 1993;88: 82-91. 6. Motwani JG, McAlpine H, Kennedy N, Struthers AD. Plasma brain natriuretic peptide as an indicator for angiotensin-converting-enzyme inhibition after myocardial infarction. Lancet. 1993;341: 1109-1113. 7. Arakawa N, Nakamura M, Aoki H, Hiramori K. Plasma brain natriuretic peptide concentrations predict survival after acute myocardial infarction. J Am Coll Cardiol. 1996;27:1656-1661. 8. Omland T, Aakvaag A, Bonarjee VV, et al. Plasma brain natriuretic peptide as an indicator of left ventricular systolic function and long-term survival after acute myocardial infarction: comparison with plasma atrial natriuretic peptide and N-terminal proatrial natriuretic peptide. Circulation. 1996;93:1963-1969. 9. Richards AM, Nicholls MG, Yandle TG, et al. Plasma N-terminal pro-brain natriuretic peptide and adrenomedullin: new neurohormonal predictors of left ven-

tricular function and prognosis after myocardial infarction. Circulation. 1998;97:1921-1929. 10. de Lemos JA, Morrow DA, Bentley JH, et al. The prognostic value of B-type natriuretic peptide in patients with acute coronary syndromes. N Engl J Med. 2001;345:1014-1021. 11. Morrow DA, de Lemos JA, Sabatine MS, et al. Evaluation of B-type natriuretic peptide for risk assessment in unstable angina/non-ST elevation MI: BNP and prognosis in TACTICS-TIMI 18. J Am Coll Cardiol. 2003;41:1264-1272. 12. Omland T, de Lemos JA, Morrow DA, et al. Prognostic value of N-terminal pro-atrial and pro-brain natriuretic peptide in patients with acute coronary syndromes. Am J Cardiol. 2002;89:463-465. 13. Jernberg T, Stridsberg M, Venge P, Lindahl B. Nterminal pro brain natriuretic peptide on admission for early risk stratification of patients with chest pain and no ST-segment elevation. J Am Coll Cardiol. 2002;40: 437-445. 14. Omland T, Persson A, Ng L, et al. N-terminal proB-type natriuretic peptide and long-term mortality in acute coronary syndromes. Circulation. 2002;106: 2913-2918. 15. Jernberg T, Lindahl B, Siegbahn A, et al. Nterminal pro-brain natriuretic peptide in relation to inflammation, myocardial necrosis, and the effect of an invasive strategy in unstable coronary artery disease. J Am Coll Cardiol. 2003;42:1909-1916. 16. James SK, Wallentin L, Armstrong PW, et al. Nterminal pro brain natriuretic peptide and other risk markers for the separate prediction of mortality and subsequent myocardial infarction in patients with unstable coronary disease: a GUSTO IV substudy. Circulation. 2003;108:275-281. 17. Heeschen C, Hamm CW, Mitrovic V, Lantelme NH, White HD. N-terminal pro-B-type natriuretic peptide levels for dynamic risk stratification of patients with acute coronary syndromes. Circulation. 2004;110:3206-3212. 18. Morrow DA, Braunwald E. Future of biomarkers in acute coronary syndromes: moving toward a multimarker strategy. Circulation. 2003;108: 250-252. 19. Silver MA, Maisel A, Yancy CW, et al. BNP Consensus Panel 2004: a clinical approach for the diagnostic, prognostic, screening, treatment monitoring, and therapeutic roles of natriuretic peptides in cardiovascular diseases. Congest Heart Fail. 2004; 10(suppl 3):1-30. 20. Blazing MA, De Lemos JA, Dyke CK, Califf RM, Bilheimer D, Braunwald E. The A-to-Z Trial: methods and rationale for a single trial investigating combined use of low-molecular-weight heparin with the glyco-

©2005 American Medical Association. All rights reserved.

protein IIb/IIIa inhibitor tirofiban and defining the efficacy of early aggressive simvastatin therapy. Am Heart J. 2001;142:211-217. 21. de Lemos JA, Blazing MA, Wiviott SD, et al. Early intensive vs a delayed conservative simvastatin strategy in patients with acute coronary syndromes: phase Z of the A to Z trial. JAMA. 2004;292:1307-1316. 22. Wu AH, Packer M, Smith A, et al. Analytical and clinical evaluation of the Bayer ADVIA Centaur automated B-type natriuretic peptide assay in patients with heart failure: a multisite study. Clin Chem. 2004;50: 867-873. 23. Maisel AS, Krishnaswamy P, Nowak RM, et al. Rapid measurement of B-type natriuretic peptide in the emergency diagnosis of heart failure. N Engl J Med. 2002;347:161-167. 24. Mega JL, Morrow DA, De Lemos JA, et al. Btype natriuretic peptide at presentation and prognosis in patients with ST-segment elevation myocardial infarction: an ENTIRE-TIMI-23 substudy. J Am Coll Cardiol. 2004;44:335-339. 25. Lindahl B, Lindback J, Jernberg T, et al. Serial analyses of N-terminal pro-B-type natriuretic peptide in patients with non-ST-segment elevation acute coronary syndromes: a Fragmin and fast Revascularisation during In Stability in Coronary artery disease (FRISC)-II substudy. J Am Coll Cardiol. 2005;45:533-541. 26. Latini R, Masson S, Anand I, et al. Effects of valsartan on circulating brain natriuretic peptide and norepinephrine in symptomatic chronic heart failure: the Valsartan Heart Failure Trial (Val-HeFT). Circulation. 2002;106:2454-2458. 27. Yusuf S, Sleight P, Pogue J, Bosch J, Davies R, Dagenais G; The Heart Outcomes Prevention Evaluation Study Investigators. Effects of an angiotensinconverting-enzyme inhibitor, ramipril, on cardiovascular events in high-risk patients. N Engl J Med. 2000;342: 145-153. 28. Richards AM, Doughty R, Nicholls MG, et al; Australia-New Zealand Heart Failure Group. Neurohumoral prediction of benefit from carvedilol in ischemic left ventricular dysfunction. Circulation. 1999;99: 786-792. 29. Committee for Laboratory Medicine Practice Guidelines. National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines: characteristics and utilization of biochemical markers in acute coronary syndromes and heart failure draft guidelines. Available at: http://www.aacc.org/meetings/beckman /beckman_present.stm. Accessed April 16, 2005. 30. Mair J, Hammerer-Lercher A, Puschendorf B. The impact of cardiac natriuretic peptide determination on the diagnosis and management of heart failure. Clin Chem Lab Med. 2001;39:571-588.

(Reprinted) JAMA, December 14, 2005—Vol 294, No. 22

Downloaded from www.jama.com at Medical Library of the PLA, on August 22, 2007

2871