Elsevier

American Heart Journal

Volume 150, Issue 4, October 2005, Pages 695-700
American Heart Journal

Clinical Investigation
Acute Ischemic Heart Disease
Percent change in B-type natriuretic peptide levels during treadmill exercise as a screening test for exercise-induced myocardial ischemia

https://doi.org/10.1016/j.ahj.2004.12.003Get rights and content

Background

Myocardial ischemia leads to changes in regional wall stress. Induction of ischemia during a treadmill exercise, although brief, may lead to transient elevation in the plasma level of B-type natriuretic peptide (BNP) from baseline levels, which could serve as a biochemical marker of myocardial ischemia.

Methods

Sixty subjects (mean age 57, 41 men) undergoing myocardial single-photon emission computed tomography (SPECT) in conjunction with Bruce protocol treadmill exercise for evaluation of chest pain or screening for ischemia had their BNPs measured (Triage Biosite Test) at baseline, immediately postexercise, and 10 to 15 minutes after exercise.

Results

Of the 60 patients, 10 had ischemic perfusion defects by SPECT (mean 14%, range 5%-37%). In patients with no evidence of ischemia, median BNP level at baseline was 15.05 pg/mL (interquartile range 7-37.7), increased significantly immediately postexercise median level (34.7 pg/mL [14.9-67.6]), and decreased toward baseline levels within 10 to 15 minutes postexercise (20.3 pg/mL [8.6-48.5], analysis of variance P < .001). This transient rise in BNP level during exercise was also observed in patients with ischemia but was more pronounced. Percent change in BNP level from baseline for each minute of exercise was significantly higher in patients with evidence of ischemia compared with those without (14% ± SEM 2.3 vs 7% ± SEM 1.2, P = .014). Patients with and without ischemia did not differ in age, exercise time, peak systolic or diastolic blood pressure, peak heart rate, or other baseline characteristics. A >10% change in BNP level from rest per minute of exercise had a sensitivity of 80%, a specificity of 71%, and a negative predictive value of 92% to detect reversible ischemia by SPECT.

Conclusion

Transient elevation in BNP occurs during treadmill exercise and is more pronounced in patients with ischemia. B-type natriuretic peptides may therefore be used in combination with treadmill exercise for the evaluation of coronary artery disease.

Section snippets

Methods

Sixty consecutive patients undergoing myocardial single-photon emission computed tomography (SPECT) in conjunction with Bruce protocol treadmill exercise for evaluation of chest pain or screening for ischemia were enrolled into our study. Exclusion criteria were defined as follows: clinical heart failure (New York Heart Association class ≥II), known left ventricular ejection fraction of <40%, unstable angina, recent evidence of myocardial infarction (<6 weeks), and known moderate-to-severe

Patient population

Sixty consecutive patients who met the criteria for inclusion were enrolled in the study. There were 41 men and 19 women, with a mean age of 57.2 ± 9.3 years. Diabetes was present in 18% of the patients. Twenty-three percent were taking β-blockers, 15% were taking angiotensin-converting enzyme inhibitors, and 11% were taking calcium-channel blockers.

Ten patients, all men, had reversible myocardial perfusion defects by SPECT (mean defect size 14%, range 5%-37%). Postexercise ejection fraction

Discussion

The present study demonstrates that, in subjects without heart failure undergoing routine treadmill exercise test for evaluation of ischemia, BNP levels increase significantly from rest to immediate postexercise and decrease toward baseline levels within 10 to 15 minutes after exercise. This transient rise in BNP levels during treadmill exercise is observed in patients with and without ischemia but is more pronounced in patients with ischemia, particularly when baseline levels, sex, and

Cited by (0)

View full text