Right coronary artery stenosis is associated with impaired cardiac endocrine function during exercise

Resting plasma levels of atrial natriuretic peptide and B-type natriuretic peptide rise with left ventricular dysfunction, but little is known about effects of cardiac ischaemia on atrial natriuretic peptide and B-type natriuretic peptide levels during exercise. We investigated exercise levels of atrial natriuretic peptide and B-type natriuretic peptide in patients with suspected angina to determine whether these measurements could improve non-invasive assessment of coronary disease severity.

One hundred patients performed an exercise test (Bruce protocol) within 2 weeks of coronary angiography. Plasma levels of atrial natriuretic peptide and B-type natriuretic peptide were measured at rest and at peak exercise. Multivariate regression analysis was used to assess effects of age, sex, coronary anatomy, exercise time and ventricular function on atrial natriuretic peptide and B-type natriuretic peptide levels. Increasing age and female sex were significantly associated with higher resting atrial natriuretic peptide levels; age alone was associated with higher exercise atrial natriuretic peptide levels. As expected, left ventricular end-diastolic pressure and disease of left anterior descending and circumflex coronary arteries were associated with increased resting B-type natriuretic peptide levels. However, the usual rise in B-type natriuretic peptide levels during exercise was independently reduced by disease of the right coronary artery.

This paradoxical effect of right coronary artery disease limits the value of natriuretic peptide measurements as predictors of coronary disease severity. Impaired release of B-type natriuretic peptide may reduce exercise tolerance in patients with right coronary artery disease.