Perioperative changes in atrial natriuretic peptide plasma levels associated with mitral and aortic valve replacement

Atrial natriuretic peptide (ANP) plasma levels are increased in patients with valvular heart disease. The present study investigates possible changes after mitral or aortic valve replacement (MVR, AVR).

In this prospective study, ANP plasma levels were measured in 11 patients undergoing MVR for mitral stenosis, in 11 patients undergoing AVR for aortic valve stenosis, and in 6 patients without heart disease undergoing thoracotomy for lung resection (control group). Blood samples were collected preoperatively (1 day before), during, and 8 days after the operation by serial blood sampling and were determined by radioimmunoassay method. ANP values were correlated with the duration of cardiopulmonary bypass (CPB), the aortic cross-clamping time, and the left atrial filling pressures.

ANP plasma levels were increased in all patients with valvular heart disease preoperatively and did not change during anesthesia or CPB; nor were they correlated with CPB duration or atrial filling pressures. The left atriotomy did not alter ANP plasma levels. The intracardiac surgical manipulations as well as CPB did not influence the ANP secretion intraoperatively and during the first postoperative week. Patients who underwent lung resection showed no change of ANP plasma levels perioperatively.

ANP levels are not altered during and 1 week after valve replacement and, therefore, do not reflect hemodynamic changes perioperatively.