EFFECT OF CONTINUOUS POSITIVE AIRWAY PRESSURE ON MITRAL REGURGITANT FRACTION AND ATRIAL-NATRIURETIC-PEPTIDE IN PATIENTS WITH HEART-FAILURE

Objectives. We sought to determine the effects of continuous positive airway pressure (CPAP) on mitral regurgitant fraction (MRF) and plasma atrial natriuretic peptide (ANP) concentra tion in patients with cong estive heart failure (CHF). Background. In patients with CHF, elevated plasma ANP concentration is associated with elevated cardiac filling pressures, Secondary mitral regurgitation may contribute to elevation in plasma ANP concentration in patients with CHF, Because CPAP reduces transmural cardiac pressures and left ventricular (LV) volume, we hyp othesized that long-term CPAP application mould decrease the MRF and p lasma ANP concentration in patients with CHF and Cheyne-Stokes respira tion,vith central sleep apnea (CSR-CSA). Methods. Seventeen patients w ith CHF and CSR CSA underwent baseline assessments of plasma ANP conce ntration and left ventricular ejection fraction (LVEF) and MRF by radi onuclide angiography. They were then randomized to receive nocturnal C PAP plus optimal medical therapy (n = 9) or optimal medical therapy al one (n = 8) for 3 months and were then reassessed. Results. In the CPA P-treated group, LVEF increased from (mean +/- SEM) 20.2 +/- 4.2% to 2 8.2 +/- 5.3% (p < 0.02); MRF decreased from 32.8 +/- 7.7% to 19.4 +/- 5.5% (p < 0.02); and plasma ANP concentration decreased from 140.9 +/- 20.8 to 103.9 +/- 17.0 pg/ml (p < 0.05), The control group experience d no significant changes in LVEF, MRF or plasma ANP concentration, Amo ng all patients, the change in plasma ANP concentration from baseline to 3 months correlated significantly with the change in MRF (r = 0.789 , p < 0.0002). Conclusions. In patients with CHF, CPAP-induced reducti ons in MRF and plasma ANP concentration in association with improvemen ts in LVEF indicate improved cardiac mechanics, Our findings also sugg est that reductions in plasma ANP concentration were at least partly d ue to reductions in MRF, (C) 1997 by the American College of Cardiolog y.