Restrictive left ventricular filling pattern and its effect on the clinical course of systolic heart failure in patients receiving carvedilol.

Background: To analyze differences in brain natriuretic peptide (BNP) levels depending on mitral flow pattern (MFP) and to assess the effects of carvedilol on changes in MFP, left ventricular function and exercise capacity.
Methods and Results: The study population consisted of 73 patients with symptomatic heart failure in NYHA classes II and III and LVEF < 40% without prior beta-blockade. In all patients at baseline, before carvedilol, and then at 3 and 12 months after initiation of treatment, the following parameters were assessed: HR(s), serum BNP, echocardiographic parameters, and exercise capacity with gas monitoring during cardiopulmonary stress test. Before carvedilol there was a positive correlation between BNP and E/A (r = 0.17; p = 0.05). BNP was significantly higher in patients with restrictive MFP (rMFP) as compared with nonrestrictive MFP (nrMFP) (541.5 +/- 206.7 vs. 412.6 +/- 207.2; p = 0.009), and lower VO(2peak) in rMFP as compared with nrMFP (12.5 +/- 3.7 vs. 16.5 +/- 4.7; p = 0.001). After initiation of carvedilol, the patients with rMFP had reduced E/A (2.9 vs. 1.4; p = 0.003), and rMFP was changed to nrMFP in 60.8% of patients. Respective BNP concentrations were 342.16 +/- 284.31 vs. 326.40 +/- 264.6; NS. In patients with rMFP VO(2peak) , %N increased significantly from 42.4 +/- 10.2 to 52.4 +/- 14.4; p = 0.012.
Conclusions: In patients with systolic congestive heart failure, the presence of rMFP is related to higher BNP levels and reduced VO(2peak). Chronic treatment with carvedilol replaces rMFP with nrMFP and improves exercise capacity in some patients.