B-type natriuretic peptide in patients after percutaneous trans-coronary-sinus mitral annuloplasty

Abstract

Background and aim: Functional mitral regurgitation (MR) remains a significant clinical problem. Surgical valve repair carries a high procedural risk. Thus, percutaneous techniques are under development. One of the most advanced devices for percutaneous mitral annuloplasty (PTMA) is the Carillon™ device. B-type natriuretic peptide (BNP) is a marker of haemodynamic status in heart failure patients. So far, its usefulness in patients after PTMA is unknown.

Methods: Thirteen consecutive patients after successful implantation of the Carillon™ device were enrolled. PTMA was achieved through the coronary sinus in order to improve leaflet coaptation. Before PTMA, immediately after, and at one month follow-up, transthoracic echocardiography was performed. Furthermore, plasma BNP levels, the six-minute walk test (6MWT) and the Naughton treadmill exercise test were evaluated before PTMA and after one month.

Results: In patients after successful PTMA, significant improvement in echocardiographic parameters was maintained at one-month follow-up: vena contracta (0.31 ± 0.03 vs. 0.64 ± 0.03 cm, p < 0.05), effective regurgitant orifice area (0.2 ± 0.02 vs. 0.32 ± 0.05 cm², p < 0.05), MR jet area/left atrial area (32.33 ± 1.98 vs. 47.06 ± 2.3%,p < 0.05) and regurgitant volume (27.84 ± 2.17 vs. 45.25 ± 7.47 mL, p < 0.05). Both the duration of the exercise test (4.3 ± 0.45 vs. 3.12 ± 0.18 min, p < 0.05) and 6MWT (320 ± 29.63 vs. 295.2 ± 13.4 m, p < 0.05) improved. Furthermore, improvement of the NYHA class was observed. Despite that, mean BNP levels remained unchanged (405.3 ± 133.9 vs. 596.5 ± 245.2 pg/mL, p = 0.191; after and before the procedure, respectively). In some patients with device located above the annulus level, an increase in BNP leve ls was observed.

Conclusions: BNP seems to be useless for the assessment of patients after PTMA. This may be related to mechanical stress on the annulus and atrial wall caused by the device itself.