Functional capacity and changes in the neurohormonal and cytokine status after long-term CRT in heart failure patients

Abstract

Background This study investigated the effects of long-term cardiac resynchronization therapy (CRT) on the neurohormonal and cytokines levels in CHF patients and its correlation with changes in functional capacity (peak VO 2 and VO 2 AT) and left ventricular function (LVEF). Methods Brain natriuretic peptide (BNP), norepinephrine (NE), tumor necrosis factor alpha (TNF α), tumor necrosis factor alpha receptor 1 (TNF α R1) and interleukin 6 (IL-6) were collected from 22 patients of the PATH-CHF II study (LVEF ≤ 30%, NYHA II–IV and QRS ≥ 120 ms) at baseline and at the 12-month follow-up. Peak VO 2, VO 2 AT and LVEF were recorded. All patients were implanted with a CRT device using atrioventricular sequential left ventricular pacing. Results CRT led to a significant improvement of peak VO 2 (from 13 ± 2.4 ml/kg/min to 14.8 ± 2.8 ml/kg/min, p < 0.05) and VO 2 AT (from 9 ± 2 ml/kg/min to 10.1 ± 1.9 ml/kg/min, p < 0.05). LVEF increased significantly from 22.2 ± 6.2% at baseline to 32 ± 10.1% at 12-month follow-up ( p < 0.05). A significant reduction of BNP (from 332.9 ± 295.2 to 193.4 ± 253 pg/ml, p = 0.049) and NE (410.6 ± 306.0 to 274.4 ±174.3 ng/l, p = 0.027) was also observed with CRT. Conclusion Long-term CRT is associated with a significant decrease of BNP and NE levels and a significant improvement in functional capacity and LVEF.