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

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 VO2 and VO2 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 VO2, VO2 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 VO2 (from 13 ± 2.4 ml/kg/min to 14.8 ± 2.8 ml/kg/min, p < 0.05) and VO2 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.