RESUMO
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 alpha), tumor necrosis factor alpha receptor 1 (TNF alpha R1) and interleukin 6 (IL-6) were collected from 22 patients of the PATH-CHF II study (LVEF< or =30%, NYHA II-IV and QRS> or =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.
