To establish the dependence of endothelium-mediated vasodilatory response on severity, etiology of CHF, depending on the availability of the phenomenon of insulin resistance and 12-months survival prognosis of CHF.Design and method:
We examined 106 hemodynamically stable CHF patients (pts), NYHA II-IV, LVEF < 40%, chronically treated by diuretic, ACE inhibitor and ß-blocker. Hypertensive heart disease (HHD) was established in 66 pts, and dilated cardiomyopathy (DCMP) in 40 pts. 42 pts (40%) had insulin resistance (IR). Diameter of a.brachialis (D) was detected ultrasonographically before (D1) and after (D2) standard forearm cuff test. Flow-mediated vasodilation (FMV) was calculated by formula: (D2-D1)/D1 × 100%. Flow-independent vasodilation (FIV) was calculated similarly, based on measurements of D before and 5 min after sublingual nitroglycerine (0,5 mg) administration. Insulin resistance index (HOMA-IR) was calculated according to the formula: fasting insulin (microU/L) x fasting glucose (nmol/L)/22,5. IR was based on the value of the index HOMA > 2,77. Kaplan-Meier 12-months survival analysis was performed for FMV based on «below-median vs above-median» approach.Results:
In CHF pts FMV was significantly impaired in comparison to age-matched controls (6,8 ± 0,5% vs 11,04 ± 1,3%, p < 0,01). More pronounced impairment of FMD in III-IV NYHA class pts than in II NYHA class was observed (6,3 ± 0,8% vs 7,1 ± 1,1%, p = 0,03). In DCMP FMV was significantly worse than in HHD (5,5 ± 0,8% vs 7,4 ± 1,3%, p < 0,001) despite comparable LVEF (p = 0,47) and NYHA class (p = 0,62) in both groups. FIV didn’t demonstrate any significant differences in NYHA III-IV and NYHA II groups (19,5 ± 3,8% vs 20,3 ± 4,1%, p = 0,6), HHD and DCMP (20,5 ± 3,9% vs 19,2 ± 3,1%, p = 0,4). In IR pts FMD was significantly lower than in pts without IR (5,2 ± 0,8% vs 7,9 ± 1,3%, p < 0,03). Respectively, significant correlation relationship was found between HOMA index and FMV (rho = −310, p = 0,004). 12-months survival was significantly better in group with better (above-median) FMV (93% of pts alive vs 85% of pts alive in below-median group, p = 0,047), although LVEF in both groups were comparable (33,5 ± 8,1% vs 32,1 ± 7,3%, p = 0,32).Conclusions:
In CHF FMV is pronounsly impaired, particularly in NYHA III-IV, DCMP pts and IR pts. The better FMV responders demonstrated the better 12-months survival than worse responders despite comparable LVEF in both groups.