Abstract
Background
Superresponders to cardiac resynchronization therapy (CRT) demonstrate significant reverse remodeling, improvement in cardiac function, decrease in inflammatory mediators and markers of cardiac fibrosis. It is not clear if superresponse (SR) can be early or late and if the time of SR to CRT is associated with different degree of biochemical improvement.
Aim
To assess structural and functional heart parameters, sympathetic activity, levels of biomarkers of myocardial fibrosis, inflammatory and neurohormonal mediators in patients with various time of SR to CRT.
Methods
The study enrolled 82 superresponders to CRT (decrease in left ventricular end-systolic volume (LVESV) >30%) (mean age 60.4±9.3 years; 80.5% men, 19.5% women; 54.9% with ischemic etiology of heart failure). Patients were divided into two groups: group 1 (n=19) – SR was achieved within 24 months (14.0 [8.0; 21.0] months); group 2 (n=63) - SR was achieved after 24 months (59 [43.0; 84.0] months). Echocardiographic parameters, plasma levels of epinephrine, norepinephrine, NT-proBNP, interleukin (IL) 1β, IL-6, IL-10, tumor necrosis factor alpha (TNF-α), metalloproteinase (MMP) 9, tissue inhibitors of metalloproteinase (TIMP) 1 and 4 were evaluated.
Results
At baseline there were no differences in demographic, clinical and echocardiographic characteristics between the groups. Levels of epinephrine (1.1 [0.1; 2.2] ng/ml vs 2.1 [0.7; 3.4] ng/ml; p=0.049) and IL-10 (1.8 [1.5; 3.5] pg/ml vs 3.9 [2.7; 5.1] pg/ml; p=0.019) were significantly higher in group 2. Both groups demonstrated significant improvement in echocardiographic parameters. On follow-up left ventricular (LV) end-systolic dimension (p=0.041), LV end-diastolic dimension (p=0.049), LVESV (p=0.014), LV end-diastolic volume (p=0.045) were lower in group 2. In group 1 IL-6 (p=0.047), TNF-α (p=0.047) decreased significantly and there was a tendency for IL-1β (p=0.064) and norepinephrine (p=0.069) levels to increase. In group 2 levels of IL-1β (p<0.001), IL-6 (p=0.030), IL-10 (p=0.003), TNF-α (p<0.001), TIMP-1 (p=0.010) and epinephrine (p=0.024) decreased significantly while MMP-9/TIMP-1 (p=0.023) increased as compared to baseline levels. Additionally there was a tendency for NT-proBNP level to decrease in group 2 (p=0.069). Follow-up level of norepinephrine (7.8 [2.9; 17.2] ng/ml vs 1.1 [0.2; 8.7] ng/ml; p=0.011 was lower and MMP-9/TIMP-4 level was higher (0.058 [0.044; 0.091] vs 0.092 [0.064; 0.111]; p=0.013) in group 2. Diverse trends were observed in IL-10 (0.4 [−0.6; 1.2] pg/ml in group 1 vs −2.3 [−3.4; −0.5] pg/ml in group 2; p=0.007) and norepinephrine (4.0 [−5.2; 14.3] ng/ml in the group 1 vs −1.2 [−11.6; 4.0] ng/ml in the group 2; p=0.015) between the groups.
Conclusion
CRT modulates sympathetic, neurohumoral, immune and fibrotic activity. Late SR to CRT is associated with decrease of sympathetic and inflammatory activity and more pronounced LV reverse remodeling.
459 Effects of cardiac resynchronization therapy on long-term serial echocardiographic parameters of left ventricular size and function
