Result: The average concentration of NT-proBNP in group without heart failure is increase dependent on age: < 50 age: 92 ± 85 pg / mL; 50 - 60 age: 108 ± 94 pg / mL; 60 - 70 age: 133 ± 118 pg / mL; 70 - 80 age: 235 ± 202 pg / mL; > 80 age: 352 ± 259 pg/mL.