Chronic heart failure is a widespread disease with a progressive course and poor prognosis. N-terminal pro-brain natriuretic peptide (NT-proBNP) are commonly used in the diagnosis of chronic heart failure (CHF).The release of NT-proBNP can occur even without an increase in diastolic pressure in the left ventricle (LV), during the brief episodes of myocardial ischemia. Revasculization for a myocardium can be one of the most effective methods of restoration of contractile abilities of a myocardium at the expense of influence on the basic pathogenetic mechanisms of CHF. Although there are few researches on the induction of ischemic myocardium release and prognostic role of NT-proBNP in patients undergoing myocardial revascularization, the results are very patchy and inconsistent.
Purpose. To determine the content of the NT-proBNP in patients underwent coronary artery bypass grafting (CABG), depending on the level of ejection fraction (EF) before surgery in the postoperative period.
Methods. 63 patients underwent CABG under on-pump without intraoperative myocardial damage were included for study. Patients were divided into two groups depending on the magnitude of left ventricular ejection fraction (LVEF): 33 patients with EF ˂ 50 % on average (45,0 ± 7,3) % and 30 patients with EF > 50 % on average (52,0 ± 5,5) %. NT-proBNP levels were determined within 12 days after surgery.
Results. Coronary artery bypass surgery resulted in improved hemodynamic indices of left ventricular myocardium, as evidenced by an increase in ejection fraction in both groups with EF ˂ 50 % and EF > 50 % to 6,5 % and 70 %, respectively (p in both cases ˂ 0,01). After coronary bypass surgery NT-proBNP levels were increased by 4,3 times in patients with EF ˂ 50 %, and in patients with EF > 50 % – by 3,4 times (Table).
NT-proBNP level in patients after coronary artery bypass grafting, depending on left ventricular ejection fraction (M ± SD)
|
NT-proBNP |
Controls n = 21 |
EF < 50 n = 33 |
EF ˃ 50 n = 30 |
р |
||
|
1 |
2 |
3 |
1–2 |
1–3 |
2–3 |
|
|
Before surgery, fmol/ml |
5,1 ± 0,6 |
16,6 ± 9,5 |
10,9 ± 1,1 |
< 0,001 |
< 0,001 |
< 0,01 |
|
Postoperative, fmol/ml |
5,1 ± 0,6 |
71,9 ± 33,0 |
37,4 ± 2,3 |
< 0,0001 |
< 0,001 |
< 0,001 |
|
р |
˃ 0,05 |
< 0,0001 |
< 0,0001 |
– |
– |
– |
Conclusions. The increase of NT-proBNP in patients after CABG on improved hemodynamics, increase in EF and absence of myocardial necrosis confirm the assumption that reversible ischemia can cause increased synthesis of NT-proBNP in the myocardium, the effect of which is aimed at the activation of myocardial healing process and is not associated with changes in hemodynamics.
The work is submitted to the International Scientific Conference “Modern science technologies”, Spain (Tenerife), November 21–28, 2014, came to the editorial office оn 12.01.2015.