Relationship between coronary collateral circulation and plasma levels of N-terminal pro-B-type natriuretic peptide

Abstract

Objective: There have been numerous investigations demonstrating protective effects of awell-grown coronary collateral circulation (CCC) on left ventricular systolic function. N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) is released by ventricular myocardium as a result of increased myocardial wall stress. The aim of the study was to evaluate the relationship between CCC and plasma NT-pro-BNP levels. Methods: Study group was retrospectively selected from patients who had a coronary angiography at our center between January 2008 and December 2009. One hundred and thirty patients having at least one totally occluded main coronary artery were included in this study. Collateral circulation was graded according to Rentrop score. Grade 0 and 1 are regarded as poor, and grade 2 and 3 -good CCC. Plasma NT-pro-BNP levels were measured by electrochemiluminescence immunoassay method and left ventricular ejection fraction (LVEF) were measured by modified Simpson method. We used Chi-square, Student t and Mann-Whitney-U tests for statistical analysis. Results: Overall 57 patients were found to have poor CCC and 73 patients have good CCC. Plasma NT-pro-BNP levels (pg/ml)-median (minimummaximum)-were 1319 (48-9753) in poor CCC group and 847 (16-5529) in good CCC group (p=0.004). LVEF was found to be -median (minimummaximum)-45% (30-55%) in poor CCC group and 50% (30-60%) in good CCC group (p=0.003). Correlation analysis demonstrated that collateral grade was negatively correlated with NT-pro-BNP levels (r=-0.252, p=0.004). 29

Influence of collaterals on the left ventricular end-diastolic pressure and serum NT-proBNP levels in patients with coronary chronic total occlusion

“…Kadı et al, have found in a study including patients with totally occluded coronary arteries (however, if they are chronic is not emphasized) that well-developed CC could lower NT-proBNP levels via protecting from myocardial ischemia. 8 Another, more recent study investigating only CTO patients, showed that poor CC was associated with significantly higher NT-proBNP levels when compared with well-developed CC. 9 This result was explained by two mechanisms – firstly, by protection against myocardial ischemia provided by well-developed collaterals, and secondly, elevated NT-proBNP levels might be only reflection of the required humoral status for the stimulation of angiogenesis in patients with poor CC.…”

“… 7 There are conflicting data regarding effect of collaterals on natriuretic peptide levels. 8 , 9 , 10 …”

The impact of the apelinergic system in coronary collateral formation

“…This can be attributed to the increased wall tension in the group with poor left ventricle, as it has been shown in many studies that NT-proBNP levels increase, particularly as myocardial tension increases. [20,21] Considering the effects of the APJ system on angiogenesis and the regulatory roles of ELA protein in the cardiovascular system, it is reasonable to associate it with the formation of coronary collaterals. In this context, the presence of both APJ receptors and ELA protein in vascular smooth muscle cells and endothelium is strong evidence supporting this inference.…”

“…In this context, the presence of both APJ receptors and ELA protein in vascular smooth muscle cells and endothelium is strong evidence supporting this inference. [19][20][21] On the other hand, the mechanisms of these effects of ELA are also clear. Namely, ELA is thought to be important for heart formation and migration of cardiac progenitor cells for heart development during embryonic development.…”

“…It has been shown in many studies that factors such as diabetes mellitus, HT, and advanced age affect the development of collateral. [ 19 , 20 ] The homogeneity of the groups in terms of these parameters enables us to examine the relationship of ELA, which is the main subject of our study, with the development of coronary collateral in a much simpler way. On the other hand, there are differences in some echocardiographic and blood parameters due to the mechanisms during the formation of coronary collateral.…”