Determination of relationship between serum levels of PRO-BNP and left ventricle mechanic functions with severity of mitral regurgitation calculated with quantitative methods in asymptomatic patients with organic mitral regurgitation and preserved left ventricular function

Mitral regurgitation is defined as escaping an amount of blood back from left ventricle to left atria in systole in the absence of complete closure of mitral leaflets. Mitral regurgitation causes left ventricular dilatation. Left ventricle end diastolic volume increases and left ventricle becomes spheric. The increase of mitral annulus diameter and end diastolic volume of left ventricle takes mitral regurgitation severity higher. In mild-severe and severe mitral regurgitation before the term of systolic dysfunction develops, left ventricular volume overloading term appears. In this period, left ventricle is dilated but hyperkinetic. Left ventricular end-diastolic diameter is increased but end-systolic diameter is normal. If volume overload pattern persists for a long time end-systolic diameter also increases and left ventricular systolic dysfunction develops. In mitral regurgitation due to the volume fleeing back to the left atrium during systole, systolic wall stress decreases and EF measured high. This incorrectly, leads to a better interpretation of the left ventricular systolic function. It is not right to expect falling of EF for surgical timing. In the postoperative period after mitral valve replacement low resistant road closes and after load increases and as a result EF decreases. In this study, subclinical left ventricular systolic dysfunction was measured by using two-dimensional speckle tracking echocardiography in patients with mild-severe MY. and the relationship of systolic dysfunction possibility were evaluated with the potential severity of MY which was detected with quantitative methods and BNP which is considered as a predictor of mitral regurgitation severity and prognosis of the patients with MY. Twenty four patients between the age of 18-65, whom have diagnosed organic mild-severe MY, EF ≥ 60% and have no symptoms were included into this study. The patients who are symptomatic, diagnosed atherosclerosis, hypertension, chronic kidney disease, KOAH, atrial fibrillation/flutter were excluded from this study. Two-dimensional, M-mode, Doppler and tissue Doppler echocardiography and BNP measurement was performed in patients. The left ventricular global longitudinal strain (LTGS), circumferential strain (SGS) and radial strain (RGS) parameters were calculated via two-dimensional speckle tracking echocardiography. A median BNP value (140 pg/ml) was calculated. And patients were divided into two groups according to their BNP value. (≥ 140 pg/ml and < 140 pg/ml). Both groups were compared in terms of systolic and diastolic functions by left ventricular two-dimensional, M-mode, Doppler and tissue Doppler, global longitudinal (LTGS), circumferential (SGS) and radial strain (RGS) parameters and BNP. In our study, demographic data was similar in both groups. A significant difference was observed in the mean values of mitral E and A wave velocities. BNP value ≥140 pg/ml group has higher E and A valve velocities (For E wave velocity p=0,023 and A wave velocity p=0,035) between psoriasis and the control group (mean: 8.2±2.0, and mean: 4.9±1.4, respectively, p <0.0001). No significant difference was observed in the left ventricular end-diastolic diameter (LVEDD) and end-systolic diameter (LVESD), ejection fraction (EF), biplane Simpson's ejection fraction and fractional shortening (FS) values between BNP value ≥140 pg/ml and BNP < 140 pg /ml group. There was a significant difference in left ventricul longitudinal total global strain (LTGS) mean values between BNP value ≥140 pg/ml and BNP < 140 pg/ml group (mean: -20,159±0,386, and mean: -15,35±0,912, respectively, p <0, 001). No significant difference was observed in both circumferential global strain (SGS) values (mean: -9,29±7,614, and mean: -19,74±1,249, respectively, p=0.119) and Radial Global Strain (RGS) values (mean: 42,708±7,044, and mean: 41,154±4,65; respectively, p=0,813). With correlation analysis, which contains parameters of subclinical left ventricular systolic dysfunction and MY severity, a strong correlation was found between LTGS and BNP (rho= 0.814, p <0,001). Between BNP-RV and BNP-ERO a moderate correlation is found (Respectively rho = 0.681; p <0.001 and rho = 0.644, p = 0.001). Finally, to see if LTGS is an appropriate benchmark to detect patients with MY who will benefit from early surgery ROC analysis was performed and showed that; if LTGS is higher than determined cut-off value of -18.07, this is an important criteria to determine patients with high-risk subgroup who wili benefit from early surgery. The clinical implications of our findings, although thought to be reflected; these data, prospective studies with larger patient populations believe that should be supported. We think that our findings will reflect to clinical outcomes as well as we believe that these data should be supported by prospective studies with a larger patient populations