ISSN: 2155-9880
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Vinu Wilson, Namit Gupta, Pankaj Prabhakar, Lakshmy Ramakrishnan, Sandeep Seth and Subir Kumar Maulik
Background: Apelin is an endogenous peptide with positive inotropic property secreted by the heart besides other tissues. Plasma apelin levels are altered in chronic heart failure with left ventricular dysfunction. However, the effect of left atrial hemodynamic overload on plasma apelin levels in mitral stenosis (MS) is unknown. In this observational study, we estimated plasma apelin level in MS patients, before and twelve weeks after percutaneous transvenous mitral commissurotomy (PTMC) and compared with plasma brain natriuretic peptide (BNP) levels, mitral valvular pressure gradient and quality of life measure.
Methods: Venous blood samples were drawn from 10 MS patients and 10 age-matched controls, with informed consent. Apelin was estimated by competitive ELISA and BNP using an auto-analyzer. PTMC was done by atrial septal puncture and Inoue balloon. Self-administered Kansas City cardiomyopathy questionnaire (KCCQ) was used to assess quality of life. Variables distributed normally were expressed as mean ± S.D. and others as median (interquartile range) and analyzed using appropriate statistical tests. A p-value<0.05 was considered statistically significant.
Results: MS patients belonged to NYHA class II & III, had pulmonary artery hypertension but left ventricular ejection fraction>50%. Plasma apelin was lower [320 (167, 515) vs. 570 (415, 680) pg/ml; p=0.028] and BNP level higher [44 (15, 117) vs. 6 (5, 10) pg/ml; p=0.001] in MS patients compared to controls, respectively. PTMC decreased mitral valvular pressure gradient [6.7 (5.0, 8.7) vs. 20.5 (12.4, 27.2) mm of Hg; p=0.012] and improved KCCQ score (84 ± 7 vs. 54 ± 10%; p<0.001) but did not change plasma apelin and BNP levels [330 (192, 465) and 42 (19, 86) pg/ml, respectively].
Conclusion: Plasma apelin is depressed and BNP level raised in MS patients. Changes in plasma apelin level may occur slower compared to hemodynamic and functional improvement post PTMC.