Change Of Serum Brain Natriuretic Peptide Concentration In Left Ventricular Diastolic Dysfunction And Impact Of Carvedilol On It

BackgroundIt has been confirmed that patients with left ventricular dysfunction (LVD) markedly reduced mortality and improved survival on early medications of angiotensin-converting enzyme inhibitors and p-blockers, therefore early diagnosis of LVD is of crucial importance. A considerably large part of patients with LVD are characterized by left ventricular diastolic dysfunction (LVDD) at their early stages; clinical diagnosis is usually quite difficult due to the absence of symptoms and signs, and previously was mainly dependent on ultrasonic cardiograhpy(UCG) detection. Because of its high cost, however , UCG is not always available in primary health care .Furthermore,obesity and lung diseases may affect UCG detection. As blood white cell increase usually helps indicate some infection,whether we can find such a convenient way as a mere detection of a certain component in the blood that can predict existence of LVD has been what many specialists have been engaged in.In recent years, some studies have proved that serum brain natriuretic peptide (BNP)levels in patients with systolic LVD significantly elevated, and was a good determination,and also correlated well with prognosis. Serum BNP level decreased and heart failure improved on medication of P-blockers such as carvedilol. But for pure LVDD,does BNP level also increase,also act as a gooddetermination,and also decrease after medication of carvedilol ?A11 these were what we studied.AimTo investigate the change of serum BNP level and its diagnostic value in patients with LVDD , and effect of carvedilolSubjects and Methods30 cases with LVDD, 15 with left ventricular systolic dysfunction. combining or not with diastolic dysfunction(LVSD ) were randomly selectedfrom 220 cases with LVD who had been hospitalized and completelyrecorded in years of 1999 to 2002,and 20 with normal cardiac function werestudied as health group.BNP levels were measured by competitive ELISA at room temperature of25 CResult1. BNP level in LVDD group was markedly higher than that in health group (209.9 133.7pg/ml vs 71.9 32.3pg/ml, P<0.05), but significantlylower than that in LVSD group (209.9 133.7pg/ml vs 1085.7 519.1pg/ml, P<0.05).2. A cutoff value of 120pg/ml had a sensitivity of 91.1 percent, a specificity of 95 percent and an accuracy of 99.1 percent for diagnosing LVD.3. BNP level >120pg/ml had a sensitivity of 86.7 percent, a specificity of 95 percent , a positive predictive value of 96.3 percent, and a negative predictive value of 82.6 percent for determining pure LVDD.4. No significant change of BNP level was found between before andafter 10-week treatment with carvedilol (169.9 90.0pg/ml vs 164.9 79.2 pg/ml, P>0.05).Conclusion1. Serum BNP level in LVDD significantly elected .2. BNP level was a good determination for LVD3. Given normal left ventricular systolic function, BNP level>120 pg/ml strongly indicated the probable existence of LVDD.. 4. No significant impact of 10-week carvedilol treatment was found on BNP level.