慢性重度心力衰竭患者血B型利钠肽浓度正常的临床意义探讨

目的 探讨慢性重度心力衰竭(心衰)患者出现血B型利钠肽(B-type natriuretic peptide,BNP)浓度正常的临床意义.方法 采用前瞻性对照研究的方法观察心功能Ⅲ～Ⅳ级的慢性重度心衰患者57例.血BNP浓度正常的13例患者为研究组(A组),血BNP浓度明显升高的44例为对照组(B组),分析两组患者的临床特点,判定血BNP浓度正常对于慢性重度心衰患者的意义.结果 两组患者的基线情况差异无统计学意义.A组的左室舒张末期内径大于B组(70.56±4.33)mm与(63.73±3.75)mm,P＜0.05];A组的左室射血分数小于B组(24.16±2.50)%与(28.49±2.63)%,P＜0.05].A组中能耐受美托洛尔的人数比例少于B组(7/13)与(39/44),P＜0.05],耐受剂量低于B组(12.5±6.25)mg/d与(24.20±11.22)mg/d,P＜0.05].两组血BNP浓度在稳定期各时间段无明显改变,但在慢性心衰急性发作与缓解后,A组无显著性改变(74.03±11.18)ng/L与(71.38±11.68)ng/L,P＞0.05],而B组改变明显(962.73±165.00)ng/L与(876.24±167.70)ng/L,P＜0.05].随访中,A组病死率高于B组(11/13与6/44,P＜0.05).Logistic多因素回归分析显示:血BNP降低为预测重度慢性心衰患者心原性死亡的独立危险因素(OR值45.488,95%可信区间5.322～388.791),P＜0.05.结论 慢性重度心衰患者出现血BNP浓度正常提示BNP分泌机制的耗竭和心脏功能的进一步恶化.

Clinical characteristics of severe chronic heart failure patients with normal blood B-type natriuretic peptide

Objective To investigate the clinical features of severe chronic heart failure patients with normal B-type natriuretic peptide (BNP). Methods A total of 57 patients with severe chronic heart failure ( New York Heart Association class Ⅲ and Ⅳ ) were included in this prospective control study from Dec. 2002 to Oct. 2009. Group A included 13 patients with normal BNP ( ＜ 100 ng/L) and group B included 44 patients with increased BNP ( ＞ 100 ng/L). Group A patients were followuped for ( 19. 6 ±14. 7)months and group B patients for (72. 5 ± 17. 1 ) months. Results The baseline clinical characteristics of two groups were comparable. Left ventricular end diastolic diameter (LVEDd) of group A was larger than group B (70. 56 ± 4. 33 ) mm vs. ( 63.73 ± 3.75 ) mm, P ＜ 0. 05 ], the left ventricular ejection fraction (LVEF) of group A was lower than group B (24. 16 ± 2. 50) % vs. (28.49 ± 2.63 ) %, P ＜ 0. 05 ]. The number of patents tolerating metoprolol in group A is lower than in group B (7/13 vs. 39/44,P ＜0. 05),and the tolerant dose of metoprolol in group A is lower than in group B ( 12. 5 ±6. 25)mg/d vs. (24. 20 ±11.22)mg/d,P ＜ 0. 05 ]. The level of BNP in group B were significantly higher at acute stages than at remission stages (962.73 ± 165.00) ng/L vs. (876.24 ± 167.70) ng/L, P ＜ 0.05], but remained unchanged in group A (74. 03 ± 11.18) ng/L vs. ( 71.38 ± 11.68) ng/L, P ＞ 0. 05 ]. The mortality of group A was higher than group B( 11/12 vs. 6/44, P ＜0.05). The binary logistic regression analysis (backward) showed that normal B-type natriuretic peptide was an independent predictor of cardiovascular mortality in patients with severe chronic heart failure ( OR = 45.488, 95% CI = 5. 322 - 388. 791 ).Conclusion Normal BNP in patients with severe chronic heart failure suggests the exhaustion of BNP secretion and associated poor prognosis.