血管紧张素转换酶抑制剂可减少心力衰竭时心脏碘-123-间碘苄胍的释放。

ACE inhibition reduces cardiac iodine-123-MIBG release in heart failure.

作者信息

Takeishi Y, Atsumi H, Fujiwara S, Takahashi K, Tomoike H

机构信息

First Department of Internal Medicine, Yamagata University School of Medicine, Japan.

出版信息

J Nucl Med. 1997 Jul;38(7):1085-9.

PMID:9225795

Abstract

UNLABELLED

Radioiodinated metaiodobenzylguanidine (123I-MIBG), an analog of norepinephrine, has been used to assess cardiac sympathetic nerve activity. Decreased myocardial accumulation and enhanced washout of 123I-MIBG have been reported in patients with congestive heart failure (CHF). The purpose of this study was to determine whether angiotensin converting enzyme (ACE) inhibition reduced 123I-MIBG release and improved cardiac 123I-MIBG accumulation in patients with CHF.

METHODS

Twenty-nine patients receiving conventional treatment for CHF, New York Heart Association (NYHA) functional class 2-3, were studied. Nineteen patients received additional treatment with enalapril, an ACE inhibitor, and 10 patients who were treated with conventional therapy alone were defined as a control group. Iodine-123-MIBG imaging and echocardiography were performed on all patients before treatment and repeated after 9.1 +/- 3.0 mo of treatment. Images were obtained 30 min and 4 hr after injection of 123I-MIBG, and a heart to mediastinum (H/M) ratio was defined to quantify cardiac 123I-MIBG uptake as a fraction of the mean counts per pixel in the heart divided by those in the mediastinum. The washout rate of 123I-MIBG from the heart was calculated as follows: (early counts - delayed counts)/early counts x 100(%).

RESULTS

In patients with enalapril group, the H/M ratio of 123I-MIBG was increased after treatment (early image: 1.60 +/- 0.22 vs. 1.73 +/- 0.28, p < 0.05, delayed image: 1.63 +/- 0.28 vs. 1.82 +/- 0.33, p < 0.01). The washout rate of 123I-MIBG was reduced from 38% +/- 11% to 30% +/- 12% after treatment (p < 0.01). However in the conventional therapy group, the H/M ratios in the early and delayed images (early image: 1.58 +/- 0.31 vs. 1.52 +/- 0.23, delayed image: 1.49 +/- 0.27 vs. 1.49 +/- 0.25) and the washout rate (34% +/- 8% vs. 33% +/- 7%) remained unchanged after treatment. In patients with an increased H/M ratio of enalapril group (n = 13), a left ventricular ejection fraction increased from 48% +/- 12% to 55% +/- 9% (p < 0.01) after treatment.

CONCLUSION

ACE inhibition reduces cardiac 123I-MIBG release and thus lowers cardiac sympathetic nerve activity. Iodine-123-MIBG may be helpful in evaluating the therapeutic effects of ACE inhibition on the cardiac sympathetic nervous system in patients with CHF.

摘要

未标记

放射性碘化间碘苄胍（123I-MIBG），去甲肾上腺素的类似物，已被用于评估心脏交感神经活性。充血性心力衰竭（CHF）患者中已报道心肌摄取123I-MIBG减少且清除增强。本研究的目的是确定血管紧张素转换酶（ACE）抑制是否能减少CHF患者123I-MIBG的释放并改善心脏对123I-MIBG的摄取。

方法

对29例接受CHF常规治疗、纽约心脏协会（NYHA）心功能分级为2-3级的患者进行研究。19例患者接受了ACE抑制剂依那普利的额外治疗，10例仅接受常规治疗的患者被定义为对照组。在治疗前对所有患者进行碘-123-MIBG显像和超声心动图检查，并在治疗9.1±3.0个月后重复检查。在注射123I-MIBG后30分钟和4小时获取图像，并定义心脏与纵隔（H/M）比值以量化心脏对123I-MIBG的摄取，计算方法为心脏中每像素平均计数除以纵隔中每像素平均计数。123I-MIBG从心脏的清除率计算如下：（早期计数 - 延迟计数）/早期计数×100（%）。

结果

依那普利组患者治疗后123I-MIBG的H/M比值升高（早期图像：1.60±0.22对1.73±0.28，p<0.05；延迟图像：1.63±0.28对1.82±0.33，p<0.01）。治疗后123I-MIBG的清除率从38%±11%降至30%±12%（p<0.01）。然而，在常规治疗组中，早期和延迟图像中的H/M比值（早期图像：1.58±0.31对1.52±0.23，延迟图像：1.49±0.27对1.49±{0.25}）以及清除率（34%±8%对33%±7%）治疗后保持不变。依那普利组中H/M比值升高的患者（n = 13），治疗后左心室射血分数从48%±12%增加到55%±9%（p<0.01）。