Schwarz K R, Hofmann M, Mäurer W, Kadel C, von Olshausen K, Rauch B, Kübler W
Z Kardiol. 1985 Jul;74(7):374-83.
Prenalterol (P), a partial adrenergic agonist with functional beta 1-specificity, has been shown to have inotropic effects when given orally and thus represents a potential substitute or adjunct to conventional digitalis therapy (D) in the long-term management of congestive cardiomyopathy (COCM). A direct comparison between both drugs has not been reported. In a blind controlled trial, 15 patients with COCM (NYHA II-III) with sinus rhythm and a left ventricular ejection fraction (LV-EF) of 34.5 +/- 2.6% received consecutively D (0.25-0.5 mg/d), placebo (PLAC), P (slow releases = SR) (80 mg/d SR) and both drugs combined in respective doses. After 4 weeks of therapy with each drug, effects were assessed by gated blood pool scintigraphy at rest (R) and during graded bicycle exercise (EX), systolic time intervals (STI), Holter monitoring and a clinical score. Plasma levels of both drugs and of catecholamines and lactate were also determined. Compared to PLAC, LV-EF was not significantly altered by D at R (34.5 +/- 2.6 vs. 31.9 +/- 2.3%, p = ns), but a shortening of the QS2-interval could be demonstrated (533 +/- 7 vs. 550 +/- 6 msec, p less than 0.05). In contrast, during EX an improvement of LV-EF was observed (34.5 +/- 3 vs. 31.3 +/- 2.8%, p less than 0.05). P alone showed no significant alterations in LV-EF and STI, along with a lack of symptomatic improvement. The addition of D (D + P) resulted in improved left ventricular performance both at R (LV-EF 37.9 +/- 3.3 vs. 31.9 +/- 2.3%, p less than 0.01, QS2 530 +/- 8 vs. 550 +/- 6 msec, p less than 0.01) and during EX (LV-EF 35.3 +/- 2.5 vs. 31.1 +/- 2.8%). Values between D and D + P were not significantly different. No drug or combination improved maximal working capacity.
Beneficial effects of chronic treatment with D could be demonstrated in patients with COCM, particularly during EX. Further studies are needed to determine why the acute effects of P are not fully sustained during long-term therapy.
普瑞特罗（P）是一种具有功能性β1特异性的部分肾上腺素能激动剂，口服时已显示出正性肌力作用，因此在充血性心肌病（COCM）的长期治疗中是传统洋地黄疗法（D）的潜在替代或辅助药物。尚未报道两种药物之间的直接比较。在一项盲法对照试验中，15例窦性心律、左心室射血分数（LV-EF）为34.5±2.6%的COCM患者（纽约心脏协会II-III级）连续接受D（0.25-0.5mg/d）、安慰剂（PLAC）、P（缓释剂=SR）（80mg/d SR）以及两种药物按各自剂量联合使用。每种药物治疗4周后，通过静息（R）和分级自行车运动（EX）时的门控心血池闪烁显像、收缩期时间间期（STI）、动态心电图监测和临床评分来评估疗效。还测定了两种药物以及儿茶酚胺和乳酸的血浆水平。与PLAC相比，D在静息时未显著改变LV-EF（34.5±2.6%对31.9±2.3%，p=无显著性差异），但可证明QS2间期缩短（533±7对550±6毫秒，p<0.05）。相比之下，在运动时观察到LV-EF有所改善（34.5±3对31.3±2.8%，p<0.05）。单独使用P时，LV-EF和STI无显著变化，且症状无改善。加用D（D+P）后，静息时（LV-EF 37.9±3.3对31.9±2.3%，p<0.01，QS2 530±8对550±6毫秒，p<0.01）和运动时（LV-EF 35.3±2.5对31.1±2.8%）左心室功能均有改善。D与D+P之间的值无显著差异。没有药物或联合用药能提高最大工作能力。
在COCM患者中可证明长期使用D有有益效果，尤其是在运动时。需要进一步研究以确定为何P的急性效应在长期治疗中未完全持续。
