Selection of a mineralocorticoid receptor antagonist for patients with hypertension or heart failure

Clinical trials have demonstrated morbidity and mortality benefits of mineralocorticoid receptor antagonists (MRAs) in patients with heart failure. These studies have used either spironolactone or eplerenone as the MRA. It is generally believed that these two agents have the same effects, and the data from studies using one drug could be extrapolated for the other. National and international guidelines do not generally discriminate between spironolactone and eplerenone, but strongly recommend using an MRA for patients with heart failure due to LV systolic dysfunction and post‐infarct LV systolic dysfunction. There are no major clinical trials directly comparing the efficacy of these two drugs. This article aims to compare the pharmacokinetics and pharmacodynamics of spironolactone and eplerenone, and to analyse the available data for their cardiovascular indications and adverse effects. We have also addressed the role of special circumstances including co‐morbidities, concomitant drug therapy, cost, and licensing restrictions in choosing an appropriate MRA for a particular patient, thus combining an evidence‐based approach with personalized medicine.     

异丙肾上腺素诱导慢性心力衰竭大鼠心肌醛固酮及其核受体的变化

目的 探讨异丙肾上腺素(isoproterenol,ISO)诱导的慢性心力衰竭SD大鼠心肌醛固酮及其核受体的变化.方法 将SD大鼠抽签随机分为心力衰竭组(9只)和对照组(10只),心力衰竭组皮下注射ISO,对照组皮下注射等量生理盐水,心功能采用超声心动图及血流动力学检查,放射免疫法测定血浆及心肌组织醛固酮水平,免疫印迹和免疫组化染色法检测盐皮质激素核受体蛋白表达的变化.结果 心力衰竭组与对照组比较心功能明显下降,左心室射血分数分别为(38.8±4.0)%与(79.4±4.6)%;左心室内压最大上升速率分别为(7164.4±502.6)mm Hg(1 mm Hg=0.133 kPa)/s与(10199.5±462.9)mm Hg/s(均P＜0.01).血浆及心肌组织醛固酮含量明显升高,分别为(0.63±0.06)μg/L与(0.30±0.07)μg/L、(0.41±0.05)μg/kg与(0.08±0.01)μg/kg(均P＜0.01),左心室心肌醛固酮核受体蛋白表达增高(P＜0.01).结论 ISO可诱导SD大鼠出现类似扩张型心肌病的慢性心力衰竭表现,在这种心力衰竭模型中其循环和左心室心肌醛固酮水平明显升高,心肌醛固酮核受体表达上调,可能在心力衰竭的发生、发展中起着重要作用.

Abstract：

Objective To investigate the changes of cardiac aldosterone and mineralocorticoid receptor (MR) in Sprague-dawley (SD) rats with chronic heart failure (CHF) induced by isoproterenol (ISO). Methods The SD rats were randomly divided into CHF group (n=9) and normal control(NC) group (n=10). The experimental CHF group was induced by subcutaneous injection of ISO, and the NC group received same dose injection of sodium chloride. The heart function was evaluated with both echocardiography and hemodynamics. The contents of aldosterone in both plasma and heart were assessed by radioimmunoassay. The expression of MR was measured by Western blot and immunohistochemistry staining. Results Compared with NC group, the heart function was decreased in CHF group, the left ventricular ejection fraction was (38.8%±4.0%) in CHF and(79. 4%±4.6%), in NC group. The maximal rate of increase of ventricular pressure (+dp/dtmax) was (7164.4±502.6) mm Hg(1 mm Hg=0.133 kPa)/s in CHF and (10199.5±462.9) mm Hg/s in NC group (both P＜0. 01 ). The contents of aldosterone both in plasma and heart were higher in CHF group than in NC group [(0.63±0.06)μg/L vs. (0.3±0.07) μg/L, (0.41±0.05) μg/kgvs. (0.08±0.01)μg/kg, both P＜0. 01]. The MR expression was increased in CHF group versus in NC group (P＜0.01). Conclusions The heart function is decreased in rats with CHF induced by ISO, which is similar to dilated cardiomyopathy. The higher levels of aldosterone both in circulation and in heart as and well as MR expression upregulation in heart may play important roles in the pathogenesis of CHF induced by ISO.     

Sleep symptoms and clinical markers of illness in patients with heart failure

The purpose of this study was to survey patients with heart failure (HF) for sleep symptoms using a standardized questionnaire and correlate symptoms with conventional markers of clinical status. A self-report paper questionnaire was offered to patients presenting to a tertiary care HF clinic. Symptoms were grouped according to “risk” categories and correlated with routine clinical information. One hundred six (52.7% of 201 with all data) respondents had a high pretest probability for sleep apnea syndrome. Sixty three (31.3%) reported symptoms suggesting the presence of chronic insomnia; seven (3.5%) and eight (4%) reported symptoms of narcolepsy and restless legs syndrome, respectively. High-risk respondents for sleep apnea had a higher body mass index (p<0.001), were younger (p<0.05), and had a higher ejection fraction (p<0.05). The odds ratio (confidence interval) for paroxysmal nocturnal dyspnea (PND) to a complaint of sleepiness was 1.99 (1.1–3.6) and to a complaint of insomnia was 3.5 (1.8–6.5). In men, complaints of sleepiness in patients with PND were correlated, 4.47 (1.9–10.3), as was a correlation to high pretest probability for sleep apnea, 2.47 (1.1–5.5). There were no correlation of New York Heart Association status classification to high risk for sleep apnea, but a complaint of insomnia tended to occur with worsening functional status (p<0.05). There was only modest correlation of self-reported symptoms as elicited by a questionnaire and risk for sleep disorders with common clinical assessments for HF. Such collection of symptoms might be useful in establishing guidelines for routine sleep testing or as an adjunct to clinical trials.