Factors affecting ST depression during cardiopulmonary exercise testing in patients with mitral stenosis without significant coronary lesions

Symptom-limited cardiopulmonary exercise testing was performed in 37 patients with mitral stenosis (MS) without significant coronary artery stenosis to evaluate factors affecting ST depression in exercise electrocardiograms. The degree of ST depression was not associated with gender or exercise tolerance. The incidence of significant ST depression was higher in the patients receiving than in those not receiving digitalis (P < 0.05). In addition, the patients with atrial fibrillation and a higher heart rate response were more likely to have a high prevalence of significant ST depression than those with sinus rhythm and a lower response (P < 0.05). We concluded that atrial fibrillation, a higher maximum heart rate, and oral digitalis administration were involved in ST depression during exercise testing in patients with mitral stenosis without coronary heart disease.

Epidemiological and pharmacological profile of congestive heart failure at Turkish academic hospitals

OBJECTIVE

We aimed to investigate the status of the treatment of congestive heart failure (CHF) in academic hospitals in Turkey.

METHODS

Overall 661 successive patients from 16 academic hospitals were included in this retrospective study. In addition to treatments given to the patients before admission to hospital, during their hospital stay, and at hospital discharge, data regarding their functional classifications, causes of CHF, and laboratory findings were also recorded.

RESULTS

In our study the mean age of patients was 61+/-12 years and the mean hospital stay 10+/-6 days. Ischemic CHF was observed more frequently in men (72% vs. 46%, p<0.001), while hypertension and rheumatic CHF were more frequent in women (27% vs. 19%, p<0.001 and 24% vs. 9%, p<0.001 respectively). While 90% of patients were in NYHA III-IV class at admission to hospital, only 2% of patients were in class IV at hospital discharge. The proportion of smokers was greater in men than in women (68% vs. 12%). Atrial fibrillation was present in 35% of patients. During hospitalization, angiotensin converting enzyme (ACE) inhibitors were used by 77%, diuretics by 95%, digitalis by 76%, nitrate by 85%, beta-blockers by 3%, aspirin by 86%, anticoagulants by 44%, Ca antagonist by 10%, positive inotropic agents by 42%; and antiarrhythmic agents by 15% of patients.

CONCLUSION

The use of ACE inhibitors, the major milestone of CHF treatment, is not on an adequate level yet. The use of beta-blockers should also be encouraged.

[Cardiac glycosides: From ancient history through Withering's foxglove to endogeneous cardiac glycosides]

For centuries, drugs that increase the power of contraction of the failing heart have been used for the treatment of congestive heart failure (dropsy). The cardiac effect is due to the content of cardiac glycosides. Squill or sea onion, Urginea (Scilla) maritima, a seashore plant, was known by the ancient Romans and Syrians and possibly also by the ancient Egyptians. Squills were used erratically, but some prescriptions indicate that they may have been used for the treatment of oedematous states. The toxic effect of strophanthus species was known from poisoned arrows used by the natives in Africa. Digitalis, derived form the foxglove plant, Digitalis purpurea, is mentioned in writings as early as 1250; a Welsh family, known as the Physicians of Myddvai, collected different herbs and digitalis was included in their prescriptions. However, the druge was used erratically until the 18th century, when William Withering, an English physician and botanist, published a monograph describing the clinical effects of an extract of the foxglove plant. Later, in 1785, the indication and the toxicity of digitalis were reported in his book, "An account of the Foxglove and some of its medical uses with practical remarks on dropsy, and other diseases". In Denmark, the leaves of Digitalis purpurea or Digitalis lanata were tested for cardiac glycoside activity. The standardized digitalis powder was used in tinctures, infusions, and tablets. The preparations were included in successive editions of the Danish pharmacopoeia, some of the tinctures already in 1828, i.e. before the standardization of the drug. Isolation of cardiac glycosides from digitalis, strophanthus and squill and determination of their chemical structures initiated biochemical and pharmacological studies. The scientific advances led to an understanding of cardiac muscle contractility and the Na,K pump as the cellular receptor for the inotropic action of digitalis. Examination of putative endogenous ligands to the receptor revealed some endogenous cardiac glycosides of similar or identical structures as those found in digitalis, strophanthus and squill. Increased concentrations of these glycosides are found in patients with heart failure. Further investigations are needed to determine whether the secretion of glycosides might be a physiologic response to a diminished cardiac output.

Anti-tumour activity of Digitalis purpurea L. subsp. heywoodii

Recent research has shown the anticancer effects of digitalis compounds suggesting their possible use in medical oncology. Four extracts obtained from the leaves of Digitalis purpurea subsp. heywoodii have been assessed for cytotoxic activity against three human cancer cell lines, using the SRB assay. All of them showed high cytotoxicity, producing IC50 values in the 0.78 - 15 microg/mL range with the methanolic extract being the most active, in non toxic concentrations. Steroid glycosides (gitoxigenin derivatives) were detected in this methanolic extract. Gitoxigenin and gitoxin were evaluated in the SRB assay using the three human cancer cell lines, showing IC50 values in the 0.13 - 2.8 microM range, with the renal adenocarcinoma cancer cell line (TK-10) being the most sensitive one. Morphological apoptosis evaluation of the methanolic extract and both compounds on the TK-10 cell line showed that their cytotoxicity was mediated by an apoptotic effect. Finally, possible mechanisms involved in apoptosis induction by digitalis compounds are discussed.

Sex, Digitalis, and the Sodium Pump

Foxglove and its constituents therapeutic agent digitalis have been used for centuries for the treatment of heart failure. All digitalis-like cardiotonic steroids enhance heart contraction through a mechanism involving the inhibition of the Na(+),K(+)- ATPase. Recently, Rathore and colleagues reported that sex-based differences may exist in the efficacy of digoxin for the treatment of heart failure. The authors of the study found that female patients exhibited increased risk of death associated with digoxin therapy, whereas male patients appeared to have no increased risk of death related to digoxin therapy. Blaustein and colleagues delve into the report and discuss possible explanations for these findings, suggest alternative ones, and advocate for enrolling greater numbers of women in clinical studies.

Herbal diuretics revisited: from "wise women" to William Withering

This contribution summarizes the use of herbal diuretics over the period of two thousand years. After describing the role of herbs in the framework of the theory of the balance of humors for well-being, it details the contributions of Pliny the Elder (23-79), Dioscorides (40-90), Hildegard von Bingen (1098-1179), Pietro Andrea Matthioli (1500-1577), and Leonard Fuchs (1501-1566) in providing increasingly more precise descriptions and illustrations of medicinal plants. Then, William Withering's (1741-1799) scientific analysis of the use of foxglove for the treatment of dropsy is presented, taking into account the role peasant "wise women" played in his discoveries and the role of "folklore medicine" before him.

Subgroup interactions in the Heart and Estrogen/Progestin Replacement Study: lessons learned

BACKGROUND

The Heart and Estrogen/Progestin Replacement Study (HERS) showed no overall benefit of postmenopausal hormone treatment in women with coronary heart disease (CHD). We analyzed the HERS data to determine whether there were specific subgroups of women who responded differently to treatment, either during the first year or in the overall study.

METHODS AND RESULTS

In the search for significant treatment interactions, we analyzed a total of 86 subgroups defined by baseline characteristics. These included demographics and lifestyle factors, laboratory and physical examination variables, medical history and symptoms by self-report, medication use, and prior CHD history by chart review. We examined within-subgroup treatment effects for baseline variables that significantly interacted with treatment assignment. Under the null hypothesis, 4 (5%) of the 86 interactions would be expected to be nominally significant (P<0.05) by chance alone at each time point. Six of the interaction values were P<0.05 at 1 year, and 3 were P<0.05 at trial completion. The findings are discussed in the context of known mechanisms of action and prior scientific knowledge. Use of digitalis and history of myocardial infarction emerged as 2 possible modifiers of the effect of hormone therapy during the first year, and lipoprotein(a) emerged as a possible modifier during the overall study.

CONCLUSIONS

Extensive post hoc analyses did not identify any subgroup of HERS participants in which postmenopausal hormone treatment was clearly beneficial or harmful, but several possibilities emerged for testing in future trials.