Antianginal efficacy of the combination of felodipine-metoprolol 10/100 mg compared with each drug alone in patients with stable effort-induced angina pectoris: a multicenter parallel group study. The TRAFFIC Study Group

Comparison of the Seattle Angina Questionnaire With Daily Angina Diary in the TERISA Clinical Trial

BACKGROUND

As new techniques emerge to quantify patients' health status, new opportunities are created to validate patient-reported outcome questionnaires. The Seattle Angina Questionnaire (SAQ), a widely used coronary artery disease-specific health status tool, has not been validated against daily records of angina frequency and sublingual nitroglycerin (SL NTG) use. Additional evidence supporting the validity of the SAQ could justify its broader use as an outcome for clinical studies designed to evaluate treatments that may improve patients' symptoms, function, and quality of life.

METHODS AND RESULTS

We used data from 917 patients with type 2 diabetes mellitus, coronary artery disease, and stable angina from the multinational Type 2 Diabetes Evaluation of Ranolazine in Subjects With Chronic Stable Angina (TERISA) trial. The number of angina episodes and SL NTG used were recorded and transmitted daily using an electronic diary. In cross-sectional analyses, there was a strong relationship between the 2 SAQ angina frequency questions (ie, frequency of angina and SL NTG use) and the corresponding diary responses, with correlation coefficients of -0.64 for angina frequency (95% confidence interval,-0.68 to -0.60) and -0.69 for SL NTG use (95% confidence interval, -0.73 to -0.66). Longitudinally, changes in SAQ angina frequency scores from day 1 to week 8 also correlated with changes in angina frequency (-0.42; 95% confidence interval, -0.48 to -0.30) and SL NTG use by diary (-0.38; 95% confidence interval, -0.43 to -0.32) over the corresponding time period. Correlations were similar when stratified by age, sex, or geography.

CONCLUSIONS

In a multinational cohort of patients with stable angina, the SAQ angina frequency domain was significantly correlated, both cross sectionally and longitudinally, with daily diary entries of angina frequency and SL NTG use. These data further support the validity of the SAQ angina frequency domain across a broad spectrum of patients with stable angina.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT01425359.

Drug-induced hypoglycaemia: an update

Drugs are the most frequent cause of hypoglycaemia in adults. Although hypoglycaemia is a well known adverse effect of antidiabetic agents, it may occasionally develop in the course of treatment with drugs used in everyday clinical practice, including NSAIDs, analgesics, antibacterials, antimalarials, antiarrhythmics, antidepressants and other miscellaneous agents. They induce hypoglycaemia by stimulating insulin release, reducing insulin clearance or interfering with glucose metabolism. Several drugs may also potentiate the hypoglycaemic effect of antidiabetic agents. Administration of these agents to individuals with diabetes mellitus is of most concern. Many of these drugs, and depending on clinical setting, may also induce hyperglycaemia. Drug-induced hepatotoxicity and nephrotoxicity may lead in certain circumstances to hypoglycaemia. Some drugs may also induce hypoglycaemia by causing pancreatitis. Drug-induced hypoglycaemia is usually mild but may be severe. Effective clinical management can be handled through awareness of this drug-induced adverse effect on blood glucose levels. Herein, we review pertinent clinical information on the incidence of drug-induced hypoglycaemia and discuss the underlying pathophysiological mechanisms, and prevention and management.

Efficacy of monotherapy compared with combined antianginal drugs in the treatment of chronic stable angina pectoris: a meta-analysis

OBJECTIVE

To determine the relative efficacy of antianginal drugs administered as monotherapy or in combination in patients with chronic stable angina.

METHODS

A meta-analysis was performed on randomized trials, published in English between 1980 and 1999, that directly compared combined treatment and monotherapy. Twenty-two articles were included, all on the comparison of -blocker monotherapies to their combination with a calcium antagonist and 10 on the comparison of calcium antagonist monotherapies to their combination with a -blocker.

RESULTS

Time to 1 mm ST-segment depression, total exercise duration and time to onset of anginal pain were significantly increased with the combined therapy compared to -blocker alone (by 8, 5 and 12%, respectively). Only time to 1 mm ST-segment depression was significantly increased with the combined therapy compared to calcium antagonist alone (by 9%). For all these parameters, the adjusted differences were significant only within 6 h following drug intake and were not significant after 6 h. No analysis of safety data could be performed.

CONCLUSION

As far as exercise testing is concerned, the combination of a calcium antagonist and a -blocker is statistically more effective than either monotherapy. Further studies are needed to confirm the higher efficacy after the first 6 h following drug intake.

First line drugs in chronic stable effort angina--the case for newer, longer-acting calcium channel blocking agents

The American College of Cardiology-American Heart Association Committee recommends first line beta-adrenergic blocking agents for chronic stable effort angina. This article reassesses some critical evidence that is new or could have been neglected by the Committee. In particular, the putative role of calcium channel blocking agents (CCBs) is reexamined. Additional evidence is culled from articles not cited by the Committee, together with added reference to recent trials. Safety, side-effects and tolerability are issues that are evaluated. Mortality data are reviewed with the aid of a meta-analysis of all placebo-controlled trials on long acting CCBs. The advice of the committee may need to be reconsidered in view of recent evidence on the tolerability and benefits in hypertension of newer, longer-acting, second-generation CCBs. Of the older agents, verapamil has been shown to be the best with regard to safety and efficacy. Especially in the elderly, angina is often associated with hypertension, with evidence showing dihydropyridine CCBs and beta-adrenergic blocking agents to be similarly effective. Beta-blockers may have undesirable side effects such impotence and impaired exercise ability, despite their proven protective effects in postinfarct patients and in heart failure. The choice of drug should be keyed to the needs and the pathophysiology of the individual patient.

Current status of safety and efficacy of calcium channel blockers in cardiovascular diseases: a critical analysis based on 100 studies

Recently, serious concerns have been expressed about the long-term safety of the calcium channel blockers (CCBs) as a group. Safety and efficacy are, however, ultimately linked to each other; therefore both must be evaluated especially in the therapy of angina and hypertension, the main clinical indications for CCBs. The structural, functional, and pharmacokinetic heterogeneity of CCBs means that the efficacy and dangers of one subclass, such as the short-acting dihydropyridines (DHPs), in one situation, such as unstable angina, do not necessarily apply in other clinical situations. One hundred studies are reviewed according to their methods of data collection: case series, case control, cohort, randomized controlled trials (RCTs), and meta-analyses. Large, well-designed RCTs and the meta-analyses based on these trials remain the gold standard. Observational studies, though potentially less reliable sources of information because of selection bias, may nevertheless produce hypotheses that must then be tested in RCTs. Regarding safety, both observational studies and RCTs suggest that adverse effects of CCBs may be linked to short-acting agents, specifically short-acting nifedipine. Two good studies favor the safety of verapamil, even in short-acting form. Incomplete but increasing overall evidence favors the safety of longer-acting DHPs. Heart failure remains a class contraindication to the use of all CCBs, with some exceptions. Regarding efficacy, there are positive results of RCTs with CCBs in 2 specific clinical situations, namely, verapamil in postinfarct protection in the absence of pre-existing heart failure, and 2 outcome studies on hypertension with longer acting DHPs. These results cannot automatically be applied to other clinical situations and to other CCBs. For example, there is no evidence for the safety or efficacy of DHPs used without beta blockers in postinfarct patients. In diabetic hypertensives, 2 relatively large RCTs show that the blood pressure can be reduced by DHP-based therapy in diabetics, with a reduction in hard end points. To achieve current blood pressure goals, combination therapy is almost always necessary, and in diabetics there is strong evidence that 1 essential component should be an angiotensin converting enzyme inhibitor. The future aim with CCBs must be to obtain a large database gathered from RCTs, which will give the same certainty about efficacy and safety that already holds for use of the diuretics in hypertension, beta-blockers in postmyocardial infarction patients, and the angiotensin converting enzyme inhibitors in heart failure.