Prognosis of patients with unstable angina or acute myocardial infarction treated with calcium channel antagonists

ACE inhibitors and calcium channel blockers: patterns of use and associations with mortality in type 1 diabetes

OBJECTIVE

To determine the frequency of ACE-I and Calcium channel blockers (CCB) use in type 1 diabetes (T1D), and associations of these medications with mortality.

RESEARCH DESIGN AND METHODS

Data from the Pittsburgh Epidemiology of Diabetes Complications (EDC) Study, a 10-year follow up of childhood onset T1D, were used to document ACE-I and CCB use. Use in subjects who died during follow up was compared to gender, age, duration (+/-5 years), hypertension, and renal status matched living controls.

RESULTS

ACE-I use increased from baseline (1986-1988) to 10 years later (1996-1998) for those with hypertension (20.8-65.8%), and microalbuminuria (2.3-31.5%). However, the majority of patients with microalbuminuria were not on ACE-I at 10 years. CCB use was 2.1% at baseline, increased to 10.4% at 8 years, and fell to 9.5% at 10 years. An increased risk of mortality was apparent for those not treated with either ACE-I or CCB when controlling for cardiovascular status and age (hazard ratio (HR) 2.6, 95% CI 1.1-6.3), while ACE-I use alone was protective (HR=0.26, 0.08-0.79). CCB use with or without ACE-I was not related to mortality status.

CONCLUSIONS

This data suggests that ACE-I use is not optimal, but more favorably associated with decreased mortality than CCB use.

Overview of therapies for prevention of restenosis after coronary interventions

Coronary artery disease is a leading cause of morbidity and mortality in the United States and across the world. The economic impact of coronary artery disease is staggering and on the rise. Percutaneous transluminal coronary angioplasty is widely used to treat severe, symptomatic coronary stenosis. The Achilles heel of angioplasty is restenosis of those treated arteries. As a result, numerous therapies, including mechanical and pharmacological approaches, to prevent restenosis have been studied. A greater understanding of the pathophysiology of restenosis has enhanced the success of these therapeutic approaches. To date, the most important and successful approach to limit restenosis has been the use of coronary stents. Stents have reduced the rate of restenosis from approximately 50% down to 20-30%. However, in-stent restenosis presents a new and an even more challenging dilemma. The success of adjunctive drug therapy has been promising, but, as of yet, very limited. Antithrombotic agents have reduced acute thrombosis and many of the acute complications of angioplasty. New approaches and therapies are very encouraging, and provide great hope in the treatment of restenosis. Brachytherapy has shown success in the treatment of in-stent restenosis, and recently has been approved by the United States Food and Drug Administration for this indication. Drug-eluting stents using antiproliferative drugs are the most exciting new advance in preventing restenosis, currently in Phase III trials. Gene therapy, targeted drug delivery, and newer antithrombotic agents are also under investigation. We will review the pathophysiology of restenosis, animal models, pharmacological therapies, and mechanical approaches for the treatment of restenosis.

Conflict of interest in the debate over calcium-channel antagonists

BACKGROUND

Physicians' financial relationships with the pharmaceutical industry are controversial because such relationships may pose a conflict of interest. It is unknown to what extent industry support of medical education and research influences the opinions and behavior of clinicians and researchers. The recent debate over the safety of calcium-channel antagonists provided an opportunity to examine the effect of financial conflicts of interest.

METHODS

We searched the English-language medical literature published from March 1995 through September 1996 for articles examining the controversy about the safety of calcium-channel antagonists. Articles were reviewed and classified as being supportive, neutral, or critical with respect to the use of calcium-channel antagonists. The authors of the articles were asked about their financial relationships with both manufacturers of calcium-channel antagonists and manufacturers of competing products (i.e., beta-blockers, angiotensin-converting-enzyme inhibitors, diuretics, and nitrates). We examined the authors' published positions on the safety of calcium-channel antagonists according to their financial relationships with pharmaceutical companies.

RESULTS

Authors who supported the use of calcium-channel antagonists were significantly more likely than neutral or critical authors to have financial relationships with manufacturers of calcium-channel antagonists (96 percent, vs. 60 percent and 37 percent, respectively; P<0.001). Supportive authors were also more likely than neutral or critical authors to have financial relationships with any pharmaceutical manufacturer, irrespective of the product (100 percent, vs. 67 percent and 43 percent, respectively; P< 0.001).

CONCLUSIONS

Our results demonstrate a strong association between authors' published positions on the safety of calcium-channel antagonists and their financial relationships with pharmaceutical manufacturers. The medical profession needs to develop a more effective policy on conflict of interest. We support complete disclosure of relationships with pharmaceutical manufacturers for clinicians and researchers who write articles examining pharmaceutical products.