Effects of angiotensin-converting enzyme inhibition on transient ischemia: the Quinapril Anti-Ischemia and Symptoms of Angina Reduction (QUASAR) trial.

OBJECTIVES: We sought to determine whether angiotensin-converting enzyme inhibition (ACE-I) (i.e., quinapril) prevents transient ischemia (exertional and spontaneous) in patients with coronary artery disease (CAD). BACKGROUND: It is known that ACE-I reduces the risk of death, myocardial infarction (MI), and other CAD-related outcomes in high-risk patients. Numerous studies have confirmed that ACE-I improves coronary flow and endothelial function. Whether ACE-I also decreases transient ischemia is unclear, because no studies have been adequately designed or sufficiently powered to evaluate this issue. METHODS: Using a randomized, double-blinded, placebo-controlled, multicenter design, we enrolled 336 CAD patients with stable angina. None had uncontrolled hypertension, left ventricular (LV) dysfunction, or recent MI, and all developed electrocardiographic (ECG) evidence of ischemia during exercise. They were randomly assigned to one of two groups: 40 mg/day quinapril (n = 177) or placebo (n = 159) for 8 weeks. Patients then entered an additional eight-week treatment phase to examine the full dose range. Those assigned to 40 mg quinapril continued that dose and those assigned to placebo were titrated to 80 mg/day. Treadmill testing, the Seattle Angina Questionnaire, and ambulatory ECG monitoring were used to assess responses at baseline and at 8 and 16 weeks. RESULTS: The groups did not differ significantly at entry or in terms of indexes assessing myocardial ischemia at 8 or 16 weeks of treatment. In this low-risk population, ACE-I was not associated with serious adverse events. CONCLUSIONS: Our findings suggest short-term ACE-I in CAD patients without hypertension, LV dysfunction, or acute MI is not associated with significant effects on transient ischemia.

Randomized comparison of T-type versus L-type calcium-channel blockade on exercise duration in stable angina: results of the Posicor Reduction of Ischemia During Exercise (PRIDE) trial.

BACKGROUND: Mibefradil is a T-type calcium-channel antagonist and arterial vasodilator with negative chronotropic effects. It is not known if T-type calcium-channel blockade is superior to L-type calcium-channel blockade in patients with stable angina pectoris. METHODS: A multicenter, randomized, double-blind trial was conducted in patients with documented coronary disease and stable angina to compare a 360 mg dose of diltiazem CD with 100 mg dose of mibefradil. The primary end point was change in time to symptom-limited exercise termination from baseline to 8 weeks. Secondary efficacy parameters included time to onset of persistent ST-segment depression, time to awareness of angina, and change in exercise duration from baseline to 2 and 4 weeks of treatment. RESULTS: A total of 121 patients were randomized to mibefradil and 113 to diltiazem CD. At 8 weeks, the increase in exercise duration was 24.5 seconds greater in the mibefradil group (P =.017; 95% CI 4.4-44.7 seconds). At 8 weeks, time to development of > or =1 mm ST-segment depression was greater by 45.3 seconds (P =.0025; 95% CI 16.2-74.5) with mibefradil, but time to development of angina was not significantly different. CONCLUSION: T-type calcium-channel antagonism with mibefradil improved treadmill exercise parameters compared with diltiazem in patients with chronic stable angina. Further investigation and development of antagonists of T-type calcium channels with fewer adverse drug interactions is warranted and may be promising in the management of ischemic heart disease.

Efficacy and safety of ursodeoxycholic acid in primary, type IIa or IIb hypercholesterolemia: a multicenter, randomized, double-blind clinical trial.

BACKGROUND: Ursodeoxycholic acid (UDCA) is a therapeutic bile acid used in dissolution of gallstones and treatment of several cholestatic liver diseases. Results obtained from primary biliary cirrhosis patients treated with UDCA suggested that this agent exerts significant cholesterol-lowering effects and justifies evaluation in primary hypercholesterolemic patients without liver disease. Purpose of this study was to determine whether UDCA had potential to be an effective, safe cholesterol-lowering agent in primary type IIa or IIb hypercholesterolemia. METHODS: This was a multicenter randomized, double blind, placebo-controlled trial. After a 6-week placebo lead-in period during which two qualifying lipid profiles were obtained, patients with a mean serum LDL-cholesterol (LDL-C) between 130 and 190mg/dL, triglycerides <400mg/dL and HDL-cholesterol >30mg/dL were randomized to UDCA or matching placebo for 24 weeks. RESULTS: Seven sites screened 200 patients with 134 patients meeting the entry criteria who were randomized to the two treatments. There were 125 patients meeting the efficacy evaluation criteria, 57 on UDCA and 68 on placebo. LDL-C change from weeks 0 to 24 showed no significant difference between groups. No significant differences in changes for total cholesterol, HDL-cholesterol and triglycerides were observed. Both groups had similar adverse event profiles. CONCLUSIONS: UDCA did not show intrinsic cholesterol-lowering properties and therefore is not a useful therapy in treating type IIa or type IIb hypercholesterolemic patients. UDCA was confirmed as a well tolerated and safe drug in this population.