Angiotensin II formation in human vasculature after chronic ACE inhibition: a prospective, randomized, placebo-controlled study. QUO VADIS Investigators.

The QUO VADIS (the effects of QUinapril On Vascular Ace and Determinants of ISchemia) study was a randomized, double-blind, placebo-controlled trial designed to evaluate the effects of long-term angiotensin-converting enzyme (ACE) inhibition on angiotensin II formation in human vasculature. Patients (n = 187) scheduled for coronary artery bypass surgery used study medication 27 +/- 1 days before surgery. Segments of internal mammary arteries were exposed to increasing doses (0.1 nM-1 microM) of angiotensin I and II in organ baths. The rate of local angiotensin II formation is a function of the reciprocal of the difference between the pEC50's of the dose response curves to angiotensin I and II (-log/mol) and of the area between the curves (units). Quinapril (40 mg) and captopril (3 x 50 mg) similarly and significantly reduced mean blood pressure compared with placebo (p = 0.04). Difference between pEC50's was 0.90 +/- 0.08 in quinapril patients compared with 0.60 +/- 0.08 for placebo (p = 0.01); the area between curves was 91 +/- 8 for quinapril patients compared with 67 +/- 8 for placebo (p = 0.03). Angiotensin II formation was decreased to a lesser extent with captopril and was not statistically different from placebo (p = 0.3); the difference between pEC50's was 0.83 +/- 0.15; the area between curves was 84 +/- 12. This is the first randomized study to demonstrate that long-term oral treatment with an ACE inhibitor reduces vascular angiotensin II formation in humans.

Influence of smoking status on angiotensin-converting enzyme inhibition-related improvement in coronary endothelial function. TREND Investigators. Trial on Reversing Endothelial Dysfunction.

Our study evaluated the influence of smoking status on coronary endothelial function in normotensive patients with coronary artery disease who received placebo or the angiotensin-converting enzyme inhibitor quinapril in the TREND study (Trial on Reversing Endothelial Dysfunction). In this retrospective analysis of data from the previously published study, patients were classified as either smokers (n = 23) or nonsmokers (n = 82). Patients underwent coronary angiography at baseline and again after 6-month follow-up. The primary response variable was the net change in acetylcholine-induced diameter of the target coronary artery segments (n = 105) between the baseline and 6-month follow-up angiograms. The secondary response variables were based on analysis of all segments (n = 300) and the mean diameter responses of target and all segments at 6 months. At baseline, coronary artery vasomotor responses were similar in smokers and nonsmokers in the placebo and quinapril groups. There was a significant improvement in the primary response variable for both smokers (P = 0.008) and nonsmokers (P = 0.047) randomized to quinapril compared with placebo. At 6-month follow-up, nonsmokers in the placebo group showed no significant change in the mean vasoconstrictor responses (8.3% vs. 8.0% at acetylcholine 10(-4) mol/L), whereas nonsmokers in the quinapril-treated group showed significantly less vasoconstriction (2.7% vs. 13.2%; P = 0.003). Among smokers in the placebo group, vasoconstriction increased nonsignificantly (21.7% vs. 17.2% at baseline) but decreased significantly in the quinapril group (0.5% vs. 17.9%; P = 0.002). These results indicate that ACE inhibition improves the coronary vasomotor response in both smokers and nonsmokers, but that smokers apparently derive greater benefit.

Influence of smoking status on progression of endothelial dysfunction. TREND Investigators. Trial on Reversing Endothelial Dysfunction.

BACKGROUND: Cigarette smoking is a major risk factor for developing coronary artery disease and is associated with increased coronary morbidity and mortality in patients with established atherosclerosis. This report describes the influence of smoking on coronary endothelial function in normotensive patients with coronary artery disease, but without left ventricular dysfunction, severe hypercholesterolemia, or insulin-dependent diabetes mellitus. METHODS: Placebo-treated patients (n = 54) from a larger study assessing coronary endothelial function were classified at baseline as smokers or nonsmokers for this subgroup analysis. Patients underwent coronary angiography at baseline and again after 6-month follow-up. RESULTS: At baseline, there was a trend for a greater decrease in target segment diameter (n = 54) in smokers compared with nonsmokers (-17.2 +/- 5.3% vs. -8.0 +/- 2.5%, acetylcholine 10(-4) mol/l). All measured coronary artery segments (n = 202) showed similar responses (-7.3 +/- 2.7% vs. -3.8 +/- 1.3%, acetylcholine 10(-4) mmol/l, for smokers vs. nonsmokers, respectively). After 6 months, smokers showed an even greater vasoconstrictor response to acetylcholine whereas nonsmokers did not (-21.7 +/- 5.3% vs. -8.3 +/- 2.5%, acetylcholine 10(-4) mmol/l). The vasodilatory response to nitroglycerin was similar in smokers and nonsmokers. CONCLUSIONS: In current smokers, a marked decline in endothelium-dependent vasomotor response was observed over a 6-month period.

Effectiveness of atorvastatin for reducing low-density lipoprotein cholesterol to National Cholesterol Education Program treatment goals.

Atorvastatin is a highly efficacious hydroxymethylglutaryl-coenzyme A reductase inhibitor that has been shown to reduce low-density lipoprotein cholesterol by 40% to 60%. Monotherapy with atorvastatin (10 to 80 mg/day) is well-tolerated, convenient, and appears to be effective for achieving National Cholesterol Education Program treatment goals in most patients, regardless of risk status.

Activity of Procanbid, procainamide twice-daily formulation, to suppress ventricular premature depolarizations. The Study Group Investigators.

Procainamide is a class IA antiarrhythmic drug indicated for the treatment of life-threatening or symptomatic ventricular arrhythmias. The current sustained-release formulation requires 6-hour dosing (qid). To improve patient compliance, a new sustained-release formulation for twice-daily (bid) administration has been developed (Procanbid, Parke-Davis). This study assesses the pharmacologic equivalence of the bid and qid formulations in the suppression of symptomatic ventricular premature depolarizations (VPDs). Fourteen centers enrolled a total of 99 patients with frequent symptomatic VPDs (average > or = 20 VPDs/hr) who previously responded to and tolerated the procainamide qid formulation. During the first week of the double-blind phase, patients were randomized to either placebo or procainamide dosages of 1000, 2000, or 4000 mg/d (bid or qid formulations). In the second week, the patients were crossed over to the alternate formulation. Seventy-seven patients qualified for the primary activity analysis. The bid and qid formulations showed comparable effectiveness in the suppression of mean VPDs with a linear dose-response relationship. The VPD suppression was not attenuated towards the end of the dosing interval for either formulation. Sixty-eight of these patients entered an optional 1-year extension to receive the bid formulation. Thirty-seven (54%) patients had adverse effects. Of those, 15 (22%) had side effects considered treatment related. Most of the adverse events occurred during the first 6 weeks of treatment. Only a few patients (8%) withdrew as a consequence of treatment with the bid formulation. The overall safety profile of the bid formulation was similar to other formulations, and the procainamide bid formulation has a low proarrhythmic rate (< 3%). In conclusion, the effectiveness of the twice-daily formulation of procainamide in the suppression of VPDs is comparable to the currently available qid formulation.

Effects of quinapril on coronary blood flow in coronary artery disease patients with endothelial dysfunction. TREND Investigators. Trial on Reversing Endothelial Dysfunction.

This pilot study evaluates the effects of quinapril, an angiotensin-converting enzyme inhibitor with high tissue-binding affinity, on microvascular endothelial function in patients with mild (<40% narrowing) coronary artery disease and epicardial endothelial dysfunction. Patients randomized to quinapril had a trend suggesting an increase in endothelium-dependent coronary blood flow response.

Baseline clinical and angiographic data in the Quinapril Ischemic Event (QUIET) Trial.

The QUinapril Ischemic Event Trial (QUIET) is the first prospective, double-blind, placebo-controlled trial to investigate the long-term antiatherosclerotic effects of angiotensin-converting enzyme inhibition. Normotensive, nonhyperlipidemic subjects (1,750) with normal left ventricular systolic function were randomly assigned to treatment or placebo at percutaneous transluminal coronary angioplasty (PTCA). The primary end point is time to first cardiac ischemic event. Baseline clinical characteristics are (mean +/- SD): age 58 +/- 9 years; blood pressure 123 +/- 15/74 +/- 10 mm Hg; low density lipoprotein cholesterol 124 +/- 27 mg/dL; high density lipoprotein cholesterol 37 +/- 10 mg/dL; and triglycerides 167 +/- 91 mg/dL. In addition, 81% are men; 22% are current smokers; 49% give a history of myocardial infarction. Baseline angiographic characteristics are (mean +/- SD): left ventricular ejection fraction 59% +/- 11%; per patient diameter stenosis (excluding the PTCA segment) 49% +/- 31%; 8.9 +/- 3.5 analyzable segments per patient (excluding the PTCA segment), 3.8 +/- 2.3 of which have visible stenosis. Including the PTCA segment, 52% have single vessel disease and 48% have multivessel disease. Baseline angiographic data for non-PTCA segments will be correlated with cardiac ischemic events which occur after 6 months. Up to 500 subjects will undergo follow-up angiography with quantitative coronary angiographic analysis (QCA) of baseline and follow-up films. The primary QCA end point will be per-patient categorical designation as progressor or nonprogressor based on the presence or absence of > or = 400 microns narrowing in > or = 1 vessels that did not undergo PTCA.

Angiotensin-converting enzyme inhibition with quinapril improves endothelial vasomotor dysfunction in patients with coronary artery disease. The TREND (Trial on Reversing ENdothelial Dysfunction) Study.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors may exert some of their benefits in the therapy of hypertension, congestive heart failure, and acute myocardial infarction by their improvement of endothelial dysfunction. TREND (Trial on Reversing ENdothelial Dysfunction) investigated whether quinapril might improve endothelial dysfunction in normotensive patients with coronary artery disease and no heart failure, cardiomyopathy, or major lipid abnormalities so that confounding variables that affect endothelial dysfunction could be minimized. METHODS AND RESULTS: Using a double-blind, randomized, placebo-controlled design, we measured the effects of quinapril (40 mg daily) on coronary artery diameter responses to acetylcholine using quantitative coronary angiography. The primary response variable was the net change in the acetylcholine-provoked constriction of target segments between the baseline (prerandomization) and 6-month follow-up angiograms. The constrictive responses to acetylcholine were comparable in the placebo (n = 54) and quinapril (n = 51) groups at baseline. After 6 months, only the quinapril group showed significant net improvement in response to incremental concentrations of acetylcholine (4.5 +/- 3.0% [mean +/- SEM] versus -0.1 +/- 2.8% at 10(-6) mol/L and 12.1 +/- 3.0% versus -0.8 +/- 2.9% at 10(-4) mol/L, quinapril versus placebo, respectively; overall P = .002). CONCLUSIONS: TREND shows that ACE inhibition with quinapril improved endothelial dysfunction in patients who were normotensive and who did not have severe hyperlipidemia or evidence of heart failure. These benefits of ACE inhibition are likely due to attenuation of the contractile effects and superoxide-generating effects of angiotensin II and to enhancement of endothelial cell release of nitric oxide secondary to diminished breakdown of bradykinin.

Reduction of LDL cholesterol by 25% to 60% in patients with primary hypercholesterolemia by atorvastatin, a new HMG-CoA reductase inhibitor.

This 6-week, double-blind clinical trial evaluated lipid parameter responses to different dosages of atorvastatin in patients with primary hypercholesterolemia. Atorvastatin is a new 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor under development. After completing an 8-week placebo-baseline dietary phase, 81 patients were randomly assigned to receive either placebo or 2.5, 5, 10, 20, 40, or 80 mg atorvastatin once daily for 6 weeks. Plasma LDL cholesterol reductions from baseline were dose related, with 25% to 61% reduction from the minimum dose to the maximum dose of 80 mg atorvastatin once a day. Plasma total cholesterol and apo B reductions were also dose related. Previously, reductions in LDL cholesterol of the magnitude observed in this study have been seen only with combination drug therapy. In this study, atorvastatin was well tolerated by hyperlipidemic patients, had an acceptable safety profile, and provided greater reduction in cholesterol than other previously reported HMG-CoA reductase inhibitors.