The goal of this study was to determine the relationship between changes in cardiac hemodynamics during intravenous adenosine (ADO) infusion, and myocardial blood flow (MBF).
The relationship between ...changes in MBF and the peripheral hemodynamic effects during peak adenosine infusion is unknown.
We studied 348 (age 57 +/- 11 years; 106 females) without evidence of obstructive coronary artery disease by positron emission tomography (PET). Patients underwent (13)Nammonia PET imaging to measure MBF and coronary vascular resistance (CVR) at rest and during a standard 6-min ADO infusion. Changes in heart rate (HR) and mean arterial pressure (MAP) were measured at baseline and during peak hyperemia.
During ADO, HR increased (delta: 24 +/- 11 beats/min) and MAP decreased (delta: -2 +/- 10 mm Hg). Overall, delta HR correlated poorly with hyperemic MBF (R = 0.10, p = 0.06) and with CVR (R = 0.11, p = 0.04). Delta MAP also showed a weak correlation with hyperemic MBF (R = 0.04, p = 0.44) and with CVR (R = 0.11, p = 0.04). Patients in the lowest tertile for delta HR showed a 7% lower hyperemic MBF (1.84 +/- 0.6 ml/min/g vs. 1.98 +/- 0.6 ml/min/g, p = 0.022) and an 8% higher CVR (54 +/- 20 mm Hg/ml/min/g vs. 50 +/- 17 mm Hg/ml/min/g, p = 0.056) compared with those in the highest tertile. Patients in the lowest tertile for delta MAP (i.e., greatest decline) showed similar hyperemic MBF, and an 8% lower CVR compared with those in the highest tertile (p = NS for both). These small differences between tertiles remain, even after adjusting for differences in age, gender, smoking status, and lipid profile.
Changes in cardiac hemodynamics during intravenous ADO are generally poor predictors of changes in MBF and CVR during peak hyperemia, and, thus, they should not be used to assess the effectiveness of vasodilator stress in myocardial perfusion imaging.
This study assessed the efficacy and safety of avasimibe (CI-1011), an inhibitor of acyl coenzyme A-cholesterol acyltransferase (ACAT) in subjects with homozygous familial hypercholesterolemia ...(HoFH). Twenty seven subjects were enrolled in a double-blind, randomized, 3-sequence crossover trial of atorvastatin 80
mg QD, avasimibe 750
mg QD, and the combined treatment of atorvastatin 80
mg QD and avasimibe 750
mg QD after a washout period of 4 weeks. Each treatment period was administered over 6 weeks for a total of 18 weeks. There were no significant lipid changes resulting from the administration of avasimibe monotherapy. Avasimibe in combination with atorvastatin resulted in a significantly better reduction of total cholesterol (TC) as compared to atorvastatin alone (−22% versus −18%) (
P<0.05). All other lipid changes were not statistically significant for combination therapy compared to atorvastatin monotherapy, however there were greater reductions in triglycerides (TG) (−24% versus −13%), low-density lipoprotein cholesterol (LDL-C) (−23% versus −19%), very low-density lipoprotein cholesterol (VLDL-C) (−24% versus −13%) and high-density lipoprotein cholesterol (HDL-C) (−11% versus −6%). Avasimibe may modestly enhance the lipid-reducing effect of atorvastatin by further inhibiting the production of intracellular cholesterol through mechanisms that appear to be compatible in this population.
Although acyl-CoA:cholesterol acyltransferase (ACAT) inhibitors have been shown to reduce lipid levels in several animal models, the safety and lipid modifying activity of any single agent in this ...class has not been demonstrated in humans. The safety and efficacy of avasimibe (CI-1011), a new, unique, wholly synthetic ACAT inhibitor, was evaluated in the treatment of 130 men and women with combined hyperlipidemia and hypoalphalipoproteinemia (low levels of high-density lipoprotein cholesterol HDL-C). Following an 8-week placebo and dietary-controlled baseline period, patients were randomly assigned to double-blind treatment with placebo, 50, 125, 250, or 500 mg avasimibe administered as capsules once daily for 8 weeks. At all evaluated doses, avasimibe treatment resulted in prompt and significant reductions (
P
<
0.05) in plasma levels of total triglycerides (TG) and very low-density lipoprotein cholesterol (VLDL-C) with mean reductions of up to 23% and 30% respectively, apparently independent of dose. No statistically significant changes in total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), HDL-C or apolipoprotein (apo) B were detected. ApoAI levels were also unchanged on all doses of avasimibe apart from the 500 mg dosage, which was associated with a significant decrease in plasma apoAI. The relevance of this latter finding in only one dosage group is not known. All doses of avasimibe were well tolerated with no resulting significant abnormalities of biochemical, hematological, or clinical parameters.
Although statins have been shown to be beneficial in the management of hyperlipidemia and the reduction of cardiovascular morbidity and mortality, rates of major cardiovascular events remain high ...despite their use. Inhibition of the acyl coenzyme A: cholesterol acyltransferase (ACAT) enzyme in the arterial wall may prevent excess accumulation of cholesteryl esters in macrophages. In addition to ACAT inhibitor monotherapy, combination of a statin with an ACAT inhibitor may be a promising approach to further prevent the progression of atherosclerosis.
This report describes the design and methodologic features of a double-blind, randomized, placebo-controlled trial to assess the effect of the ACAT inhibitor avasimibe at 50-, 250-, and 750-mg daily dosages on the progression of coronary atherosclerosis as assessed by intravascular ultrasound (IVUS). All patients receive background lipid-lowering therapy when necessary. The study population consists of patients with at least one 20% to 50% diameter stenosis in a coronary artery with a reference diameter of > or =2.5 mm. IVUS and coronary angiography are performed at baseline and repeated at 24 months. The primary study end point is the change from baseline in plaque volume in a 30-mm segment of the coronary artery assessed by 3-dimensional IVUS. Several other IVUS and angiographic end points are measured.
The Avasimibe and Progression of coronary Lesions assessed by intravascular UltraSound (A-PLUS) trial is among the first large imaging trials to use IVUS as a primary end point and assesses the effects of the ACAT inhibitor avasimibe on atherosclerosis progression.
Qualification and interpretation standards are essential for establishing
Tc-SPECT MPI accuracy vs. alternative modalities.
Rest-stress
Tc-SPECT phantom scans were acquired on 35 cameras. LV defects ...were quantified with summed stress (SSS) and difference scores (SDS) at 2 core labs. SDS ≥ 2 in the right coronary artery (RCA) was the qualifying standard. Twenty rest (R)-stress (S) patient images were acquired on qualified cameras and interpreted by core labs. Global scoring differences > 3 between labs or discordant clinical interpretations underwent review. Scoring, interpretation, image quality, and diagnostic parameter agreement were assessed.
Phantom scans: visual scoring confirmed RCA-ischemia on all cameras. Regional SSS, SDS agreement was moderate to very good: ICC-r = 0.57, 0.84. Patient scans: 90% of global SSS, 85% of SDS differences were ≤ 3. Regional SSS, SDS agreement: ICC-r = 0.87, 0.86, and global abnormal (SSS ≥ 4) and ischemic (SDS ≥ 2) interpretation: ICC-r = 0.90 were excellent. Clinical interpretation agreement was 100% following review. Image quality agreement was 70%. Automated metrics also agreed: ischemic total perfusion deficit ICC-r = 0.75, reversible perfusion defect, transient ischemic dilation, and S-R LV ejection fraction ICC-r ≥ 0.90.
Quantitative scoring and interpretation of scans were highly repeatable with site qualification and clinical interpretation standardization, indicating that dual-core lab interpretation is appropriate to determine
Tc-SPECT MPI accuracy.
Background Although statins have been shown to be beneficial in the management of hyperlipidemia and the reduction of cardiovascular morbidity and mortality, rates of major cardiovascular events ...remain high despite their use. Inhibition of the acyl coenzyme A: cholesterol acyltransferase (ACAT) enzyme in the arterial wall may prevent excess accumulation of cholesteryl esters in macrophages. In addition to ACAT inhibitor monotherapy, combination of a statin with an ACAT inhibitor may be a promising approach to further prevent the progression of atherosclerosis. Methods This report describes the design and methodologic features of a double-blind, randomized, placebo-controlled trial to assess the effect of the ACAT inhibitor avasimibe at 50-, 250-, and 750-mg daily dosages on the progression of coronary atherosclerosis as assessed by intravascular ultrasound (IVUS). All patients receive background lipid-lowering therapy when necessary. The study population consists of patients with at least one 20% to 50% diameter stenosis in a coronary artery with a reference diameter of ≥2.5 mm. IVUS and coronary angiography are performed at baseline and repeated at 24 months. The primary study end point is the change from baseline in plaque volume in a 30-mm segment of the coronary artery assessed by 3-dimensional IVUS. Several other IVUS and angiographic end points are measured. Conclusions The Avasimibe and Progression of coronary Lesions assessed by intravascular UltraSound (A-PLUS) trial is among the first large imaging trials to use IVUS as a primary end point and assesses the effects of the ACAT inhibitor avasimibe on atherosclerosis progression. (Am Heart J 2002;144:589-96.)
The effects of atorvastatin (lipitor) on cholesterol-rich and triglyceride-rich lipoproteins were evaluated in this multicenter trial. Following a 6-week baseline period, 47 patients with elevated ...cholesterol and triglyceride levels were treated with atorvastatin 10 mg once daily (QD) for the initial 12 weeks (Period 1) increasing to 20 mg QD for the following 12 weeks (Period 2). At both the 10 and 20 mg doses, atorvastatin treatment resulted in significant reductions compared to pretreatment levels in low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), very low-density lipoprotein cholesterol (VLDL-C), apolipoprotein (apo) B, apoB in LDL (LDL-apo B), apo B in VLDL (VLDL-apo B), lipoprotein (Lp)B, lipoprotein B-complex (LpB
c), triglycerides (TG), low-density lipoprotein triglycerides (LDL-TG), very low-density lipoprotein triglyceride (VLDL-TG), high-density lipoprotein triglycerides (HDL-TG), and apo C-III. Atorvastatin 10 and 20 mg QD also resulted in significant increases in high-density lipoprotein cholesterol (HDL-C), apo AI, and LpAII:B:C:D:E. Due to its unique ability to normalize both cholesterol-rich and triglyceride-rich particles, atorvastatin is a promising candidate for monotherapy in a broad range of patients including those with varying degrees of hypercholesterolemia and hypertriglyceridemia.
This 24-week, randomized, open-label multicenter study evaluated the efficacy and safety of atorvastatin compared with fenofibrate in the treatment of patients with combined hyperlipidemia (CHL). ...Following a 6-week baseline period, 84 patients with CHL were randomly assigned to either atorvastatin treatment, 10 mg QD for 12 weeks increasing to 20 mg QD for 12 weeks, or fenofibrate treatment, 100 mg TID for 24 weeks. Changes from baseline in lipid parameters were evaluated at weeks 12 and 24. At both 10- and 20-mg doses, atorvastatin treatment resulted in significantly greater reductions in LDL cholesterol, apolipoprotein (apo) B, total cholesterol, LDL-apoB, and lipoprotein-B compared to 300-mg fenofibrate treatment (P < .05). While atorvastatin also resulted in clinically significant reductions in triglyceride, VLDL cholesterol, apoB in VLDL, triglyceride in VLDL, and apoC-III and significant increases in HDL cholesterol and apoA-I levels, fenofibrate was more effective than atorvastatin in altering all these parameters. However, by significantly affecting both the cholesterol-rich and triglyceride-rich particles, atorvastatin holds promise as a lipid-regulator able to adequately treat a broad range of patients that includes those with CHL.
Background: Atorvastatin, a new HMG-CoA reductase inhibitor in clinical development has demonstrated an acceptable safety profile and marked cholesterol and triglyceride reduction at doses ranging ...from 10-80 mg/day. Since bile acid sequestering resins are often used in combination with HMGRIs to enhance cholesterol reduction, this trial was conducted to explore the use of atorvastatin alone and combined with colestipol in patients with primary hyperlipidemia.
Methods and Results: One hundred six patients with low-density lipoprotein (LDL) cholesterol > 4.1 mM/L (160 mg/dL) and plasma triglycerides < 3.9 mM/L (350 mg/dL) were randomized to treatment consisting of 20 g/day colestipol, 10 mg/day atorvastatin, or 10 mg/day atorvastatin plus 20 g/day colestipol for 12 weeks. Percent change from baseline in lipid variables was measured. The atorvastatin group showed a significant reduction in LDL cholesterol of 35% after 12 weeks. Combination therapy provided an additional 10% reduction in LDL cholesterol over that observed for atorvastatin alone. Twenty-one percent of all patients in the atorvastatin monotherapy group experienced associated adverse events compared with 60% in the combination therapy group. Ninety percent of atorvastatin monotherapy patients were compliant at every visit compared with 75% receiving combination therapy. Conclusions: Although the combination of atorvastatin plus colestipol was more effective in lowering LDL cholesterol than atorvastatin alone, atorvastatin 10 mg/day monotherapy provided a better safety profile and improved patient compliance. which may result in improved long-term cholesterol control.
Conclusions: Although the combination of atorvastatin plus colestipol was more effective in lowering LDL cholesterol than atorvastatin alone, atorvastatin 10 mg/day monotherapy provided a better safety profile and improved patient compliance. which may result in improved long-term cholesterol control.
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