Secondary prevention with lipid lowering therapy in familial hypercholesterolemia: a correlation between new evolution of stenotic lesion and achieved cholesterol levels after revascularization procedures.
(25/2109)
OBJECT: To assess the value of secondary prevention with lipid lowering therapy following either balloon angioplasty (PTCA) or bypass surgery (CABG) in familial hypercholesterolemia patients, the correlation of the new evolution of stenotic lesions and therapeutically achieved cholesterol levels was studied in 50 patients. METHODS: All surviving patients were followed angiographically after 5 years, and findings were correlated with the annually determined total serum cholesterol (TC) levels. RESULTS: New coronary atherosclerotic plaques were not observed in 18 patients in whom the TC was controlled to <220 mg/dl but in 19 of 32 patients in whom the TC was >220 mg/dl, a new evolution of stenotic lesions was observed angiographically. CONCLUSION: The new evolution of stenotic lesions following revascularization in patients with FH can be controlled significantly by lipid lowering therapy to maintain a TC level of <220 mg/dl, and if diet alone can not achieve it, aggressive medication and even LDL apheresis might be justified. (+info)
Individual and combined effects of estrogen/progestin therapy and lovastatin on lipids and flow-mediated vasodilation in postmenopausal women with coronary artery disease.
(26/2109)
OBJECTIVES: We sought to examine the individual and combined effects of estrogen/progestin therapy versus lovastatin on lipids and flow-mediated vasodilation in postmenopausal women with heart disease. BACKGROUND: Little information is available regarding the relative benefits of estrogen replacement therapy versus reductase inhibitors and the potential utility of their combination as lipid-lowering therapy for postmenopausal women. METHODS: We conducted a randomized, double-blind, crossover trial in 24 postmenopausal women, each of whom received the following drug regimens during three consecutive six-week treatment periods: 1) hormone replacement (oral dose of 0.625 mg/day conjugated equine estrogens and 2.5 mg/day medroxyprogesterone acetate); 2) 20 mg lovastatin/day and 3) hormone replacement plus lovastatin. RESULTS: Total and low density lipoprotein (LDL) cholesterol were significantly lowered and high density lipoprotein (HDL) cholesterol was significantly increased by all three regimens compared with baseline (p < 0.05). Lovastatin was more effective than estrogen/progestin in reducing LDL (p < 0.001), but estrogen/progestin was slightly more effective in increasing HDL. The hormone replacement and lovastatin regimen blocked the estrogen-associated increase in triglycerides. Hormone replacement (alone and with lovastatin) resulted in increases in brachial artery flow-mediated vasodilator capacity (p = 0.01 for both regimens) and the area under the curve (p = 0.016 and p = 0.005, respectively) compared with baseline. Percent dilation was greatest after the hormone replacement regimen, whereas the area under the curve was greatest after hormone replacement plus lovastatin (69% improvement vs. baseline). CONCLUSIONS: In postmenopausal women with coronary disease and hyperlipidemia, conjugated equine estrogen produced significant improvements in lipids and vasodilator responses despite the concurrent administration of low dose medroxyprogesterone acetate. Low dose lovastatin produced greater reductions in LDL, but less dramatic improvements in vasodilator responses. Estrogen/progestin plus lovastatin may provide additional benefits via a greater reduction in the LDL/HDL ratio and attenuation of estrogen-associated hypertriglyceridemia. More information is needed about the safety and efficacy of such combinations of hormone replacement and reductase inhibitor therapy. (+info)
PPARalpha activators inhibit cytokine-induced vascular cell adhesion molecule-1 expression in human endothelial cells.
(27/2109)
BACKGROUND: Adhesion molecule expression on the endothelial cell (EC) surface is critical for leukocyte recruitment to atherosclerotic lesions. Better understanding of transcriptional regulation of adhesion molecules in ECs may provide important insight into plaque formation. Peroxisome proliferator-activated receptor-alpha (PPARalpha), a member of the nuclear receptor family, regulates gene expression in response to certain fatty acids and fibric acid derivatives. The present study investigated PPARalpha expression in human ECs and their regulation of vascular cell adhesion molecule-1 (VCAM-1). METHODS AND RESULTS: Immunohistochemistry revealed that human carotid artery ECs express PPARalpha. Pretreatment of cultured human ECs with the PPARalpha activators fenofibrate or WY14643 inhibited TNF-alpha-induced VCAM-1 in a time- and concentration-dependent manner, an effect not seen with PPARgamma activators. Both PPARalpha activators decreased cytokine-induced VCAM-1 mRNA expression without altering its mRNA half-life. Transient transfection of deletional VCAM-1 promoter constructs and electrophoretic mobility shift assays suggest that fenofibrate inhibits VCAM-1 transcription in part by inhibiting NF-kappaB. Finally, PPARalpha activators significantly reduced adhesion of U937 cells to cultured human ECs. CONCLUSIONS: Human ECs express PPARalpha, a potentially important regulator of atherogenesis through its transcriptional control of VCAM-1 gene expression. Such findings also have implications regarding the clinical use of lipid-lowering agents, like fibric acids, which can activate PPARalpha. (+info)
Probucol improves symptoms and reduces lipoprotein oxidation susceptibility in patients with Raynaud's phenomenon.
(28/2109)
OBJECTIVE: Reactive oxygen species have been implicated in the pathogenesis of inflammatory and vascular disease. We have undertaken a controlled trial to evaluate probucol, a synthetic antioxidant, as a potential therapy for Raynaud's phenomenon. METHODS: The study cohort included patients with systemic sclerosis (SSc; n = 20), primary Raynaud's phenomenon (n = 15) or 'autoimmune Raynaud's' (n = 5). Patients were allocated to receive either probucol (500 mg daily) or nifedipine (20 mg daily) for 12 weeks. Clinical and biochemical variables at baseline were compared with those at completion of treatment. Evaluation included assessment of Raynaud's attack frequency and severity by visual analogue scale, measurement of low-density lipoprotein (LDL) oxidation lag time, and plasma concentrations of cholesterol, triglyceride, vitamin E and vitamin C. RESULTS: There was a significant reduction of both the frequency and severity of Raynaud's attacks in the patients who received probucol, but not in the control group. LDL oxidation lag time, reflecting in vitro susceptibility to oxidation, was also increased by probucol therapy and serum cholesterol levels were significantly reduced. Similar changes were observed in both SSc- and non-SSc-associated Raynaud's cases. CONCLUSION: These data suggest that probucol may be useful for the symptomatic treatment of Raynaud's phenomenon and also reduces LDL oxidation susceptibility. Since oxidized lipoproteins may mediate vascular damage in SSc, the use of probucol could have additional disease-modifying benefits. Based upon the results of this pilot study, further evaluation of this novel form of therapy is warranted. (+info)
Modification of chitosan to improve its hypocholesterolemic capacity.
(29/2109)
Cholestyramine is the most widely used bile acid sequestrant in the treatment of hypercholesterolemia. However, cholestyramine has unpleasant side effects as a consequence of its hydrophobic backbone. Therefore, high-capacity bile acid sequestering biopolymers with cationic chitosan derivatives were developed, because electrostatic interactions are important for binding with bile acid anions. Dialkylaminoalkylation and reductive amination of chitosan were done to add dialkylaminoalkyl and an additional free amino group at a hydroxyl site in the chitosan backbone respectively and the amino-derivatized chitosan derivatives were quaternized with methyl iodide to produce a cationic polyelectrolyte. The in vitro bile acid binding capacity of the chitosan derivatives in aqueous NaCl was measured by reversed-phase HPLC. The binding capacities of sodium glycocholate (a major bile acid) to chitosan, DEAE-chitosan, quaternized DEAE-chitosan, and cholestyramine were 1.42, 3.12, 4.06, and 2.78 mmol/g resin, respectively. With quaternized DEAE-chitosan, the bile acid binding capacity increased approximately 50% over that of cholestyramine. The bile acid binding capacity of dialkylaminoalkyl chitosan derivatives increased with the number of carbons in the alkyl groups, indicating that hydrophobic interaction is a secondary factor for the sequestration of bile acids. (+info)
Cholesterol reduction rapidly improves endothelial function after acute coronary syndromes. The RECIFE (reduction of cholesterol in ischemia and function of the endothelium) trial.
(30/2109)
BACKGROUND: Cholesterol lowering reduces coronary events. One mechanism could be improvement of endothelial function. In line with this hypothesis, this study investigates whether cholesterol reduction can result in rapid improvement of endothelial function after acute coronary syndromes. METHODS AND RESULTS: Patients with acute myocardial infarction or unstable angina and total cholesterol levels at admission >/=5.2 mmol/L or LDL >/=3.4 mmol/L were randomized to placebo (n=30) or pravastatin 40 mg daily (n=30) for 6 weeks. Brachial ultrasound was used to measure endothelium-dependent flow-mediated dilatation (FMD) and response to endothelium-independent nitroglycerin. Changes in the levels of markers of platelet activation, coagulation factors, and plasma endothelin levels were also assessed. Total and LDL cholesterol levels were similar at admission and before randomization in both groups. With pravastatin, but not with placebo, they decreased by 23% (P<0.05) and 33% (P<0.01), respectively. FMD was unchanged with placebo, 5.43+/-0.74% (mean+/-SEM) to 5.84+/-0.81%, but increased with pravastatin, 4.93+/-0.81% to 7.0+/-0.79% (P=0.02), representing a 42% relative increase. Responses to nitroglycerin were similar during the time course of the study in the 2 groups. Markers of platelet activity, coagulation factors, and endothelin levels were not affected by pravastatin. CONCLUSIONS: Cholesterol reduction with pravastatin initiated early after acute coronary syndromes rapidly improves endothelial function after 6 weeks of therapy. (+info)
Aggressive cholesterol lowering delays saphenous vein graft atherosclerosis in women, the elderly, and patients with associated risk factors. NHLBI post coronary artery bypass graft clinical trial. Post CABG Trial Investigators.
(31/2109)
BACKGROUND: The NHLBI Post Coronary Artery Bypass Graft trial (Post CABG) showed that aggressive compared with moderate lowering of low-density lipoprotein-cholesterol (LDL-C) decreased obstructive changes in saphenous vein grafts (SVGs) by 31%.1 Using lovastatin and cholestyramine when necessary, the annually determined mean LDL-C level ranged from 93 to 97 mg/dL in aggressively treated patients and from 132 to 136 mg/dL in the others (P<0.001). METHODS AND RESULTS: The present study evaluated the treatment effect in subgroups defined by age, gender, and selected coronary heart disease (CHD) risk factors, ie, smoking, hypertension, diabetes mellitus, high-density lipoprotein cholesterol (HDL-C) <35 mg/dL, and triglyceride serum levels >/=200 mg/dL at baseline. As evidenced by similar odds ratio estimates of progression (lumen diameter decrease >/=0.6 mm) and lack of interactions with treatment, a similar beneficial effect of aggressive lowering was observed in elderly and young patients, in women and men, in patients with and without smoking, hypertension, or diabetes mellitus, and those with and without borderline high-risk triglyceride serum levels. The change in minimum lumen diameter was in the same direction for all subgroup categories, without significant interactions with treatment. CONCLUSIONS: Aggressive LDL-C lowering delays progression of atherosclerosis in SVGs irrespective of gender, age, and certain risk factors for CHD. (+info)
Discontinuation rates of cholesterol-lowering medications: implications for primary care.
(32/2109)
OBJECTIVE: To evaluate long-term continuation rates for cholesterol-lowering therapy (niacin, sequestrants, statins) in a multidisciplinary lipid clinic and to evaluate the effectiveness of 2 different dosing strategies designed to improve long-term continuation of therapy. STUDY DESIGN: An observational study was done at the Milwaukee Department of Veterans Affairs Medical Center Lipid Clinic, where healthcare personnel were trained to improve patient tolerance to cholesterol-lowering medications. Primary outcomes were recorded prospectively. PATIENTS AND METHODS: Patients were 970 consecutive veterans who began therapy with niacin, sequestrants, or statins between March 1988 and December 1995. In 1992, two different dosing strategies were initiated to reduce the discontinuation rates for niacin and sequestrants: (1) the niacin titration schedule was lengthened from 3 to 6 weeks and (2) the initial sequestrant dose was reduced from four to two scoops daily. RESULTS: Discontinuation rates for niacin and sequestrants were both very high. For niacin, 48% and 71% of all patients who began therapy discontinued the drug by 1 and 4 years, respectively. For sequestrants, drug discontinuation rates were 59% and 83% at 1 and 4 years, respectively. On the other hand, statin discontinuation rates at 1 and 4 years were only 10% and 28%, respectively. Neither the longer niacin titration schedule nor the lower sequestrant initiation dose reduced these high discontinuation rates. CONCLUSIONS: Despite initiation of niacin and sequestrant therapy in the setting of a multidisciplinary lipid clinic, drug discontinuation rates were high and were similar to rates observed in primary-care settings. Neither the specialized resources available in a lipid clinic nor protocols designed to improve tolerance to therapy reduced the high drug discontinuation rate. Unless more tolerable niacin and sequestrant formulations become available, reliance on statins as the preferred cholesterol-lowering agents will continue because they have fewer side effects and lower discontinuation rates. (+info)