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Beinart R, Zhang Y, Lima JAC, Bluemke DA, Soliman EZ, Heckbert SR, Post WS, Guallar E, Nazarian S. The QT interval is associated with incident cardiovascular events: the MESA study. J Am Coll Cardiol 2014; 64:2111-9. [PMID: 25457400 DOI: 10.1016/j.jacc.2014.08.039] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Accepted: 08/06/2014] [Indexed: 11/25/2022]
Abstract
BACKGROUND Prolonged heart rate-corrected QT interval on electrocardiograms (ECGs) is associated with increased risk of myocardial infarction and cardiovascular disease (CVD)-related deaths in patients with prevalent coronary heart disease. OBJECTIVES This study sought to examine the prognostic association between the baseline QT interval and incident cardiovascular events in individuals without prior known CVD. METHODS The corrected baseline 12-lead ECG QT interval duration (QTcorr) was determined by adjustment for age, sex, race/ethnicity, and RR interval duration in 6,273 participants in MESA (Multi-Ethnic Study of Atherosclerosis). Cox proportional hazards models adjusting for demographic and clinical risk factors were used to examine the association of baseline QTcorr with incident cardiovascular events. RESULTS The mean age at enrollment was 61.7 ± 10 years, and 53.4% of participants were women. Cardiovascular events occurred in 291 participants over a mean follow-up of 8.0 ± 1.7 years. Each 10-ms increase in the baseline QTcorr was associated with incident heart failure (hazard ratio [HR]: 1.25; 95% CI: 1.14 to 1.37), CVD events (HR: 1.12; 95% CI: 1.05 to 1.20), and stroke (HR: 1.19; 95% CI: 1.07 to 1.32) after adjustment for CVD risk factors and potential confounders. There was no evidence of interaction with sex or ethnicity. CONCLUSIONS The QT interval was associated with incident cardiovascular events in middle-aged and older adults without prior CVD.
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Affiliation(s)
- Roy Beinart
- Division of Cardiology, Johns Hopkins University, Baltimore, Maryland; Leviev Heart Center, Sheba Medical Center, Tel Aviv University, Tel Aviv, Israel
| | - Yiyi Zhang
- Department of Epidemiology, Johns Hopkins University, Baltimore, Maryland
| | - João A C Lima
- Division of Cardiology, Johns Hopkins University, Baltimore, Maryland
| | - David A Bluemke
- Radiology and Imaging Sciences, National Institutes of Health, Bethesda, Maryland
| | - Elsayed Z Soliman
- Epidemiological Cardiology Research Center, Department of Epidemiology and Prevention and Department of Internal Medicine, Cardiology Section, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Susan R Heckbert
- Cardiovascular Health Research Unit and Department of Epidemiology, University of Washington, Seattle, Washington
| | - Wendy S Post
- Division of Cardiology, Johns Hopkins University, Baltimore, Maryland
| | - Eliseo Guallar
- Department of Epidemiology, Johns Hopkins University, Baltimore, Maryland
| | - Saman Nazarian
- Division of Cardiology, Johns Hopkins University, Baltimore, Maryland; Department of Epidemiology, Johns Hopkins University, Baltimore, Maryland.
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Freis ED. Current status of diuretics, beta-blockers, alpha-blockers, and alpha-beta-blockers in the treatment of hypertension. Med Clin North Am 1997; 81:1305-17. [PMID: 9356600 DOI: 10.1016/s0025-7125(05)70584-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The article describes the current status of four main antihypertensives. Diuretics are making a bit of a comeback after seeing their popularity wane during the 1980s. beta-blockers also saw a bit of a popularity decrease in the 1980s due to some adverse side effects which the author feels were somewhat exaggerated. alpha-blockers have yet to be particularly successful in the treatment of hypertension, due to adverse side effects. alpha-beta-blockers appear to hold significant promise in the further treatment of hypertension.
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Affiliation(s)
- E D Freis
- Department of Veterans Affairs Medical Center, Washington, DC, USA
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3
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Kaplan JR, Manuck SB. Antiatherogenic effects of beta-adrenergic blocking agents: theoretical, experimental, and epidemiologic considerations. Am Heart J 1994; 128:1316-28. [PMID: 7977013 DOI: 10.1016/0002-8703(94)90254-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Theoretical considerations and results from experimental studies in animal models suggest that long-term beta-adrenergic blockade should be antiatherogenic. Some of these experimental results indicate that beta-blockers could inhibit atherogenesis and thus prevent clinical events independently of any effects on blood pressure through concomitant reductions in heart rate, blood velocity and energy, endothelial permeability to lipoproteins, and the likelihood of plaque rupture. Any such independent inhibition of atherogenesis implies, in turn, that beta-blockers might be more desirable than alternative antihypertensive therapies in persons at high risk for atherosclerotic diseases. Results of the three major trials directly comparing beta-blockers to diuretics in the primary prevention of coronary heart disease among patients with hypertension were largely inconclusive. However, ancillary data from these and other trials are consistent in demonstrating that beta-adrenergic blockade is associated with anti-coronary heart disease effects and, thus, is perhaps antiatherogenic. A definitive evaluation of the antiatherogenic effects of beta-blockers is not forthcoming because no large clinical trials directly assessing the effect of these drugs on atherosclerosis have been done or are planned.
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Affiliation(s)
- J R Kaplan
- Department of Comparative Medicine, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, NC 27157-1040
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Sun YP, Zhu BQ, Sievers RE, Glantz SA, Parmley WW. Metoprolol does not attenuate atherosclerosis in lipid-fed rabbits exposed to environmental tobacco smoke. Circulation 1994; 89:2260-5. [PMID: 8181151 DOI: 10.1161/01.cir.89.5.2260] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
BACKGROUND We previously demonstrated that exposure to environmental tobacco smoke (ETS) increases the development of atherosclerosis in lipid-fed rabbits. Clinical studies have suggested a protective effect of beta-blockers in smokers. Accordingly, we evaluated the effects of metoprolol in this animal model to see whether this beta-blocker would block the atherogenic effects of ETS. METHODS AND RESULTS Thirty-two New Zealand White male rabbits on a 0.3% cholesterol diet were randomly divided into four groups: ETS-metoprolol (ETS-M), ETS-control (ETS-C), and non-ETS with metoprolol (NETS-M) and without metoprolol (NETS-C). The two metoprolol-treated groups received metoprolol at a dose of 0.4 mg.kg-1.h-1 administered subcutaneously by an osmotic pump. Rabbits in the ETS groups were exposed to sidestream smoke from four Marlboro cigarettes per 15 minutes, 6 hours a day, for 10 weeks. Average air carbon monoxide (CO), nicotine, and total particulates (TP) in the exposure chambers were 67.2 +/- 3.1 (SEM) ppm, 1133.7 +/- 78.4 micrograms/m3, and 37.7 +/- 3.0 mg/m3, respectively. Plasma nicotine was significantly higher in ETS-exposed rabbits than in nonexposed rabbits (7.1 +/- 1.9 versus 0.5 +/- 0.1 ng/mL, P < .01). Blood carbon monoxide hemoglobin (COHb) in the ETS-M group was significantly higher than that in the NETS-M group (4.0 +/- 0.2% versus 1.3 +/- 0.1%, P < .0001). The lipid lesions in the aorta and pulmonary artery were 57.2 +/- 7.6% and 33.1 +/- 6.4% (ETS-M), 62.8 +/- 8.4% and 58.4 +/- 6.1% (ETS-C), 38.7 +/- 9.4% and 24.8 +/- 7.7% (NETS-M), and 49.8 +/- 8.7% and 32.7 +/- 7.1% (NETS-C). There were significant differences in lipid deposits of the arteries between the controls and the ETS-exposed rabbits (37 +/- 1% versus 53 +/- 1%, P = .004) and between the controls and metoprolol-treated rabbits (51 +/- 1% versus 38 +/- 1%, P = .027). The benefit of metoprolol was independent of ETS exposure (ETS x metoprolol interaction, P = .595). CONCLUSIONS Exposure to ETS significantly accelerated and metoprolol decreased the development of atherosclerosis in lipid-fed rabbits, but there was no interaction between the effects of ETS exposure and metoprolol. Metoprolol did not protect against the effects of ETS on atherosclerosis, suggesting that the beta-adrenergic system is not the mechanism of ETS-induced atherosclerosis.
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Affiliation(s)
- Y P Sun
- Department of Medicine, University of California, San Francisco 94143-0124
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5
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Swindell AC, Krupp MN, Twomey TM, Reynolds JA, Chichester CO. Effects of doxazosin on atherosclerosis in cholesterol-fed rabbits. Atherosclerosis 1993; 99:195-206. [PMID: 8503948 DOI: 10.1016/0021-9150(93)90022-m] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Doxazosin was administered to rabbits fed diets enriched in cholesterol and peanut oil for 7.5 or 12 weeks, in 2 separate experiments. Doxazosin suppressed the accumulation of cholesterol and formation of atherosclerotic plaques in the aortas of treated rabbits and prevented a diet-induced increase in aortic collagen and wall mass. Doxazosin was more effective in the thoracic and abdominal segments of the aorta than in the aortic arch. Pharmacokinetic analysis indicated that treated rabbits were exposed to concentrations of doxazosin, integrated over 24 h, which were consistent with the therapeutic range of doxazosin measured in patients treated for hypertension. Doxazosin did not alter serum levels of cholesterol or triglycerides, nor were there any consistent effects on glucose, free fatty acid or ketone levels. Hypotheses of the mechanism of action of doxazosin are discussed, including the possible involvement of alpha 1-adrenergic receptors in recruitment of smooth muscle cells by subintimal macrophages and nonadrenergic mechanisms of inhibition of lipid infiltration.
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Affiliation(s)
- A C Swindell
- Central Research Division, Pfizer Inc, Groton, CT 06340
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Andrianova IV, Rekhter MD, Tertov VV, Andreeva ER, Mironov AA, Orekhov AN. Papaverine abolishes the atherogenic effect of the beta-blocker propranolol. Bull Exp Biol Med 1992. [DOI: 10.1007/bf00783112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Plosker GL, Clissold SP. Controlled release metoprolol formulations. A review of their pharmacodynamic and pharmacokinetic properties, and therapeutic use in hypertension and ischaemic heart disease. Drugs 1992; 43:382-414. [PMID: 1374320 DOI: 10.2165/00003495-199243030-00006] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Conventional formulations of metoprolol have become well established in cardiovascular medicine and are particularly useful in the management of hypertension and ischaemic heart disease. Recently developed controlled release metoprolol delivery systems (metoprolol CR/ZOK and metoprolol OROS) were designed to overcome the drug delivery problems of matrix-based sustained release forms by releasing the drug at a relatively constant rate over a 24-hour period, and thus producing sustained and consistent metoprolol plasma concentrations and beta 1-blockade while retaining the convenience of once daily administration. Clinically and statistically significant reductions in blood pressure have been observed with metoprolol CR/ZOK and metoprolol OROS 24 hours after administration in mildly or moderately hypertensive patients. Studies in patients with mild to moderate hypertension have demonstrated that a similar or higher percentage of patients achieved a goal response with metoprolol CR/ZOK compared with matrix-based sustained release formulations of metoprolol, or conventional atenolol or bisoprolol, while metoprolol OROS achieved an equal or greater response rate compared with conventional or matrix-based sustained release metoprolol preparations. In patients with stable effort angina pectoris, once daily administration of metoprolol CR/ZOK provided at least equal antianginal efficacy as conventional metoprolol in divided doses, while metoprolol OROS reduced the mean number of anginal attacks by the same margin as atenolol. Controlled release metoprolol formulations have been well tolerated in clinical trials. Metoprolol CR/ZOK was associated with a similar or lesser degree of adverse effects related to the central nervous system compared with atenolol or long acting propranolol. Metoprolol CR/ZOK also demonstrated less pronounced beta 2-mediated bronchoconstrictor effects than atenolol in asthmatics, and less general fatigue and leg fatigue in healthy subjects. Metoprolol OROS produced less pronounced bronchoconstrictor effects than atenolol, matrix-based sustained release metoprolol or long acting propranolol in patients with asthma or obstructive airways disease, and healthy volunteers. These results are presumably due to the beta 1-selectivity of metoprolol in addition to the relatively low plasma concentrations maintained by metoprolol CR/ZOK and metoprolol OROS, and the avoidance of high peak plasma concentrations with these agents. Despite the relative safety of the controlled release forms of metoprolol, the use of all beta-adrenoceptor antagonists should be avoided in patients with a history of bronchospasm. Thus, controlled release metoprolol formulations offer the potential to maximise the confirmed benefits of this agent in the management of hypertension and angina, by maintaining clinically effective plasma concentrations within a narrow therapeutic range over a 24-hour dose interval.
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Affiliation(s)
- G L Plosker
- Adis International Limited, Auckland, New Zealand
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Andrianova IV, Rekhter MD, Tertov VV, Andreeva ER, Ragimov S�, Mironov AA, Orekhov AN. Atherogenic effect of the beta-blocker propranolol exhibited on the de-endothelized rabbit aorta. Bull Exp Biol Med 1991. [DOI: 10.1007/bf00841481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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9
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Olsson G, Ablad B, Rydén L. Long-term cardiovascular effects of metoprolol therapy: a review article. J Clin Pharmacol 1990; 30:S118-23. [PMID: 2179279 DOI: 10.1002/j.1552-4604.1990.tb03509.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Long-term studies in primary and secondary prevention using metoprolol have showed improvement in prognosis. This review summarizes the clinical results of such studies, and puts these results into the perspective of findings in mechanistic and explanatory studies. Many possible factors may have contributed to explain the beneficial effects on prognosis. The antihypertensive action, cardiac anti-ischemic action, antifibrillatory action, antiatherogenic and antithrombotic actions of metoprolol are discussed. The additive effects of these actions may explain the clinically observed beneficial effects. In the evaluation of a specific intervention, it is important to realize the multiple actions that may contribute, and not only discuss single factors.
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Affiliation(s)
- G Olsson
- Department of Medicine, Karolinska Institutet, Danderyd Hospital, Sweden
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Ostlund-Lindqvist AM, Eklund A, Sjöblom L, Jönsson L. Effect of metoprolol on plasma lipids and arterial intimal lipid deposition in spontaneously hypertensive rats. Atherosclerosis 1989; 80:135-42. [PMID: 2610725 DOI: 10.1016/0021-9150(89)90021-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The purpose of the present study was to characterize possible effects of dietary-induced plasma lipid elevations on the development of arterial lesions in spontaneously hypertensive rats (SHR) and to reveal any influence of treatment with metoprolol on these parameters. Metoprolol treatment caused an 8% decrease in heart rate and a 13% decrease in blood pressure and led to a rise in plasma triglycerides, 24%, 17% and 34% after 1, 3 and 6 months of metoprolol treatment, respectively. However, no effect on plasma triglycerides was observed after 9 months of metoprolol treatment while a reduced cholesterolemic response was observed. Intimal proliferations containing accumulations of lipids were observed in small intramural branches of coronary arteries (greater than 100 microns) in 11 of 31 control rats fed the atherogenic diet for 9 months. In contrast, similar changes were observed in only 1 of 34 metoprolol-treated rats fed an otherwise identical diet. The corresponding figures for the frequency of lipid containing intimal plaques in aorta were 6/19 in controls and 2/24 in the metoprolol-treated group.
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12
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Ablad B, Björkman JA, Gustafsson D, Hansson G, Ostlund-Lindqvist AM, Pettersson K. The role of sympathetic activity in atherogenesis: effects of beta-blockade. Am Heart J 1988; 116:322-7. [PMID: 2899391 DOI: 10.1016/0002-8703(88)90109-3] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Clinical and experimental evidence points to potential antiatherosclerotic effects of certain beta-adrenoreceptor antagonists. Long-term treatment with metoprolol resulted in significant reductions of total and cardiovascular mortality or morbidity due to decreased incidence of coronary and cerebrovascular complications both in a primary prevention trial in hypertensive patients and in a secondary prevention trial in patients surviving myocardial infarction. The observations suggest that a retardation of atherosclerosis development might have contributed to the reduced incidence of cardiovascular complications. An antiatherosclerotic effect of beta-blockers has been directly demonstrated in animal studies. In cholesterol-fed rabbits, metoprolol significantly reduced the development of atherosclerotic plaques in the aortic intima in the absence of any changes in blood lipids. Similar findings were reported for propranolol, which prevented psychosocial stress-induced atherosclerosis of the coronary artery in monkeys. Furthermore, beta-blockers have been shown to prevent stress-induced endothelial injury and platelet accumulation to intima at atherosclerotic predilection sites in animal models. These antiatherogenic effects may be due to biochemical and hemodynamic factors. Two biochemical effects of beta-blockade may lead to reduced cholesterol accumulation in arterial intima at unchanged serum cholesterol levels. One is a beta-blocker-induced increase of prostacyclin biosynthesis, and the other a metabolic change of low-density lipoprotein, reducing its potential for deposition in the arterial wall. The antiatherogenic effect of these factors may be reinforced by beta-blocker-induced hemodynamic changes leading to reductions of arterial flow aberrations and pressure-related wall stress.
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Affiliation(s)
- B Ablad
- Hässle Cardiovascular Research Laboratories, Mölndal, Sweden
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