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Vitamin E Use in Preventing Coronary Heart Disease in Patients Undergoing Dialysis
Mayo Clin Proc, March 2002, Vol 77
Letters to the Editor
295
Letters to the Editor Vitamin E Use in Preventing Coronary Heart Disease in Patients Undergoing Dialysis
antioxidant therapy, whereas treatment with simvastatin resulted in a clear benefit in all subgroups. Although both the HATS and the HPS involved combinations of antioxidants, the negative results make it unlikely that similar doses of vitamin E administered separately would be beneficial. As outlined in our review and the aforementioned studies, there is little evidence that vitamin E is protective against CHD in the general population. Very high-risk groups, such as patients receiving hemodialysis, may respond differently to vitamin E supplementation. Further studies are needed to confirm or refute the findings of the SPACE study.
To the Editor: The review of vitamin E supplementation for prevention of coronary heart disease by Pruthi et al1 neglected an important study. The Secondary Prevention With Antioxidants of Cardiovascular Disease in Endstage Renal Disease (SPACE) trial showed a statistically and clinically significant benefit of vitamin E supplementation for secondary prevention of myocardial infarction in patients receiving hemodialysis.2 The discrepancy between these results and those of other trials discussed in their review may be due to the high dose of vitamin E used (800 IU/d), as well as the SPACE cohort’s high incidence of events and the relatively greater role oxidative stress may play in atherogenesis in patients receiving dialysis.
Donald D. Hensrud, MD, MPH Sandhya Pruthi, MD Thomas G. Allison, PhD, MPH Mayo Clinic Rochester, Minn
Jeffrey Rein, MD El Rio Health Center Tucson, Ariz 1.
2.
1.
Pruthi S, Allison TG, Hensrud DD. Vitamin E supplementation in the prevention of coronary heart disease. Mayo Clin Proc. 2001;76: 1131-1136. Boaz M, Smetana S, Weinstein T, et al. Secondary prevention with antioxidants of cardiovascular disease in endstage renal disease (SPACE): randomised placebo-controlled trial. Lancet. 2000;356: 1213-1218.
2.
Brown BG, Zhao X-Q, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med. 2001;345:1583-1592. Cheung MC, Zhao XQ, Chait A, Albers JJ, Brown BG. Antioxidant supplements block the response of HDL to simvastatin-niacin therapy in patients with coronary artery disease and low HDL. Arterioscler Thromb Vasc Biol. 2001;21:1320-1326.
Treatment of Diastolic Heart Failure In reply: We agree with Dr Rein that vitamin E appeared to benefit patients receiving hemodialysis in the SPACE study, which used a primary end point of combined nonfatal and fatal myocardial infarction, ischemic stroke, peripheral vascular disease, and unstable angina. If this study is replicated, vitamin E may provide an important adjunctive treatment in this high-risk group. Our review focused on the effect of vitamin E in the primary and secondary prevention of coronary heart disease (CHD) in the general population. Recent studies have lent further support to our conclusions. In the HDL-Atherosclerosis Study (HATS) 160 patients with coronary artery disease were randomized to receive simvastatin and niacin; an antioxidant combination of 800 IU of vitamin E, 1000 mg of vitamin C, 25 mg of natural beta carotene, and 100 µg of selenium; simvastatin, niacin, and antioxidants; or placebo. The antioxidants did not significantly reduce either the incidence of cardiovascular events or coronary artery stenosis as measured angiographically.1 In fact, the protective effect of simvastatin and niacin on highdensity lipoprotein cholesterol was attenuated by antioxidant therapy.2 Preliminary results of the Heart Protection Study (HPS) were discussed at the American Heart Association meeting in November 2001. In this study 20,000 people at high risk for CHD were randomized to receive simvastatin, antioxidants (600 mg of vitamin E, 250 mg of vitamin C, and 20 mg of beta carotene), both, or placebo. No benefit was observed from Mayo Clin Proc. 2002;77:295-298
To the Editor: In their article on diastolic heart failure, a perplexing, costly, and highly prevalent entity, Drs Elesber and Redfield1 recommend avoiding use of digoxin, whereas other authors2,3 have supported the role of digoxin among other agents to alleviate symptoms of heart failure and reduce the need for hospitalization. Although data are scarce, in the Digitalis Investigation Group ancillary trial4 comprising 492 patients taking digoxin and 496 taking placebo (ejection fraction >45%), rate of hospitalization was reduced in the digoxin group. Sumer K. Dhir, MD Indiana University School of Medicine Indianapolis 1. 2. 3.
4.
Elesber AA, Redfield MM. Approach to patients with heart failure and normal ejection fraction. Mayo Clin Proc. 2001;76:1047-1052. Kitzman DW. Diastolic dysfunction in the elderly: genesis and diagnostic and therapeutic implications. Cardiol Clin. 2000;18:597-617. Dauterman KW, Massie BM, Gheorghiade M. Heart failure associated with preserved systolic function: a common and costly clinical entity. Am Heart J. 1998;135(6, pt 2 Su):S310-S319. Digitalis Investigation Group. The effect of digoxin on mortality and morbidity in patients with heart failure. N Engl J Med. 1997;336: 525-533.
In reply: We thank Dr Dhir for his comments regarding the use of digoxin in the treatment of diastolic heart failure. We did 295
© 2002 Mayo Foundation for Medical Education and Research
For personal use. Mass reproduce only with permission from Mayo Clinic Proceedings.
Letters to the Editor
295
Letters to the Editor Vitamin E Use in Preventing Coronary Heart Disease in Patients Undergoing Dialysis
antioxidant therapy, whereas treatment with simvastatin resulted in a clear benefit in all subgroups. Although both the HATS and the HPS involved combinations of antioxidants, the negative results make it unlikely that similar doses of vitamin E administered separately would be beneficial. As outlined in our review and the aforementioned studies, there is little evidence that vitamin E is protective against CHD in the general population. Very high-risk groups, such as patients receiving hemodialysis, may respond differently to vitamin E supplementation. Further studies are needed to confirm or refute the findings of the SPACE study.
To the Editor: The review of vitamin E supplementation for prevention of coronary heart disease by Pruthi et al1 neglected an important study. The Secondary Prevention With Antioxidants of Cardiovascular Disease in Endstage Renal Disease (SPACE) trial showed a statistically and clinically significant benefit of vitamin E supplementation for secondary prevention of myocardial infarction in patients receiving hemodialysis.2 The discrepancy between these results and those of other trials discussed in their review may be due to the high dose of vitamin E used (800 IU/d), as well as the SPACE cohort’s high incidence of events and the relatively greater role oxidative stress may play in atherogenesis in patients receiving dialysis.
Donald D. Hensrud, MD, MPH Sandhya Pruthi, MD Thomas G. Allison, PhD, MPH Mayo Clinic Rochester, Minn
Jeffrey Rein, MD El Rio Health Center Tucson, Ariz 1.
2.
1.
Pruthi S, Allison TG, Hensrud DD. Vitamin E supplementation in the prevention of coronary heart disease. Mayo Clin Proc. 2001;76: 1131-1136. Boaz M, Smetana S, Weinstein T, et al. Secondary prevention with antioxidants of cardiovascular disease in endstage renal disease (SPACE): randomised placebo-controlled trial. Lancet. 2000;356: 1213-1218.
2.
Brown BG, Zhao X-Q, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med. 2001;345:1583-1592. Cheung MC, Zhao XQ, Chait A, Albers JJ, Brown BG. Antioxidant supplements block the response of HDL to simvastatin-niacin therapy in patients with coronary artery disease and low HDL. Arterioscler Thromb Vasc Biol. 2001;21:1320-1326.
Treatment of Diastolic Heart Failure In reply: We agree with Dr Rein that vitamin E appeared to benefit patients receiving hemodialysis in the SPACE study, which used a primary end point of combined nonfatal and fatal myocardial infarction, ischemic stroke, peripheral vascular disease, and unstable angina. If this study is replicated, vitamin E may provide an important adjunctive treatment in this high-risk group. Our review focused on the effect of vitamin E in the primary and secondary prevention of coronary heart disease (CHD) in the general population. Recent studies have lent further support to our conclusions. In the HDL-Atherosclerosis Study (HATS) 160 patients with coronary artery disease were randomized to receive simvastatin and niacin; an antioxidant combination of 800 IU of vitamin E, 1000 mg of vitamin C, 25 mg of natural beta carotene, and 100 µg of selenium; simvastatin, niacin, and antioxidants; or placebo. The antioxidants did not significantly reduce either the incidence of cardiovascular events or coronary artery stenosis as measured angiographically.1 In fact, the protective effect of simvastatin and niacin on highdensity lipoprotein cholesterol was attenuated by antioxidant therapy.2 Preliminary results of the Heart Protection Study (HPS) were discussed at the American Heart Association meeting in November 2001. In this study 20,000 people at high risk for CHD were randomized to receive simvastatin, antioxidants (600 mg of vitamin E, 250 mg of vitamin C, and 20 mg of beta carotene), both, or placebo. No benefit was observed from Mayo Clin Proc. 2002;77:295-298
To the Editor: In their article on diastolic heart failure, a perplexing, costly, and highly prevalent entity, Drs Elesber and Redfield1 recommend avoiding use of digoxin, whereas other authors2,3 have supported the role of digoxin among other agents to alleviate symptoms of heart failure and reduce the need for hospitalization. Although data are scarce, in the Digitalis Investigation Group ancillary trial4 comprising 492 patients taking digoxin and 496 taking placebo (ejection fraction >45%), rate of hospitalization was reduced in the digoxin group. Sumer K. Dhir, MD Indiana University School of Medicine Indianapolis 1. 2. 3.
4.
Elesber AA, Redfield MM. Approach to patients with heart failure and normal ejection fraction. Mayo Clin Proc. 2001;76:1047-1052. Kitzman DW. Diastolic dysfunction in the elderly: genesis and diagnostic and therapeutic implications. Cardiol Clin. 2000;18:597-617. Dauterman KW, Massie BM, Gheorghiade M. Heart failure associated with preserved systolic function: a common and costly clinical entity. Am Heart J. 1998;135(6, pt 2 Su):S310-S319. Digitalis Investigation Group. The effect of digoxin on mortality and morbidity in patients with heart failure. N Engl J Med. 1997;336: 525-533.
In reply: We thank Dr Dhir for his comments regarding the use of digoxin in the treatment of diastolic heart failure. We did 295
© 2002 Mayo Foundation for Medical Education and Research
For personal use. Mass reproduce only with permission from Mayo Clinic Proceedings.