doi: 10.1161/01.CIR.0000066314.93922.59
(Circulation. 2003;107:e9016.)
© 2003 American Heart Association, Inc.
Cardiovascular News
Circulation Newswriter
Women With Rheumatoid Arthritis at Increased Risk of Myocardial Infarction
In this latest iteration of the Nurses’ Health Study, a group of researchers from Harvard University School of Public Health, Harvard Medical School, and The Brigham and Women’s Hospital in Boston, Mass, prospectively studied a cohort of 114 341 women and determined that women with rheumatoid arthritis were at increased risk of myocardial infarction but not stroke. The report appears in this week’s issue of Circulation (Circulation. 2003;107:1303–1307).
A total of 527 new cases of rheumatoid arthritis and 3622 myocardial infarctions and strokes were found among the cohort. The adjusted relative risk of heart attack among women with rheumatoid arthritis compared with those without was 2.00. The adjusted relative risk of stroke was 1.48.
Among women who had had rheumatoid arthritis for at least 10 years, the myocardial infarction risk was 2.10. The authors, led by Daniel Solomon, MD, MPH, of The Brigham and Women’s Hospital, noted: "If these data are confirmed, aggressive coronary heart disease prevention strategies should be tested for persons with rheumatoid arthritis."
Mutation at Fault in Inherited Human Dilated Cardiomyopathy Identified
An international team of researchers reported on the identification of a mutation in a protein called phospholamban that results in disruption of the heart’s calcium regulation and an inherited form of dilated cardiomyopathy. The report appears in the February 28, 2003, issue of Science (Science. 299:1410–1414).
The researchers from Harvard Medical School, Howard Hughes Medical Institute, and The Brigham and Women’s Hospital, in Boston, Mass, the University of Toronto, Canada, and the University of Cincinnati, Ohio, said they hoped that the finding could lead to targeted treatment for dilated cardiomyopathy. They hope that the finding, although found in a rare inherited form of the problem, may be beneficial in other forms of heart failure that affect an estimated 4.7 million US residents each year.
Dilated cardiomyopathy indicates that the left ventricle is stretched, a factor that reduces the ability of the heart to pump. It causes early death.
"Before our work, it was thought that calcium dysregulation might be involved in dilated cardiomyopathy, but it was uncertain whether this was contributing to myocyte dysfunction (ie, an inciting event) or a secondary consequence, and that is a big difference, said Christine E. Seidman, MD, and Jonathan Seidman, PhD, both professors at Harvard and Howard Hughes Medical Institute investigators who were senior authors on the report.
The researchers found that phospholamban is a key regulator molecule in the reuptake of calcium, an important factor in the contract-relax mechanism of the heart. Dr Seidman and her colleagues found a subtle mutation in the DNA sequence of the gene for phospholamban in people who had inherited dilated cardiomyopathy.
Joachim Schmitt, MD, a fellow in the Seidman laboratory, created a transgenic mouse with the phospholamban defect. "Substituting only one amino acid in the phospholamban produced profound changes in cardiac function, causing a premature death of the mice with evidence of heart failure that recapitulates what we saw in our human families," said Dr Christine Seidman.
"We’ve shown a clear link between the genetic mutation of a protein called phospholamban and the disruption of calcium regulation in the heart," says David MacLennan, PhD, a professor at the University of Toronto who was also a co-author of the report. "Scientists at [the University of Toronto] and elsewhere have learned how this process functioned in mice but this is the first time we’ve seen the same mechanism in people."
Dr MacLennan and postdoctoral fellow Michio Asahi, PhD, in his laboratory, used biochemical approaches to find that genetic mutations of phospholamban chronically inhibited the calcium pump, which led to dilated cardiomyopathy and heart failure.
"This phospholamban gene mutation is quite rare, accounting for less than one per cent of dilated cardiomyopathy," said Dr MacLennan. "But it can be deadly, striking people in their teens and 20s. While we’ve known that phospholamban mutations can cause dilated cardiomyopathy in mice, this is the first study showing that this mutation can cause dilated cardiomyopathy in humans."
Poll Shows Americans Worried About Insurance Costs
Officials of the Kaiser Family Foundation were surprised to find in a recent poll that Americans are more worried about the costs of healthcare than they are about losing their jobs, paying rent or mortgage, losing money on the stock market, or becoming terrorist victims.
In their poll released February 28, 2003, the foundation’s officials found that nearly 4 of 10, or 37% of Americans, said they are very worried that they will face increased costs of healthcare services or health insurance over the next 6 months. A similar percentage is worried that their incomes will not keep pace with rising healthcare costs in the next half years.
By comparison, only 22% said they were worried about losing money in the stock market, and 19% said they were concerned about their ability to pay rent or make mortgage payments. In addition, 19% said they were worried about being victimized by terrorism and 15% said they were concerned about losing their jobs.
More than 1 in 4 Americans (26%) said they were concerned that they might not be able to afford prescription drugs that would be needed in the next 6 months. One in 5 (18%) were concerned that they would lose their health insurance coverage.
The Kaiser Family Foundation noted that they interpreted the data to show that Americans are not more concerned about healthcare costs than they are about the economy. However, the healthcare costs are in the forefront of their economic worries.
The results can be found at http://www.kff.org/healthpollreport/templates/detail.php?page=9&feature=hsw.
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