Heart disease in African Americans often has been assumed to be associated with socio-economic conditions, but a new study suggests a prominent genetic factor as perhaps an even more significant culprit. Appearing in a recent issue of the journal Science, the study indicates the large presence of a gene variant called Y1102 in black Americans suffering cardiac arrhythmias, and that the variant increases by eight-fold the risk of such an arrhythmia. Overall, the study estimates 13% of African Americans have the gene variant.

The conclusion comes from the researchers' screening of DNA specimens looking for forms of the SCN5A gene, thought to have a key role in regulating the heartbeat, and they then found the large incidence of the variation in those specimens taken from blacks. By contrast, the variant did not appear in the screenings of white and Asian patients, and it was found in only one of 123 specimens from Hispanics.

Mark Keating, MD, a researcher at Children's Hospital and Harvard Medical School (both Boston, Massachusetts) and lead author of the study, said that the variant alone probably does not create the arrhythmia but appears to interact with other risk factors such as variations in blood electrolytes, which in turn have a key role in controlling heart rhythms. Keating theorized that the discovery of the variant provides a new path for diagnosing and managing heart disease in this population, especially in combination with other findings, such as electrolyte imbalances. And it suggests the key role being played by findings evolving out of the human genome project.

In another report related to this minority patient group, the Association of Black Cardiologists (ABC; Atlanta, Georgia) last month announced its support of the African American Heart Failure Trial (A-HeFT), described as the first study designed to examine the ability of the drug BiDil to extend the lives and improve the quality of life of black heart patients. BiDil is a nitric oxide-enhanced drug produced by NitroMed (Bedford, Massachusetts), and the trial is being conducted as a partnership between NitroMed and Humana (Louisville, Kentucky).

The trial will enroll about 600 black men and women with New York Heart Association heart failure function classifications III-IV and a reduced ejection fraction. It is a double blind, placebo-controlled study, with participants receiving BiDil in addition to their regular medication, and they are then being evaluated every three months to assess heart function and quality of life measurements. Another focus of the trial partnership is the economic barrier to participation in clinical trials and the fact that these expenses are not traditionally reimbursed by medical insurance. Thus, Humana and NitroMed said that they are partnering in the effort as a response to he national coverage determination directive which encourages expanded access to clinical trials and allows Medicare to cover the expenses.

B. Waine Kong, PhD, chief executive officer of the ABC, said that improving access to trials such as A-HeFT "will be an important factor in improving health outcomes in minority populations." The Association of Black Cardiologists was founded in 1974 to focus on the critical impact of heart disease on African Americans and to support the improvement of cardiac awareness and access to care for this population.

Report sees cardiovascular gender gap

The fact that heart disease hits women with greater impact than men may be the product of a gender gap, according to research released last month at the annual meeting of the American Psychological Association. Charles Emery, PhD, of Ohio State University (Columbus, Ohio), reported on research indicating a lower quality of life for women with heart disease as compared to men, "regardless of cardiac diagnosis, age, race or cardiac risk profile."

Using a questionnaire method, Emery and his team tracked emotional content, stress and physical activity over a one-year period in a group of 410 patients averaging nearly 60 years of age. Additionally, the questionnaires attempted to assess each person's perception of the amount of support they received from friends and family members. Overall, women tested lower than men in terms of mental and physical quality of life and they reported a lower level of social support. The researchers theorized that one key to the difference was the heavier pressures put on women by gender roles.

"Women are returning to a home environment and a work environment where their demands haven't changed that much," Emery said. He recommended the development of new techniques for supporting women with heart disease in order to improve the quality of their lives.

LIPS supports fluvastatin effectiveness

Results of the landmark Lescol Intervention Prevention Study (LIPS) reported in the Journal of the American Medical Association (JAMA) earlier this summer demonstrate that cholesterol-lowering medication fluvastatin reduced the risk of fatal and serious nonfatal cardiac events by 22% in patients with average cholesterol levels after undergoing a first angioplasty. "LIPS identified a new treatment strategy for patients undergoing percutaneous coronary intervention (PCI) procedures, such as an angioplasty, to open blocked coronary arteries," said Patrick Serruys, MD, PhD, professor of interventional cardiology at Erasmus Medical Center of University Hospital (Rotterdam, the Netherlands) and LIPS' principal investigator. "The results clearly support the early use of lipid-lowering therapy fluvastatin in these patients, regardless of their cholesterol levels, to help prevent future cardiac events, including heart attacks and bypass surgery."

The study demonstrated that early treatment with fluvastatin post-PCI would be both cost-effective and socially beneficial by preventing one fatal or non-fatal major adverse cardiac event in every 19 people treated for four years. The fact that the study population had a mean LDL cholesterol level of 132 – within the upper end of the normal range – suggests that the decision to begin statin therapy should be based on an overall risk assessment of a patient and not just baseline cholesterol levels, he said.

The four-year study followed 1,677 patients recruited from 57 centers in 10 countries. Major adverse cardiac events were defined as cardiac death, nonfatal heart attack, coronary artery bypass grafting, or repeat PCI. LIPS also yielded important long-term safety data in this high-risk population. There were no significant elevations of creatine phosphokinase (CPK), a possible side effect of cholesterol-lowering statin therapies and an indication of muscle breakdown. Serruys noted that fluvastatin was used in this study "because of its established safety profile and pleiotropic effects." Novartis Pharma AG (Basel, Switzerland), manufacturer of fluvastatin, sponsored the study.