Presented by: Rajesh Dash, MD, PhD
Assistant Professor, Cardiovascular Medicine
Stanford University Medical Center
September 25, 2014
A healthy 44-year-old Indian man who exercises regularly, has normal cholesterol and blood pressure, and who smokes and drinks only occasionally should not have to worry about a heart attack. On paper, everything looked fine. His doctor found no cause for putting him on statins to lower his cholesterol.
However a family history found that his brother already had a heart attack, his mother had three stents implanted to open her vessels, and three uncles had died from a heart attack before age 60. When the patient agreed to have a coronary CT scan, the results showed that one of the vessels near his heart was almost completely blocked. He received a stent and was put on an aggressive medical regimen.
The question remains: Why him?
The fact is, people from South Asia—India, Pakistan, Bangladesh, Nepal, and Sri Lanka—have a four times greater risk of heart disease than the general population and have a much greater chance of having a heart attack before age 50. Heart attacks strike South Asian men and women at younger ages and are more deadly compared to any other ethnic group: Almost a third dies from heart disease before age 65. In India cardiovascular disease remains the No. 1 cause of death. One study found that South Asians developed heart disease 10 years earlier than other groups,
“South Asian men and women age 20 to 55 are at high risk, show higher mortality rates, and symptoms and risk factors appear to begin earlier,” said Rajesh Dash, MD, PhD, an assistant professor of cardiovascular medicine, who spoke at a presentation sponsored by Stanford Hospital Health Library. “They’re younger, sicker (at first presentation), and dying earlier.”
High Risk Factors
Traditional risk factors like diet and lifestyle are a big part of the problem, he said. South Asians tend to be smokers, and the traditional South Asian diet tends to be high in sugar, refined grains, and fatty foods. Many South Asians appear to be insulin resistant, a pre-diabetic condition in which the body does not process insulin efficiently.
“Insulin-resistant patients have similar rates of cardiovascular events as those with full-blown diabetes,” Dr. Dash said. “Most people are not normally tested for the condition, but it is especially important for South Asians to be tested. If diagnosed, the condition often can be controlled with diet and lifestyle changes.”
Other traditional risk assessments, like body mass index (BMI), appear to be poor predictors for South Asians, who often show a “thin-fat” syndrome where they fall within BMI standards but have more visceral fat—abdominal fat that is more likely to lead to a cardiovascular event. Waist circumference or waist-to-hip ratio may be more predictive measurements for this group, who also should aim for a lower overall BMI.
More than one third of South Asian men and 17 percent of South Asian women have metabolic syndrome, a cluster of conditions such as high blood pressure, high blood sugar levels, excess body fat around the waist, and abnormal cholesterol levels that increase the risk of heart disease, stroke, and diabetes. If more than one of these conditions occur in combination, the risk is even greater. This syndrome is not normally checked during an annual physical exam. South Asians are more likely to have high triglycerides and low HDL (the “good” cholesterol). A variant of HDL known as HDL2b is low in as much as 93 percent of South Asian men and 63 percent of women.
“Despite having a low BMI and low cholesterol, the composition of the cholesterol is abnormal,” said Dr. Dash. “A nontraditional assessment is called for.”
Dr. Dash is the medical and scientific director for the Stanford South Asian Translational Heart Initiative (SSATHI), a new program designed to address the unique concerns of the South Asian population. It combines researchers who are looking at genetic and metabolic factors with clinicians who are treating patients and refining screenings for risk.
“Our target is younger people so that we have the opportunity to address and treat symptoms and risks before they develop into cardiovascular disease,” he said. “Our mission is to reduce the incidence of cardiovascular disease through aggressive screening, aggressive treatment, expedited appointments, and long-term follow-up in management and risk reduction. The disease is more aggressive, so we have to treat it that way.”
The research team is made up of experts in genetics, imaging, bioinformatics, cardiovascular medicine, heart surgery, and stem cell therapy. They are looking at biomarkers for genetic risk, cardiac fibrosis, drug sensitivity, insulin resistance, and vascular reactivity. In particular, program physicians are looking at nontraditional risk factors like elevated lipoprotein levels, insulin resistance, low HDL2b, and relevant genetic mutations.
The clinical team is focused on risk reduction, prevention, and treatment. Patients first provide a family history and undergo a detailed laboratory evaluation. They are stratified for risk and short-term goals are set. A second visit about two months later includes diet consultation with a South Asian cuisine-trained dietitian, cardiovascular risk scoring, a review of lab test results, and a request to enroll in the program’s research trials. A third visit after six months summarizes the research results, tracks compliance, repeats the biomarker screening, and develops a long-term plan. Some patients may continue receiving care through SSATHI, while others may find their risk is sufficiently reduced to continue their care elsewhere.
In time, Dr. Dash hopes to develop partnerships to address the issue at a global scale and expand the program’s studies beyond the South Asian population.
“We want to teach people how to protect themselves from cardiovascular disease,” Dr. Dash said. “The problem is very real and accelerating. It’s a troubling trend that has not been addressed sufficiently and one that needs to be addressed earlier.”
About the Speaker
Rajesh Dash, MD, PhD, is an assistant professor of medicine (cardiovascular medicine) and the medical and scientific director of the Stanford South Asian Translational Heart Initiative (SSATHI). He received an MD and a PhD in pharmacology and cell biophysics from the University of Cincinnati. He did his residency at the University of Washington School of Medicine and completed his fellowship at UCSF Medical Center. He is board certified in echocardiography by the National Board of Echocardiography and in cardiovascular disease and internal medicine by the American Board of Internal Medicine.
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