Researchers yesterday said a sibling’s heart disease is potentially a greater risk predictor for the nation’s deadliest disease than whether a parent had it, and that shared genes or similar childhood diets are likely to blame.
“Sibling cardiovascular disease (CVD) was associated with a stronger risk for CVD incident than was parental premature CVD,” said the report by Dr. Christopher J. O’Donnell, associate director of the National Heart, Lung and Blood Institute’s Framingham Heart Study.
Investigators concluded that middle-aged adults whose sibling got CVD had a 45 percent higher risk of heart attack, stroke, or a blood clot in the leg. The risk of getting CVD, which kills 700,000 annually, if a parent has it is 25 percent.
The researchers acknowledged that other research has shown that parental CVD doubles the risk for the disease in offspring.
The Framingham Heart Study, which tracked the health of 2,500 residents of the Massachusetts city since 1971, was one of two reports on heart ailments published in yesterday’s Journal of the American Medical Association.
In a separate study, researchers found that heart attack patients are often given overdoses of powerful blood-thinning drugs in the emergency room, increasing their risk of serious bleeding.
Of the 30,136 heart attack patients studied who were treated last year at 387 U.S. hospitals, 42 percent got excessive doses of blood thinners. Overdoses were particularly common in thin people, women, the elderly and those with kidney problems.
Those given too much of two newer blood thinners — low molecular weight heparin and drugs sometimes called “super-aspirin” — had more than a 30 percent increased chance of major bleeding than those given the recommended dose.
“Physicians ought to take this into account,” Dr. Steven Nissen, a Cleveland Clinic cardiologist who was not involved with the research told the Associated Press. “These drugs are not very forgiving.”
The drugs studied were heparin; low molecular weight heparin; and glycoprotein IIb-IIIa blockers, which are sometimes called “super-aspirin” because of their blood-thinning potency. Injected or given intravenously, they are very effective at helping prevent clots and further heart damage.
In the CVD study in which subjects were followed up for eight years, Dr. O’Donnell said the Framingham team documented all reported cases of sibling CVD with medical evidence, unlike some prior research. The average age of onset was 48, which is considered “premature” for a heart attack or stroke.
To analyze the potential risk of parental CVD, the NHLBI team examined a subsample of offspring with both parents enrolled in the Framingham Heart Study. Parental “premature” CVD was defined as the occurrence of a validated CVD event that occurred prior to the start of the study and before age 55 in fathers and age 65 in mothers.
Dr. O’Donnell said this research was needed, as it was previously not clear whether sibling CVD was an independent risk factor and how much of a risk it represented. What’s more, he said, the findings suggest sibling CVD is at least as serious a risk factor as parental CVD.
Dr. O’Donnell said the risk of a male adult getting CVD if a parent had it was 29 percent. The same risk in a female was 21 percent.
This article is based in part on wire service reports.