Low Good Cholesterol
A study of nearly 7,000 people led by a researcher at Indiana University analyzed the relationship between HDL, or good cholesterol, and major coronary events. The study concluded that low HDL was the third strongest predictor of coronary events, after prior heart disease and age.
Infection
If you are diagnosed with flu or another respiratory tract infection, your odds of having a heart attack are five times higher during the three days after diagnosis than it would be otherwise. The reason: Infections can bring on an inflammatory response, which can trigger a heart attack or stroke. A flu vaccine may help protect against infection-induced heart stress.
Kidney Problems
A study of elderly patients in Rotterdam in the Netherlands found that having weak kidneys, even without full-blown kidney disease, can put you at a significantly higher risk for heart attack.
Urban Living
Exposure to heavy traffic—whether you're traveling by car, bike, or public transit—may double your risk of a heart attack, according to a German study. Another earlier study found that death from cardiopulmonary causes was nearly twice as high among people living close to a major road.
Calcium Supplements
A New Zealand study found that women who took one gram of calcium citrate for five years had twice the risk for heart attack. A second study found that people (particularly women in their 70s) who took at least 500 milligrams of calcium daily had a 30% higher heart attack risk than those who did not.
One possible reason could be that extra calcium builds up in the arteries, however this has not yet been confirmed. (Consult your doctor if you take supplemental calcium; some research has suggested that calcium could protect the heart.)
Stopping Aspirin
Numerous studies have shown that heart patients are at an increased risk of heart attack for at least a week after stopping aspirin therapy or other nonsteroidal anti-inflammatory drugs (NSAIDs). "If you have or are at risk for heart disease and want to stop taking aspirin, do so gradually and under the supervision of a doctor," warns Matthew Sorrentino, MD, a cardiologist at the University of Chicago.
Prostate Cancer Treatment
Hormone treatment for prostate cancer can increase the likelihood of sudden death from heart attack, according to a 2006 observational study by researchers at Harvard Medical School. The researchers say the finding does not prove a direct link between the two but that it should be taken into account when considering prostate cancer treatment.
Psoriasis
"In certain patients, psoriasis is a risk factor for heart attack comparable to diabetes," says Joel M. Gelfand, MD, assistant professor of dermatology at the University of Pennsylvania. Patients with severe psoriasis, a skin condition that usually requires medical treatment, are more likely to smoke, be overweight, and have high blood pressure, but Dr. Gelfand's research shows that psoriasis is an independent risk factor. He points out that psoriasis is an autoimmune disorder that may cause chronic inflammation, which can trigger a heart attack.
Relationship Issues
A negative relationship with your significant other can be bad for your heart, literally. According to a study by epidemiologists at University College London, relationship problems can up your risk of having a heart attack by 34%.