Patients with heart problems who take aspirin and also take ibuprofen for arthritis pain are nine times more likely to suffer a heart attack, according to a new study.

Researchers from the Mount Sinai School of Medicine said that people should also be cautious about the combination. (Note: Earlier versions of this story incorrectly indicated that the effect was also seen with naproxen and the Cox-2 inhibitor lumiracoxib).

The problem, according to a news release, is that the other painkillers inhibit the blood-thinning properties of aspirin that benefit those at a high risk of heart disease.

"Ibuprofen has a significantly higher rate of major cardiovascular events, mostly heart attacks, when compared to a cox-2 inhibitor," said Dr. Michael E. Farkouh.

The cardiovascular health of 18,523 patients over 50 years age with osteoarthritis was compared by researchers in the study.

"This is the first randomized trial evidence to show risk of interaction between ibuprofen and aspirin to be real," said Farkouh. "Doctors should not give high-risk cardiovascular patients ibuprofen for pain while they are taking aspirin for their heart."