Lead author Rosebud Roberts, a health sciences researcher at Mayo Clinic in Rochester, Minn., said mild cognitive impairment -- known as non-amnestic -- because it doesn't include memory loss, may be a precursor to vascular and other non-Alzheimer's dementias.
Mild cognitive impairment is an important stage for early detection and intervention in dementia, Roberts said.
"Prevention and management of cardiac disease and vascular risk factors are likely to reduce the risk," Roberts said in a statement.
Researchers evaluated 2,719 people ages 70-89 at the beginning of the study and every 15 months after.
Of the 1,450 study subjects without mild cognitive impairment at the beginning, 669 had heart disease and 59 developed non-amnestic mild cognitive impairment; in comparison 34 of 781 who did not have heart disease developed non-amnestic mild cognitive impairment.
The association varied by sex; cardiac disease and mild cognitive impairment appeared together more often among women than in men, Roberts said.
The findings were published in the journal Neurology.