New research finds that silent heart attacks may need to be recognized as a new risk factor for stroke. Preliminary research presented by the American Stroke Association showed that silent heart attacks appear to increase stroke risk in adults 65 and older.
A silent heart attack often goes undiagnosed as it has minimal or unrecognized symptoms. Also known as a silent myocardial infarction, the condition can only be diagnosed with an electrocardiogram (ECG) or some form of heart imaging, such as an echocardiogram or a cardiac magnetic resonance imaging (MRI).
Some symptoms of a silent heart attack include chest pain, discomfort in the arms or legs, and dizziness. Nausea and cold sweats are also common signs that tend to be unrecognized. While some of these symptoms may be similar to those associated with a traditional heart attack, they may be less painful or intense, which is why they are often overlooked.
“Long-term risk of death can be as high after a silent heart attack as it is with a recognized heart attack, and it turns out silent heart attacks are more frequent than traditional chest-crushing heart attacks in older adults,” said study author Alexander E. Merkler, M.D.
The study consisted of Merkler and his colleagues analyzing health information from more than 4,200 adults who participated in the Cardiovascular Health Study. All participants were 65 years or older and were enrolled from 1989 – 1990. Each was required to attend an annual study visit at multiple centers across the U.S. for ten years.
It was found that those who had evidence of a silent heart attack had a 47% increased risk of developing a stroke compared to participants who did not have a silent heart attack. Participants who had classic symptoms of heart attack had an 80-fold increase risk of stroke within one month after their heart attack. After this high-risk, one-month period, those with classic heart attack symptoms had a 60% increased stroke risk.
“Our research suggests the increased risk for having a stroke in those with silent heart attacks is similar to the risk found in traditional heart attacks. A silent heart attack may be capable of causing clots in the heart that dislodge and travel to the brain, causing a stroke,” Merkler said.
More research is needed to understand how to treat patients with a silent heart attack to help reduce the risk of stroke. Researchers believe future studies could evaluate the value of conducting a routine cardiac evaluation for silent heart attacks.