Faster diagnosis for heart attacks

Haley Bridger, February 18th, 2011
  • A surgical technique called septal ablation (depicted here) was the key
    to finding biomarkers that appear shortly after a heart attack since the
    surgery gave researchers the opportunity to take blood samples before
    and after a planned heart attack at known time intervals.
    Image by Sigrid Knemeyer

An ambulance brings a patient to the hospital with chest pains, shortness of breath, and nausea. Is it a panic attack? Or is it a heart attack? Diagnosing a myocardial infarction (heart attack) quickly is critical: heart attacks kill more than 600,000 people in the United States every year, but if a doctor can diagnose and begin treating a patient within the “golden hour” following a heart attack, the patient’s chances of survival and recovery improve substantially.

Researchers at the Broad Institute study proteins and metabolic compounds in the blood to look for clues about diseases. If they can find a collection of proteins or biochemicals that are released when heart cells are injured (biomarkers), doctors might be able to diagnose a patient within the 90-minute window during which drug or catheter-based interventions to prevent permanent damage are most effective. Currently, the biomarkers that scientists use are only detectable after several hours.

The key to finding biomarkers that appear shortly after a heart attack may come from a drastic but life-saving surgery. In patients with the disease hypertrophic cardiomyopathy (HCM), a portion of the tissue in the heart’s main pumping chamber is abnormally thickened, which can lead to sudden cardiac death, especially in young athletes. In patients with severe forms of the disease, interventional cardiologists can cause a planned myocardial infarction with a special surgical technique known as alcohol septal ablation to relieve symptoms and improve the heart’s function.

The surgery gives researchers a rare opportunity: they can take blood samples before and after a planned heart attack at known time intervals. By measuring tiny quantities of molecules using mass spectrometry and liquid chromatography, they look for changes over time in the levels of markers.

Researchers are using these blood samples to find new biomarkers, some of which appear just 10 minutes after a heart attack. Before a diagnostic tool can be built and brought into the clinic, researchers must conduct large-scale studies and will also examine other bodily fluids, such as urine, to find the most effective biomarkers and sampling techniques.

Broad researchers are currently working with collaborators at Massachusetts General Hospital, Harvard Medical School, Brigham and Women's Hospital, and Beth Israel Deaconess Medical Center to use both proteomic and metabolite profiling technologies to explore other heart diseases (such as ischemia, a restriction in blood supply) and are also trying to derive a more basic understanding of the pathophysiology of the disease process. Key collaborators include Robert Gerszten of MGH and HMS and Marc Sabatine of BWH and HMS.