Johns Hopkins Researchers Uncover Protein Basis for Accurate Heart Attack Indicators

Patients suffering from ischemia- the deficiency of blood flow in an organ or a part of it- are more susceptible to cardiac arrests. Now, Johns Hopkins researchers have discovered a set of five proteins in blood which they hope can help set up a highly accurate early warning test to predict heart attack in such patients.

The team comprising over a dozen scientists revealed that it took them a year to perform the study. They believe that theirs is the largest protein analysis ever done at Hopkins.

Heart Attack - Overview
Heart attack is the death of the heart muscle due to loss of blood supply. Heart disease is the leading cause of death in the United States. Other names for heart attack include acute myocardial infarction, coronary thrombosis, and coronary occlusion.

According to the researchers, their study was based on 76 arterial blood samples from 19 men and women, which had been taken immediately before and after a period of medically induced ischemia lasting as long as 45 minutes.

They called their method of selecting proteins from tens of thousands present in the blood "a pipeline approach".

"From the start, we knew that we were looking for rare, almost unique biomarkers that bore some direct relationship with ischemia," says study senior investigator Dr. Jennifer Van Eyk, whose first step was to remove from the analysis common blood proteins, such as albumin and globulins.

Angioplasty
Arteries supplying the heart is sometimes blocked by plaque leading to heart attack.Angioplasty is a method by which a part of the blocked artery is expanded to place a stent.Once this is done normal blood flow resumes and the heart regains its normal function.

Presenting their work at the American Heart Association's annual Scientific Sessions in New Orleans on November 9, the researchers said that only five proteins were present in significantly increased amounts after ischemia occurred, with at least a doubling in the blood concentration, compared with those recorded during healthy blood flow.

They said that the five proteins were lumican, semenogelin, angiogenin, extracellular matrix protein, and so-called long palate, lung and nasal epithelium carcinoma-associated protein 1.

Animation on Coronary Artery Bypass Surgery (CABG)
Coronary Artery Bypass Surgery (CABG) is performed to restore the blood supply to areas of heart that have been reduced or has no blood supply due to blockage in the artery.

While all of them are believed to originate in the heart, they can also be found in other tissues varying from the corneas of the eyes, lumican, to semen.

The researchers also revealed that semenogelin had not been seen in the heart ever before, while others like angiogenin are more predictably found in growing blood vessels and muscle tissue, and are actively involved in tissue repair.

Animation of heart attack symptoms
Heart attack can cause symptoms such as Chest pain or discomfort, Shortness of breath and pain in neck, back, arm, or shoulder and is due to blockage of blood supply to the heart muscles

They further said that little was known about the remaining two, which ironically have the longest names: extracellular matrix protein, secreted in a rare inflammatory disease; and long palate, lung and nasal epithelium carcinoma-associated protein 1, thought to play a role in innate immunity.

The Johns Hopkins team believes that the presence of all or even a selected set of these proteins in a simple, rapid blood test could aid emergency paramedics and physicians during the critical 12- to 24-hour window before ischemia causes substantial heart tissue damage or death from heart attack.

"Our results lay the foundation for a first-of-a-kind, early-warning system that could save tens of thousands of people on the brink of a heart attack," says Van Eyk, a professor at the Johns Hopkins University School of Medicine and its Heart and Vascular Institute.

The researchers are currently planning to further analyze the five proteins to map their molecular structures, so that an antibody can be identified to bind to one or several of the proteins, laying the basis for a blood test for ischemia. They will also conduct tests to verify that their study findings also apply to ischemia in stroke.

Source-ANI
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