Washington, Nov 16 There is an increased level of cardiac biomarkers in the blood of heart attack patients for several months after leaving the hospital, which often leads to more shortness of breath and chest pain, according to a Henry Ford Hospital study.

A biomarker is a protein measured in the blood whose concentration can indicate the presence or severity of disease.

In the study, researchers examined a subset of patients in a 4,500-patient heart attack registry from 24 U.S. hospitals.

They found that 9 percent of these participants had elevated levels of the biomarker troponin (TnT) after six months.

Thirty three percent had elevated level of the biomarker N-terminal pro-B-type Natriuretic Peptide (NTBNP) after six months.

Both TnT and NTBNP are associated with shortness of breath; NTBNP is associated with angina.

"These elevated biomarkers are definitely associated with a reduced quality of life for patients and may signal even worse outcomes," said Dr. David Lanfear.

"This data raises two important issues. The first is whether the biomarkers are a sign of ongoing problems or a reflection of the past heart attack itself. The second is whether closer monitoring of patients post heart attack can help target our treatment to those who need it most," he added.

For the study, researchers assessed the biomarker levels in patients one month and six months following their discharge from the hospital.

At one and six months, 14 percent and 9 percent of patients had elevated levels of TnT; at one and six months, 55 percent and 33 percent of patients had elevated levels of NTBNP.

The study is presented at the American Heart Association's annual scientific conference in Orlando. (ANI)