br br Testing for circulating troponin is a mainstay of a heart attack workup. Troponin is a cardiac protein that is released into the bloodstream by damaged heart muscle. br br To investigate whether more routine troponin level testing might be of predictive value, University of Edinburgh researchers drew troponin levels on 4240 subjects with a history of angina, chest pains of cardiac origin. Troponin levels were 2-fold higher in those subsequently found to have coronary artery disease on cardiac angiography. Those with troponin levels higher than 10 ngL had a 50 higher risk of heart attack or death.br br The researchers suggest that more routine troponin level determinations may alert patients and their medical teams to potential risks and thereby save lives.