What are other reasons other than heart attack for increased level of troponin?

Any heart problem: Troponin is an enzyme released by damaged heart muscle. While the major cause is a heart attack, and large increases are usually due to this, almost any condition affecting the heart can cause small increases. Viral infections of the heart, pulmonary embolus or medial procedures such as angioplasty often result in increases of troponin.

Many: Abnormal values have been described in non-coronary conditions like myocarditis, pulmonary embolism, acute heart failure, septic shock, and as a result of cardiotoxic drugs as well as after therapeutic procedures like coronary angioplasty, electrophysiological ablations, or electrical cardioversions. It's also frequently seen in dialysis or severe kidney disease patients.