Marker Predicts Heart Damage after Chemotherapy

High levels of troponin 1(TN1) in the blood may be a sign of heart damage after chemotherapy, according to new research reported in the May 17, 2004, online issue of Circulation.

TN1 is a protein present exclusively in heart cells, and TN1 blood concentration is a well-established marker of heart muscle injury that is widely used to diagnose and treat heart attacks and other acute coronary syndromes. The report suggests that by tracking TN1 levels, doctors can identify those patients at greatest risk and form a disease prevention plan.

The researchers took blood samples of 703 cancer patients to measure TN1 soon after high-dose chemotherapy and one month later. TN1 values higher than 0.08 ng/ml were considered "positive,” while lower values were TN1 "negative.” Out of the 703 patients, 145 (21%) were TN1 positive right after chemotherapy, and 63 (9%) were positive immediately after chemotherapy and one month later.

No significant reduction in heart function was found at three years in patients who were TN1-negative, and these patients had only a 1% incidence of cardiac events. In contrast, there was a 37% incidence of cardiac events among the TN1-positive patients immediately after chemotherapy and 84% among those who remained positive a month later.

"Evaluating TN1 values after chemotherapy is an easy, noninvasive, low-cost method that allows us to categorize the risk of cardiac events in cancer patients in the three years following chemotherapy,” said lead author Daniela Cardinale, M.D., deputy director of the cardiology unit at the European Institute of Oncology (Milan, Italy).

In cancer patients who have chemotherapy, doctors usually use extensive testing and monitoring equipment to identify those who may have cardiac toxicity, but these methods have low sensitivity, poor predictive value, and technical limitations, noted Dr. Cardinale.
She summarized the three important implications for cancer treatment: TN1 testing could categorize heart disease risk early, long before impairment and symptoms develop, when preventive treatments could probably help prevent long-term effects; TN1 testing could assess and monitor the safety and effectiveness of different treatments; heart-protective therapies that might limit or prevent the TN1 rise after chemotherapy, and heart treatments that interfere with TN1 persistence could improve the future heart health of these patients.

"The results of this study provide a rational need for doctors to use this marker to guide them in their cardiac evaluations and treatments of high-dose chemotherapy patients,” noted Dr. Cardinale.




Related Links:
European Institute of Oncology