Serum cardiac troponin T in cardiac amyloidosis: serial observations in five patients.

The most common cause of death of patients suffering from amyloidosis is heart failure and sudden death, and cardiac troponin T (cTnT), a highly specific and sensitive biomarker of myocardial injury, has been reported to be a prognostic marker at presentation. But the relationship between serial measurements of serum cTnT and clinical course of the disease has not been described. An illustrative case was a 55-year-old man with normal renal function presenting with congestive heart failure (CHF), whose initial concentration of cTnT was 0.72 ng/ml. Eight samples of initial endomyocardial biopsy specimens showed the presence of myocyte degeneration and interstitial fibrosis with a small amount of amyloid infiltration. However, the cTnT values remained at 0.69 ng/ml after successful management of CHF, and four months later, a second endomyocardial biopsy revealed diffuse massive amyloid protein deposition. He died of CHF, 9 months after initial presentation. In addition, we present 4 cases of amyloidosis with increased serum cTnT levels. We therefore propose that serial measurements of serum cTnT might be helpful for early diagnosis and prediction of prognosis of patients with amyloidosis.