Incidence, diagnosis and prognosis of cardiac amyloidosis

Cardiac involvement is frequent in systemic amyloidosis and is the most important determinant of the clinical outcome. The aims of this study were to assess the incidence and prognosis of cardiac amyloidosis and discuss the diagnostic issues related to cardiac amyloidosis.

We retrospectively studied all patients diagnosed with systemic amyloidosis who presented to our institution from January 1999 to December 2011.

Of the 129 patients with systemic amyloidosis, cardiac amyloidosis was diagnosed in 62 patients. At the 3 years' follow-up of the patients with systemic amyloidosis, there was a statistically significant difference in mortality between patients with cardiac amyloidosis and the rest of the patients (58.1% vs. 37.3%, p=0.008). In the Cox proportional hazard model, old age {hazard ratio (HR) 18.336, p=0.006}, elevation of cardiac troponin I (cTNI) (HR 13.246, p=0.020), left ventricular (LV) systolic dysfunction (HR 5.137, p=0.041) and diastolic dysfunction (HR 64.595, p=0.022) were independently associated with survival in cardiac amyloidosis. In the diagnosis of monoclonal gammopathy, serum or urine protein electrophoresis was not sensitive enough to be used clinically compared to serum free light chain assay (35.8% vs. 96.4%).

In systemic amyloidosis, cardiac involvement was the most important determinant of the prognosis, and old age, elevation of cTNI, LV systolic dysfunction and diastolic dysfunction were independently associated with survival in cardiac amyloidosis.