Cardiac involvement in acute thrombotic thrombocytopenic purpura: association with troponin T and IgG antibodies to ADAMTS 13.
BACKGROUND
Evidence for cardiac involvement in thrombotic thrombocytopenic purpura (TTP) is uncommonly described.


METHODS
We retrospectively reviewed 41 patients assessing troponin T as a marker for cardiac involvement in acute TTP with clinical symptoms, electrocardiograms (ECG) and echocardiograms. A histopathological review of five patients who died of acute TTP was also undertaken.


RESULTS
In 54% (22/41) of patients, troponin T was >or=0.05microg L(-1) (normal range 0-0.01 microg L(-1)). Half (12/22) had cardiac symptoms and 8/22 with a raised troponin T reported chest pain. ECG changes were present in 62% of patients with a raised troponin T. Median anti-ADAMTS 13 IgG antibody was significantly higher (P=0.018) in patients with troponin T>or=0.05 microg L(-1) (58.5% (range 17-162%), compared with patients with troponin T<0.05 microg L(-1) (35%, range 9-134%). Patients who died had higher troponin T levels (median 0.305 microg L(-1)) and raised anti-ADAMTS 13 IgG (median 66.5%). On admission, there were no deaths in those with troponin T<or=0.04microg L(-1). Histology confirmed widespread myocardial microvascular thrombi.


CONCLUSIONS
Clinical symptoms, ECG changes and echocardiograms are poor predictors of cardiac disease in acute TTP. Troponin T is specific for cardiac muscle and a sensitive marker of myocardial damage. In TTP patients, raised levels (>or=0.05 microg L(-1)) signify myocardial necrosis associated with microvascular thrombi. Mortality and acute morbidity was associated with higher admission troponin T and raised IgG antibody (>67%) to ADAMTS 13.
Hughes
C
C
Department of Haematology, University College London Hospitals, London, UK.
McEwan
J R
JR
Longair
I
I
Hughes
S
S
Cohen
H
H
Machin
S
S
Scully
M
M
D051722:ADAM Proteins / Q000276:immunology*; D000071120:ADAMTS13 Protein; D000208:Acute Disease; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D006331:Heart Diseases / Q000175:diagnosis* / Q000401:mortality; D006801:Humans; D007074:Immunoglobulin G; D009017:Morbidity; D009026:Mortality; D011697:Purpura, Thrombotic Thrombocytopenic / Q000150:complications* / Q000453:epidemiology / Q000401:mortality; D012189:Retrospective Studies; D020107:Troponin T / Q000097:blood*
D001323:Autoantibodies; D015415:Biomarkers; D007074:Immunoglobulin G; D020107:Troponin T; D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human