Author Interviews, Columbia, Heart Disease, JAMA, Medical Imaging / 25.08.2016
Technetium Cardiac Imaging Predicts Prognosis of Cardiac Amyloidosis
MedicalResearch.com Interview with:
Adam Castano, M.D., M.S.
Division of Cardiology
Columbia University Medical Center
New York Presbyterian Hospital
MedicalResearch.com: What is the background for this study?
Response: Transthyretin cardiac amyloidosis (ATTR-CA) is an increasingly recognized cause of heart failure with preserved ejection fraction (HFpEF). Traditionally, the gold standard for diagnosis has required an endomyocardial biopsy coupled with either immunohistochemistry or mass spectroscopy. These specialized tests are only performed at centers with experienced satff, do not yield prognostically useful information, may be inadvisable for frail older adults, and often present logistical challenges that lead to delayed care.
Fortunately, single center studies have demonstrated excellent diagnostic accuracy using technetium 99m pyrophosphate (Tc99mPYP) cardiac imaging for noninvasively detecting ATTR-CA and differentiating it from another major type of cardiac amyloidosis called light chain (AL). But the diagnostic accuracy of this technique in a multicenter study and the association of Tc99mPYP myocardial uptake with survival were not known prior to this study.
Therefore, we assessed in a multicenter study Tc99mPYP cardiac imaging as a diagnostic tool and its association with survival. We conducted a retrospective cohort study of 229 patients evaluated at 3 academic specialty centers for cardiac amyloidosis and also underwent Tc99mPYP cardiac imaging. We measured retention of Tc99mPYP in the heart using a semiquantitative visual score (range 0-3) and a more quantitative heart-to-contralateral (H/CL) ratio calculated as total counts in a region of interest over the heart divided by background counts in an identical size region of interest over the contralateral chest. The outcome measured was time to death after Tc99mPYP imaging.
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