Bone Scintigraphy Can Help ID Cardiac Amyloidosis

TUESDAY, Jan. 17, 2023 (HealthDay News) -- For individuals undergoing bone scintigraphy, positive ^99mTc-3,3- diphosphono-1,2-propanodicarboxylic-acid (^99mTc-DPD), indicative of cardiac amyloidosis (CA), is associated with poor outcomes, according to a study published in the December issue of the Journal of Nuclear Medicine.

Christian Nitsche, M.D., Ph.D., from the Medical University of Vienna, and colleagues examined CA prevalence among individuals undergoing ^99mTc-DPD bone scintigraphy between 2010 and 2020. Low-grade ^99mTc-DPD uptake defined Perugini grade 1, while grades 2 and 3 indicated confirmed CA. A total of 17,387 scans from 11,527 patients were analyzed.

The researchers found that ^99mTc-DPD positivity had a prevalence of 3.3 percent overall, with higher prevalence seen among cardiac than noncardiac referrals (18.2 versus 1.7 percent). Progression from grade 1 to grades 2 or 3 was seen among individuals with more than one scan. The portion of light-chain CA was significantly higher in grade 1 than grades 2 and 3 among those with biopsy-proven CA (73.3 versus 15.4 percent). Clinical event rates were 29.4 percent for mortality, 2.6 percent for cardiovascular death, and 1.5 percent for heart failure hospitalization after a median of six years; all were independently predicted by ^99mTc-DPD. Adverse outcomes were driven by confirmed CA versus grade 0 (adjusted hazard ratios, 1.46, 2.34, and 2.25 for mortality, cardiovascular death, and heart failure hospitalization, respectively). Compared with noncancer patients, cancer patients had higher one-year mortality.

"Facing worse outcomes and given the availability of novel treatment options for cardiac amyloidosis, efforts should be maximized to reliably diagnose DPD uptake," a coauthor said in a statement.

One author disclosed financial ties to Pfizer, which partially funded the study.

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