Tafamidis treatment in ATTR-CM patients resulted in a significant reduction in SUV retention index (P<0.001), which was associated with significant benefits in NT-proBNP and biventricular function.
Cohort (n=40)
Does serial quantitative 99mTc-DPD SPECT/CT imaging with SUV retention index correlate with structural and functional treatment response to tafamidis in patients with wild-type ATTR-CM?
Serial quantitative 99mTc-DPD SPECT/CT imaging with SUV retention index can monitor and quantify treatment response to tafamidis in patients with wild-type ATTR-CM.
p-value: p=<0.001
AIMS: Tafamidis treatment positively affects left ventricular (LV) structure and function and improves outcomes in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). We aimed to investigate the relationship between treatment response and cardiac amyloid burden identified by serial quantitative 99mTc-DPD SPECT/CT. We furthermore aimed to identify nuclear imaging biomarkers that could be used to quantify and monitor response to tafamidis therapy. METHODS AND RESULTS: Forty wild-type ATTR-CM patients who underwent 99mTc-DPD scintigraphy and SPECT/CT imaging at baseline and after treatment with tafamidis 61 mg once daily median, 9.0 months (interquartile range 7.0-10.0) were divided into two cohorts based on the median (-32.3%) of the longitudinal percent change in standardized uptake value (SUV) retention index. ATTR-CM patients with a reduction greater than or equal to the median (n = 20) had a significant decrease in SUV retention index (P < 0.001) at follow-up, which translated into significant benefits in serum N-terminal prohormone of brain natriuretic peptide levels (P = 0.006), left atrial volume index (P = 0.038), as well as LV LV global longitudinal strain: P = 0.028, LV ejection fraction (EF): P = 0.027, LV cardiac index (CI): P = 0.034 and right ventricular (RV) RVEF: P = 0.025, RVCI: P = 0.048 functions compared with patients with a decrease less than the median (n = 20). CONCLUSION: Treatment with tafamidis in ATTR-CM patients results in a significant reduction in SUV retention index, associated with significant benefits for LV and RV function and cardiac biomarkers. Serial quantitative 99mTc-DPD SPECT/CT imaging with SUV may be a valid tool to quantify and monitor response to tafamidis treatment in affected patients. TRANSLATIONAL PERSPECTIVE: 99mTc-DPD SPECT/CT imaging with determination of SUV retention index as part of a routine annual examination can provide evidence of treatment response in ATTR-CM patients receiving disease-modifying therapy. Further long-term studies with 99mTc-DPD SPECT/CT imaging may help to evaluate the relationship between tafamidis-induced reduction in SUV retention index and outcome in patients with ATTR-CM and will demonstrate whether highly disease-specific 99mTc-DPD SPECT/CT imaging is more sensitive than routine diagnostic monitoring.
Rettl et al. (Tue,) conducted a cohort in transthyretin amyloid cardiomyopathy (ATTR-CM) (n=40). Tafamidis vs. Patients with a decrease in SUV retention index less than the median was evaluated on Relationship between treatment response and cardiac amyloid burden identified by serial quantitative 99mTc-DPD SPECT/CT (p=<0.001). Tafamidis treatment in ATTR-CM patients resulted in a significant reduction in SUV retention index (P<0.001), which was associated with significant benefits in NT-proBNP and biventricular function.