What does this research mean for the field?

99mTc-PYP-positive individuals have a higher heart-to-lung ratio (1.92 vs 1.15) and prolonged QTc interval (456 msec vs 422 msec), aiding in the diagnosis of transthyretin cardiac amyloidosis (ATTR-CA). Novelty: ClaimNovelty.CONFIRMATORY. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

To identify electrocardiographic characteristics in patients with transthyretin cardiac amyloidosis using 99mTc-PYP scintigraphy.

January 10, 2026Open Access

Electrocardiographic Features in Transthyretin Cardiac Amyloidosis

Key Result

In 76 patients, 99mTc-PYP-positive individuals had a higher heart-to-lung ratio (1.92 vs 1.15) and prolonged QTc interval (456 msec vs 422 msec), aiding ATTR-CA diagnosis.

Key Points

To identify electrocardiographic characteristics in patients with transthyretin cardiac amyloidosis using 99mTc-PYP scintigraphy.
Analyzed 76 patients who underwent 99mTc-PYP scintigraphy from December 2020 to March 2022.
Grouped patients into 99mTc-PYP-positive and -negative based on scintigraphy results.
Conducted comparisons of electrocardiographic and echocardiographic features between the groups.
11.8% of patients were positive for 99mTc-PYP.
Significantly higher heart-to-contralateral lung ratio in the P group (1.92) compared to the N group (1.15).
Increased left ventricular posterior wall thickness in the P group (15.5 mm) versus the N group (12.5 mm).
Lower prevalence of left ventricular hypertrophy in the P group (11.1%) compared to the N group (44.8%).
QTc interval was significantly prolonged in the P group (456 msec) compared to the N group (422 msec).

Structured PICO

Do electrocardiographic and echocardiographic features differ between 99mTc-PYP-positive and -negative patients evaluated for transthyretin cardiac amyloidosis?

Population

76 patients who underwent 99mTc pyrophosphate scintigraphy (99mTc-PYP) from December 2020 to March 2022

Intervention

99mTc-PYP-positive (diagnosed with ATTR-CA)

Comparator

99mTc-PYP-negative

Outcome

Electrocardiographic and echocardiographic characteristics (including LVH, LVPW thickness, and QTc interval)surrogate

The discordance between significant echocardiographic left ventricular hypertrophy and the absence of electrocardiographic LVH, along with prolonged QTc, is a useful marker for diagnosing transthyretin cardiac amyloidosis.

Main Result

Absolute Event Rate: 0% vs 0%

Abstract

Background: 99mTc pyrophosphate scintigraphy (99mTc-PYP) is useful for diagnosing transthyretin amyloid cardiomyopathy (ATTR-CA). We examined the characteristics of 99mTc-PYP-positive patients at our institution. Methods: A total of 76 patients who underwent 99mTc-PYP from December 2020 and March 2022 were grouped into 99mTc-PYP-positive (P) and -negative (N) groups and compared. Results: Nine of seventy-six patients were positive (11.8%), and all patients were diagnosed with ATTR-CA by myocardial biopsy or clinical findings. The heart-to-contralateral lung ratio in the P group was significantly higher (N Group: 1.15, P Group: 1.92, p < 0.001). In the P group, the left ventricular posterior wall thickness was significantly thickened (N Group; 12.5 mm, P Group; 15.5 mm, p = 0.003). Electrocardiogram showed left ventricular hypertrophy (LVH) was observed more frequently in the N group (N Group; 30 patients (44.8%) and the P Group; 1 patient (11.1%), p < 0.001). In addition, the QTc interval was significantly prolonged in the P group (N Group; 422 msec, P Group; 456 msec, p = 0.001). Conclusions: In patients who have significant LVH on echocardiogram but not on electrocardiogram, 99mTc-PYP may be useful for diagnosing ATTR-CA. However, the present study is a single-center retrospective study with a small number of patients, and the results are exploratory and hypothesis-generating. Prospective studies with a larger number of subjects are needed.

اسأل الذكاء الاصطناعي

Bookmark

View Full Paper