Prognostic implications of post-stress ejection fraction decrease detected by gated SPECT in the absence of...

Area of Science:

• Cardiology
• Nuclear Cardiology
• Diagnostic Imaging

Background:

• The prognostic significance of a post-stress ejection fraction (EF) decrease identified via gated SPECT remains uncertain.
• This uncertainty is particularly relevant in patients without concurrent stress-induced perfusion abnormalities.

Purpose of the Study:

• To investigate the prognostic value of a post-stress EF decrease in patients without perfusion abnormalities on gated SPECT.
• To compare the outcomes of patients with and without post-stress EF decrease, controlling for perfusion status.

Main Methods:

• Prospective enrollment of 57 patients with a post-stress EF drop ≥ 5 EF units and a summed difference score (SDS) ≤ 1.
• Follow-up exceeding 1 year, comparing outcomes with sex- and age-matched controls exhibiting normal SDS and no EF decrease.

Main Results:

• A significantly higher event rate (13 events) was observed in the post-stress EF decrease group compared to controls (6 events).
• Events included cardiac death, myocardial infarction, congestive heart failure, and late revascularizations.
• Event-free survival curves showed a significant difference between the groups (p<0.0001).

Conclusions:

• Post-stress EF decrease of ≥ 5 EF units, even with normal perfusion, is associated with a relatively high and significantly worse event rate.
• These findings underscore the need for cautious interpretation of post-stress EF decreases in the absence of perfusion abnormalities.
• This highlights a potential indicator of underlying cardiac risk not fully captured by perfusion imaging alone.