Correlates of markers of dyssynchrony in patients with STEMI and multivessel disease: an analysis from the IAEA SPECT...

Area of Science:

• Cardiology
• Nuclear Cardiology
• Cardiac Imaging

Background:

• Assessing myocardial scar and ischemia is crucial in ST-elevation myocardial infarction (STEMI) patients with multivessel disease post-primary percutaneous coronary intervention (PCI).
• Gated-single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) can evaluate infarct size and ischemia.
• Cardiac dyssynchrony at rest may be influenced by infarct size and residual ischemia.

Purpose of the Study:

• To investigate the relationship between infarct size and resting cardiac dyssynchrony in STEMI patients.
• To determine if stress-inducible ischemia correlates with resting dyssynchrony in this patient cohort.

Main Methods:

• Analysis of 48 patients from the Value of Gated-SPECT MPI for Ischemia-Guided PCI trial.
• Gated-SPECT MPI performed with vasodilator stress using technetium-99m-labeled tracers.
• Quantification of cardiac dyssynchrony using phase histogram bandwidth (HBW), phase standard deviation (SD), and entropy via QGS software.
• Spearman correlation test used to assess relationships between dyssynchrony, infarct size, and inducible ischemia.

Main Results:

• Resting dyssynchrony parameters were abnormal in men, with only HBW abnormal in women.
• A significant correlation was found between the summed rest score and entropy (P=0.035).
• No significant correlation was observed between resting dyssynchrony and stress-induced ischemia.

Conclusions:

• Entropy may serve as a valuable measure for assessing dyssynchrony in STEMI patients with multivessel disease after primary PCI.
• Smaller residual myocardial scars in PCI-reperfused STEMI patients might explain the lack of correlation between resting dyssynchrony, infarct size, and stress-induced ischemia.