Impact of imaging protocol on left ventricular ejection fraction using gated-SPECT myocardial perfusion imaging

Area of Science:

• Cardiology
• Nuclear Cardiology
• Cardiac Imaging

Background:

• Limited data exist on the impact of single-day (SD) versus dual-day (DD) stress-rest imaging protocols on left ventricular (LV) ejection fraction (EF) changes related to ischemia and patient outcomes.
• Assessing the change in LV ejection fraction (post-stress-rest) is crucial for understanding myocardial stunning and its relationship with ischemia.

Purpose of the Study:

• To compare the impact of single-day (SD) and dual-day (DD) stress-rest myocardial perfusion imaging protocols on the change in left ventricular ejection fraction (LVEF) in patients with known coronary artery disease (CAD).
• To evaluate the relationship between imaging protocol, ischemia severity, LVEF changes, and clinical outcomes, including coronary revascularization (CR) and hard cardiac events.

Main Methods:

• A propensity score-matched analysis of 490 patients with known CAD from a multicenter study, comparing SD and DD gated-SPECT myocardial perfusion imaging protocols.
• Quantification of LV perfusion, EF, and volumes using stress and rest gated-SPECT.
• Assessment of clinical outcomes, including coronary revascularization and hard events, at an average follow-up of 3.2 years.

Main Results:

• Post-stress LVEF was comparable between SD and DD protocols across all ischemia severities.
• The change in LVEF was greater in the DD protocol for patients with severe ischemia, irrespective of CAD extent.
• Ischemic burden was independently associated with CR and hard events; post-stress LVEF predicted CR, but LVEF change did not predict either outcome.

Conclusions:

• The single-day (SD) protocol may underestimate post-stress myocardial stunning in patients with severe ischemia.
• Post-stress LVEF and the extent of ischemia are significant predictors of coronary revascularization and hard cardiac events.
• The change in LVEF is not a reliable predictor of hard cardiac events or the need for coronary revascularization.