Anatomically and functionally relevant coronary stenoses in patients with normal single-photon emission computed...

Area of Science:

• Cardiology
• Nuclear Medicine
• Interventional Cardiology

Background:

• Single-photon emission computed tomography (SPECT) is a common diagnostic tool for coronary artery disease (CAD).
• Concerns exist regarding potential false-negative SPECT findings, leading to underdiagnosis of significant coronary stenoses.
• Fractional flow reserve (FFR) measurements invasively assess the functional significance of coronary artery stenoses.

Purpose of the Study:

• To determine the prevalence of anatomically and functionally significant coronary artery stenoses in patients with persistent symptoms despite a normal SPECT.
• To evaluate the diagnostic accuracy of SPECT in identifying significant CAD when FFR is used as a reference standard.

Main Methods:

• A cohort of 133 consecutive patients with normal SPECT underwent 180 invasive FFR measurements.
• Anatomically significant stenosis was defined as luminal narrowing ≥70% (≥50% for left main).
• Functionally significant stenosis was defined as FFR ≤0.80. Separate analyses considered FFR <0.75.

Main Results:

• Only 16% of patients with normal SPECT had both anatomically and functionally significant coronary stenoses (FFR ≤0.80).
• When a stricter FFR threshold of <0.75 was used, this prevalence decreased to 7.5%.
• No significant differences in baseline characteristics, symptoms, or pre-test likelihood predicted functionally relevant obstructive CAD, except for nitrate use.

Conclusions:

• The prevalence of significant coronary artery stenoses is low in patients with persistent symptoms following a normal SPECT.
• These findings suggest that SPECT has a low prevalence of false-negative results for detecting functionally significant coronary artery disease.