CMR vs. RbPET: Head-to-Head Comparison for Obstructive CAD by FFR

Quick Takes

  • Among patients with suspected obstructive stenosis at coronary CTA, CMR and RbPET show similar and moderate sensitivities but high specificities compared with ICA with FFR.
  • The high sensitivities for identification of severe stenoses with MPI could potentially identify patients with symptomatic benefit of invasive assessment and revascularization and avoid unnecessary initial invasive testing.

Study Questions:

What is the diagnostic performance of selective myocardial perfusion imaging (MPI) by 3.0-T cardiac magnetic resonance (CMR) and 82rubidium positron emission tomography (RbPET) in patients with suspected obstructive stenosis at coronary computed tomography angiography (CTA) using invasive coronary angiography (ICA) with fractional flow reserve (FFR) as reference?

Methods:

The investigators included consecutive patients (n = 1,732, mean age: 59.1 ± 9.5 years, 57.2% men) referred for coronary CTA with symptoms suggestive of obstructive coronary artery disease (CAD). Patients with suspected stenosis were referred for both CMR and RbPET and subsequently ICA. Obstructive CAD was defined as FFR ≤0.80 or >90% diameter stenosis by visual assessment. The diagnostic performance of both MPIs was evaluated by sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy. Comparison of sensitivities and specificities was tested using McNemar test and weighted generalized score statistics for comparison of predictive values of diagnostic tests.

Results:

In total, 445 patients had suspected stenosis on coronary CTA. Of these, 372 patients completed both CMR, RbPET, and subsequent ICA with FFR. Hemodynamically obstructive CAD was identified in 164 of 372 (44.1%) patients. Sensitivities for CMR and RbPET were 59% (95% confidence interval [CI], 51%-67%) and 64% (95% CI, 56%-71%); p = 0.21, respectively, and specificities 84% (95% CI, 78%-89%) and 89% (95% CI, 84%-93%]); p = 0.08, respectively. Overall accuracy was higher for RbPET compared with CMR (73% vs. 78%; p = 0.03).

Conclusions:

The authors report that in patients with suspected obstructive stenosis at coronary CTA, CMR and RbPET show similar and moderate sensitivities but high specificities compared with ICA with FFR.

Perspective:

This prospective head-to-head comparison of diagnostic performance of CMR and RbPET in a cohort of patients with suspected obstructive CAD at coronary CTA found similar moderate sensitivities but high specificities for diagnosing obstructive CAD using invasive FFR as reference standard. Despite only moderate sensitivities for identification of obstructive CAD by a guideline-endorsed reference of invasive FFR, the high sensitivities for identification of severe stenoses with MPI could potentially identify patients with symptomatic benefit of invasive assessment and revascularization and avoid unnecessary initial invasive testing.

Clinical Topics: Cardiac Surgery, Cardiovascular Care Team, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Prevention, Atherosclerotic Disease (CAD/PAD), Cardiac Surgery and Arrhythmias, Interventions and Coronary Artery Disease, Interventions and Imaging, Angiography, Computed Tomography, Magnetic Resonance Imaging, Nuclear Imaging

Keywords: Coronary Angiography, Coronary Artery Disease, Coronary Stenosis, Computed Tomography Angiography, Diagnostic Imaging, Fractional Flow Reserve, Myocardial, Magnetic Resonance Imaging, Myocardial Ischemia, Myocardial Perfusion Imaging, Myocardial Revascularization, Positron-Emission Tomography, Rubidium, Secondary Prevention, Tomography, X-Ray Computed


< Back to Listings