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Correlation between intracoronary physiology and myocardial perfusion imaging in patients with severe aortic stenosis

Roberto Scarsini1, Rosaria Cantone2, Gabriele Venturi2

  • 1Division of Cardiology, Department of Medicine, University of Verona, Verona, Italy; Oxford Heart Centre, Oxford University Hospitals, NHS Trust, Oxford, United Kingdom.

International Journal of Cardiology
|April 29, 2019
PubMed

Insights

Fractional flow reserve (FFR) effectively detects ischemia in aortic stenosis patients, outperforming instantaneous wave-free ratio (iFR). iFR showed lower accuracy but improved with a lower threshold, highlighting FFR

Area of Science:

  • Cardiology
  • Interventional Cardiology
  • Diagnostic Imaging

Background:

  • Aortic stenosis (AS) frequently co-occurs with coronary artery disease (CAD).
  • Optimal functional assessment of CAD in AS patients is not established.
  • Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) lack validation in AS.

Purpose of the Study:

  • To compare the diagnostic accuracy of FFR and iFR against stress single-photon emission computed tomography (SPECT) in severe AS patients.
  • To determine the best invasive physiological index for assessing significant coronary lesions in this population.

Main Methods:

  • FFR, iFR, and SPECT were performed in 28 patients with severe AS and 41 borderline coronary lesions.
  • Correlation and receiver operating characteristic (ROC) analysis were used to compare FFR and iFR against SPECT.
  • Agreement and discrepancies between the indices and SPECT were analyzed.

Main Results:

  • FFR demonstrated strong correlation with SPECT (AUC=0.91, NPV=95%) for detecting ischemia.
  • iFR showed significantly poorer agreement with SPECT (59% vs 85%, p=0.014) compared to FFR.
  • iFR had a higher rate of false positives, which decreased when using a lower threshold (0.82).

Conclusions:

  • FFR is a reliable tool for detecting ischemia-provoking lesions in severe AS patients, showing good correlation and high NPV with SPECT.
  • iFR's diagnostic performance is inferior to FFR in this setting.
  • Adjusting the iFR threshold may improve its agreement with SPECT, but FFR remains superior.
Abstract

Keywords:
Aortic stenosisCoronary artery diseaseFractional flow reserveInstantaneous wave-free periodSingle photon emission computed tomographyTranscatheter aortic valve implantation

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