Author + information
- Received July 27, 2017
- Revision received August 28, 2017
- Accepted September 12, 2017
- Published online November 15, 2017.
- Abdul Rahman Ihdayhid, MBBS,
- Anthony White, MBBS, PhD and
- Brian Ko, MBBS, MD, PhD∗ ()
- Monash Cardiovascular Research Centre, Monash University and MonashHeart, Monash Health, Clayton, Victoria, Australia
- ↵∗Address for correspondence:
A. Prof. Brian Ko, Monash Cardiovascular Research Centre and MonashHeart, Monash Health, Clayton, Victoria, Australia.
- coronary artery disease
- CT-derived fractional flow reserve
- fractional flow reserve
- percutaneous coronary intervention
- serial stenosis
- virtual stenting
A 64-year-old man with hyperlipidemia and crescendo angina was investigated with a computed tomography coronary angiogram (CTCA) that demonstrated moderate serial stenoses in the proximal and mid-left anterior descending coronary artery (LAD) with comparable angiographic findings invasively (Figure 1A). Fractional flow reserve (FFR) in the distal LAD was 0.77. Pullback FFR gradient was higher across lesion B (Figures 1A and 1B), hence it was stented first. Post-percutaneous coronary intervention (PCI) FFR in the distal vessel remained in the ischemic range at 0.78, with a significant gradient across lesion A (Figures 1D and 1E). Lesion A was stented, and the final post-PCI FFR was 0.85, indicating resolution of the lesion-specific ischemia (Figures 1G and 1H).
FFR guidance of PCI in serial lesions is challenging. Distal vessel FFR reflects the net effect of both lesions on coronary flow. Each stenosis limits the maximal flow through the other, hence the hemodynamic assessment of each lesion is difficult to predict without complex and impractical calculations (1). In practice, interventionists stent the lesion with the largest pressure pullback gradient, with further stenting potentially required upon repeating the FFR pullback.
FFRCT is a computed tomography-derived approach for assessing lesion-specific hemodynamic significance that predicts invasive FFR with high accuracy (2). Virtual stenting is a novel noninvasive technique for using CTCA to plan optimal treatment strategies with high accuracy in isolated lesions at predicting residual distal vessel ischemia post-PCI (3) (Figure 2). Its application in serial stenoses has not been reported. Using a blinded core laboratory (HeartFlow, Redwood City, California), we retrospectively determined the feasibility of FFRCT and virtual stenting applied on pre-PCI CTCA at predicting invasive FFR results pre- and post-PCI (Online Video 1).
FFRCT in the LAD was 0.78, which correlated to an invasive FFR of 0.77 (Figure 1C). FFRCT accurately predicted persistence of ischemia post-PCI of lesion B and its resolution post-PCI of lesion A and B (Figures 1F and 1I). The patient was angina free at 3-month follow-up. Figure 3 demonstrates a hypothetical situation in which virtual stenting is applied to lesion A only, resulting in a FFRCT in the distal vessel of 0.84, indicating resolution of ischemia.
This case demonstrates the challenges of assessing serial stenoses with invasive FFR and suggests that FFRCT-guided virtual stenting may be useful in determining the hemodynamic significance of serial stenosis to assist in PCI planning.
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received July 27, 2017.
- Revision received August 28, 2017.
- Accepted September 12, 2017.
- 2017 American College of Cardiology Foundation
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