Virtual Coronary Intervention

Figures

• 

  Figure 1. Simulated Stent Placement Within the VIRTUheart System (A) The 3-dimensional reconstruction of the artery is displayed on the screen, and the operators mark the arterial location where they wish to deploy a stent identified by the red (proximal) and blue (distal) markers. In the text (left), the vessel radii at both selected points are displayed as well as the distance between them. The operator can adjust the radius of the desired virtual stent in the box below (“stent size”). The length can be altered by moving the position of the redandblue dots. In the example shown, a 3.0- × 20-mm virtual stent has been inserted by the operator. The surface mesh is manipulated to match these stenting criteria. (B) The new surface (the virtually stented artery) is shown overlaying the original vessel (right panel).

• 

  Figure 2. Example of VCI (A) A 66-year-old man presented with chronic stable angina. The LAD had a severe mid vessel stenosis (arrow). The mFFR between the proximal and distal points (dashed line) was 0.77. (B) Angiograms were used to model the vFFR by using the VIRTUheart system, which was calculated to be 0.75 over the same segment. This is displayed in false color yellow, the straight yellow line connecting the same 2 points between which the vFFR was calculated, exactly matching the 2 spots marked by the dashed line (A). (C) After implantation of a 2.75- × 18-mm stent at the stenosis, the mFFR was 0.88 over the same segment. (D) VCI using the VIRTUheart system was then used to implant a virtual 2.75- × 18-mm stent, and the recalculated vFFR was 0.88, corresponding to the green line connecting the 2 points. LAD = left anterior descending; mFFR = measured fractional flow reserve; VCI = virtual coronary intervention; vFFR = virtual FFR.

• 

  Figure 3. Bland Altman Plots (A) These figures demonstrate the differences between mFFR and vFFR plotted against the mean value pre-PCI and (B) post-PCI and VCI. The 2 pink lines represent the limits of agreement 2 SD above and below the mean delta. PCI = percutaneous coronary intervention; other abbreviations as in Figure 2.

• 

  Figure 4. Correlation Between vFFR and mFFR (A) Correlation between virtual vFFR and mFFR pre-PCI and (B) post PCI and VCI with a line of best fit passing through the origin. R = 0.87 and 0.80, respectively. Abbreviations as in Figure 2.

• 

  Figure 5. Using VCI To Assess the Functional Significance of Tandem Lesions A 67-year-old man presented with chronic stable angina. There were tandem lesions in the left circumflex artery. (A) The measured FFR at the distal vessel was 0.68. (B) The angiogram was used to model the vFFR, which was 0.65 over the same segment of artery. (C) PCI was undertaken to the proximal lesion with implantation of a 3.5- × 12-mm drug-eluting stent, and the post-procedural FFR was 0.85. The distal lesion was left untreated. VCI was used to assess the lesions individually. The proximal stenosis was removed by inserting a 3.5- × 12-mm virtual stent. (D) The recalculated vFFR at the distal vessel was 0.84. (E) The distal stenosis was removed by inserting a 2.75- × 20-mm virtual stent, and the recalculated vFFR at the distal vessel was 0.75. (F) Following VCI to both stenoses in sequence, the vFFR was 0.96. Abbreviations as in Figures 2 and 3.