Procedural Outcomes After Percutaneous Coronary Interventions in Focal and Diffuse Coronary Artery Disease

Abstract

Background Coronary artery disease (CAD) patterns play an essential role in the decision-making process about revascularization. The pullback pressure gradient (PPG) quantifies CAD patterns as either focal or diffuse based on fractional flow reserve (FFR) pullbacks. The objective of this study was to evaluate the impact of CAD patterns on acute percutaneous coronary intervention (PCI) results considered surrogates of clinical outcomes. Methods and Results This was a prospective, multicenter study of patients with hemodynamically significant CAD undergoing PCI. Motorized FFR pullbacks and optical coherence tomography (OCT) were performed before and after PCI. Post-PCI FFR >0.90 was considered an optimal result. Focal disease was defined as PPG >0.73 (highest PPG tertile). Overall, 113 patients (116 vessels) were included. Patients with focal disease were younger than those with diffuse CAD (61.4±9.9 versus 65.1±8.7 years, P=0.042). PCI in vessels with high PPG (focal CAD) resulted in higher post-PCI FFR (0.91±0.07 in the focal group versus 0.86±0.05 in the diffuse group, P<0.001) and larger minimal stent area (6.3±2.3 mm² in focal versus 5.3±1.8 mm² in diffuse CAD, P=0.015) compared withvessels with low PPG (diffuse CAD). The PPG was associated with the change in FFR after PCI (R²=0.51, P<0.001). The PPG significantly improved the capacity to predict optimal PCI results compared with an angiographic assessment of CAD patterns (area under the curve_PPG 0.81 [95% CI, 0.73-0.88] versus area under the curve_angio 0.51 [95% CI, 0.42-0.60]; P<0.001). Conclusions PCI in vessels with focal disease defined by the PPG resulted in greater improvement in epicardial conductance and larger minimal stent area compared with diffuse disease. PPG, but not angiographically defined CAD patterns, distinguished patients attaining superior procedural outcomes. Registration URL: https://clinicaltrials.gov/ct2/show/NCT03782688.

Keywords: CAD patterns; diffuse disease; percutaneous coronary interventions; pullback pressure gradient.

Figure 1. Study flow chart.

FFR indicates fractional flow reserve; OCT, optical coherence tomography; PCI, percutaneous coronary intervention; and PPG, pullback pressure gradient.

Figure 2. Relationships between pullback pressure gradient and morphological lesions characteristics before and after PCI.

The top row shows the relationship between the PPG (x‐axes) and minimal lumen area (left), and minimal stent area (right). The mid‐row shows the relationship between PPG and acute luminal gain (minimal stent area minus minimal lumen area) on the left side and stent expansion on the right side. The bottom panel shows the lumen area change achieved by PCI stratified by PPG (x‐axis). The red arrows identify patients with diffuse disease, whereas the blue arrows focal disease with the corresponding mean acute lumen gain. PCI indicates percutaneous coronary intervention; and PPG, pullback pressure gradient.

Figure 3. Relationships between pullback pressure gradient, post‐PCI, and delta FFR.

The top row shows the correlations between the PPG (x‐axes) and post‐PCI FFR (left), and delta FFR (right). In the mid panel, the changes in FFR stratified by the PPG are presented. The red arrows categorize patients with diffuse disease, whereas the blue arrows identify focal disease. The bottom panel shows the distribution of the PPG. The red shaded area points to PPG values considered diffuse CAD, whereas the blue shade is focal CAD. The dashed vertical lines show each vessel analyzed. CAD indicates coronary artery disease; FFR, fractional flow reserve; PCI, percutaneous coronary intervention; and PPG, pullback pressure gradient.

Figure 4. Proportions of patients attaining optimal anatomical and functional outcomes stratified by CAD patterns.

In the top panel, the pie charts show the proportion of patients achieving high post‐PCI FFR (defined as ≥0.90) and large MSA (>5.5 mm²). The stacked bars next to the pie charts show the proportion of patients with focal and diffuse CAD having high or low post‐PCI FFR (right) and large or small MSA (right). At the bottom, the proportion of patients with focal and diffuse CAD in the different morphological and functional PCI outcomes combination are shown. A significantly higher proportion of patients with diffuse disease had small MSA and low post‐PCI FFR. CAD indicates coronary artery disease; FFR, fractional flow reserve; MSA, minimal stent area; PCI, percutaneous coronary intervention; and PPG pullback pressure gradient.

Figure 5. Case examples of focal and diffuse CAD.

Left panel: Functional focal CAD, Right panel: Functional diffuse CAD. (a) and (a'): pre‐PCI FFR pullbacks. (b) and (b'): post‐PCI FFR and FFR pullbacks. (c) and (c'): pre‐PCI coronary angiography, white arrowheads show target lesions. (d) and (d'): post‐PCI angiographies. (e) and (e'): post‐PCI OCT with a cross‐sectional view at MSA. (f) and (f'): post‐PCI OCT longitudinal view indicating the position of the MSA. CAD indicates coronary artery disease; FFR, fractional flow reserve; MSA, minimum stent area; and OCT, optical coherence tomography; PCI, percutaneous coronary intervention; and PPG, pullback pressure gradient.