Abstract 5602: Initial Angle and Overcorrected Angle at Coronary Lesion Predicts Delayed Drug-Eluting Stent Fracture: Quantitative Angle Analysis in Stent Fracture Patients
Background: Stent fracture (SF) is a potential cause of restenosis, pseudoaneurysm or thrombosis, which acquire special significance in the treatment failure with drug-eluting stent (DES). From a point of view that chronic fatigue stress associated with anlge and angular momentum, we quantitatively analyzed the initial native maximum and minimum angles (Ai-max, Ai-min) and the change (ΔAi) in repetitive bending movement of coronary lesion before stenting, angles (Ap-max, Ap-min, ΔAp) after immediate stenting, corrected angle [A corr-max=Δ (Ap−Ai) max] by stent, and angles (Asf-max, Asf-min, ΔAsf) after SF in delayed DES fracture patients.
Methods: From October 2005 to July 2006, 139 patients underwent follow-up coronary angiography after 258 DES implantations. DES fractures were detected at 13 patients (M:F=12:1, Age: 60.3±9.4 year-old). We quantitatively analyzed the angles (Ai, Ap, ΔA, Asf) at the same plane view by Nexus 1.0 in 13 patients.
Results: The follow-up duration was 255.7±75.7 days. All 13 DES fractured patients had no clinical symptoms associated with SF, and had a male-predominance. The number of stent implantation at target lesion associated fracture site was 1.9±0.6. Stent diameter and length were 3.00±0.25 and 53.0±17.4 mm. Four of 13 patients had multiple fractures (LAD; 2, RCA: 2 cases). Nine patients had single fracture (LAD; 1, LCX; 3, RCA; 5 cases). All most all fracture sites (92.3%, 12/13cases) were angulated and bending lesion. Only 1 fracture site was not associated with angulated lesion. The mean ΔAi, Ai-max and Ai-min were 18.9°, 145.5° and 125.8°. Mean ΔAp, Ap-max and Ap-min were 4.9°, 158.8° and 154.1°. Mean maximal corrected angle by PCI were 28.3°. In SF, The mean ΔAsf, Asf-max and Asf-min were 13.8°, 149.4° and 133.5°. These Asf values had a strong tendency to recover the initial native physiologic angle (Ai) against corrected angle by stenting. The simulation program for evaluation of angular momentum in DES supports the same results.
Conclusion: Theses findings suggest that the initial angle and extent of overcorrected angle against physiologic coronary configuration are important at delayed DES fracture. And it has considering potential as a new marker for assessing risk of DES fracture.