Relationship Between Thickness of Calcium on Optical Coherence Tomography and Crack Formation After Balloon Dilatation in Calcified Plaque Requiring Rotational Atherectomy

Aim Clinical outcomes after percutaneous coronary intervention (PCI) in hemodialysis (HD) patients are significantly worse than those in non‐HD patients. Optical coherence tomography (OCT) is a high resolution imaging modality and provides a detailed assessment of post‐interventional abnormal findings that influence worse clinical outcomes. However, little is known about the abnormal post‐stent OCT findings in HD patients. Therefore, in this study, we compared the abnormal post‐stent OCT findings between HD and non‐HD patients. Methods One hundred thirty‐nine consecutive OCT guided PCI (21 lesions in HD patients and 118 lesions in non‐HD patients) were enrolled. We compared the post‐stent OCT findings, including the edge dissections, under expansion index (minimum stent area/mean reference area), and stent eccentricity index (minimum stent diameter/maximum stent diameter) between HD and non‐HD patients. We also compared the device‐oriented clinical events (DoCEs) at 8 months of follow up. Results There was a significantly higher prevalence of distal edge dissections (16.7% vs. 2.8%, P = 0.011) in HD patients. HD patients had a significantly lower under expansion index (0.76 ± 0.21 vs. 0.85 ± 0.14, P = 0.029) and stent eccentricity index (0.82 ± 0.09 vs. 0.88 ± 0.18, P = 0.018). The cumulative rate of DoCEs was significantly higher in the HD patients (23.8% vs. 5.2%, P = 0.013). Conclusions A higher prevalence of distal edge dissections, under expansion and stent eccentricity were detected by the detailed OCT findings in HD patients.

Section: Discussionmentioning

confidence: 95%

Characteristics of abnormal post‐stent optical coherence tomography findings in hemodialysis patients

Matsuhiro

Matsunaga‐Lee

Nakamura

et al. 2019

“…Stent malapposition was defined as stent adjacent to the lumen surface distance >0.2 mm, and percent malapposition CSA (malapposition CSA/lumen CSA) was calculated. The presence of calcium fracture was defined as complete discontinuity, not partial, of the calcified plaque after stenting—that is, full‐thickness calcium fracture . Calcium fracture was considered as a single calcium fracture when the frames with the fracture were connected longitudinally; calcium thickness on both sides of the fracture in every cross‐section was measured and the thicker of the two selected to represent maximum calcium thickness.…”

Section: Methodsmentioning

confidence: 99%

“…The detailed mechanisms of OA and its efficacy when treating calcified lesions have not been well described, especially using intravascular imaging. Recent reports using OCT have shown that calcium fracture was one of the mechanisms of better stent expansion in severely calcified lesions, while calcium fracture appeared to be limited to segments with thin vs thick calcium . We used OCT to assess calcified lesions treated by OA prior to stenting to clarify the ability and mechanism of OA to facilitate calcium fracture and stent expansion.…”

Section: Introductionmentioning

confidence: 99%

Effect of orbital atherectomy in calcified coronary artery lesions as assessed by optical coherence tomography

Yamamoto

Maehara

Kim

et al. 2018

Objectives We sought to assess plaque modification and stent expansion following orbital atherectomy (OA) for calcified lesions using optical coherence tomography (OCT). Background The efficacy of OA for treating calcified lesions is not well studied, especially using intravascular imaging in vivo. Methods OCT was performed preprocedure, post‐OA, and post‐stent (n = 58). Calcium modification after OA was defined as a round, concave, polished calcium surface. Calcium fracture was complete discontinuity of calcium. Results Comparing pre‐ vs post‐OA OCT (n = 29), calcium area was significantly decreased post‐OA (from 3.4 mm2 [2.4–4.7] to 2.9 mm2 [1.9–3.9], P < 0.001). Poststent percent calcium fracture (calcium fracture length/calcium length) correlated with post‐OA percent calcium modification (calcium modification length/calcium length) (r = 0.31, P = 0.01). Among 75 calcium fractures in 35 lesions, maximum calcium thickness at the fracture site was greater with vs without calcium modification (0.58 mm [0.50–0.66] vs 0.45 mm [0.38–0.52], P = 0.003). Final optimal stent expansion, defined as minimum stent area ≥6.1 mm2 or stent expansion ≥90% (medians of this cohort) at the maximum calcium angle site, was observed in 41 lesions. Larger post‐OA lumen area (odds ratio 2.64; 95% CI 1.21–5.76; P = 0.02) and the presence of calcium fracture (odds ratio 6.77; 95% CI 1.25–36.6; P = 0.03) were independent predictors for optimal stent expansion. Conclusions Calcium modification by OA facilitates poststent calcium fracture even in thick calcium. Greater calcium modification correlated with greater calcium fracture, in turn resulting in better stent expansion.

“…The mechanism of the CB is to create discrete incisions in the atherosclerotic plaque, enabling greater expansion while preventing uncontrolled dissections . Optical coherence tomography (OCT) can evaluate the thickness of calcium and assess calcium fracture with great accuracy . We hypothesized that adjunctive use of the CB following RA, but before stent implantation could further modify severely calcified lesions to achieve greater stent expansion compared with RA followed by conventional ballooning and that OCT could delineate these mechanisms and assess efficacy.…”

Section: Introductionmentioning

confidence: 99%

Effect of cutting balloon after rotational atherectomy in severely calcified coronary artery lesions as assessed by optical coherence tomography

Amemiya

Yamamoto

Maehara

et al. 2019

Objectives Using optical coherence tomography (OCT), we evaluated the effect of a cutting balloon (CB) compared with a conventional balloon after rotational atherectomy (RA) and before stenting in severely calcified coronary lesions. Background A CB is designed to create discrete incisions to facilitate fracture of severely calcified plaque. Methods OCT was performed preintervention (if possible), post‐RA, and poststent implantation. RA modification of calcium was defined as a polished, concave, round‐shaped surface. Calcium fracture was defined as a break in the calcium plate. The effects of calcium modification and stent expansion between CB (n = 18) versus conventional balloon (n = 23) following RA were compared. Results Median patient age was 72 years with 24% on hemodialysis. The amount of calcium and the length of RA modification were comparable between the CB and conventional balloon groups. Final poststent OCT showed that the number and thickness of calcium fracture were greater after CB versus conventional balloon, resulting better stent expansion (78.9% [IQR: 72.4–88.1] vs. 66.7% [IQR: 55.0–76.7], p < 0.01). In the multivariable model, after adjusting for the amount of calcium, CB use was an independent predictor of the presence of calcium fracture (odds ratio 30.0; 95% confidence interval 2.7–994.1, p = 0.004) and an independent predictor for greater stent expansion (regression coefficient 7.4; 95% confidence interval 0.5–14.3, p = 0.04). Conclusion In severely calcified lesions calcium fracture was more often associated with RA followed by CB compared with RA followed by conventional balloon predilation before stenting. CB use was also a determinant of greater stent expansion.