Serial gray scale intravascular ultrasound findings in late drug-eluting stent restenosis

Prevalence, predictors, and management for balloon uncrossable or undilatable lesions in patients undergoing percutaneous coronary intervention with in-stent restenosis chronic total occlusion

Background

Percutaneous coronary intervention for in-stent restenosis (ISR) chronic total occlusion (CTO) has been a great challenge. There are occasions when the balloon is uncrossable or undilatable (BUs) even though the guidewire has passed, leading to failure of the procedure. Few studies have focused on the incidence, predictors, and management of BUs during ISR-CTO intervention.

Methods

Patients with ISR-CTO were recruited consecutively between January 2017 and January 2022 and divided into two groups based on the presence of BUs. The clinical data of the two groups (BUs group and non-BUs group) were retrospectively analyzed and compared to explore the predictors and clinical management strategies of BUs.

Results

A total of 218 patients with ISR-CTO were included in this study, 23.9% (52/218) of whom had BUs. The percentage of ostial stents, stent length, CTO length, the presence of proximal cap ambiguity, moderate to severe calcification, moderate to severe tortuosity, and J-CTO score were higher in the BUs group than in the non-BUs group (p < 0.05). The technical success rate and the procedural success rate were lower in the BUs group than in the non-BUs group (p < 0.05). Multivariable logistic regression analysis showed that ostial stents (OR: 2.011, 95% CI: 1.112-3.921, p = 0.031), the presence of moderate to severe calcification (OR: 3.383, 95% CI: 1.628-5.921, p = 0.024) and moderate to severe tortuosity (OR: 4.816, 95% CI: 2.038-7.772, p = 0.033) were independent predictors of BUs.

Conclusion

The initial rate of BUs in ISR-CTO was 23.9%. Ostial stents, presence of moderate to severe calcification, and moderate to severe tortuosity were independent predictors of BUs.

Incidence of coronary drug-eluting stent fracture: A systematic review and meta-analysis

Background

Reported evidence of coronary stent fracture (CSF) has increased in recent years. The purpose of this study was to determine reliable estimates of the overall incidence of CSF.

Methods and results

The MEDLINE, Embase and Cochrane databases were searched until March 18, 2022. Pooled estimates were acquired using random effects models. Meta-regression and subgroup analysis were used to explore sources of heterogeneity, and publication bias was evaluated by visual assessment of funnel plots and Egger’s test. Overall, 46 articles were included in this study. Estimates of CSF incidence were 5.5% [95% confidence interval (CI): 3.7–7.7%] among 39,953 patients based on 36 studies, 4.8% (95% CI: 3.1–6.8%) among 39,945 lesions based on 29 studies and 4.9% (95% CI: 2.5–9.4%) among 19,252 stents based on 8 studies. There has been an obvious increase in the incidence of CSF over the past two decades, and it seems that the duration of stent placement after stent implantation has no impact on incidence estimation.

Conclusion

The incidence of CSF was 5.5% among patients, 4.8% for lesions and 4.9% for stents and increased over the past 20 years. The duration of stent placement after stent implantation was found to have no impact on the incidence of CSF, but drug-eluting stent (DES) types and right coronary artery (RCA) lesions influenced the pooled incidence.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022311995], identifier [CRD42022311995].

The role of intravascular ultrasound in percutaneous coronary intervention of complex coronary lesions

Intravascular ultrasound (IVUS) is a catheter-based coronary imaging technique. It utilises the emission & subsequent detection of reflected high frequency (30-60 MHz) sound waves to create high resolution, cross-sectional images of the coronary artery. IVUS has been the cornerstone of intracoronary imaging for more than two decades. When compared to the invasive coronary angiogram which studies only the silhouette of the contrast-filled artery lumen, IVUS also crucially images the vessel wall. Because of this capability, IVUS has greatly facilitated understanding of the coronary atherosclerosis process. Such insights from IVUS reveal how commonly and extensively plain angiography underestimates the true extent of coronary plaque, the characteristics of plaques prone to rupture and cause acute coronary syndromes (lipid rich, thin cap atheroma), and a realisation of the widespread occurrence of vessel remodelling in response to atherosclerosis. Similarly, IVUS has historically provided salutary mechanistic insights that have guided many of the incremental advances in the techniques of percutaneous coronary intervention (PCI). Examples include mechanisms of in-stent restenosis, and the importance of high-pressure post-dilatation of stents to ensure adequate stent apposition and thereby reduce the occurrence of stent thrombosis. IVUS also greatly facilitates the choice of correct diameter and length of stent to implant. Overall, a compelling body of evidence indicates that use of intravascular ultrasound in PCI helps to achieve optimal technical results and to mitigate the risk of adverse cardiac events. In this review, the role of intravascular ultrasound as an adjunct to PCI in complex coronary lesions is explored. The complex coronary situations discussed are the left main stem, ostial stenoses, bifurcation stenoses, thrombotic lesions, the chronically occluded coronary artery, and calcified coronary artery disease. By thorough review of the available evidence, we establish that the advantages of IVUS guidance are particularly evident in each of these complex CAD subsets. In particular, some consider the use of IVUS to be almost mandatory in left main PCI. A comparison with other intracoronary imaging techniques is also explored.

Chronic stent recoil in severely calcified coronary artery lesions. A serial optical coherence tomography study

Chronic second-generation drug-eluting stent recoil in severely calcified coronary lesions has not been studied. We aimed to evaluate chronic stent recoil by optical coherence tomography (OCT) in severely calcified lesions treated with thin strut stents after rotational atherectomy. In 28 lesions (26 patients with 23% on hemodialysis) treated with everolimus-eluting stents after rotational atherectomy, baseline and 8-month follow-up OCT were compared. Stent recoil was defined as >10% decrease in stent area from baseline to follow-up. Overall, there was no change in minimal stent area (6.0 mm² [5.0, 8.1] to 6.0 mm² [4.8, 8.6], p = 0.51) from baseline to follow-up, although neointimal hyperplasia measured 16.3 ± 15.8%. Thirty-six percent of lesions showed stent recoil associated with 6 non-nodular calcifications, 1 calcified nodule, and 3 stent deformations. The overall mean calcium angle with attenuation decreased (54° [29-76] to 31° [19-48], p < 0.0001), and calcium without attenuation increased (28° [21-67] to 64° [34-93], p < 0.0001), but primarily at the location of stent recoil. Furthermore, in the stent recoil segments in 10 recoil lesions, the stent circumference decreased primarily at non-calcium segments rather than at calcium with or without attenuation. One lesion with stent recoil and 2 lesions without stent recoil required repeat revascularization. Thin strut stents can chronically recoil in severely calcified lesions, but this rarely causes restenosis.

Clinical outcomes of rotational atherectomy in severely calcified in-stent restenosis: a single-center, retrospective study

Neointimal calcification after stent implantation has been reported as one of the forms of neoatherosclerosis. There are a few patients with in-stent restenosis (ISR) and an undilatable calcified neointima who require rotational atherectomy to achieve sufficient acute gain in lumen diameter. However, the clinical outcomes of rotational atherectomy for undilatable calcified ISR have not been fully elucidated. Therefore, we investigated the safety and efficacy of rotational atherectomy for treating calcified ISR. This retrospective study included 17 patients (20 lesions) who had undergone percutaneous coronary intervention including rotational atherectomy to treat ISR with severely calcified neointima. Kaplan-Meier analysis was used to analyze the data. The mean age of the enrolled patients was 67±18 years, and 71% were men. The patients had highly atherogenic characteristics: 65% had diabetes mellitus and 53% were receiving hemodialysis. Procedural success was obtained in 19 (95%) patients, and the acute gain in lumen diameter was acceptable (1.7±0.6 mm). However, during a median follow-up of 571 days, the incidences of major adverse cardiac and cerebrovascular events per patient and clinical-driven target lesion revascularizations per lesion were relatively high. There were no differences in clinical outcomes according to the baseline characteristics, type of restenotic stents, and therapeutic strategy. In conclusion, clinical outcomes of rotational atherectomy for severely calcified ISR were unfavorable despite a high success rate and acceptable acute gain in lumen diameter.

Incidence, predictive factors, and clinical impact of stent recoil in stent fracture lesion after drug-eluting stent implantation

BACKGROUND

Stent fracture (SF) after drug-eluting stent (DES) implantation was reported to be associated with target lesion revascularization (TLR). We have noted abnormal late acquired stent axial deformation in lesions after DES implantation, especially in SF lesions, and defined it as stent recoil (SR). We evaluated the incidence, predictive factors, and clinical impact of SR in SF lesions.

METHODS

Between 2003 and 2012, 5456 patients (11,712 lesions) underwent DES implantations and follow-up angiography within one year after the index procedure. SR was defined as an axial recoil deformation less than 80% of the stent diameter and SF was defined as the separation of stent segments or stent struts. SF and SR were confirmed by follow-up angiography. The primary endpoint was defined as clinically driven TLR.

RESULTS

SF was observed in 494 lesions (4.2%) and SR in 138 of SF lesions (27.9%). According to multinomial logistic regression analyses, severe calcification and ostial lesion in the right coronary artery were stronger predictive factors of SF with SR lesions. The cumulative incidences of any and clinically driven TLR at 5years were both significantly higher in the SF with SR group than in the SF without SR group (51.7% versus 35.0%, P<0.001; 22.2% versus 12.8%, P=0.019; respectively).

CONCLUSIONS

SR in SF lesions after DES implantation could be related to the lesion characteristics. SF with SR was highly associated with subsequent TLR compared with SF without SR.

Intravascular imaging of coronary calcification and its clinical implications

Calcium impacts the natural history and treatment of coronary artery disease in many ways. Intravascular imaging studies, mostly intravascular ultrasound, but more recently studies using optical coherence tomography, have been instrumental in increasing our understanding of the relationship between calcium and coronary atherosclerosis, the predictors, the natural history of this relationship, and the impact on treatment. On one hand, stable coronary lesions are associated with more calcium than unstable lesions; and the amount of calcium may affect the success of percutaneous coronary intervention. On the other hand, calcium correlates with plaque burden; unstable lesions are associated with focal calcium deposits; and calcific nodules are one of the morphologies of vulnerable plaque. This review focuses on more than 20 years of intravascular imaging studies of the relationship between calcium and coronary atherosclerosis.

The clinical characteristics and prognosis of lesions with in-stent eccentric tissue proliferation and strong signal attenuation detected by optical coherence tomography

There are still some patients who require repeat revascularization despite of drug-eluting stent (DES) implantation. The present study aimed to investigate the relationship between optical coherence tomography (OCT) findings and recurring target lesion revascularization (TLR) after percutaneous coronary intervention (PCI) for in-stent restenosis (ISR). We reviewed 50 patients (54 coronary lesions) who underwent PCI for ISR, which included 25 DES-ISR lesions. The PCI strategy depended on the interventionalist's discretion, and DES implantation was performed for 38 (70 %) lesions. Tissue characteristics were assessed qualitatively and quantitatively using the frame showing maximal lumen narrowing (minimal lumen area). In qualitative analysis, OCT detected coexistence of eccentric tissue proliferation and strong signal attenuation (ESA). ESA was observed in six lesions (11 %) in five patients (10 %). Hemodialysis (80 vs. 20 %, p = 0.013) and DES-ISR (100 vs. 40 %, p = 0.0069) were significantly more frequent in ESA patients/lesions than in others. One-year follow-up revealed that re-TLR was more frequently performed for ESA lesions (83 vs. 8 %, p = 0.0002). The findings reveal that ESA detected in OCT images of ISR is related to TLR after PCI for DES-ISR especially in patients undergoing maintenance hemodialysis.

Alagebrium inhibits neointimal hyperplasia and restores distributions of wall shear stress by reducing downstream vascular resistance in obese and diabetic rats

Mechanisms of restenosis in type 2 diabetes mellitus (T2DM) are incompletely elucidated, but advanced glycation end-product (AGE)-induced vascular remodeling likely contributes. We tested the hypothesis that AGE-related collagen cross-linking (ARCC) leads to increased downstream vascular resistance and altered in-stent hemodynamics, thereby promoting neointimal hyperplasia (NH) in T2DM. We proposed that decreasing ARCC with ALT-711 (Alagebrium) would mitigate this response. Abdominal aortic stents were implanted in Zucker lean (ZL), obese (ZO), and diabetic (ZD) rats. Blood flow, vessel diameter, and wall shear stress (WSS) were calculated after 21 days, and NH was quantified. Arterial segments (aorta, carotid, iliac, femoral, and arterioles) were harvested to detect ARCC and protein expression, including transforming growth factor-β (TGF-β) and receptor for AGEs (RAGE). Downstream resistance was elevated (60%), whereas flow and WSS were significantly decreased (44% and 56%) in ZD vs. ZL rats. NH was increased in ZO but not ZD rats. ALT-711 reduced ARCC and resistance (46%) in ZD rats while decreasing NH and producing similar in-stent WSS across groups. No consistent differences in RAGE or TGF-β expression were observed in arterial segments. ALT-711 modified lectin-type oxidized LDL receptor 1 but not RAGE expression by cells on decellularized matrices. In conclusion, ALT-711 decreased ARCC, increased in-stent flow rate, and reduced NH in ZO and ZD rats through RAGE-independent pathways. The study supports an important role for AGE-induced remodeling within and downstream of stent implantation to promote enhanced NH in T2DM.

Reproducibility of grayscale and radiofrequency IVUS data acquisition in stented coronary arteries

OBJECTIVES

Variability in data acquisition from intervened coronary arteries could represent a source of error that has implications for the design of serial stent studies. We assessed inter-pullback reproducibility of volumetric grayscale and radiofrequency intravascular ultrasound (IVUS) data in stented coronary arteries.

DESIGN

Fifteen patients with coronary artery lesions treated with stent implantation were included and examined with two separate pullbacks using the Eagle Eye Gold-phased array 20 MHz IVUS catheter (Volcano). The arteries were divided into five segments, giving a total of 150 sub-segments for analyses. Matching of frames was performed using landmarks that were clearly visible in coronary angiography and intravascular pullbacks. Data were analyzed off-line at an independent Corelab.

RESULTS

The inter-pullback reproducibility of geometrical data was very good for non-stented segments with relative differences less than 5% between pullbacks for lumen-, vessel-, and plaque volumes. For stented segments reproducibility was poorer with relative differences between pullbacks in the range of 5-10%. The inter-pullback reproducibility of compositional data demonstrated large standard deviations of relative differences, indicating a weaker agreement.

CONCLUSIONS

Agreements between pullbacks were weaker in stented than those in non-stented segments. Based on our data, future longitudinal IVUS studies in intervened vessels should account for a variability of 5-10% attributed to the acquisition of images.

The efficacy of "hybrid" percutaneous coronary intervention in chronic total occlusions caused by in-stent restenosis: insights from a US multicenter registry

OBJECTIVES

To examine the success and complication rates in percutaneous coronary intervention (PCI) for chronic total occlusions (CTO) caused by in-stent restenosis (ISR).

BACKGROUND

PCI for in-stent total occlusive disease has traditionally been associated with low success rates. We sought to examine angiographic and procedural outcomes of patients who underwent CTO PCI due to ISR using the novel "hybrid" algorithm, and compare them with patients with de novo CTOs.

METHODS

We examined 521 consecutive patients who underwent CTO PCI at five high-volume PCI centers in the United States using the "hybrid" approach. Clinical, angiographic, and procedural outcomes were compared between CTOs due to ISR and de novo CTOs.

RESULTS

The target CTO was due to ISR in 57 of 521 patients (10.9%). Compared to patients with de novo CTOs, those with CTO due to ISR had higher frequency of diabetes (56.1% vs. 39.6%, P = 0.02) and less calcification (5.3% vs. 16.2%, P <0.001), but longer occlusion length [38 (29-55) vs. 30 (20-51), P = 0.04]. Technical success in the ISR and de novo group was 89.4% and 92.5% (P = 0.43), respectively; procedural success was 86.0% and 90.3% (P = 0.31), respectively; and the incidence of major adverse cardiac events was 3.5% and 2.2% (P = 0.63), respectively.

CONCLUSIONS

Use of the "hybrid" approach to CTO PCI was associated with similarly high procedural success and similarly low major complication rates in patients with de novo and ISR CTOs.