Evaluation of neointimal morphology of lesions with or without in-stent restenosis: an optical coherence tomography study

BACKGROUND

Characterization of neointimal tissue is essential to understand the pathophysiology of in-stent restenosis (ISR) after drug-eluting stent (DES) implantation. Using optical coherence tomography (OCT), we compared the morphologic characteristics of in-stent neointimal tissue from 33 ISR lesions with those of 192 non-ISR lesions after DES implantation.

HYPOTHESIS

We hypothesized that the morphologic characteristics of in-stent neointimal tissue from ISR lesions were different from those of non-ISR lesions after DES implantation.

METHODS

The DES were coated with sirolimus (n=52), paclitaxel (n=57), zotarolimus (n=84), or everolimus (n=32). In-stent restenosis was defined as ≥50% diameter stenosis at the follow-up angiogram. Lesions with ≥10% neointimal burden ([neointima area × 100]/[stent area]), as determined by OCT, were included in this study. A follow-up OCT (mean follow-up duration, 12.0 ± 10.5 mo) was performed in 209 patients with 225 lesions (ISR lesions, n=33; non-ISR lesions, n=192). Qualitative OCT was used to assess tissue structure, backscatter, visible microvessels, and presence of intraluminal material.

RESULTS

The following characteristics were more common in ISR lesions than in non-ISR lesions: heterogeneous or layered tissues (78.8% vs 22.9%, P<0.001), low backscatter (60.6% vs 20.8%, P<0.001), and microvessels (48.5% vs 5.7%, P<0.001). The independent predictors for heterogeneous or layered neointimal tissues were increased neointima burden (odds ratio [OR]: 1.218, 95% confidence interval [CI]: 1.096-1.354, P<0.001), lumen area (OR: 4.672, 95% CI: 1.371-15.914, P = 0.014), and hypertension (OR: 0.415, 95% CI: 0.186-0.926, P = 0.032).

CONCLUSIONS

This follow-up OCT study demonstrated that morphologic characteristics of neointimal tissues of ISR lesions differ from those of non-ISR lesions.

[Long-term results of chronic occlusion recanalization in patients with coronary heart disease]

The study was undertaken to assess the long-term results of recanalization of chronically occluded coronary arteries, by applying drug-eluting stents to patients with coronary heart disease. The study enrolled 585 patients with one-vessel occlusive lesion of one of three great coronary arteries (TIMI 0; occlusion duration, > or = 3 months): 321 patients who underwent successful recanalization of chronic occlusion and further implantation of drug-eluting stents and 264 patients who received drug therapy (a control group). The short- and long-term results of recanalization were investigated. The follow-up averaged 1095 +/- 36 days; reexaminations were made after 1, 2, and 3 years. The direct success rate of recanalization of chronically occluded coronary arteries was 84.9% (321/378). The results of a 3-year follow-up showed the efficiency and expediency of endovascular recanalization of chronic occlusions: the invasively treated patients had the symptoms of angina pectoris and heart failure significantly less frequently, showed higher exercise tolerance and a less need for antianginal therapy, and had a better long-term prognosis.

Delayed Coverage in Malapposed and Side-Branch Struts With Respect to Well-Apposed Struts in Drug-Eluting Stents

Background—

Pathology studies on fatal cases of very late stent thrombosis have described incomplete neointimal coverage as common substrate, in some cases appearing at side-branch struts. Intravascular ultrasound studies have described the association between incomplete stent apposition (ISA) and stent thrombosis, but the mechanism explaining this association remains unclear. Whether the neointimal coverage of nonapposed side-branch and ISA struts is delayed with respect to well-apposed struts is unknown.

Methods and Results—

Optical coherence tomography studies from 178 stents implanted in 99 patients from 2 randomized trials were analyzed at 9 to 13 months of follow-up. The sample included 38 sirolimus-eluting, 33 biolimus-eluting, 57 everolimus-eluting, and 50 zotarolimus-eluting stents. Optical coherence tomography coverage of nonapposed side-branch and ISA struts was compared with well-apposed struts of the same stent by statistical pooled analysis with a random-effects model. A total of 34 120 struts were analyzed. The risk ratio of delayed coverage was 9.00 (95% confidence interval, 6.58 to 12.32) for nonapposed side-branch versus well-apposed struts, 9.10 (95% confidence interval, 7.34 to 11.28) for ISA versus well-apposed struts, and 1.73 (95% confidence interval, 1.34 to 2.23) for ISA versus nonapposed side-branch struts. Heterogeneity of the effect was observed in the comparison of ISA versus well-apposed struts (H=1.27; I 2 =38.40) but not in the other comparisons.

Conclusions—

Coverage of ISA and nonapposed side-branch struts is delayed with respect to well-apposed struts in drug-eluting stents, as assessed by optical coherence tomography.

Clinical Trial Registration—

http://www.clinicaltrials.gov . Unique identifier: NCT00389220, NCT00617084.

[Potential of plasma adiponectin concentrations as a predictive marker for in-stent restenosis after percutaneous coronary intervention in patients on hemodialysis]

Success of coronary stenting is limited by in-stent restenosis. We aimed to determine whether circulating levels of adiponectin could be associated with the occurrence of coronary in-stent restenosis in patients with end-stage renal disease (ESRD). We enrolled 71 consecutive ESRD patients undergoing hemodialysis (mean age: 64.9 +/- 8.9 years; 19 women, 52 men; mean hemodialysis duration: 78.2 +/- 87.5 months), who received stenting for a single coronary lesion. Plasma adiponectin concentrations were measured within one week before coronary stenting. Of 71 patients who had received stenting, in-stent restenosis occurred in 37 patients (52.1%) within 6 months after stenting. In univariate logistic analysis, homeostasis model assessment index of insulin resistance, blood hemoglobin, serum concentrations of high density lipoprotein cholesterol or triglycerides, and plasma concentrations of insulin or adiponectin were significantly associated with coronary in-stent restenosis. In multiple logistic regression analysis among these variables, however, only the plasma adiponectin concentration was associated with the coronary in-stent restenosis: the odds ratio of increase in 1 microg/ml of plasma adiponectin concentration for having restenosis was 0.651 (p = 0.001, 95% confidence interval: 0.506-0.839). Patients with restenosis had lower plasma adiponectin concentrations than those without [6.2 +/- 2.2 microg/ml (2.1-10.4 microg/ml; n=37) versus 27.2 +/- 10.8 microg/ml (17.9-79.8 microg/ml; n=34); p = 0.0001]. Circulating adiponectin concentrations may be associated with the occurrence of coronary in-stent restenosis in ESRD patients undergoing maintenance hemodialysis.

[Noninvasive radiodiagnosis of late coronary stent stenoses]

OBJECTIVE

To study the diagnostic value of stress echocardiography (stress echoCG) in the early diagnosis of coronary stent stenoses in the late postoperative period.

SUBJECTS AND METHODS

The study enrolled 39 men aged 37 to 58 years with symptoms of cardialgia, who had previously (3 to 8 years earlier) undergone balloon angioplasty and coronary artery stenting to treat coronary heart disease. To exclude coronary stent stenoses, all the patients had dobutamine stress echoCG, transesophageal atrial electrostimulation, and further coronary angiographies (CAG).

RESULTS

Stress echoCG showed a lesion of the stented coronary artery in 34 patients and that of previously angiographically intact coronary arteries in 5 patients. According to CAG data, there was stenosis of > 70% in the coronary stent lumen in 16 patients and that of 40 to 70% in 12 patients. Six patients were found to have de novo stenoses in the previously stented coronary artery. Stress echoCG showed that the diagnostic accuracy and sensitivity of both stenoses of intracoronary stents and de novo ones in the stented artery and previously intact coronary arteries was 100%.

CONCLUSION

Stress echoCG is a highly informative method for the early topical diagnosis of both stenoses of coronary stents and a stenotic lesion of previously intact portions of coronary arteries. The early diagnosis of coronary stent stenoses permits mini-invasive endovascular treatment to be performed.

Evaluation of re-endothelization extent at mid-term follow-up after drug eluting balloon plus bare metal stent implantation during primary coronary angioplasty: insight from OCT imaging

One quarter of patients with STEMI submitted to primary percutaneous coronary intervention (PCI) need repeated target vessel revascularization (TVR) because of stent restenosis or thrombosis. Introduction of DES has effectively reduced the incidence of these complications but the safety of this type of stent in the setting of AMI is limited due to the unpredictable risk of stent malapposition and vessel remodelling in the long term follow-up. Recently, treatment with drug eluting balloon (DEB) in association with bare metal stenting (BMS) has been reported to have an excellent efficacy and safety profile. However, little is known regarding the extent of stent coverage in BMS after DEB utilization.

[Interventional revascularization for cardiovascular disease in patients with chronic kidney disease]

Chronic kidney disease (CKD) is an independent risk factor for cardiac mortality. Accelerated atherosclerosis is frequently seen in patients with CKD. However, even in drug eluting stent era, higher restenosis rate after percutaneous coronary intervention (PCI) for coronary artery disease remains a clinical limitation in patients with CKD. Similar tendency is also seen when treated with endovascular therapy (EVT) for peripheral artery disease. Thus, management for atherosclerotic disease is very difficult in patients with CKD. Recent reports have shown that improvement of devices and/or intensive medical treatment may contribute better clinical outcomes after PCI or EVT in patients with CKD. In addition, inflammatory markers such as C-reactive protein may predict worse clinical outcomes including restenosis in such population.

[Predictors of stent thrombosis in patients with ST-elevation acute coronary syndrome subjected to primary coronary artery intervention]

Basing on complex evaluation of clinical, angiographic, and laboratory data we revealed predictors of stent thrombosis in patients with ST-elevation acute coronary syndrome (ACS) subjected to percutaneous coronary interventions (PCI). Among studied sample of patients (n=124) we distinguished a group of patients with proven stent thrombosis at various stages of follow-up (n=22, group 1) and a group of patients with favorable outcome (n=102, group 2). Unifactorial analysis revealed unfavorable prognostic influence (p=0.025) of hemodynamically significant stenosis of proximal segment of anterior distending artery, disturbances of rhythm and conduction (p=0.0002), as well as degree of heart failure (HF) according to Killip on day 1 of development of symptoms of ACS, and also of high selectin P level on day 10 (p=0.031). With the aim of assessment of prognostic significance of revealed factors we conducted stepwise discriminant analysis according to results of which most significant parameter affecting development of stent thrombosis in patients with ST-elevation ACS appeared to be high Killip class of HF (p&lt;0.0003), to a lesser degree - elevated level of sP-selectin on day 10 of observation (p=0.005). Parameter for which prognostic significance was not revealed as a result of multifactorial analysis was lesion in proximal segment of anterior descending artery (p=0.496). Probability of correct classification of the model was 88.7% at p&lt;0.0001.

Clinical characteristics of coronary drug-eluting stent fracture: insights from a two-center des registry

Stent fracture (SF) has been implicated as a risk factor for in-stent restenosis, but its incidence and clinical characteristics are not well established. Therefore we investigated the conditions associated with stent fracture and its clinical presentation and outcome. Between 2004 and 2007, consecutive cases of SF were collected from the Seoul National University Hospital. Clinical characteristics and outcome of patients with fractured stents were compared with a ten-fold cohort of age and gender matched controls (n = 236). A total of 4,845 patients received percutaneous coronary intervention and 3,315 patients (68.4%) underwent angiographic follow-up. Twenty-eight fractured stents were observed in 24 patients. The incidence of SF was 0.89% for sirolimus-eluting stents (SES) and 0.09% for paclitaxel-eluting stents. Chronic kidney disease, stent implantation in the right coronary artery (RCA), and SES use were independent predictors of drug-eluting stent fracture by multivariate analysis. SF was significantly associated with binary restenosis (11.4% vs 41.7%, P < 0.001) and increased risk of target lesion revascularization (8.1% vs 33.3%, P = 0.001). Patients with SF but without significant restenosis showed excellent outcome despite only medical treatment. In conclusion, SF is associated with increased rates of restenosis and repeat revascularization. Significant risk factors include chronic kidney disease, RCA intervention, and SES use.

Biventricular pacing leading to coronary stent fracture

WEB-SITE FEATURE

Intracoronary optical coherence tomography for the assessment of in-stent restenosis

Optical coherence tomography (OCT) is a novel imaging modality in interventional cardiology. With its clear image quality, it has attracted considerable attention as a tool to accurately evaluate atherosclerosis and coronary stents in vivo. It has a 10-fold higher resolution compared to intravascular ultrasound and utilises near-infrared light that requires temporary blood clearance during image acquisition. We present a case of in-stent restenosis in a patient five years after percutaneous intervention. Optical coherence tomography clearly showed the mechanism behind the stent failure and helped appropriately plan the subsequent repeat intervention. The technology heralds an exciting advance in the invasive assessment of the coronary arteries that will improve our understanding of heart disease into the future.

Very late stent thrombosis after sirolimus-eluting stent implantation observed using optical coherence tomography and coronary angioscopy

Sirolimus-eluting stents (SES) are now commonly used for percutaneous coronary intervention (PCI) because they dramatically reduce the rates of restenosis and target lesion revascularization, even in small vessels and long lesions as compared with bare-metal stent. The unresolved issue about SES use is the possibility of late stent thrombosis. Late stent thrombosis is a very rare, but serious complication that may result in acute myocardial infarction or sudden cardiac death. However, the mechanism of late stent thrombosis with SES has not been established. We report a patient with very late stent thrombosis 37 months after SES implantation who underwent optical coherence tomography and coronary angioscopy.

Drug-eluting stent for unprotected left main coronary artery disease: early and mid-term outcomes

BACKGROUND

PCI is increasingly performed in patients with ULMCA disease. The efficacy and safety of drug-eluting stents in ULMCA disease have been reported.

OBJECTIVE

To evaluate the early and mid-term clinical outcome of the Percutaneous Coronary Intervention (PCI) with Drug-Eluting stent (DES) in unprotected left main coronary artery (ULMCA) disease patients.

MATERIAL AND METHOD

PCI with DES was performed with 90 consecutive patients having ULMCA disease between January 2006 and June 2009.

RESULTS

At a median follow-up of 22.8 +/- 12.2 months, major adverse cardiac or cerebrovascular events (MACCE) occurred in 11 (12.2%) patients. There were seven (7.8%) deaths including two (2.2%) cardiac deaths and five (5.6%) non-cardiac deaths. There was one MI (1.1%), and four (4.4%) target vessel revascularization. Restenosis in the left main occurred only in two patients (2.2%) and definite stent thrombosis occurred in two patients (2.2%).

CONCLUSION

The present study demonstrates that PCI with Drug-Eluting stent implantation in unprotected left main coronary artery disease is a safe form of treatment and has favorable outcomes.

Target lesion revascularization after bare-metal or drug-eluting stents: clinical presentations and outcomes

OBJECTIVE

We sought to examine the clinical presentations and subsequent clinical outcomes of patients undergoing target lesion revascularization (TLR) after either bare-metal stent (BMS) or drug-eluting stent (DES) placement.

BACKGROUND

The widely held notion that BMS TLR is benign has recently been challenged. While DES substantially reduce TLR, little is known about the clinical syndromes accompanying DES TLR and the long-term clinical outcomes after TLR.

METHODS

The clinical syndrome at the time of hospitalization when TLR was performed and subsequent clinical outcomes after TLR were assessed in 1,147 BMS patients and 1,246 DES patients who were followed for 3 years. Patients were considered to have TLR when repeat target lesion PCI was required including those with myocardial infarction (MI) and stent thrombosis.

RESULTS

At 3 years, the overall incidence of TLR was higher after BMS compared to DES 98/1,147 (9.2%) vs. 56/1,246 (4.5%); p < 0.001. The clinical presentations at the time of TLR were not always benign with non-STelevation myocardial infarction (N-STEMI) or STEMI in 25% of BMS vs. 34% DES; p = 0.217. The risk of non-fatal MI or death outcomes over 3 years were significantly worse in those with TLR compared to those without TLR; hazard ratio (HR) 2.65 (2.00-3.52), independent of stent type.

CONCLUSIONS

The clinical presentation at the time of TLR is not always a benign clinical event and identifies a subgroup of stent-treated patients at high risk for non-fatal MI or death in the 3 years following the index percutaneous coronary intervention, independent of stent type.

Very late bare metal stent thrombosis: The role of restenosis

Stent endothelization is complete after one month in the absence of radiation therapy. The incidence of late stent thrombosis associated with bare metal stents is low beyond this one month period. In this paper, we report on a case of very late acute stent thrombosis that occurred after 118 months of first bare metal stent implantation. A 55-year-old male patient was admitted with chest pain and was diagnosed to have acute anterior myocardial infarction. He had a history of bare metal stent implantation for a critical stenosis in the left anterior descending coronary artery. Immediate coronary angiography demonstrated occlusion of the stent in the left coronary artery. Thromboaspiration was not an available option, so a new bare metal stent was implanted and TIMI III flow was established after balloon angioplasty.

Prolonged double antiplatelet therapy in a cohort of "de novo" diabetic patients treated with drug-eluting stent implantation

Diabetes mellitus (DM) accounts for >25% of all percutaneous coronary interventions. In patients with DM, drug-eluting stent implantation is associated with a reduced risk of restenosis and target lesion revascularization. However, concern has been raised about the incidence of late and very late stent thrombosis and the increased mortality rate, mostly after thienopyridine withdrawal. We evaluated the long-term prognostic effect of thienopyridine discontinuation after drug-eluting stent implantation on the subsequent occurrence of stent thrombosis and all-cause death among a cohort of high-risk "de novo" diabetic patients. From May 2002 to December 2005, 542 consecutive patients with DM underwent drug-eluting stent implantation at 2 hospitals in Milan, Italy. For study purposes, only the 217 patients who had not previously undergone percutaneous or surgical revascularization were considered in the final analysis. The follow-up time was curtailed at 3.5 years. Detailed information about dual antiplatelet therapy (DAT) were collected for all patients included. Of the 217 patients, 15 died (6.9%); in 9 cases, the cause of death was cardiac (4.1%). The incidence of cumulative stent thrombosis was 4.6% (10 patients); 3 stent thromboses were early (1.38%), 5 late (2.3%), and only 2 were very late (0.9%). Of the 10 cases of stent thrombosis, 5 were definite and 5 were probable. Most (80%) of the stent thromboses occurred within the first 6 months during DAT. The median duration of DAT was 420 days (interquartile range 350 to 859). DAT discontinuation was the only independent predictor of the follow-up events (hazard ratio 20.42, 95% confidence interval 4.99 to 83.62). In conclusion, DM remains an independent adverse factor on clinical outcome. In this setting, prolonged DAT, even beyond that recommended in the guidelines, might be beneficial.

Effects of combined therapy with ezetimibe plus simvastatin after drug-eluting stent implantation in a porcine coronary restenosis model

The aim of this study was to examine the anti-proliferative and anti-inflammatory effects of ezetimibe/simvastatin (E/S) after drug-eluting stent (DES) implantation in a porcine coronary restenosis model. Pigs were randomized into two groups in which the coronary arteries (23 pigs) had DES. Stents were deployed with oversizing (stent/artery ratio 1.3:1) in porcine coronary arteries. Fifteen pigs were taken 10/20 mg of E/S and eight pigs were not taken E/S. Histopathologic analysis was assessed at 28 days after stenting. In neointima, most inflammatory cells were lymphohistiocytes. Lymphohistiocyte count was not different between two groups (337+/-227 vs. 443+/-366 cells, P=0.292), but neointima area was significantly smaller (1.00+/-0.49 mm(2) vs. 1.69+/-0.98 mm(2), P=0.021) and percent area stenosis was significantly lower (23.3+/-10% vs. 39+/-19%, P=0.007) in E/S group compared with control group. There were no significant differences in fibrin score (1.99+/-0.79 vs. 1.81+/-0.88, P=0.49), endothelial score (1.75+/-0.66 vs. 1.80+/-0.59, P=0.79), and the percent of endothelium covered lumen (43+/-21% vs. 45+/-21%, P=0.84) between E/S group and control group. Combined therapy with ezetimibe and simvastatin inhibits neointimal hyperplasia, but does not inhibit inflammatory infiltration and arterial healing after DES implantation in a porcine coronary restenosis model.