Evaluation by optical coherence tomography of neointimal coverage of sirolimus-eluting stent three months after implantation

Confirming complete neointimal coverage after implantation of a drug-eluting stent is clinically important because incomplete stent coverage is responsible for late thrombosis and sudden cardiac death. Optical coherence tomography is a high-resolution (approximately 10 microm) imaging technique capable of detecting a thin layer of neointimal hyperplasia (NIH) inside a sirolimus-eluting stent (SES) and stent malapposition. This investigation evaluated stent exposure and malapposition 3 months after SES implantation using optical coherence tomography in a different clinical presentations, such as acute coronary syndrome (ACS) and non-ACS. Motorized optical coherence tomographic pullback (1 mm/s) was performed at 3-month follow-up to examine consecutive implanted 31 SESs in 21 lesions in 21 patients (9 with ACS and 12 with non-ACS). NIH thickness inside each strut and percent NIH area in each cross section were measured. In total, 4,516 struts in 567-mm single-stented segments were analyzed. Overall, NIH thickness and percent NIH area were 29 +/- 41 microm and 10 +/- 4%, respectively. Rates of exposed struts and exposed struts with malapposition were 15% and 6%, respectively. These were more frequent in patients with ACS than in those with non-ACS (18% vs 13%, p <0.0001; 8% vs 5%, p <0.005, respectively). In conclusion, neointimal coverage over a SES at 3-month follow-up is incomplete in ACS and non-ACS. Our study suggests that dual antiplatelet therapy might be continued >3 months after SES implantation.

[Clinical and angiographic parameters affecting the quality of 16 slice spiral CT in the diagnosis of restenosis after stenting the left main coronary artery]

The metallic component of coronary stents makes it difficult to study their lumen by angio scanner. The object of this preliminary study was to appreciate the factors influencing the diagnosis of restenosis after stenting the left main coronary artery by 16-slice spiral angio CT. This Monocentric study included 27 patients who underwent 16-slice spiral angio CT six months after stenting of the left main coronary artery. It was possible to assess the stent lumen in 21 patients (78%) and no cases of > 50% restenosis were observed. In 4 patients, hypodense zones adjacent to the stent links were observed suggesting moderate intimal hyperplasia. The tests for ischaemia were normal in 3 of these patients. Coronary angiography and endocoronary ultrasound excluded significant restenosis in the fourth patient. In univariable analysis, the facors associated with good or excellent angioscanner quality (45% of patients) were Ostial stenosis (p = 0.03), no or minimal calcification on initial coronary angiography (p = 0.0S), stent diameters > 3.5mm (p = 0.03), heart rates < 60/min (p = 0.04), absence of extrasystoles (p = 0.05) during acquisition. In multivariable analysis, the only significant factors were absent or minimal calcification and stent diameters > 3.5mm (p = 0.02). The multidetector scanner seems a very promising method of investigating patients who have undergone stenting of the left main coronary artery but this study shows that certain clinical and angiographic parameters are limiting factors of surveillance with a 16-slice angioscanner.

Routine functional testing after percutaneous coronary intervention: results of the aggressive diagnosis of restenosis in high-risk patients (ADORE II) trial

BACKGROUND

It is unclear whether routine or selective functional testing is optimal following percutaneous coronary intervention (PCI) in high-risk patients.

OBJECTIVES

The aim of this trial was to compare exercise endurance, functional status, and quality of life (QOL) among high-risk patients randomized to either routine or selective functional testing following PCI.

METHODS

We randomized 84 patients to either routine or selective functional testing. Patients had one or more of the following: multivessel PCI, diabetes mellitus, left ventricular ejection fraction < 35%, and/or PCI of the proximal left anterior descending artery. Patients in the routine arm (n = 41) underwent maximum endurance exercise treadmill testing (ETT) with nuclear perfusion imaging at 1.5 and 6 months. Patients in the selective arm (n = 43) only underwent functional testing for a clinical indication. All patients underwent a maximum endurance ETT at 9 months. Exercise endurance, functional status, and QOL were assessed at 9 months.

RESULTS

Most patients were middle-aged men (58 +/- 10 years old; 87% male) who underwent PCI with stenting (94%). Among routine functional testing patients, 27.0% and 41.9% had a positive functional test at 1.5 and 6 months, respectively. Exercise endurance was improved in the routine vs. selective arm at 9 months (metabolic equivalents: 10.3 +/- 2.6 vs. 8.6 +/- 3.0, P = 0.013). There was no difference in improvement from baseline for the Duke Activity Status Index, the Seattle Angina Questionnaire, or the SF-36. Nine-month cumulative incidences of cardiac procedures and clinical events were not significantly different.

CONCLUSIONS

Routine functional testing following PCI in high-risk patients may lead to improved exercise endurance but not improved QOL.

In-stent pseudo-restenosis due to an organized thrombus six months after implantation of a sirolimus-eluting stent

Restenosis after sirolimuseluting stent (SES) implantation has been reported to be usually focal. We report a case of focal in-stent stenosis discovered angiographically 6 months after SES implantation, despite continuation of dual antiplatelet medication. Continuity and uniform distribution of the struts were confirmed by intravascular ultrasound (IVUS). Material from the lesion was extracted and found to be an organized thrombus on histological inspection. This observation suggests that special attention should be paid to focal stenotic lesions, particularly when IVUS shows proper and circular stent expansion, since it might represent an atypical form of late stent thrombosis.

A new approach to the assessment of lumen visibility of coronary artery stent at various heart rates using 64-slice MDCT

Coronary artery stent lumen visibility was assessed as a function of cardiac movement and temporal resolution with an automated objective method using an anthropomorphic moving heart phantom. Nine different coronary stents filled with contrast fluid and surrounded by fat were scanned using 64-slice multi-detector computed tomography (MDCT) at 50–100 beats/min with the moving heart phantom. Image quality was assessed by measuring in-stent CT attenuation and by a dedicated tool in the longitudinal and axial plane. Images were scored by CT attenuation and lumen visibility and compared with theoretical scoring to analyse the effect of multi-segment reconstruction (MSR). An average increase in CT attenuation of 144 ± 59 HU and average diminished lumen visibility of 29 ± 12% was observed at higher heart rates in both planes. A negative correlation between image quality and heart rate was non-significant for the majority of measurements (P > 0.06). No improvement of image quality was observed in using MSR. In conclusion, in-stent CT attenuation increases and lumen visibility decreases at increasing heart rate. Results obtained with the automated tool show similar behaviour compared with attenuation measurements. Cardiac movement during data acquisition causes approximately twice as much blurring compared with the influence of temporal resolution on image quality.

Prediction of infarction-related artery occlusion and multivessel disease in postinfarction angina

CONDENSED ABSTRACT

To investigate the predictive value of clinical data for infarction-related artery (IRA) occlusion and multivessel coronary disease in postinfarction angina (PIA), we studied 181 consecutive patients presenting PIA following a first uncomplicated ST elevation AMI. Multivariate analysis showed ECG changes during PIA and the absence of thrombolytic therapy as independent predictors of IRA occlusion. Independent clinical predictors of multivessel coronary disease were age, previous history of angina and the number of cardiovascular risk factors. We conclude that reversible ECG changes during PIA correlated to IRA occlusion but failed to predict a multivessel coronary disease.

AIM

To identify clinical variables predictive of infarction-related artery (IRA) occlusion and multivessel coronary disease in patients with postinfarction angina pectoris (PIA) after a first uncomplicated acute myocardial infarction (AMI).

METHODS

We studied 181 consecutive patients with PIA following a first uncomplicated AMI. Clinical variables included cardiovascular risk factors, clinical history of angina before the event of inclusion, use of thrombolytic therapy in the previous AMI, ST-T changes during PIA, time to onset, number of episodes and delay to angiography after PIA. Angiographic variables were IRA TIMI flow, number of diseased vessels and ventricular function.

RESULTS

The IRA was occluded in 67 patients with PIA (37.0%). Reversible ECG changes during PIA were detected in 121 patients (67.0%): 79 cases (43.6%) with ST/T elevation and 42 cases (23.2%) with ST/T depression. Multivariate logistic regression analysis showed ECG changes during PIA (OR 3.12 CI 95% 1.48-6.54, p<0.01) and the absence of thrombolytic therapy (OR 2.21 95% CI 1.11-4.43, p<0.05) as independent predictors of IRA occlusion. We found multivessel coronary disease in 89 patients (49.2%) without any correlation to ECG changes during PIA. Independent clinical predictors of multivessel coronary disease were age (OR 1.03 95% CI 1.01-1.06, p<0.05), previous history of angina (OR 2.37 95% CI 1.06-5.28, p<0.05) and the number of cardiovascular risk factors (OR 1.37 95% CI 0.97-1.92, p=0.07).

CONCLUSIONS

ECG changes during PIA was correlated to IRA occlusion in spite of previous thrombolytic therapy but failed to predict a multivessel coronary disease in our patients.

In-stent restenosis in idiopathic isolated ostial left main coronary artery stenosis

Idiopathic isolated ostial left main artery stenosis is a rare disease with uncertain etiology, clinical course and prognosis. We described a young woman with no cardiovascular risk factors, who developed the disease 3 years ago with a bare-metal stent implanted in the left main artery ostium. She presented again with severe angina of rapid onset. Coronary angiography revealed ostial left main artery in-stent restenosis. A drug-eluting stent was successfully deployed over the previous stent with good angiographic result. The etiology and management of this disorder were briefly discussed.

Factors predictive of cardiac events and restenosis after sirolimus-eluting stent implantation in small coronary arteries

OBJECTIVES

Predictors of cardiac events and restenosis after sirolimus-eluting stent (SES) implantation in small coronary arteries were evaluated.

BACKGROUND

Although SES implantation has markedly reduced the risk of restenosis, small vessel disease remains a major cause of SES failure.

METHODS

We prospectively investigated the factors predictive of cardiac events and restenosis in 1,092 consecutive patients who received SES implantation for 1,269 lesions in small coronary arteries (< or = 2.8 mm). Follow-up angiography at 6 months was performed in 751 patients with 889 lesions (follow-up rate 70.3%).

RESULTS

Restenosis (diameter stenosis > or = 50%) was angiographically documented in 65 patients with 77 lesions (8.7%): 55 focal (71.4%), 8 diffuse (10.4%), 2 diffuse proliferative (2.6%), and 12 total (15.6%). Lesion length, stent length, reference artery size, and in-stent restenotic lesions were univariate predictors of restenosis. By multivariate analysis, lesion length (OR 1.04; 95% CI 1.02-1.05; P < 0.001) and in-stent restenotic lesions (OR 3.38; 95% CI 1.80-6.35; P < 0.001) were significant independent predictors of restenosis. During follow-up (23.2 +/- 7.9 months), there were 17 deaths (5 cardiac and 12 noncardiac), 5 nonfatal Q-wave myocardial infarctions, and 42 target lesion revascularizations. The cumulative probability of survival without major adverse cardiac events (MACE) was (96.6 +/- 0.6)% at 1 year and (95.1 +/- 0.7)% at 2 years. In multivariate analysis, lesion length (HR 1.04; 95% CI 1.01-1.07; P = 0.004) and in-stent restenotic lesions (HR 3.29; 95% CI 1.58-6.86; P = 0.001) were independently related to MACE.

CONCLUSIONS

SES implantation in small coronary arteries is safe and effective, with lesion length having a major impact on restenosis and MACE.

The effect of intracoronary fibroblast growth factor-2 on restenosis after primary angioplasty or stent placement in a pig model of atherosclerosis

BACKGROUND

Therapeutic angiogenesis, if combined with primary percutaneous transluminal coronary angioplasty or stent placement, could improve the outcome of patients suffering from multifocal coronary disease.

HYPOTHESIS

Because of the concern that angiogenic growth factors might promote restenosis, we studied the effect of a single intracoronary administration of recombinant fibroblast growth factor (rFGF)-2 on restenosis after balloon angioplasty and stent placement in a pig model of coronary atherosclerosis.

METHODS

In 24 Yucatan minipigs, coronary lesions were induced by arterial injury and 3 months of atherogenic diet. After 3 months, repeat catheterization was performed with balloon dilation or stent placement at the injured sites, with a follow-up of 6 weeks. Results were monitored using quantitative angiography, intravascular ultrasound (IVUS), and histomorphometry.

RESULTS

Intracoronary rFGF-2 2 microg/kg did not affect neointima formation or remodeling in this model. A small but significant aggravation of late lumen loss was observed in the reference segments of the rFGF-2-treated group. Angiographic and echographic late lumen loss, intimal hyperplasia, and arterial remodeling, as well as histologic neointima were all similar in the rFGF-2- and the vehicle-treated group. Confirming earlier studies from our group and those of others, stented arteries compared with balloon-dilated arteries had increased angiographic late lumen loss, a trend toward increased intimal hyperplasia and decreased remodeling.

CONCLUSION

We conclude that rFGF-2 does not aggravate restenosis after balloon dilation or stenting in this pig model of coronary atherosclerosis. Future combinations of angioplasty and therapeutic angiogenesis in a single session should be pursued as a feasible and safe strategy.

Health-related quality of life following percutaneous coronary intervention: the impact of age on outcome at 1 year

This study was performed to assess the possibility that patient age may independently affect improvements in health-related quality of life following percutaneous coronary intervention. One hundred five patients undergoing elective percutaneous coronary intervention at a single tertiary referral center between January 10, 2001 and January 6, 2002 were enrolled and prospectively evaluated. Health-related quality of life was assessed before and 1 year following percutaneous coronary intervention using Short Form-12 and the Seattle Angina Questionnaire. For the purpose of analysis, patients were divided according to age (younger than 60, 60-70, and older than 70 years). One hundred patients (95%) completed both questionnaires. Baseline characteristics among the age groups were similar in terms of gender, cardiac risk factors, and procedural details. All health-related quality-of-life indices demonstrated improvements with at least four variables in each group achieving a clinically significant increase (>20%). At least eight modalities in each group achieved statistical significance (p=0.01). With the exception of physical functioning, the improvements in health-related quality of life were not significantly different among age groups.

[Visualization of the intra-stent lumen in the coronary arteries and detection of restenoses with 64-slices tomography scanners with cardiac synchronization: first experience]

PURPOSE

to assess the value of the new high spatial resolution 64-slice CT (0.4 mm collimation) technology for non-invasive visualization of coronary artery stent lumen and the characterization of significant in-stent restenosis.

MATERIALS AND METHODS

a total of 100 stents were visualized in 50 consecutive patients. All CT examinations were performed with a 64-slice CT (sensation 64; Siemens), with a slice thickness of 0.75 mm at 0.5 mm intervals with retrospective gating. Images were evaluated by two readers and the quality of the in-stent lumen was classified on 5-point scale (1 = not visible; 5 = excellent visibility). Fifty-eight stents in 29 patients were also examined by conventional coronary angiography one week after CT examination. Attenuation values were measured in the vessel upstream from the stent and within the stent, using 1 mm2 regions of interest. The intra stent attenuation ratio (ISAR) was calculated as vessel enhancement/intra stent hypodense area. Interobserver agreement was evaluated by kappa statistics,

RESULTS

the interobserver agreement was k= 0.82. The in-stent lumen was visible (score > or =3) in 88 stents (88%), with good visibility (> or = 4) in 54% of stents. Unsatisfactory in-stent lumen visibility was associated with heart rate > 65 beat/min (p < 0.001) and stent size < 3 mm (p < 0.0001). In-stent visibility was also lower in circumflex than other arteries (p= 0.02). Thirteen stenoses or occlusions were detected in 8 patients. In-stent restenosis was associated with hypodense areas within the stent. A ISAR>2 was an accurate criteria (2 false positives, 0 false negative) for detection of significant (> 50%) intra-stent restenosis.

CONCLUSION

high resolution 64-slice CT allows reliable in-stent visualization for stents of 3 mm or more in diameter, if heart rate is below 65 bpm. Significant restenosis can be detected with a high sensitivity by determining the ISAR. Arch Mal

[Timing and modality of control after acute coronary syndrome treated with revascularization: some reflections]

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Stent graft implantation for in-stent restenosis of coronary artery stenosis after Kawasaki disease

Coronary artery stenosis is a major complication of Kawasaki disease (KD). Several interventional methods in treating coronary artery stenosis have been introduced. However, there are few reports on the management of in-stent restenosis after coronary stent implantation in children. Reported is a 10-year-old boy who underwent successful stent graft insertion for treating in-stent restenosis with neoaneurysm formation after stent implantation for severe coronary stenosis after KD. Twenty-eight months follow-up studies showed no significant restenosis and perfusion defect.

Predictors of recurrent in-stent restenosis after beta-radiation: An analysis from the START 40/20 trial

OBJECTIVE

The purpose of this study was to identify potential predictors, including clinical, procedural, angiographic, and intravascular ultrasound (IVUS) parameters, for recurrent in-stent restenosis (ISR) following beta-radiation 90Strontium/Yttrium (90Sr/Y) in a large multicenter trial.

BACKGROUND

Although adjunct brachytherapy reduces recurrent ISR after primary catheter-based intervention, recurrence of stenosis after brachytherapy still occurs.

METHODS

We analyzed 185 IVUS cohort patients in the STent And Restenosis Therapy (START) 40/20 trial where a 40-mm, 90Sr/Y, radioactive source train was exclusively used for treatment of ISR to be treatable with a 20-mm balloon.

RESULTS

Thirty-nine patients underwent target lesion revascularization. Preliminary univariate analysis showed that age, smoking, balloon/artery ratio, geographic miss, minimum lumen diameter, and diameter stenosis at baseline were associated with target lesion revascularization, while none of IVUS variables were (minimum lumen area, minimum stent area, or residual plaque burden). The multivariate logistic regression analysis showed that younger age, lower balloon/artery ratio, and presence of geographic miss were independent predictors of target lesion revascularization.

CONCLUSIONS

Even with adjunct beta-radiation therapy, initial mechanical optimization, such as appropriate balloon sizing and positioning, may be critical for the prevention of recurrent ISR.

Clinical variables related with in-stent restenosis late regression after bare metal coronary stenting

In-stent restenosis (ISR) has an incidence between 20% and 30% using bare metal stents. ISR late regression phenomenon (ISRLR) has been previously described, but clinical variables related with this phenomenon remain unclear. The aim of the study was to identify the variables related with ISRLR.

METHODS

We identified from our data base 30 patients between November 1995 and September 2002 that fulfilled the following criteria: 1) Documented ISR at follow-up angiography (CA-1); 2) treated medically; and 3) Referred for a second follow-up angiography (CA-2). at least 3 months after CA-1. ISRLR was defined as a > 0.2 mm increase in MLD between CA-1 and CA-2, calculated as the 2-fold of our inter-observer variability. ISR late progression was defined as a > 0.2 mm decrease in minimum lumen diameter (MLD) between CA-1 and CA-2.

RESULTS

At the time of CA-2 only 2 patients (6.7%) had symptoms related with the previously stented vessel. We found a mean MLD of 1.03+/-0.34 mm and 1.54+/-0.48 mm at CA-1 and CA-2 respectively (AMLD = 0.51 +/-0.34 mm; p < 0.001). Twenty four patients (80.0%) had ISRLR. Two variables were related to the presence or absence ISRLR: Current smoking at the time of coronary stenting (70.8% vs 20.0% respectively, p = 0.026) and acute coronary syndrome as clinical indication for coronary stenting (and 83.5% vs 40.0% respectively, p = 0.029).

CONCLUSION

ISRLR is a frequent phenomenon in patients with ISR treated medically, probably contributing to the benign long-term clinical outcome that has been previously described in patients with asymptomatic or mildly symptomatic ISR. Current smoking at the time of coronary stenting and acute coronary syndrome as clinical indication for coronary stenting are associated with this phenomenon.

Temporal trends in target vessel revascularization in clinical practice: long-term outcomes following coronary stenting from the Duke Database for Cardiovascular Disease

OBJECTIVE

We examined outcomes of clinical restenosis and temporal trends in repeat target vessel revascularization (TVR) among a broad, unselected patient population undergoing percutaneous coronary revascularization.

BACKGROUND

The extent to which clinical trials involving protocol-specified follow-up angiography reflect real-world practice where interventions are driven by clinical restenosis is not completely understood. Whether clinical outcomes have varied over a long-term period that has paralleled substantial advances in stent design, balloon delivery catheter and adjunctive pharmacologic therapies is uncertain.

METHODS

To characterize the effectiveness of coronary stenting in routine practice, we examined 1-year clinical outcomes of death and repeat TVR among 5,765 patients enrolled in the Duke Database for Cardiovascular Disease who underwent stent placement between 1994 and 2002. To assess for temporal trends in outcomes, patients were further divided into tertiles according to the year of initial revascularization.

RESULTS

Overall, the 1-year occurrence of TVR and death was 11.4% and 4.9%, respectively. Rates of repeat TVR increased at 3-month intervals, with most events occurring prior to 9 months. In an adjusted analysis over an 8-year period, 1-year survival did not significantly differ across patient tertiles (p = 0.95), although rates of recurrent TVR significantly decreased (1994-1996, 11.1%; 1997-1999, 11.5%; 2000-2002, 9.3%; p = 0.003).

CONCLUSIONS

In a broad patient population in whom repeat angiography is not protocol-specified, most events occur within the initial months following revascularization, yet late clinical restenosis continues. Although survival has not improved since the introduction of coronary stents, overall rates of repeat revascularization have modestly, but significantly, declined.

In-stent restenosis and remote coronary lesion progression are coupled in cardiac transplant vasculopathy but not in native coronary artery disease

OBJECTIVES

The purpose of this study was to describe the clinical, angiographic, and histological features of concomitant in-stent restenosis (ISR) and cardiac allograft vasculopathy (CAV) progression.

BACKGROUND

Cardiac allograft vasculopathy is a major challenge to long-term success of heart transplantation. Coronary stenting for CAV is hampered by ISR.

METHODS

Quantitative coronary angiography compared late lumen loss (LL) at stented and reference, non-stented segments during 1-year follow-up in post-heart transplant and control atherosclerosis patients. Stented and non-stented arteries with CAV were also obtained post-mortem for immunohistochemical analysis.

RESULTS

In 37 stented lesions (25 patients), 1-year binary restenosis occurred in 37.8%. Patients with ISR had higher long-term cardiac death/myocardial infarction rates than patients without ISR (53.8% vs. 9.1%, p = 0.03). In the same 25 patients, 34 CAV lesions with non-significant obstructions were identified as reference controls. After 1 year, patients who developed ISR also had more control lesion LL (0.78 +/- 0.38 mm vs. 0.39 +/- 0.27 mm, p < 0.006) compared to patients without ISR. In the post-transplant patients, in-stent LL was closely coupled to control segment LL (R(2) = 0.63, p < 0.05). Conversely, in native atherosclerosis patients, ISR and remote disease progression were not correlated. Histological staining of stented and control arteries from CAV patients revealed similar pathologies common to ISR and non-intervened CAV segments.

CONCLUSIONS

Progression of CAV at non-intervened segments and ISR correlate strongly and share common histopathology. Optimized treatment for patients with aggressive CAV needs to address the widespread nature of this disease, even when it presents as an initially focal lesion.