Morphologic features of vulnerable coronary atherosclerotic plaque: intravascular ultrasound demonstration with prospective follow-up study

Neointima Inhibition: Comparison of Effectiveness of Non–Stent-based Local Drug Delivery and a Drug-eluting Stent in Porcine Coronary Arteries

PURPOSE

To compare the inhibition of neointimal proliferation by using non-stent-based local drug delivery and a drug-eluting stent in porcine coronary arteries.

MATERIALS AND METHODS

Experiments were conducted with permission of the animal protection committee of the local government. Paclitaxel was either dissolved in a nonionic contrast medium or coated on balloons. Stents were crimped on the coated balloons. Effectiveness was tested in 22 pigs. Two coronary stents were placed in each pig, and slight overstretch was applied. The animals were treated as follows: group A (control group), uncoated balloons, bare stents, and "plain" contrast medium; group B, same treatment as group A, but with paclitaxel in the contrast medium; group C, paclitaxel-coated balloons, with premounted bare stents and plain contrast medium; and group D, sirolimus-eluting stents, noncoated balloons, and plain contrast medium. Stenosis was assessed 4 weeks later at angiography and histomorphometry. For exploratory purposes, continuous variables of quantitative coronary angiography and histomorphometry were compared by using analysis of variance.

RESULTS

Results at follow-up angiography indicated a mean of 1.00 mm +/- 0.18 (standard deviation) lumen diameter loss in the control group and 0.14 mm +/- 0.18 loss in the group treated with the paclitaxel-coated balloon (group C; P < .001). Findings at histomorphometry confirmed the effectiveness of drug delivery, with the most impressive inhibition of neointimal proliferation from coated balloons-the neointimal area was 2.4 mm2 +/- 0.3 (P < .01 vs all other groups), compared with 5.2 mm2 +/- 0.3 in group A (control group), 4.3 mm2 +/- 0.3 in group B, and 3.8 mm2 +/- 0.3 in group D.

CONCLUSION

In spite of the short intima contact time, paclitaxel coated on the balloon inhibits neointimal formation in the porcine model of coronary stent placement.

Endovascular revascularization below the knee: 6-month results and predictive value of C-reactive protein level

PURPOSE

To determine the association between pre- and postintervention serum C-reactive protein (CRP) levels and 6-month restenosis after endovascular treatment of atherosclerotic lesions in arteries below the knee.

MATERIALS AND METHODS

Eighty-nine patients with peripheral arterial disease underwent primary successful percutaneous transluminal angioplasty (PTA) of the distal popliteal, anterior tibial, posterior tibial, and fibular arteries. Six-month patency was evaluated with the ankle brachial index (ABI) and color-coded duplex ultrasonography (US). The association between restenosis and preintervention and 48-hour postintervention CRP levels was assessed with multiple logistic regression analysis.

RESULTS

ABI improved from a preintervention median of 0.54 to a postintervention median of 0.75 (P <.001). The primary technical success rate was 94% (100 of 106). In 50 patients, a suboptimal technical result was achieved with 30%-40% residual stenosis at the dilated segment. The median ABI at 6 months was 0.65, and it was inversely correlated with preintervention (r = -0.27, P =.009) and 48-hour postintervention (r = -0.40, P <.001) CRP levels. With duplex US at 6 months, restenosis (> or =50%) occurred in 36 patients. Patients with a preintervention CRP level of 0.23-0.92 mg/dL (2.3-9.2 mg/L) had a 3.7-fold increased adjusted risk for restenosis (P =.05); patients with a preintervention CRP level greater than 0.92 mg/dL (9.2 mg/L) had a 4.7-fold increased adjusted risk (P =.03). Postintervention CRP values greater than 2.42 mg/dL (24.2 mg/L) were associated with a 10.7-fold adjusted risk for restenosis (P =.002). Suboptimal PTA result was the only other parameter associated with an increased risk for restenosis (odds ratio, 3.7; P =.03).

CONCLUSION

Pre- and postintervention CRP levels were associated with restenosis after PTA of the distal popliteal and tibioperoneal arteries, which indicates that inflammation plays a crucial role in the pathophysiology of this process.

Acute-phase response after stent implantation in the carotid artery: association with 6-month in-stent restenosis

PURPOSE

To determine the prognostic importance of periintervention serum levels of acute-phase reactants in 6-month restenosis after stent implantation in the carotid artery.

MATERIALS AND METHODS

One hundred eight consecutive patients with 70% or greater stenosis of the internal carotid artery (ICA) according to the North American Symptomatic Carotid Endarterectomy Trial criteria underwent successful stent implantation in the ICA in a prospective cohort study. Six-month patency was evaluated at color-coded duplex ultrasonography. The association between in-stent restenosis (> or =50%, North American Symptomatic Carotid Endarterectomy Trial criterion) and C-reactive protein (CRP) and serum amyloid A levels at baseline and at 24 and 48 hours after intervention was assessed.

RESULTS

Restenosis was found in 15 (14%) patients within 6 months. CRP level at 48 hours, exemplary for the postintervention acute-phase response, was significantly (P =.01) associated with 6-month restenosis by using multiple logistic regression analysis. Recurrent stenosis after prior stent implantation in the carotid artery (odds ratio, 9.2; 95% CI: 1.6, 53.2; P =.01) and residual stenosis of 10%-30% after stent implantation (odds ratio, 9.7; 95% CI: 1.6, 59.3; P =.01) were independent clinical predictors of restenosis.

CONCLUSION

Extent of vascular inflammatory response after stent implantation in the carotid artery measured with acute-phase reactants is associated with 6-month patency. Recurrent stenosis after prior stent implantation and initial suboptimal technical result seem to be clinically relevant predictors of postangioplasty outcome.

Vascular inflammation and percutaneous transluminal angioplasty of the femoropopliteal artery: association with restenosis

PURPOSE

To determine the association of pre- and postprocedural serum levels of C-reactive protein (CRP), serum amyloid A (SAA), and fibrinogen at 6-month evaluation of restenosis after percutaneous transluminal angioplasty (PTA) of the femoropopliteal artery.

MATERIALS AND METHODS

In a prospective cohort study, 172 consecutive patients with peripheral artery disease of Fontaine stage IIa, IIb, or III who underwent successful PTA of the superficial femoral and popliteal arteries were included. Patency at 6 months was evaluated by using oscillography, ankle-brachial index, and color-coded duplex ultrasonography. The association of restenosis and CRP, SAA, and fibrinogen levels at baseline, 24 hours, and 48 hours after intervention was assessed by means of multivariate analysis with adjustment for known risk factors for restenosis.

RESULTS

Restenosis was found in 56 patients (33%) within 6 months. CRP values at baseline (adjusted odds ratio, 2.2; 95% CI: 1.1, 4.2) and 48 hours after intervention (adjusted odds ratio, 2.3; 95% CI: 1.6, 3.1) were independently associated with 6-month restenosis. SAA and fibrinogen values at any time interval were not significantly associated with patency in the multivariate models.

CONCLUSION

The extent of vascular inflammation as measured by means of acute-phase reactants before and after PTA of the femoropopliteal artery is associated with 6-month restenosis. Baseline and 48-hour CRP levels were independent predictors of postangioplasty outcome.

Inflammatory response to stent implantation: differences in femoropopliteal, iliac, and carotid arteries

PURPOSE

To investigate the postintervention course of serum acute-phase reactants after stent implantation in the femoropopliteal, iliac, and carotid arteries.

MATERIALS AND METHODS

This prospective cohort study included 274 consecutive patients who underwent stent implantation in the femoropopliteal (n = 95), iliac (n = 70), and carotid (n = 109) arteries. C-reactive protein (CRP), serum amyloid A (SAA), and fibrinogen levels were measured at baseline and at 48 hours after intervention. Polynomial logistic regression analysis was applied to assess the independent association of the course of acute-phase reactants and the site of stent implantation.

RESULTS

Stent implantation in the femoropopliteal artery was associated with a higher postintervention increase in CRP (P =.01), SAA (P =.04), and fibrinogen (P =.01) values compared with values with iliac artery stent implantation, with adjustment for age, sex, fluoroscopy duration, contrast agent dose, complication occurrence, stenosis grade, total vessel occlusion, and stent cumulative length. No significant difference in the postintervention course of CRP (P =.9) and SAA (P =.1) levels was determined for stents implanted in the carotid artery compared with those implanted in the iliac artery; however, a higher increase in fibrinogen levels (P =.04) was noted.

CONCLUSION

Stent implantation in the muscular femoropopliteal artery was associated with a more extensive vascular inflammatory response than was stent implantation in the elastic iliac and carotid arteries, independent of lesion morphology and interventional factors.

Femoropopliteal arteries: immediate and long-term results with a Dacron-covered stent-graft

PURPOSE

To assess immediate and long-term outcome after femoropopliteal implantation of a Dacron-covered stent-graft in patients with peripheral arterial disease.

MATERIALS AND METHODS

This prospective cohort study included 30 consecutive patients who underwent Dacron-covered stent-graft implantation because of recurrent stenosis after percutaneous transluminal angioplasty in the femoropopliteal segment. After interventional treatment, 100 mg of acetylsalicylic acid daily and oral anticoagulation therapy (therapeutic level, international normalized ratio, 2.0-3.0) were administered. Patients were followed up with ankle-brachial index measurement, color-coded duplex ultrasonography, and angiography. Primary and secondary patency rates and postintervention complications were documented as was initial technical success. Kaplan-Meier and life table analyses were used for calculation of patency rates.

RESULTS

Initial technical success was achieved in all 30 patients, with significant improvement of ankle-brachial index from a preintervention mean of 0.5 +/- 0.14 (SD) to a postintervention mean of 0.8 +/- 0.17 (P <.001). Postimplantation noninfectious fever and leukocyte and C-reactive protein level elevation occurred in 12 patients (40%), and 17 patients (57%) reported persistent pain at the site of implantation for a mean of 5 days (range, 2-28 days). Early recurrent occlusion within the first 24 hours was found in five patients (17%). Within the mean follow-up period of 60 months +/- 10, restenosis occurred in 25 patients (83%). At 6, 12, 36, and 72 months, respectively, primary patency rates were 27%, 23%, 17%, 17%, and secondary patency rates were 63%, 60%, 34%, 34%.

CONCLUSION

Implantation of Dacron-covered stent-grafts for treatment of femoropopliteal lesions leads to high early and late restenosis rates, with a considerable rate of complications, such as fever and pain.