Elevated lipoprotein(a) and increased incidence of restenosis after femoropopliteal PTA. Rationale for the higher risk of recurrence in females?

Coating and Pharmacokinetic Evaluation of Air Spray Coated Drug Coated Balloons

Drug coated balloons (DCB) are becoming the standard-care treatment for peripheral arterial disease (PAD). DCB use excipients to transfer and retain anti-proliferative drugs, such as paclitaxel. Excipients thus play a vital role in the design and function of DCB, however methods to coat balloons with excipients and anti-proliferative drugs remain unknown. The goal of this study was to thus develop an approach to coat and evaluate DCB for various excipients. An air sprayer method was developed to deposit paclitaxel and various excipients onto non-coated commercially available angioplasty balloons. The coating of the angioplasty balloons was evaluated for drug deposition and coating efficiency using high performance liquid chromatography tandem mass spectrometry. Drug transfer and retention of the coated angioplasty balloons into arterial segments were evaluated ex vivo using harvested pig arteries in a pulsatile flow bioreactor. The air sprayer method successfully delivered varying excipients including bovine serum albumin (BSA), urea and iohexol. The air spray method was configured to coat four angioplasty balloons simultaneously with paclitaxel and iohexol with an average paclitaxel load of 4.0 ± 0.70 µg/mm². The intra-day (within) and inter-day (between) coating precisions, defined as relative standard deviation (RSD), was 17.2 and 15.5%, respectively. Ex vivo deployment of iohexol-paclitaxel DCB yielded an arterial paclitaxel concentration of 123.4 ± 44.68 ng/mg (n = 3) at 1 h, 126.7 ± 25.27 ng/mg (n = 3) at 1 day, and 12.9 ± 12.88 ng/mg (n = 3) at 7 days. This work provides proof-of-concept of a quick, inexpensive approach to coat commercially available angioplasty balloons with paclitaxel and various excipients.

Acute lower limb ischemia due to thrombo-embolic arterial occlusions in two previously healthy men with markedly elevated Lp(a)

Lipoprotein (a) (Lp(a)) is a well-documented risk factor for atherosclerotic cardiovascular disease. Its role in acute thrombo-embolic occlusions of peripheral arteries is not known. We describe two cases of multiple, acute, peripheral arterial occlusions in two previously healthy men with markedly elevated Lp(a). Both cases had unsatisfactory results after percutaneous and surgical revascularization procedures. Experience yielded in these two cases suggests that when an unfavorable out-come occurs in a peripheral artery disease patient in the absence of the regular risk factors, Lp(a) should be determined and its role investigated.

Lipoprotein(a) and other serum lipid subfractions influencing primary patency after infrainguinal percutaneous transluminal angioplasty

PURPOSE

To evaluate the influence of serum lipid subfraction concentrations on arterial patency after percutaneous transluminal angioplasty (PTA) in patients with infrainguinal peripheral artery occlusive disease (PAOD).

METHODS

From January 2007 to June 2008, a prospective study was conducted involving 39 patients (29 men; mean age 68.6+/-10.0 years) with infrainguinal PAOD in 41 limbs who had preprocedural lipid assessment and underwent successful PTA (<30% residual stenosis). Patient demographics, Fontaine clinical stage classification, Texas University Classification of ulcers, coexisting medical conditions, endovascular procedures, and lipid profiles were collected in a database. Follow-up included clinical and duplex ultrasound evaluation at discharge and at 1, 3, 6, and 12 months. To analyze any correlation between various lipid subfractions and the loss of primary patency (Cox proportional hazards modeling), the patients were dichotomized into high and low groups according to these thresholds: LDL-C >100 mg/dL, HDL-C <40 mg/dL, Lp(a) >30 mg/dL, and an Apo(B)/Apo(A) ratio >0.8 mg/dL.

RESULTS

Mean follow-up was 7.5 months (range 3-12). After 1, 3, and 6 months, the primary patency rates by Kaplan-Meier analysis were 94.9%, 73.7%, and 64.1%, respectively. Restenosis at 6 months was significantly related to female gender (HR 95.9, 95% CI 6.8 to 1352.5, p = 0.001), HDL-C <40 mg/dL (HR 86.9, 95% CI 6.4 to 1183.1, p = 0.001), LDL-C >100 mg/dL (HR 9.6, 95% CI 1.6 to 57.4, p = 0.013), and Lp(a) >30 mg/dL (HR 6.1, 95% CI 1.4 to 26.3, p = 0.016).

CONCLUSION

Our results suggest that Lp(a), LDL-C, and HDL-C are independent risk factors for restenosis after infrainguinal PTA.

Stenting for superficial femoral artery atherosclerotic occlusion: long-term follow-up results

Recent advances in interventional devices and technology have greatly improved the results of percutaneous transluminal angioplasty (PTA), and it is now being widely used. However, it is important to obtain information regarding its results and its long-term patency. We examined the primary success rates and long-term patency in 29 limbs out of 27 patients with superficial femoral artery (SFA) occlusion who underwent PTA with self-expandable stents. Among the 29 lesions, 19 were long occlusions (>10 cm) and 10 were short (<10 cm). Overall primary success was achieved in 26 of the 29 limbs (90%). There were three unsuccessful cases in which the patients were on dialysis and had hard calcification in the arterial walls. After 3 years, primary patency, primary-assisted patency, and secondary-assisted patency were 81%, 86%, and 96%, respectively. In the case of short occlusions (<10 cm), the 3-year patency was 100%. Both the primary success rate and the long-term patency were considerably better than expected. Our results with self-expanding stents were superior to previously reported results and were not inferior to those of surgical bypass. Therefore, PTA may be considered as a good first option for the treatment of SFA occlusions.

Restenosis after percutaneous angioplasty: the role of vascular inflammation

Restenosis after endovascular treatment of atherosclerotic lesions in the peripheral, cerebrovascular, and coronary circulation is the major drawback of this minimally invasive technique. Although certain advances have been made during recent years to improve patency rates after percutaneous angioplasty, restenosis remains a challenging clinical problem. Understanding factors that contribute to the pathophysiology of late lumen loss is an effective strategy to improving patients' postangioplasty outcome. Vascular inflammation after balloon angioplasty or stent implantation has been identified as a cornerstone of the restenotic process, and several markers of inflammation have been referred to as potential predictors of outcome. This article reviews recent findings on the issue of inflammation and restenosis after percutaneous angioplasty with special attention given to the role of inflammatory parameters as markers for the restenosis risk in the peripheral vessel area.

Influence and interaction of diabetes and lipoprotein (a) serum levels on mortality of patients with peripheral artery disease

BACKGROUND

Diabetes mellitus is a risk factor for early complications and mortality in patients with peripheral artery disease. Lipoprotein (a) [Lp(a)] is also suggested to be a marker of increased cardiovascular risk. We investigated the association and interaction between diabetes mellitus, lipoprotein(a) and mortality in high risk patients with peripheral artery disease (PAD).

METHODS

We studied 700 consecutive patients [median age 73 years, interquartile range (IQR) 62-80, 393 male (56%)] with PAD from a registry database. Atherothrombotic risk factors (diabetes, smoking, hyperlipidaemia, arterial hypertension) and Lp(a) serum levels were recorded. We used stratified multivariate Cox proportional hazard analyses to assess the mortality risk at a given patient's age with respect to the presence of diabetes and Lp(a) serum levels (in tertiles).

RESULTS

Patients with Lp(a) levels above 36 mg dL(-1) (highest tertile) and insulin-dependent type II diabetes had a 3.01-fold increased adjusted risk for death (95% confidence interval 1.28-6.64, P = 0.011) compared to patients without diabetes or patients with non-insulin-dependent type II diabetes. In patients with Lp(a) serum levels below 36 mg dL(-1) (lower and middle tertile), diabetes mellitus was not associated with an increased risk for death.

CONCLUSION

Insulin-dependent type II diabetes mellitus seems to be associated with an increased risk for mortality in PAD patients with Lp(a) serum levels above 36 mg dL(-1). PAD patients with non-insulin-dependent type II diabetes, and patients with diabetes and Lp(a) levels below 36 mg dL(-1) showed survival rates comparable to PAD patients without diabetes.

Endovascular stent implantation for treatment of peripheral artery disease

Endovascular stent implantation is a rapidly emerging technology for treatment of arterial obstructions in the entire circulation. During recent years, several randomized studies evaluated the effects of stenting in lower limb arteries. We herein provide an overview on data of trials in the iliac and femoropopliteal vessel area discussing the benefits and limitations of endovascular stents. In the iliac arteries, midterm and long-term data from one randomized trial including analysis on patency, clinical outcomes, cost-effectiveness and quality of life indicate that balloon angioplasty with selective stenting remains the therapy of choice for endovascular revascularization. In the femoropopliteal arteries, balloon-expanding stents were not superior to balloon angioplasty for treatment of short lesions, and self-expanding nitinol stents also failed to show a beneficial effect in short lesions below 5 cm. However, including longer lesions, one randomized trial indicated a beneficial effect of nitinol stents in lesions with a median length around 10-12 cm. Further studies and longer follow-up intervals are needed to confirm these data. Meanwhile, balloon angioplasty with optional stenting also remains the recommended endovascular approach for the femoropopliteal segment.

Insulin, C-Peptide, and Restenosis after Femoral Artery Balloon Angioplasty in Type II Diabetic and Nondiabetic Patients

PURPOSE

Endogenous and exogenous insulin is suggested to stimulate hypertrophic wound-healing responses and therefore may promote neointimal hyperplasia and restenosis after balloon angioplasty. The ratio of C-peptide to insulin reflects endogenous insulin secretion. In diabetic patients with insulin substitution, lower ratios display a higher proportion of exogenous insulin. The association and interaction of insulin and C-peptide with restenosis after percutaneous transluminal angioplasty (PTA) was investigated in type II diabetic and nondiabetic patients.

MATERIALS AND METHODS

The study group included 76 patients (median age, 68 years; interquartile range [IQR], 58-74 years; 55 men [72%]; 31 patients [41%] with type II diabetes) with intermittent claudication (n = 49; 64%) or critical limb ischemia (n = 27; 36%) who underwent primary successful femoral PTA. C-peptide and insulin levels were measured at baseline, and patients were followed to determine restenosis (> or =50%) at 12 months by color-coded duplex sonography.

RESULTS

Restenosis was found in 34 patients (45%) at 12 months. Patients with restenosis had higher insulin levels (median, 21.3 microU/mL IQR, 11.3-35.5 microU/mL) and a lower C-peptide/insulin ratio (median, 16; IQR, 10-21) compared with patients without restenosis (median insulin level, 11.6 microU/mL; IQR, 9.1-22.0 microU/mL [P = .008]; median ratio, 19 [IQR, 17-25], P = .039). In nondiabetic patients, insulin levels were significantly associated with restenosis (P = .046), whereas the ratio of C-peptide to insulin showed no association with restenosis. In patients with type II diabetes (n = 31; 41%), in contrast, the C-peptide/insulin ratio was associated with restenosis (P = .047), whereas insulin levels showed no significant association with restenosis (P = .14).

CONCLUSIONS

Insulin levels and the C-peptide/insulin ratio were associated with restenosis after femoral PTA. Exogenous and endogenous insulin may play a role in the pathogenesis of recurrent lumen loss after balloon angioplasty.

Association Between Plasma Lipoprotein(a) Concentration and Restenosis After Stent Implantation

BACKGROUND

The plasma concentration of lipoprotein (a) [Lp(a)] is associated with atherosclerotic and thrombotic vascular diseases. The aim of the present study was to evaluate the association between plasma Lp(a) concentration and in-stent restenosis.

METHODS AND RESULTS

One hundred and 9 patients with successful elective coronary stent implantation underwent follow-up angiography at 24+/-6 weeks. Restenosis after stent implantation occurred in 38 patients. Univariate analysis showed that the reference diameter of the lesion was smaller in the restenosis group (2.93+/-0.29 mm) than in the no-restenosis group (3.21+/-0.43 mm) (p < 0.05). The lesion was longer in the restenosis group (14.2+/-5.3 mm) than in the no-restenosis group (11.6+/-4.9 mm) (p < 0.05). Plasma Lp(a) concentrations in the restenosis group (30.5+/-23.9 mg/dl) were higher than in the no-restenosis group (16.9+/-11.1 mg/dl) (p < 0.01). Other lipid concentrations were similar in both groups. Among the plasma Lp(a) concentrations, the rate of restenosis (71.4%) in the high Lp(a) group (> 40 mg/dl) (n = 14) was greater compared with the other groups: 33.3% in the intermediate Lp(a) group (10-40 mg/dl) (n = 54), and 24.4% in the low Lp(a) group (< 10 mg/dl) (n = 41) (p < 0.01). The late loss (0.57+/-0.53 mm) in the low Lp(a) group was significantly less than the other groups: 0.88+/-0.47 mm in the intermediate Lp(a) group, and 1.08+/-0.56 mm in the high Lp(a) group (p < 0.05). In a multivariate regression model, plasma Lp(a) concentration remained significant as an independent predictor of restenosis in patients undergoing stent implantation (p = 0.020 odds ratio (OR) 1.37 95%conficence interval (CI) 1.050-1.793), although the reference diameter (p = 0.025 OR 0.23 95%CI 0.061-0.830) and lesion length (p = 0.021 OR 1.12 95%CI 1.017-1.232) were related to stent restenosis.

CONCLUSIONS

Plasma Lp(a) concentration is an independent predictor of stent restenosis.

Effect of Smoking on Restenosis during the 1st Year after Lower-Limb Endovascular Interventions

PURPOSE

To investigate whether smoking has an effect on recurrent lumen narrowing after percutaneous transluminal angioplasty (PTA) or stent placement in lower-limb arteries.

MATERIALS AND METHODS

A total of 650 patients (median age, 70 years; 389 men) with peripheral artery disease who underwent iliac artery PTA (n = 95), iliac artery stent placement (n = 83), femoropopliteal PTA (n = 406), or femoropopliteal stent placement (n = 66) were selected from a prospective database. Patients were categorized according to their preintervention smoking habits as nonsmokers (n = 352), light smokers (one to nine cigarettes daily) (n = 54), habitual smokers (10-20 cigarettes daily) (n = 82), or heavy smokers (>20 cigarettes daily) (n = 162). Multivariate Cox proportional hazards analysis was used to determine whether there was an association between smoking habits and restenosis (> or =50%) in the treated vessel segment within 1 year after treatment.

RESULTS

Cumulative restenosis rates at 6 and 12 months according to patients' smoking habits were 99 and 190 nonsmokers, 18 and 22 light smokers, 16 and 29 habitual smokers, and 26 and 47 heavy smokers, respectively (P <.001). Adjusted hazard ratios for restenosis in smokers compared with nonsmokers were 1.51 (95% CI: 0.92, 2.50) for light smokers, 0.49 (95% CI: 0.28, 0.87) for habitual smokers, and 0.46 (95% CI: 0.30, 0.71) for heavy smokers, indicating a reduced restenosis risk in patients who smoked 10 or more cigarettes daily. These patients had reduced restenosis rates after either iliac (P =.011) or femoropopliteal intervention (P =.009). However, endovascular treatment at a younger age, coronary artery disease, and history of myocardial or cerebrovascular infarction were more frequently found in smokers.

CONCLUSION

Smoking 10 or more cigarettes daily is associated with a reduced rate of intermediate-term restenosis after lower-limb endovascular interventions.

Restenosis after femoropopliteal PTA and elective stent implantation: predictive value of monocyte counts

PURPOSE

To investigate the association of baseline peripheral blood monocyte counts and restenosis after femoropopliteal percutaneous transluminal angioplasty (PTA) and PTA plus elective stent implantation.

METHODS

Three hundred thirty consecutive patients (170 men; median age 71 years, interquartile range 61-78) with peripheral artery disease underwent femoropopliteal PTA (n=258) or PTA plus elective stent implantation (n=72). Multivariate Cox regression analysis was used to determine the predictive value of baseline peripheral blood monocyte counts on the rate of restenosis (> or =50% luminal reduction) in follow-up.

RESULTS

Cumulative patency at 6 and 12 months was 55% and 39% after PTA and 70% and 41% after elective stenting, respectively (p=0.19). Pretreatment monocyte counts (in tertiles) were associated with restenosis after PTA (p=0.002) and stent implantation (p=0.02). Compared to patients with monocyte counts <0.3x10(9)/L (lower tertile, n=128), patients with monocytes from 0.3 to 0.4x10(9)/L (middle tertile, n=91) had a 1.8-fold increased adjusted risk for restenosis (95% CI 1.1 to 2.8, p=0.01). Patients with monocytes >0.4x10(9)/L (upper tertile, n=87) had a 2.3-fold increased adjusted risk (95% CI 1.4 to 3.5, p<0.0001).

CONCLUSIONS

Baseline monocyte counts were associated with restenosis after femoropopliteal PTA and elective stent implantation, suggesting that circulating monocytes play a pivotal role in the development of recurrent lumen narrowing.

Angioplasty and elective stenting of de novo versus recurrent femoropopliteal lesions: 1-year follow-up

PURPOSE

To investigate patency rates after percutaneous transluminal angioplasty (PTA) and PTA plus elective stenting in de novo versus recurrent femoropopliteal lesions.

METHODS

The data were collected from a prospective registry including 533 consecutive patients (284 men; median age 71 years, interquartile range [IQR] 72-78) with severe claudication (n=387) or critical limb ischemia (n=146) who underwent femoropopliteal percutaneous interventions during a 36-month period. PTA was used to treat 357 de novo and 99 recurrent lesions; PTA plus elective stent implantation was performed in 58 de novo and 19 recurrent lesions. Patients were followed for a median 12 months (IQR 7-14) using color duplex sonography. Rates of restenosis (>/=50%) were compared by multivariate analysis.

RESULTS

Overall primary technical success was achieved in 517 (97%) patients; 31 (6%) periprocedural complications were encountered. Restenosis occurred in 213 (40%) patients after a median 6 months (IQR 4-7). Twelve-month patency after PTA was 61% in de novo and 33% in recurrent lesions (p<0.0001). Patients with recurrent lesions had a 2.3-fold increased adjusted risk for restenosis after PTA (95% confidence interval 1.7 to 3.2). Twelve-month patency after stenting was 58% in de novo and 52% in recurrent lesions (p=0.9). In patients with de novo lesions, patency rates after PTA and stent were similar (p=0.8); however, in patients with recurrent lesions, elective stenting performed better (p=0.05).

CONCLUSIONS

Recurrent stenosis after prior femoropopliteal balloon angioplasty is an independent risk factor for restenosis; these lesions exhibit disappointing patency after repeated PTA. Stent implantation may improve intermediate-term results in these patients.

Duplex ultrasound-guided femoropopliteal angioplasty: initial and 12-month results from a case controlled study

PURPOSE

To evaluate initial technical success, procedural complications, and 12-month patency of duplex-guided angioplasty compared to conventional fluoroscopically-guided procedures.

METHODS

One hundred four patients (65 men; mean age 69 years) who underwent duplex-guided femoropopliteal angioplasty were compared to 104 patients undergoing fluoroscopically-guide procedures who were matched for age, sex, baseline ankle-brachial index (ABI), and length and grade of lesion. Patients were followed for 12 months, and restenosis was assessed by ABI and duplex sonography.

RESULTS

Technical success was achieved in 88 (84.6%) patients from the duplex-guided group and in 102 (98.1%) control patients (p=0.001). Periprocedural complications occurred in 12.5% (n=13) and 18.3% (n=19), respectively (p=0.4). Contrast-induced transient renal impairment was observed in 7 (6.7%) patients in the fluoroscopic group. One hundred (96.1%) patients in the duplex and 102 (98.1%) patients in the fluoroscopic group completed the 12-month follow-up. Restenosis was found in 35 (39.8%) patients of the duplex group and in 38 (37.2%) patients of the fluoroscopic group (p=0.8).

CONCLUSIONS

Technical success of duplex-guided procedures was significantly lower compared to fluoroscopic angioplasty; complications and 12-month patency were similar with both techniques. Duplex-guided angioplasty may be a feasible alternative, particularly for patients at high risk for contrast-induced complications.

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.

Clinical outcome and prognostic factors for ischaemic ulcers treated with PTA in lower limbs

OBJECTIVE

To analyse the clinical outcome of patients with ischaemic ulcers (Fontaine stage IV) undergoing percutaneous transluminal angioplasty (PTA).

METHODS AND DESIGN

Retrospective cohort study of 40 patients (21 males) treated between January 1998 and December 1998. Cardiovascular risk factors, co-morbid, baseline laboratory, angiographic data and technical success were recorded. Patients were followed for a median of 20 (inter quartile range (IQR) 8-26) months.

RESULTS

Cumulative ulcer healing rates at 3, 6, 12, and 24 months were 15, 40, 54 and 81%, respectively. The median time to healing was 5 (IQR 2-7) months. Cumulative restenosis at 1, 3, 6 and 12 months was 3, 10, 29 and 52%, respectively. Nine patients (22%) suffered ulcer reappearance. Lipoprotein (a) serum levels > 30 mg/dl (HR 0.2, 95% CI 0.05-1.0, p = 0.05) and diabetes mellitus (HR 0.2, 95% CI 0.5-0.7, p = 0.01) were associated with delayed ulcer healing.

CONCLUSION

PTA leads to ulcer healing in the majority of patients. Elevated lipoprotein (a) levels > 30 mg/dl and diabetes mellitus are independently associated with ulcer persistence.

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.

Influence of lipoprotein(a) on restenosis after femoropopliteal percutaneous transluminal angioplasty in Type 2 diabetic patients

OBJECTIVE

The influence of vascular morphology and metabolic parameters including lipoprotein(a) (Lp(a)) on restenosis after peripheral angioplasty has been compared in Type 2 diabetes (DM) vs. non-diabetic patients (ND).

RESEARCH DESIGN AND METHODS

The clinical course and risk profile of 132 (54 DM vs. 78 ND) patients with peripheral arterial occlusive disease (PAD) were observed prospectively following femoropopliteal angioplasty (PTA). Clinical examination, oscillometry, ankle brachial blood pressure index (ABI) and the toe systolic blood pressure index (TSPI) were used during follow-up. Duplex sonography and reangiography were also used to verify suspected restenosis or reocclusion.

RESULTS

At the time of intervention patients with DM had a lower median Lp(a) of 9 vs. 15 mg/dl (P < 0.01) in patients without diabetes. Recurrence within 1 year after PTA occurred in 25 diabetic (= 46%, Lp(a) 12 mg/dl) and 30 non-diabetic (= 38%, Lp(a) 48 mg/dl) patients. DM patients with 1 year's patency had a median Lp(a) of 7 vs. 11 mg/dl in non-diabetic patients (P < 0.05). However, 12 months after angioplasty Lp(a) correlated negatively with the ABI (r = -0.44, P < 0.01) in diabetic and in non-diabetic patients (r = -0.20, P < 0.05). The probability of recurrence after PTA continuously increased with higher levels of Lp(a) in each subgroup of patients.

CONCLUSIONS

Our data indicate that Lp(a) is generally lower in those with peripheral arterial occlusive disease and Type 2 diabetes than in non-diabetic individuals. The increased risk for restenosis with rising levels of Lp(a) is set at a lower Lp(a) in diabetes and may be more harmful for diabetic patients.

Cardiovascular risk factors do not predict clinically defined restenosis after percutaneous transluminal angioplasty for lower limb ischemia

The purpose of this study was to evaluate risk factors predicting restenosis and primary patency after percutaneous transluminal angioplasty. Follow-up data (including cardiovascular risk factor scores according to SCVIR criteria, preinterventional and postinterventional clinical data and patient history) of all patients who underwent successful percutaneous transluminal angioplasty for lower limb ischemia were analyzed retrospectively and patients, relatives, or referring physicians underwent a telephone interview. Patients with incomplete follow-up data were examined by means of a clinical examination, including Doppler measurements and treadmill test. Additionally all angiograms were evaluated to calculate lesion length, number of treated lesions, lesion type (SCVIR score), and runoff. The outcome was categorized into four groups: early recurrence (< 1 month, group I), mean recurrence (1-6 months, group II), late recurrence (>6 months, group III), and no recurrence (group IV). According to common concepts group I was defined as early (thrombotic) reocclusion, group II as clinically defined restenosis, and group III as progression of atherosclerosis. One hundred thirty-seven patients underwent percutaneous transluminal angioplasty of 148 extremities. The groups differ significantly only with respect to a higher diabetes score for group I in comparison to group IV (p=0.002, Kruskal-Wallis test), and a worse runoff of group I compared with group IV (p =0.008). There was a trend toward a higher diabetes score for group II in comparison to group IV (p = 0.014). There were no differences with regard to hyperlipemia, hypertension, and tobacco use between patient groups. Mean primary patency was 436 days. Predictors for lower patency rates were diabetes mellitus (p<0.001), runoff (p=0.005), and number of treated lesions (p=0.007) in a stepwise, multiple regression analysis. Patients with clinically defined restenosis showed no specific risk factor profile in this study. Predictors for lower primary patency were diabetes mellitus, number of treated lesions, and runoff.

Heme oxygenase-1 gene promoter microsatellite polymorphism is associated with restenosis after percutaneous transluminal angioplasty

PURPOSE

To determine if an association exists between postdilation restenosis and heme oxygenase-1 (HO-1), which is induced by balloon injury and inhibits neointimal formation through the action of endogenous carbon monoxide. A dinucleotide repeat in the promoter region of the HO-1 gene shows a length polymorphism that modulates the level of gene transcription.

METHODS

This cohort study included 96 consecutive patients (64 men; median age 69 years, interquartile range 60-75) who underwent successful balloon dilation in the femoropopliteal segment. Six-month patency was evaluated using oscillography, ankle-brachial index, and duplex sonography. The association of patency and the length of (GT) repeats in the HO-1 gene promoter was assessed in univariate and multivariate analyses.

RESULTS

Restenosis was found in 23 (24%) patients within the first 6 months. Patients with short (<25 GT) dinucleotide repeats in the HO-1 gene promoter on either allele had restenosis significantly less often than patients with longer (> or = 25 GT) dinucleotide repeats (p = 0.01). Multivariate analysis revealed a significantly reduced risk for restenosis in these patients compared to patients without the short allele (odds ratio 0.2, 95% Cl 0.06 to 0.70, p = 0.007).

CONCLUSIONS

Genetic risk factors for restenosis after percutaneous transluminal angioplasty have not been investigated. In this patient population, short repeat alleles of the heme oxygenase-1 gene promoter polymorphism were associated with reduced postdilation restenosis at 6 months. Upregulation of HO-1 may be an important protective factor after balloon angioplasty by inhibition of vascular smooth muscle cell proliferation.

Restenosis after percutaneous transluminal angioplasty in the femoropopliteal segment: the role of inflammation

PURPOSE

To determine the value of baseline C-reactive protein (CPR), fibrinogen, and white blood cell (WBC) counts in predicting 1-year patency after percutaneous transluminal angioplasty (PTA) in the femoropopliteal segment.

METHODS

In a retrospective cohort study, 168 consecutive patients (103 men; median age 70 years, interquartile range 61-77) who underwent successful PTA of the femoral and/or popliteal arteries were analyzed. Twelve-month patency was evaluated using oscillography, ankle brachial index, duplex sonography, and angiography. The predictive value of inflammatory markers was assessed in a multivariate model controlling for cardiovascular risk factors, technical success, and hemodynamic factors.

RESULTS

Transient WBC elevation was found 6 hours after PTA, but this returned to baseline after 24 hours. Fibrinogen was elevated at 24 hours. Duplex scanning disclosed restenosis in 66 (39%) patients within the first 12 months after PTA. Only residual postdilation stenosis (> or = 30%) in the target segment (odds ratio 3.6, p=0.001) and baseline CRP levels (odds ratio 4.2, p=0.02) were independent predictors of outcome; neither WBC counts nor fibrinogen levels at any time point was associated with restenosis.

CONCLUSIONS

Primary technical success and postinterventional hemodynamic flow at the dilated segment seem to be more important for intermediate-term patency than atherogenic risk factors. The predictive value of preprocedural serum CRP levels on restenosis should be further investigated.

Atherogenecity of lipoprotein(a) and oxidized low density lipoprotein: insight from in vivo studies of arterial wall influx, degradation and efflux

The accumulation of atherogenic lipoproteins in the arterial intima is pathognomonic of atherosclerosis. Modification of LDL by covalent linkage of apo(a) (resulting in the formation of Lp(a)) or oxidation probably enhances its atherogenecity. Although the metabolism of LDL in arterial intima has been rather extensively characterized, little has been known about the interaction of Lp(a) and oxidized LDL (ox-LDL) with the arterial wall. The present paper reviews a series of recent in vivo studies of the interaction of Lp(a) and ox-LDL with the arterial wall. The results have identified several factors that affect the accumulation of Lp(a) and ox-LDL in the arterial intima and have provided fresh insight into unique metabolic characteristics of Lp(a) and ox-LDL that may explain the large atherogenic potential of these modified LDL species.

Biochemical risk factors and patient's outcome: the case of lipoprotein(a)

Lipoprotein(a) (Lp(a)) is a genetic variant of low density lipoproteins and consists of the covalent association of the unique and enigmatic apolipoprotein(a) to apoliprotein B100. Despite the high degree of homology with low density lipoproteins, Lp(a) displays distinctive physico-chemical properties, function and metabolism. The present article reviews the main biological and clinical evidences about the association between raised concentration of Lp(a) and atherothrombotic diseases and provides tentative guidelines to improve the clinical usefulness of Lp(a) measurements.

Outcome of femoropopliteal angioplasty

OBJECTIVE

To assess prospectively the outcome of femoropopliteal angioplasty and investigate prognostic indicators of success.

BACKGROUND

Percutaneous transluminal angioplasty is commonly used to treat symptomatic femoropopliteal stenoses or occlusions, but the durability of the procedure is uncertain.

METHODS

Seventy-four consecutive patients treated by femoropopliteal angioplasty for intermittent claudication (43), rest pain (4), and tissue loss (27) were followed by assessment of symptoms, ankle-brachial pressure index (ABPI) to measure hemodynamic outcome, and duplex monitoring of velocity gradient at the angioplasty site to identify restenosis at 1 day and 3, 6, 9, and 12 months. Univariate comparisons, life table analysis, and backward stepwise regression were used to investigate factors predicting the symptomatic and hemodynamic outcome and restenosis.

RESULTS

Technical success was obtained in 67 patients (91%); failure occurred in 7 patients. At 1 year, a successful symptomatic outcome was achieved in 35 patients (51%), hemodynamic success was achieved in 41 patients (58%), and restenosis developed in 39%. ABPI at 24 hours after angioplasty was the most significant variable predicting a symptomatic outcome, hemodynamic outcome, and restenosis at 12 months. Life table analysis demonstrated that in 24% of patients with a 24-hour ABPI > or =0.9, restenosis developed by 12 months, compared with 64% of patients with a 24-hour ABPI <0.9.

CONCLUSION

Only half of the patients treated by femoropopliteal angioplasty had symptomatic improvement at 1 year, raising concern about the cost-benefit ratio of this procedure. Restoration of ABPI to >0.9 predicted a favorable outcome.

Long-term variability of serum lipoprotein(a) concentrations in healthy fertile women

Lipoprotein(a) is a unique lipoprotein with atherothrombogenic properties. Although its blood concentration is mainly genetically determined, various factors exist which may cause variability. These may influence the clinical use of the results. We studied lipoprotein(a) biological variation by a rate nephelometric assay over a period of two years in a population of healthy fertile women. The study was performed in 12 volunteers, healthy subjects with various lipoprotein(a) concentrations, by monthly determinations during one year and a single determination one year later, together with measurements of total, high density lipoprotein and high density lipoprotein2 cholesterol, triglycerides and apolipoproteins A1 and B. The intra-individual variability of lipoprotein(a) ranged between 4 to 20%, with three subjects showing a coefficient of biological variation higher than 15%. In absolute terms, the difference between two determinations could represent 0.44 g/l or 50% of the mean value. This study suggests that physiological lipoprotein(a) variations should be taken into account for clinical purposes, especially in patients in need of thorough risk evaluation.

Standardization and clinical management of lipoprotein(a) measurements

The present article proposes personal suggestions to improve determinations and clinical interpretation of results of lipoprotein(a) assays. Methods and procedures for sampling and quantification of the various isoforms of lipoprotein(a) in serum, plasma and urine are reviewed with the aim of improving the reliability and reproducibility of results and reinforcing the clinical utility of lipoprotein(a) measurements.