Cardiac Complications Attributed to Chloroquine and Hydroxychloroquine: A Systematic Review of the Literature.

INTRODUCTION: Chloroquine and hydroxychloroquine are widely used in the long-term treatment of connective tissue disease and usually considered safe. However, chloroquine- or hydroxychloroquine-related cardiac disorder is a rare but severe adverse event, which can lead to death. This systematic review investigates cardiac complications attributed to chloroquine and hydroxychloroquine. METHODS: PubMED, EMBASE, and Cochrane database searches were conducted using keywords derived from MeSH terms. Reports published prior to 31 July, 2017 were eligible for inclusion, without restriction to study design. Searches were also conducted on reference lists of included studies. RESULTS: Eighty-six articles were identified, reporting individual cases or short series, providing information on 127 patients (65.4% female). A majority of patients were treated with chloroquine (58.3%), with the remaining treated with hydroxychloroquine (39.4%), or both in succession. Most patients had been treated for a long time (median 7 years, minimum 3 days; maximum 35 years) and with a high cumulative dose (median 1235 g for hydroxychloroquine and 803 g for chloroquine). Conduction disorders were the main side effect reported, affecting 85% of patients. Other non-specific adverse cardiac events included ventricular hypertrophy (22%), hypokinesia (9.4%), heart failure (26.8%), pulmonary arterial hypertension (3.9%), and valvular dysfunction (7.1%). For 78 patients reported to have been withdrawn from treatment, some recovered normal heart function (44.9%), while for others progression was unfavorable, resulting in irreversible damage (12.9%) or death (30.8%). LIMITATIONS: The risk of cardiac complications attributed to chloroquine/hydroxychloroquine was not quantified because of the lack of randomized controlled trials and observational studies investigating the association. CONCLUSIONS: Clinicians should be warned that chloroquine- or hydroxychloroquine-related cardiac manifestations, even conduction disorders without repercussion, may be initial manifestations of toxicity, and are potentially irreversible. Therefore, treatment withdrawal is required when cardiac manifestations are present.

Prognostic Impact of Calcium Score after Transcatheter Aortic Valve Implantation Performed With New Generation Prosthesis.

Calcium score (CS) is a well-known prognostic factor after transcatheter aortic valve implantation (TAVI) performed with first generation prosthesis but few data are available concerning new generation valves. The aim of this study was to evaluate if CS remains a prognostic factor after Sapien 3 and Evolut R valves implantation. Agatston CS was evaluated on multislice computed tomography before TAVI in 346 patients implanted with Sapien XT (n = 61), CoreValve (n = 57) devices, (group 1, n = 118), and with new generation Sapien 3 (n = 147), Evolut R (n = 81) prosthesis, (group 2, n = 228). Major adverse cardiovascular events and aortic regurgitation (AR) were evaluated at 1 month. The 2 groups were similar at baseline except for logistic Euroscore (20.1% in group 1 vs 15.0 % in group 2; p = 0.001), chronic renal failure (44.1% vs 37.2% respectively, p = 0.007) and preprocedural CS (4,092 ± 2,176 vs 3,682 ± 2,109 respectively, p = 0.022). In group 1, 28 patients (23.7%) had adverse clinical events vs 21 (9.2%) in group 2 (p <0.01). In multivariate analysis, a higher CS was predictive of adverse events in group 1 (5,785 ± 3,285 vs 3,565 ± 1,331 p <0.0001) but not in group 2 (p = 0.28). A higher CS was associated with AR in group 1 (6,234 ± 2711 vs 3,429 ± 1,505; p <0.001) and in patients implanted with an Evolut R device from group 2 (4,085 ± 3,645 vs 2,551 ± 1,356; p = 0.01). In conclusion, CS appears as an important prognostic factor of major events after TAVI with first generation valves but not with new generation devices. CS remains associated with AR only with new generation self-expandable Evolut R devices.

Area at risk can be assessed by iodine-123-meta-iodobenzylguanidine single-photon emission computed tomography after myocardial infarction: a prospective study.

BACKGROUND: Myocardial salvage is an important surrogate endpoint to estimate the impact of treatments in patients with ST-segment elevation myocardial infarction (STEMI). AIM: The aim of this study was to evaluate the correlation between cardiac sympathetic denervation area assessed by single-photon emission computed tomography (SPECT) using iodine-123-meta-iodobenzylguanidine (I-MIBG) and myocardial area at risk (AAR) assessed by cardiac magnetic resonance (CMR) (gold standard). PATIENTS AND METHODS: A total of 35 postprimary reperfusion STEMI patients were enrolled prospectively to undergo SPECT using I-MIBG (evaluates cardiac sympathetic denervation) and thallium-201 (evaluates myocardial necrosis), and to undergo CMR imaging using T2-weighted spin-echo turbo inversion recovery for AAR and postgadolinium T1-weighted phase sensitive inversion recovery for scar assessment. RESULTS: I-MIBG imaging showed a wider denervated area (51.1±16.0% of left ventricular area) in comparison with the necrosis area on thallium-201 imaging (16.1±14.4% of left ventricular area, P<0.0001). CMR and SPECT provided similar evaluation of the transmural necrosis (P=0.10) with a good correlation (R=0.86, P<0.0001). AAR on CMR was not different compared with the denervated area (P=0.23) and was adequately correlated (R=0.56, P=0.0002). Myocardial salvage evaluated by SPECT imaging (mismatch denervated but viable myocardium) was significantly higher than by CMR (P=0.02). CONCLUSION: In patients with STEMI, I-MIBG SPECT, assessing cardiac sympathetic denervation may precisely evaluate the AAR, providing an alternative to CMR for AAR assessment.

Vascular Complications and Bleeding After Transfemoral Transcatheter Aortic Valve Implantation Performed Through Open Surgical Access.

Major vascular complications (VC) remain frequent after transcatheter aortic valve implantation (TAVI) and may be associated with unfavorable clinical outcomes. The objective of this study was to evaluate the rate of VC after transfemoral TAVI performed using an exclusive open surgical access strategy. From 2010 to 2014, we included in a monocentric registry all consecutive patients who underwent transfemoral TAVI. The procedures were performed with 16Fr to 20Fr sheath systems. VC were evaluated within 30 days and classified as major or minor according to the Valve Academic Research Consortium 2 definition. The study included 396 patients, 218 were women (55%), median age was 85 years (81 to 88), and the median logistic Euroscore was 15.2% (11 to 23). The balloon-expandable SAPIEN XT and the self-expandable Medtronic Core Valve prosthesis were used in 288 (72.7%) and 108 patients (27.3%), respectively. The total length of the procedure was 68 ± 15 minutes including 13 ± 5 minutes for the open surgical access. Major and minor VC were observed in 9 (2.3%) and 16 patients (4%), respectively, whereas life-threatening and major bleeding concerned 18 patients (4.6%). The median duration of hospitalization was 5 days (interquartile range 2 to 7), significantly higher in patients with VC (7 days [5 to 15], p <0.001). Mortality at 1-month and 1-year follow-up (n = 26, 6.6%; and n = 67, 17.2%, respectively) was not related to major or minor VC (p = 0.6). In multivariable analysis, only diabetes (odds ratio 2.5, 95% confidence interval 1.1 to 6.1, p = 0.034) and chronic kidney failure (odds ratio 3.0, 95% confidence interval 1.0 to 9.0, p = 0.046) were predictive of VC, whereas body mass index, gender, Euroscore, and lower limb arteriopathy were not. In conclusion, minimal rate of VC and bleeding can be obtained after transfemoral TAVI performed using an exclusive surgical strategy, with a particular advantage observed in high-risk bleeding patients.

Osteoprotegerin and sclerostin in chronic kidney disease prior to dialysis: potential partners in vascular calcifications.

BACKGROUND: Osteoprotegerin (OPG), sclerostin and DKK1 constitute opposite bone turnover inhibitors, OPG inhibiting osteoclastogenesis while sclerostin and DKK1 exerting their inhibitory effects on osteoblastogenesis. Both proteins have been recognized as strong risk factors of vascular calcifications in non-dialysis chronic kidney disease (ND-CKD) patients. The aim of this study was to investigate the relationships between these inhibitors and coronary artery calcifications (CAC) in this population. METHODS: A total of 241 ND-CKD patients [143 males; 69.0 (25.0-95.0) years; median estimated glomerular filtration rate using CKD-EPI 35.1 (6.7-120.1) mL/min/1.73 m(2)] were enrolled in this cross-sectional study. All underwent chest multidetector computed tomography for CAC scoring. OPG, sclerostin, DKK1 and mineral metabolism markers including PTH and bone alkaline phosphatase were measured. Logistic regression analyses were used to study the relationships between CAC and these markers. RESULTS: Decline in renal function was associated with a significant increase in OPG and sclerostin while a slight but significant decrease in DKK1 was observed. The main crude associations with presence of CAC were a high level of OPG [OR = 2.55 95% confidence interval (95% CI) (1.35-4.82) for a level ranging from 6.26 to 9.15 pmol/L and OR = 5.74 95% CI (2.87-11.5) for a level ≥9.15 pmol/L; P < 0.0001] and a high level of sclerostin [OR = 2.64 95% CI (1.39-5.00) for a level ranging from 0.748 to 1.139 ng/mL and OR = 3.78 95% CI (1.96-7.31) for a level ≥1.139 ng/mL; P = 0.0002]. A logistic regression model clearly showed that the risk to present CAC was significantly increased when both OPG (≥6.26 pmol/L) and sclerostin (≥0.748 ng/mL) levels were high [crude model: OR = 11.47 95% CI (4.54-29.0); P < 0.0001; model adjusted for age, gender, diabetes, body mass index and smoking habits: OR = 5.69 95% CI (1.76-18.4); P = 0.02]. No association between DKK1 and presence of CAC was observed. CONCLUSIONS: Our results strongly suggest that bone turnover inhibitors, OPG and sclerostin, are independently associated with CAC with potential additive effects in ND-CKD patients.

Bone biomarkers help grading severity of coronary calcifications in non dialysis chronic kidney disease patients.

BACKGROUND: Osteoprotegerin (OPG) and fibroblast growth factor-23 (FGF23) are recognized as strong risk factors of vascular calcifications in non dialysis chronic kidney disease (ND-CKD) patients. The aim of this study was to investigate the relationships between FGF23, OPG, and coronary artery calcifications (CAC) in this population and to attempt identification of the most powerful biomarker of CAC: FGF23? OPG? METHODOLOGY/PRINCIPAL FINDINGS: 195 ND-CKD patients (112 males/83 females, 70.8 [27.4-94.6] years) were enrolled in this cross-sectional study. All underwent chest multidetector computed tomography for CAC scoring. Vascular risk markers including FGF23 and OPG were measured. Logistic regression analyses were used to study the potential relationships between CAC and these markers. The fully adjusted-univariate analysis clearly showed high OPG (≥10.71 pmol/L) as the only variable significantly associated with moderate CAC ([100-400[) (OR = 2.73 [1.03;7.26]; p = 0.04). Such association failed to persist for CAC scoring higher than 400. Indeed, severe CAC was only associated with high phosphate fractional excretion (FEPO(4)) (≥38.71%) (OR = 5.47 [1.76;17.0]; p = 0.003) and high FGF23 (≥173.30 RU/mL) (OR = 5.40 [1.91;15.3]; p = 0.002). In addition, the risk to present severe CAC when FGF23 level was high was not significantly different when OPG was normal or high. Conversely, the risk to present moderate CAC when OPG level was high was not significantly different when FGF23 was normal or high. CONCLUSIONS: Our results strongly suggest that OPG is associated to moderate CAC while FGF23 rather represents a biomarker of severe CAC in ND-CKD patients.

[Stenting in superficial femoral artery and usCRP: Multicentric study SAFE in 255 patients]. / Stenting de l'artère fémorale superficielle et C-Reactive Protein ultrasensible (CRPus) : étude multicentrique SAFE de 255 patients.

OBJECTIVE: To evaluate mid-term primary patency of the femoral artery stenting in correlation with usCRP level and characteristics of the population, morphological aspect of the lesions and interventional techniques. METHODS: Patients were prospectively included in a multicenter study (18 centers in France) after stenting (SMART, Cordis Johnson & Johnson, Issy-les-Moulineaux, France) of the superficial femoral artery (SFA). Inclusion and exclusion criteria were based on recommendations and every day practice of the centers. RESULTS: Thus 255 patients (183 men; mean age: 69 years; range 44-92) were included. Technical success of the SFA stenting was 100% without any complications and primary angiographic success 97%. usCRP level increased significantly (p < 0.05) between before and 24h after SFA stenting. In the subgroup of patients without initial inflammation (n = 157), usCRP increased significantly (p < 0.05) in the group of patient with initial thrombosis and additional intervention (graft, amputation, angioplasty on other arterial bed) in the same procedure compared to the remaining patients. Restenosis rate was 12.4% (26/209 patients) at 7 ± 2 months. Before stenting, usCRP level was not predictive of a restenosis, whereas after stenting, an increase of the 24h usCRP level was significantly higher in the subgroup of patient with an occlusion at mid-term (8 patients; p < 0.05). CONCLUSION: This study demonstrated good patency at 7 months of SFA stenting with nitinol SMART with an increase of the usCRP level 24h after stenting in favour of the presence of an occlusion at mid-term follow-up.

Non-invasive assessment of small airway remodelling in smokers.

Smoking associated COPD progression is likely to be directly linked to differential injury and repair dynamics in small airways (SA). Although IL8 is a well-accepted marker for injured airway epithelium, Clara cells [the predominant proliferating cells in SA] and SCGB1A1 protein [their major secretory product] have only recently emerged as potential SA repair markers. We therefore postulate that the SCGB1A1/IL8 ratio in the airways of smokers would be inversely associated with physiological, radiological and clinical measures of COPD. A cross-sectional cohort of 28 smokers undergoing surgery for peripheral nodule was recruited (24M/4F, age 61 +/- 11 y, FEV1s 76 +/- 20%, smoking 40 +/- 12 p.y). SCGB1A1 and IL8 were measured by ELISA in the induced sputum (IS) 3 to 5 days prior to surgery as well as by immunohistochemistry from lung tissue (also assessed morphometrically) obtained distant to the cancer surgery site. COPD was assessed using standard clinical, functional and radiological parameters. Log-transformed IS-SCGB1A1 was linearly correlated with SCGB1A1-positive epithelial cells detected via immunohistochemistry (r = .533, p = .001), while IS-IL8 was positively related to SA infiltrating neutrophils (Elastase-positive cells). There was a striking negative correlation between IS-SCGB1A1/IL8 levels and whole airway thickness [SA < 2 mm] at morphometry (r = -0.83, p < 0.0001). IS-SCGB1A1/IL8 levels were also inversely associated with nitrogen slope [r = -0.52, p < 0.001] and HRCT SA score [r = -0.51, p < 0.001]. In a multivariate analysis the IS-SCGB1A1/IL8 ratio was a stronger predictor than both the physiological and radiological measures of SA disease assessed. The SCGB1A1/IL8 ratio measured in sputum is a potentially valuable biomarker for non-invasive assessment of SA remodelling in smokers.

Effect of cyclosporine on left ventricular remodeling after reperfused myocardial infarction.

OBJECTIVES: This study examined the effect of a single dose of cyclosporine administered at the time of reperfusion on left ventricular (LV) remodeling and function by cardiac magnetic resonance 5 days and 6 months after myocardial infarction. BACKGROUND: In a human study, administration of cyclosporine at the time of acute reperfusion was associated with a smaller infarct size. METHODS: Twenty-eight patients of the original cyclosporine study had an acute (at 5 days) and a follow-up (at 6 months) cardiac magnetic resonance study to determine LV volumes, mass, ejection fraction, myocardial wall thickness in infarcted and remote noninfarcted myocardium, and infarct size. RESULTS: There was a persistent reduction in infarct size at 6 months in the cyclosporine group compared with the control group of patients (29 +/- 15 g vs. 38 +/- 14 g; p = 0.04). There was a significant reduction of LV end-systolic volume (and a trend for LV end-diastolic volume; p = 0.07) in the cyclosporine group compared with the control group, both at 5 days and 6 months after infarction. There was no significant difference between the 2 groups in either global LV mass or regional wall thickness of the remote noninfarcted myocardium at 5 days or 6 months. Attenuation of LV dilation and improvement of LV ejection fraction by cyclosporine at 6 months were correlated with infarct size reduction. CONCLUSIONS: Cyclosporine used at the moment of acute myocardial infarction reperfusion persistently reduces infarct size and does not have a detrimental effect on LV remodeling. These results are preliminary and must be supported by further studies. (Ciclosporin A and Acute Myocardial Infarction; NCT00403728).

A cut-off value of plasma osteoprotegerin level may predict the presence of coronary artery calcifications in chronic kidney disease patients.

BACKGROUND: Expression of bone proteins resulting from transdifferentiation of vascular smooth muscle cells into osteoblasts suggests that vascular calcifications are a bioactive process. Osteoprotegerin (OPG) could play a key role in bone-vascular calcification imbalance and could be a marker of vascular calcification extent and progression. The purpose of this study was to evaluate relationships between vascular risk biomarkers (including classic risk factors and OPG) and coronary artery calcification (CAC) extent in chronic kidney disease (CKD) patients and to establish within the markers the appropriate cut-off value to predict CAC. METHODS: A total of 133 non-dialyzed CKD patients at various stages of kidney disease [75 males/58 females, median age: 69.9 (27.4-94.6)] were enrolled, excluding extrarenal replacement therapy patients. All underwent chest multidetector computed tomography for CAC scoring. Blood samples were collected for measurement of vascular risk markers (kidney disease, inflammation, nutrition, calcium phosphate and OPG). A potential relationship between CAC and these biological markers was investigated, and a receiver-operating characteristic (ROC) curve was designed thereafter to identify a cut-off value of involved markers that best predicted the presence of CAC. RESULTS: After adjustment for age, diabetes, smoking and gender, among biological markers, only low-estimated glomerular filtration rate using Modification of Diet in Renal Disease [OR = 3.63 (1.10-12.02)], high FEPO(4) [OR = 3.99 (1.17-13.6)] and high OPG levels [OR = 8.54 (2.14-34.11)] were associated with the presence of CAC. A protective effect of 1.25(OH)(2) vitamin D [OR = 0.20 (0.05-0.79)] and LDL cholesterol [OR = 0.27 (0.08-0.94)] on CAC was also observed. ROC curve analysis showed that the OPG best cut-off value predicting CAC was 757.7 pg/mL. CONCLUSION: These results suggest that a CAC increase is strongly associated with a plasma OPG increase in CKD patients. The values of OPG >757.7 pg/mL allow us to predict the presence of CAC in these patients.

Epstein Barr virus (EBV) and acute myopericarditis in an immunocompetent patient: first demonstrated case and discussion.

Acute viral infections can lead to heart inflammation, including acute myocarditis. We report the first case of myopericarditis in a young immunocompetent adult, in the context of recent Epstein-Barr virus infection. Clinical presentation was common acute pericarditis, but with risk biomarkers: high troponin I levels and multiple inflammation-compatible images on MRI. Diagnosis of myopericarditis was established, and then hospitalization was necessary. Clinical electrocardiographic settings and MRI are shown; EBV cardiac effects are discussed.

Abdominal CT angiography before surgery as a predictor of postoperative death in acute aortic dissection.

OBJECTIVE: The purpose of our study was to search for a relationship between postoperative death in acute aortic dissection and abdominal helical CT findings before surgery. MATERIALS AND METHODS: We retrospectively included 48 patients admitted to our institution for emergent surgery of acute aortic dissection diagnosed with helical CT angiography. We recorded postoperative deaths and analyzed abdominal helical CT vessels and parenchymal abnormalities, including the presence of dissected abdominal aortic branches, a compressed aortic lumen, and low enhancement of the parenchyma in abdominal organs. RESULTS: Among the 48 patients, 11 died after surgery. Postoperative death occurred in one of five patients with low enhancement of the parenchyma in one abdominal organ and in seven of eight patients with low enhancement of the parenchyma in at least two abdominal organs. The postoperative death rates strongly correlated with the number of low-enhanced abdominal organs per patient (p < 0.00005) but did not correlate with the number of dissected abdominal aortic branches. CONCLUSION: The rate of abdominal organs with low enhancement of the parenchyma seen on CT before surgery is a strong factor in outcome in patients with acute aortic dissection. Additional analysis of low enhancement of the parenchyma in abdominal organs on CT might be a useful tool to detect, before surgery, patients at risk of postoperative death.

Off-Pump Coronary Artery Bypass Grafts Assessment by Multislice Computed Tomography.

Abstract Background: Selective coronary angiography is the standard but invasive procedure for postoperative assessment of coronary artery bypass graft patency. The aim of this prospective study is to evaluate the multislice computed tomography (CT) as a means of postoperative patency assessment and anastomotic site control of arterial and venous coronary bypass grafts performed with off-pump coronary artery bypass techniques. Methods: Over a 6-month period, 20 patients underwent isolated coronary artery bypass (beating heart technique) and benefited, 7 days later, from a patency and anastomotic site control by multidetector angio multislice CT with cardiac gating. Results: Whole internal thoracic artery bypasses and venous grafts were visualized perfectly on their entire length, including the anastomotic site, and 3-dimensional reconstruction was possible. The relationship between cardiac cavities and the bypasses were well visualized, allowing quantification of bypass stenosis ensured by software analysis. Conclusions: Postoperative control of coronary bypasses is possible by multislice CT with a very satisfactory resolution, thus making it possible to check the patency of coronary bypasses and the quality of anastomosis with a noninvasive method. Three-dimensional reconstructions are very useful in the event of redo surgery.

Wall mechanics of the stented extracranial carotid artery.

BACKGROUND AND PURPOSE: Abrupt compliance changes and concomitant nonlaminar flow patterns may contribute to endothelial dysfunction and subsequent neointimal thickening. The aim of this study was to test the feasibility of wall mechanics measurement using B-mode ultrasound image analysis by dedicated software in the stented human carotid artery. METHODS: Carotid Wallstents (Schneider) were placed in the extracranial carotid arteries of 15 patients. B-mode ultrasound examination was performed with a 7.5-MHz probe on the carotid artery upstream; at the proximal, mid, and distal stent levels; downstream from the stent; and on the contralateral internal and common carotid arteries. Carotid diameter (d) and systolic diameter changes (Deltad) were measured with a dedicated image processing system (IO version 3.1, IODP), while pulse blood pressure (DeltaP) was measured. Diameter compliance (Cd) and distensibility coefficient (DC) were calculated as Cd=2Deltad/DeltaP and DC=2Deltad/DeltaP/d and compared between measurement sites. RESULTS: The evaluation could be completed in 8 of 15 patients. Compliance was significantly lower at the proximal, mid, and distal stent levels (27.77+/-1.11, 27.38+/-1.08, 27.38+/-1.09x10(-3) mm x kPa(-1)) than upstream (103.3+/-36.7x10(-3) mm x kPa(-1)), downstream (91.5+/-41.3x10(-3) mm x kPa(-1)), or on the contralateral internal (87.6+/-28x10(-3) mm x kPa(-1)) and common (149.3+/-47.6x10(-3) mm x kPa(-1)) carotid arteries. CONCLUSIONS: Stenting of the extracranial carotid artery induces a compliance mismatch between the native and the stented artery.

Experimental model for comparative evaluation of pharmacologically induced vasodilation of arterial wall mechanical properties.

Arterial wall compliance (C) and distensibility coefficient (DC) are key factors of pathologic physiology, especially in arteries less than 2 mm in diameter. The aim of this study was to design an experimental model allowing comparative measurement of C and DC during pharmacologically induced vasodilation on small-diameter arteries. Both femoral arteries were exposed in eight New Zealand White rabbits. Diameter (d) and systolic/diastolic diameter changes (deltad) were measured simultaneously, and C and DC were calculated before and after topical application of 1 mL of 4% papaverine on the right side and topical application of 1 mL of 1% lidocaine on the left side. Diameter measurements were performed by echo tracking with 20-MHz implanted microprobes. After papaverine and lidocaine application, respectively, d increased from 1.36 mm to 2.23 mm (P < 0.0001) and from 1.45 mm to 2.4 mm (P < 0.0001), deltad increased from 0.0568 mm to 0.0571 mm (P = 0.34) and from 0.064 mm to 0.077 mm (P < 0.01), C increased from 5.7 x 10(-3) mm/mm Hg to 6 x 10(-3) mm/mm Hg (P < 0.02) and from 6.23 x 10(-3) mm/mm Hg to 8.49 x 10(-3) mm/mm Hg (P < 0.01), and DC decreased from 4.22 x 10(-3) mm Hg(-1) to 2.61 x 10(-3) mm Hg(-1) (P < 0.0004) and from 4.36 x 10(-3) mm/mm Hg to 3.46 x 10(-3) mm/mm Hg (P < 0.005). Papaverine- and lidocaine-induced changes were significantly different for deltad, C, and DC (P < 0.01). These results suggest that, unlike that with papaverine, lidocaine-induced vasodilation leads the artery up to the nonlinear part of its pressure/diameter relationship, with decreased distensibility contrasting with increased diameter and compliance. Our experimental model may be useful to compare the effects of different vasoactive drugs at different concentrations on the mechanical properties of the arterial wall.

Wall mechanics of the stented rabbit aorta: long-term study and correlation with histological findings.

PURPOSE: To evaluate long-term changes in arterial wall mechanics induced by stenting of the rabbit aorta. METHODS: Eighteen New Zealand white rabbits had initial stent deployment (3x8 mm Multilink) at 110% of the pre-stenting abdominal aortic diameter. Group A (n=10) had no postdeployment stent expansion and group B (n=8) had 30% overdilation of the stent. A noninvasive B-mode ultrasound examination coupled with image processing allowed measurement of diameters at systole and diastole and the calculation of diameter compliance. Measurements were performed before stenting and compared to those recorded immediately after stenting and at 3 months at 3 locations: upstream from the stent, at the stent level, and downstream from the stent. Measurements were also compared among measurement sites. The pathological study included measurement of intimal thickening and calculation of an injury score. RESULTS: At the stent level, diameter compliance was significantly lower after initial stenting and at 3 months than before stenting (group A: p<0.005; group B: p<0.001) and than downstream or upstream from the stent (group A: p<0.0001, group B: p<0.005). No significant difference in diameter compliance was found between groups A and B. In group B, intimal thickening and the injury score were greater than in group A (p<0.05 and p<0.0001, respectively). CONCLUSIONS: Endovascular stenting of the rabbit aorta impairs wall mechanics. Performing 30% overdilation of the stent does not worsen this impairment but induces greater in-stent intimal hyperplasia.

Validation of a newly developed B-mode image-processing technique versus wall-tracking ultrasound for the study of wall mechanics in small-calibre arteries.

PURPOSE: To validate a newly developed image-processing technique for the assessment of arterial wall compliance and distensibility from non-invasive B-mode ultrasound compared with the invasive wall-tracking technique. MATERIALS AND METHODS: Arterial wall compliance and distensibility coefficient were measured invasively by wall-tracking with an ultrasonic transducer implanted on the vessel wall, and non-invasively by automatic processing of B-mode ultrasound images, with a dedicated workstation and software (IO 3.1, IODP, Paris). Measurements were performed in the normal aorta of five animals, and upstream, at the stent level, and downstream from the stent in eight other animals (immediately after stenting in six, and 3 months later in four), for a total of 35 paired measurements. RESULTS: There was no significant difference between the two techniques for compliance but there was a significant difference in diameter (P<0.005) and distensibility (P<0.05) as external ultrasound measured the inner diameter, while wall-tracking measured the outer diameter. Agreement between the two methods as assessed by the Bland-Altman approach was acceptable for aortic diameter, compliance and distensibility. CONCLUSION: Automatic processing of B-mode ultrasound images is a reliable non-invasive technique to assess the compliance of small-calibre arteries.

Arterial stenting and overdilation: does it change wall mechanics in small-caliber arteries?

PURPOSE: To evaluate changes in arterial wall mechanics induced by stent overdilation in the rabbit aorta. METHODS: Twenty New Zealand white rabbits had initial stent deployment (3-mm x 8-mm Multilink) at 10% overdilation. Group A (n=11) had no subsequent balloon expansion of the stent and Group B (n=9) had 30% overdilation of the stent. A noninvasive B-mode ultrasound examination coupled with image processing allowed the measurement of systolic and diastolic diameter and the calculation of diameter compliance (Cd) and distensibility coefficient (DC) as indexes of arterial wall biomechanics. Measurements were performed before stenting in the infrarenal aorta, after initial stenting, and after stent overdilation at 3 locations: upstream, at the stent level, and downstream from the stent. RESULTS: Cd was significantly lower in the stented aorta after initial stenting (p<0.0001) and after stent overdilation (p<0.0001) than before stenting. At the stent level, Cd and DC were significantly lower than downstream (p<0.0001) or upstream (p<0.0001) from the stent after initial stenting, as well as after stent overdilation. Downstream from the stent, Cd and DC were significantly lower after stent overdilation than before stenting (p<0.05). CONCLUSIONS: Endovascular stenting of the rabbit aorta produces a significant decrease in arterial wall compliance and distensibility. Stent overdilation is responsible for a slight additional decrease of compliance downstream from the stent.