Periprocedural embolic events related to carotid artery stenting detected by diffusion-weighted MRI: comparison between proximal and distal embolus protection devices

PURPOSE: To evaluate and compare the efficacy of proximal versus distal embolus protection devices (EPD) during carotid artery angioplasty/stenting (CAS) based on diffusion-weighted magnetic resonance imaging (DW-MRI). METHODS: Forty-four patients (31 men; mean age 68 years, range 48-85) underwent protected CAS and had DW-MRI before and after the intervention. The cohort was analyzed according to the type of EPD used: a proximal EPD was deployed in 25 (56.8%) patients (17 men; mean age 66 years, range 48-85) and a distal filter in 19 (14 men; mean age 70 years, range 58-79). Fifteen (60.0%) patients with proximal protection were symptomatic of the target lesion; in the distal protection group, 10 (52.6%) were symptomatic. RESULTS: New lesions were seen on the postinterventional DW-MRI in 28.0% (7/25) of the proximal EPD group versus 32.6% (6/19) of those with a distal filter (p = NS). The majority were clinically silent. The new lesions in the vascular territory of the stented carotid artery in the group as a whole and per patient were fewer in the proximal EPD group (p = NS). No significant differences were noted in the T(2) appearance of the new lesions or the number of new lesions observed away from the vascular territory of the stented artery. CONCLUSION: Proximal embolus protection devices show a nonsignificant trend toward fewer embolic events, which warrants large-scale studies. Furthermore, proximal protection devices can be useful to control and treat acute in-stent thrombosis.

Stent-grafts in the treatment of emergent or urgent carotid artery disease: review of 25 cases

PURPOSE: To report the authors' initial experience with carotid artery stent-grafts in a comparatively large patient series for the treatment of acute bleeding and impending rupture or the prevention of distal embolization. MATERIALS AND METHODS: This retrospective study was approved by the institutional review boards and performed according to HIPPA standards. Twenty-five patients were treated with 27 carotid artery stent-grafts (Gore Viabahn, n = 10; Bard Fluency, n = 9; polytetrafluoroethylene-covered Palmaz, n = 5; and Wallgraft, n = 3). Thirteen stent-grafts were placed in patients with carotid blow-out syndrome (including three patients with carotid-airway fistula), 12 in patients with either pseudoaneurysm (n = 9) or true aneurysm (n = 3), and two in patients with intractable high-grade bare stent restenosis. RESULTS: The technical success rate was 100% (27 of 27 cases). No acute procedural transient ischemic attacks or strokes occurred. Procedural dissections occurred in two of the 27 cases (7.4%). Short-term complications occurred in three of the 27 cases (11%) (repeat hemorrhage, n = 2; common carotid artery occlusion, n = 1). The overall patient mortality rate was 36% (nine of 25 patients, all with carotid blow-out syndrome). Six-month follow-up in 15 of the 16 living patients demonstrated widely patent stent-grafts. Two patients with pseudoaneurysm also demonstrated patent stents at 18- and 33-month follow-up. CONCLUSIONS: Stent-grafts may be useful in the treatment of carotid artery bleeding syndrome, aneurysm, and stenosis, with a high procedural success rate in selected cases. The results of mid-term follow-up are encouraging, but results of long-term follow-up must be evaluated in future studies.

Automated end-to-side anastomosis to the middle cerebral artery: a feasibility study

The treatment of complex cerebrovascular or skull base pathological conditions necessitates a microsurgical blood flow preservation or augmentative revascularization procedure as either an adjunctive safety measure or a definitive treatment. The brain is susceptible to ischemia, and procedure-related risks can be minimized by the reduction of occlusion time or the use of a nonocclusive technique. The authors therefore analyzed the feasibility of an automatic device (C-Port xA, Cardica) designed for constructing an end-to-side anastomosis with or without flow interruption for a middle cerebral artery (MCA) bypass in a human cadaveric model and in an in vivo craniotomy simulation model.

Cardiovascular risk factor control and outcomes in peripheral artery disease patients in the Reduction of Atherothrombosis for Continued Health (REACH) Registry

OBJECTIVES: To examine differences in risk factor (RF) management between peripheral artery disease (PAD) and coronary artery (CAD) or cerebrovascular disease (CVD), as well as the impact of RF control on major 1-year cardiovascular (CV) event rates. METHODS: The REACH Registry recruited >68000 outpatients aged >/=45 years with established atherothrombotic disease or >/=3 RFs for atherothrombosis. The predictors of RF control that were evaluated included: (1) patient demographics, (2) mode of PAD diagnosis, and (3) concomitant CAD and/or CVD. RESULTS: RF control was less frequent in patients with PAD (n=8322), compared with those with CAD or CVD (but no PAD, n=47492) [blood pressure; glycemia; total cholesterol; smoking cessation (each P<0.001)]. Factors independently associated with optimal RF control in patients with PAD were male gender (OR=1.9); residence in North America (OR=3.5), Japan (OR=2.5) or Latin America (OR=1.5); previous coronary revascularization (OR=1.3); and statin use (OR=1.4); whereas prior leg amputation was a negative predictor (OR=0.7) (P<0.001). Optimal RF control was associated with fewer 1-year CV ischemic symptoms or events. CONCLUSIONS: Patients with PAD do not achieve RF control as frequently as individuals with CAD or CVD. Improved RF control is associated with a positive impact on 1-year CV event rates.

Influence of stent type on hemodynamic depression after carotid artery stent placement

PURPOSE: To assess the effect of stent type on hypotension and bradycardia after carotid artery stent placement. MATERIALS AND METHODS: A retrospective analysis on a prospectively maintained database was conducted in 256 patients (126 men; mean age, 71.8 years +/- 8.6; 194 de novo lesions) undergoing carotid artery stent placement between January 1996 and January 2007 by using self-expanding stents. Braided Elgiloy stents (Wallstents) were used in 44 of the 256 patients (17.2%) and slotted-tube nitinol stents were deployed in 212 (82.8%). Bivariate and multivariable logistic regression models were used to determine the influence of stent design on procedural and 24-hour hypotension and bradycardia. RESULTS: Procedural hemodynamic depression (HD) was encountered in 73 of the 256 patients (28.5%) due to hypotension in 24 (9.4%), bradycardia in 12 (4.7%), or both in 37 (14.5%) patients. Rates of procedural hypotension were 11.3% with nitinol stents and 0% with braided Elgiloy stents (P = .0188). Persistent postprocedural HD occurred in 91 of the 256 patients (35.5%) due to hypotension in 40 patients (15.6%), bradycardia in 23 (9.0%), or both in 28 (10.9%). Within a multivariable analysis adjusted for clinically relevant factors affecting rates of HD, the use of braided Elgiloy stents was associated with a decreased rate of procedural hypotension (odds ratio: 0.165; 95% confidence interval: 0.038, 0.721; P = .017). Procedural hypotension and bradycardia were not correlated to incidence of major adverse events but were associated with an increased duration of hospital stay (P = .0059 and P = .0335, respectively). CONCLUSIONS: Nitinol stents are associated with a higher risk of hypotension as compared to braided Elgiloy stents during carotid artery stent placement.

"HIT on Trousseau" double trouble: acquired coagulopathy with femoral artery thrombosis

Trousseau Syndrome is a paraneoplastic procoagulant phenomenon. Heparin-induced thrombocytopenia (HIT) is a rare complication of anticoagulation with heparin. To our knowledge, the coincidence of the two has not been reported so far. We report a case of an acute thrombosis of the left femoral artery and distal leg arteries in a patient with an otherwise normal cardiovascular status. Endovascular revascularization attempts using mechanical rotational thrombectomy catheter, aspiration and local thrombolysis were unsuccessful. Progressive coagulation along the intra-arterial catheter was seen. Surgical thrombectomy of the femoral-pedal axis was successful, but the patient developed an immune-mediated HIT postoperatively. An adenocarcinoma of the colon was the likely cause for the initial arterial thrombosis, and probably adversely affected endovascular revascularization attempts. Subsequent HIT with microvascular thrombosis worsened ischemic damage leading to a below knee-amputation, despite patent large vessels. Compared to venous thrombosis, arterial thrombosis is a rare manifestation of Trousseau syndrome. The coincidence of it with HIT is even rarer. There may be a causal relationship between the two.

Pulmonary-artery pressure and exhaled nitric oxide in Bolivian and Caucasian high altitude dwellers

There is evidence that high altitude populations may be better protected from hypoxic pulmonary hypertension than low altitude natives, but the underlying mechanism is incompletely understood. In Tibetans, increased pulmonary respiratory NO synthesis attenuates hypoxic pulmonary hypertension. It has been speculated that this mechanism may represent a generalized high altitude adaptation pattern, but direct evidence for this speculation is lacking. We therefore measured systolic pulmonary-artery pressure (Doppler chocardiography) and exhaled nitric oxide (NO) in 34 healthy, middle-aged Bolivian high altitude natives and in 34 age- and sex-matched, well-acclimatized Caucasian low altitude natives living at high altitude (3600 m). The mean+/-SD systolic right ventricular to right atrial pressure gradient (24.3+/-5.9 vs. 24.7+/-4.9 mmHg) and exhaled NO (19.2+/-7.2 vs. 22.5+/-9.5 ppb) were similar in Bolivians and Caucasians. There was no relationship between pulmonary-artery pressure and respiratory NO in the two groups. These findings provide no evidence that Bolivian high altitude natives are better protected from hypoxic pulmonary hypertension than Caucasian low altitude natives and suggest that attenuation of pulmonary hypertension by increased respiratory NO synthesis may not represent a universal adaptation pattern in highaltitude populations.

Respiratory nitric oxide and pulmonary artery pressure in children of aymara and European ancestry at high altitude

Invasive studies suggest that healthy children living at high altitude display pulmonary hypertension, but the data to support this assumption are sparse. Nitric oxide (NO) synthesized by the respiratory epithelium regulates pulmonary artery pressure, and its synthesis was reported to be increased in Aymara high-altitude dwellers. We hypothesized that pulmonary artery pressure will be lower in Aymara children than in children of European ancestry at high altitude, and that this will be related to increased respiratory NO. We therefore compared pulmonary artery pressure and exhaled NO (a marker of respiratory epithelial NO synthesis) between large groups of healthy children of Aymara (n = 200; mean +/- SD age, 9.5 +/- 3.6 years) and European ancestry (n = 77) living at high altitude (3,600 to 4,000 m). We also studied a group of European children (n = 29) living at low altitude. The systolic right ventricular to right atrial pressure gradient in the Aymara children was normal, even though significantly higher than the gradient measured in European children at low altitude (22.5 +/- 6.1 mm Hg vs 17.7 +/- 3.1 mm Hg, p < 0.001). In children of European ancestry studied at high altitude, the pressure gradient was 33% higher than in the Aymara children (30.0 +/- 5.3 mm Hg vs 22.5 +/- 6.1 mm Hg, p < 0.0001). In contrast to what was expected, exhaled NO tended to be lower in Aymara children than in European children living at the same altitude (12.4 +/- 8.8 parts per billion [ppb] vs 16.1 +/- 11.1 ppb, p = 0.06) and was not related to pulmonary artery pressure in either group. Aymara children are protected from hypoxic pulmonary hypertension at high altitude. This protection does not appear to be related to increased respiratory NO synthesis.

Elective implantation of sirolimus-eluting stents for bifurcated and non-bifurcated unprotected left main coronary artery lesions: clinical outcomes at one year

AIMS: Recent studies of drug-eluting stents for unprotected left main coronary artery (LMCA) disease have been encouraging. We examined the performance of sirolimus-eluting stents (SES) for this indication. METHODS AND RESULTS: This retrospective study included 228 consecutive patients (mean age = 68 +/- 11 years, 80.6% men, 26.3% diabetics) who underwent implantation of SES for de novo LMCA stenoses. The mean additive and logistic EuroSCOREs were 5.2 +/- 3.9 and 8.2 +/- 13.2, respectively. The main objective of this study was to measure the rate of major adverse cardiac events (MACE), including death, myocardial infarction and target lesion revascularisation (TLR) at 12 months. Other objectives were to measure the rates of in-hospital MACE and 12-month TLR. Outcomes in 143 patients with (BIF+ group), versus 84 patients without (BIF-group) involvement of the bifurcation were compared. The pre-procedural percent diameter stenosis (%DS) was 60.1 +/- 11.2 in the BIF+ versus 54.7 +/- 12.2% in the BIF- group (p=0.008), and decreased to 18.0 +/- 9.7 and 13.9 +/- 11.3%, respectively (ns), after SES implant. The overall in-hospital MACE rate was 3.5%, and similar in both subgroups. The 1-year MACE rate was 14.5% overall, 16.8% in the BIF+ and 10.7% in the BIF- subgroup (ns). CONCLUSIONS: SES implants in high-risk patients with LMCA stenoses were associated with a low 1-year MACE rate. Stenting of the bifurcation was associated with significant increases in neither mortality nor 1-year MACE rate.

10-year follow-up of a prospective randomized trial comparing bare-metal stenting with internal mammary artery grafting for proximal, isolated de novo left anterior coronary artery stenosis the SIMA (Stenting versus Internal Mammary Artery grafting) trial

OBJECTIVES: This study was designed to compare the long-term clinical outcome of coronary artery bypass grafting (CABG) with intracoronary stenting of patients with isolated proximal left anterior descending coronary artery. BACKGROUND: Although numerous trials have compared coronary angioplasty with bypass surgery, none assessed the clinical evaluation in the long term. METHODS: We evaluated the 10-year clinical outcome in the SIMA (Stent versus Internal Mammary Artery grafting) trial. Patients were randomly assigned to stent implantation versus CABG. RESULTS: Of 123 randomized patients, 59 underwent CABG and 62 received a stent (2 patients were excluded). Follow-up after 10 years was obtained for 98% of the randomized patients. Twenty-six patients (42%) in the percutaneous coronary intervention group and 10 patients (17%) in the CABG group reached an end point (p < 0.001). This difference was due to a higher need for additional revascularization. The incidences of death and myocardial infarction were identical at 10%. Progression of the disease requiring additional revascularization was rare (5%) and was similar for the 2 groups. Stent thrombosis occurred in 2 patients (3%). Angina functional class showed no significant differences between the 2 groups. CONCLUSIONS: Both stent implantation and CABG are safe and highly effective in relieving symptoms in patients with isolated, proximal left anterior descending coronary artery stenosis. Stenting with bare-metal stents is associated with a higher need for repeat interventions. The long-term prognosis for these patients is excellent with either mode of revascularization.

Impact of drug-eluting stent selection on long-term clinical outcomes in patients treated for unprotected left main coronary artery disease: the sirolimus vs paclitaxel drug-eluting stent for left main registry (SP-DELFT)

AIM: To compare the long-term relative efficacy and safety of SES and PES in patients undergoing percutaneous coronary intervention (PCI) for unprotected left main coronary artery (ULMCA) disease and to evaluate the role of lesion location and stenting technique in determining outcomes. METHODS AND RESULTS: From April 2002 to April 2004, 288 consecutive patients who underwent elective PCI with DES implantation for de novo lesions on ULMCA have been retrospectively selected and analyzed in seven European and US tertiary care centers. All patients had a minimum follow-up of 3 years. SES was used in 152 patients while 136 received PES. Isolated ostial-shaft disease was present in 27% of patients. Distal LM disease (73%) was treated with single and double stent approach in 29.5% and 43.4% of patients respectively. After 3 years, rates of survival free from any of the events investigated, were independent from lesion location and stenting approach and did not differ significantly between SES and PES groups. Freedom from MACE (SES vs. PES) was 76.3% vs. 83.1% in the ostial/shaft group, 80.3% vs. 72.8% in the distal-single stent group and 67.1% vs. 66.2% in the distal-double stent group. Definite stent thrombosis occurred only in 1(0.3%) patient at 439 days. CONCLUSIONS: In elective patients who underwent PCI for de novo lesions in the ostium, shaft or distal ULMCA, long-term clinical outcomes with SES and PES use were similar independently of lesion location and stenting technique.

Longest available clinical outcomes after drug-eluting stent implantation for unprotected left main coronary artery disease: the DELFT (Drug Eluting stent for LeFT main) Registry

OBJECTIVES: The purpose of this study was to investigate the long-term safety and efficacy of percutaneous coronary intervention (PCI) with drug-eluting stent (DES) implantation for unprotected left main coronary artery (ULMCA) disease. BACKGROUND: Long-term clinical outcomes after DES implantation for ULMCA disease have not yet been ascertained. METHODS: From April 2002 to April 2004, 358 consecutive patients who underwent PCI with DES implantation for de novo lesions on ULMCA were retrospectively selected and analyzed in 7 European and U.S. tertiary care centers. No patients were excluded from the analysis, and all patients had a minimum follow-up of 3 years. RESULTS: Technical success rate was 100%. Procedural success rate was 89.6%. After 3 years, major adverse cardiovascular events (MACE)-free survival in the whole population was 73.5%. According to the Academic Research Consortium definitions, cardiac death occurred in 9.2% of patients, and reinfarction, target lesion revascularization (TLR), and target vessel revascularization (TVR) occurred in 8.6%, 5.8%, and 14.2% of patients, respectively. Definite stent thrombosis occurred in 2 patients (specifically at 0 and 439 days). In elective patients, the 3-year MACE-free survival was 74.2%, with mortality, reinfarction, TLR, and TVR rates of 6.2%, 8.3%, 6.6%, and 16%, respectively. In the emergent group the 3-year MACE-free survival was 68.2%, with mortality, reinfarction, TLR, and TVR rates of 21.4%, 10%, 2.8%, and 7.1%, respectively. CONCLUSIONS: Routine DES implantation in ULMCA disease seems encouraging, with favorable long-term clinical results.

Flow impairment during protected carotid artery stenting: impact of filter device design

PURPOSE: To investigate the impact of filter design on blood flow impairment in the internal carotid artery (ICA) among patients undergoing carotid artery stenting (CAS) using filter-type emboli protection devices (EPD). METHODS: Between July 2003 and March 2007, 115 filter-protected CAS procedures were performed at an academic institution in 107 consecutive patients (78 men; mean age 68 years, range 38-87). The Angioguard, FilterWire EZ, and Spider filters were used in 68 (59%), 32 (28%), and 15 (13%) of cases, respectively. Patient characteristics, procedural and angiographic data, and outcomes were prospectively entered into an electronic database and reviewed retrospectively along with all angiograms. RESULTS: Flow impairment while the filter was in place was observed in 25 (22%) cases. The presumptive reason of flow impairment was filter obstruction in 21 (18%) instances and flow-limiting spasm at the level of the filter in 4 (4%). In all cases, flow was restored after retrieval of the filter. Flow obstruction in the ICA occurred more frequently with Angioguard (22/68; 32.3%) than with FilterWire EZ (2/32; 6.2%) or Spider (1/15; 6.7%; p = 0.004). No flow occurred in 13 (19%) procedures, all of them protected with Angioguard; no patient treated with other devices experienced this event (p = 0.007). Two (8.0%) strokes occurred in procedures associated with flow impairment, while 1 (1.1%) event was observed in the presence of preserved flow throughout the intervention (p = 0.11). CONCLUSION: Flow impairment in the ICA during filter-based CAS is common and related to the type of filter used.

Functionally relevant coronary artery disease: comparison of 64-section CT angiography with myocardial perfusion SPECT

PURPOSE: To prospectively determine the accuracy of 64-section computed tomographic (CT) angiography for the depiction of coronary artery disease (CAD) that induces perfusion defects at myocardial perfusion imaging with single photon emission computed tomography (SPECT), by using myocardial perfusion imaging as the reference standard. MATERIALS AND METHODS: All patients gave written informed consent after the study details, including radiation exposure, were explained. The study protocol was approved by the local institutional review board. In patients referred for elective conventional coronary angiography, an additional 64-section CT angiography study and a myocardial perfusion imaging study (1-day adenosine stress-rest protocol) with technetium 99m-tetrofosmin SPECT were performed before conventional angiography. Coronary artery diameter narrowing of 50% or greater at CT angiography was defined as stenosis and was compared with the myocardial perfusion imaging findings. Quantitative coronary angiography served as a reference standard for CT angiography. RESULTS: A total of 1093 coronary segments in 310 coronary arteries in 78 patients (mean age, 65 years +/- 9 [standard deviation]; 35 women) were analyzed. CT angiography revealed stenoses in 137 segments (13%) corresponding to 91 arteries (29%) in 46 patients (59%). SPECT revealed 14 reversible, 13 fixed, and six partially reversible defects in 31 patients (40%). Sensitivity, specificity, and negative and positive predictive values, respectively, of CT angiography in the detection of reversible myocardial perfusion imaging defects were 95%, 53%, 94%, and 58% on a per-patient basis and 95%, 75%, 96%, and 72% on a per-artery basis. Agreement between CT and conventional angiography was very good (96% and kappa = 0.92 for patient-based analysis, 93% and kappa = 0.84 for vessel-based analysis). CONCLUSION: Sixty-four-section CT angiography can help rule out hemodynamically relevant CAD in patients with intermediate to high pretest likelihood, although an abnormal CT angiography study is a poor predictor of ischemia.