Ischemia triggers BNP expression in the human myocardium independent from mechanical stress.

BACKGROUND: It is unknown whether the increased B-type natriuretic peptide (BNP) values found in ischemic heart disease are triggered directly by ischemia or whether they are caused indirectly by ischemia through diastolic contractures or regional wall motion abnormalities. Therefore, we investigated the BNP expression in isolated human muscle strips under conditions of ischemia with and without mechanical stress. METHODS: Muscle strips (n=90) were isolated from human right atria (n=46). Contractures were induced by oxygen and glucose withdrawal. In 18 muscle strips contractures were prevented by means of butanedione monoxime (BDM). Sarcomere lengths were measured by electron microscopy (n=12). The gene expression and protein amount of BNP were determined and compared to control muscle strips contracting under physiological conditions. RESULTS: Hypoxia significantly decreased systolic force and induced diastolic contractures. This mechanical stress could be prevented in the group treated with BDM as evidenced by electron microscopy. Ischemia significantly increased BNP expression in both groups as evidenced by Northern blot analysis and immunohistochemistry. This increase was independent from mechanical stress. CONCLUSION: Our results indicate that ischemia is a potent mechanism for the expression of BNP. The increase in BNP expression under ischemic conditions is independent from concomitant mechanical alterations.

Results after balloon angioplasty or stenting of atherosclerotic subclavian artery obstruction.

INTRODUCTION: Endovascular therapy is an accepted treatment strategy in occlusive disease of the subclavian artery. The purpose of this study was to evaluate the technical and clinical long-term outcome following either balloon angioplasty (plain balloon angioplasty (PTA)) or stenting. PATIENTS AND METHODS: The authors retrospectively analyzed 108 interventions of atherosclerotic lesions of subclavian arteries or the brachiocephalic trunk (107 patients; mean age of 66 +/- 9 years; 90% symptomatic) representing 92% of the patients treated with subclavian artery obstructive disease during a 10-year period. Primary endpoint of the study was the 1-year primary patency rate. Follow-up was based on oscillometry, Doppler blood pressure measurements, and duplex ultrasound. RESULTS: The primary success rate was 97% (100% for stenoses (78/78) and 87% for total occlusions (26/30)). Treatment modalities included PTA alone (13%; n = 14) or stenting (87%; n = 90) with balloon-expandable (n = 61), self-expanding (n = 17), or both types of devices (n = 12). The 1-year primary patency rate of the 97 patients eligible for follow-up was 88%, for the subgroups 79% (PTA) and 89% (stenting; P = 0.2). The blood pressure difference between both limbs at baseline was 45 +/- 26 mm Hg and dropped to 10 +/- 14 mm Hg (P < 0.001) after the intervention and 15 +/- 19 mm Hg at 1 year (P < 0.01). CONCLUSION: Endovascular therapy of atherosclerotic subclavian artery obstructions result in excellent acute success rates even in total occlusions. Results evince good durability of endovascular therapy for atherosclerotic occlusive disease of subclavian arteries and with a trend towards better outcome with stenting compared to PTA.

Arterial puncture closure using a clip device after transpopliteal retrograde approach for recanalization of the superficial femoral artery.

PURPOSE: To report the safety and efficacy of a clip device to close retrograde popliteal artery puncture sites used in recanalization of the superficial femoral artery (SFA). METHODS: From January 2005 to March 2007, 28 patients (20 men; mean age 66+/-10 years) with stable chronic peripheral artery disease were treated for chronic total SFA occlusion. All patients received aspirin and clopidogrel and were heparinized during the procedure. After failed antegrade recanalization, the SFA was revascularized via a retrograde transpopliteal access. The StarClose Vascular System was used to seal the popliteal artery puncture site. RESULTS: All (100%) interventions were finished successfully, and hemostasis was secured with the StarClose device in all cases. There was 1 (3.6%) major complication with the StarClose system: a transient popliteal artery occlusion induced by plaque shift during sheath removal, which was corrected with balloon angioplasty via the femoral access. Three (10.8%) small hematomas (<5 cm) occurred at the puncture site without causing significant patient discomfort. CONCLUSION: In this small experience, the StarClose Vascular Closure System appeared to be an effective and safe sealing device after percutaneous transpopliteal interventions. Plaque shifting leading to stenosis or occlusion at the puncture site can occur.

Initial experience with directed laser atherectomy using the CLiRpath photoablation atherectomy system and bias sheath in superficial femoral artery lesions.

PURPOSE: To report a safety and efficacy study of directed excimer laser atherectomy with the Bias Sheath guiding catheter to create larger lumens in the superficial femoral artery (SFA). METHODS: Fourteen patients (9 men; mean age 66+/-9 years, range 46-76) with chronic lower limb ischemia (Rutherford class 2 to 5) referable to SFA stenoses were treated with the 8-F-compatible Bias Sheath and a 1.7- or 2.0-mm laser catheter. Eight (57%) lesions were de novo and 6 (43%) were in-stent restenoses (ISR). Mean diameter stenosis was 96%+/-8% (range 80%-100%; 10 total occlusions), and mean lesion length was 126+/-78 mm (range 30-290). The primary study endpoint was laser success, defined as <50% angiographic residual stenosis post-laser, without major perforations. RESULTS: The primary endpoint was achieved in 8 (57%) lesions; all patients underwent additional balloon angioplasty, which achieved an angiographic residual stenosis <30% in all. Three lesions could not be completely traversed with the study device. Two dissections were detected after Bias Sheath application; 1 required stenting. There were 2 embolic events (specific to the antegrade device design); both were treated with aspiration therapy. Intravascular ultrasound (IVUS)-based minimal lumen diameters were 0.23+/-0.2 mm (range 0-1.0) at baseline and 3.2+/-0.8 mm after Bias Sheath application. Rutherford category improved at 1 month in 10 (71%) patients. One patient remained unchanged, another worsened (category 2 to 3), 1 died, and the fourth was not examined. The ankle-brachial index improved from 0.41+/-0.18 at baseline to 0.79+/-0.19 at discharge and to 0.80+/-0.19 at 1 month. Primary 1-month patency (<50% restenosis by duplex) was 85% (11/13 lesions). CONCLUSION: SFA lesions, including ISR, can be treated in the majority of cases with directed laser atherectomy, significantly reducing plaque burden as measured by IVUS. Embolization was attributed to device-specific features of the prototype antegrade sheath design, which was discontinued. Larger studies are mandatory to document the long-term technical and clinical impact of this new device.

Treatment of reoccurring instent restenosis following reintervention after stent-supported renal artery angioplasty.

BACKGROUND: Reoccurrence of restenosis following angioplasty of renal instent restenosis is a considerable drawback of stent-supported angioplasty of renal artery stenosis especially in small vessel diameters. We therefore prospectively studied the long-term outcome of different techniques of endovascular treatment of reoccurrence of instent renal artery restenosis after primarily successful reangioplasty focusing on the impact of covered and drug eluting stents, respectively. PATIENTS AND METHODS: The study included 31 consecutive patients (33 lesions) presenting with their at least second instent restenosis following renal artery stenting who were included in a prospective follow-up program (mean follow-up 36+/-25 months, range 1-85). Primary endpoint of the study was the reoccurrence rate of instent stenosis after primarily successful treatment of instent restenosis determined by duplex ultrasound. RESULTS: Primary success rate was 100%, no major complication occurred. Seven lesions were treated with balloon angioplasty (21%, group 1), 7 lesions with stent-in-stent placement (21%, group 2), 6 lesions with placement of a covered stent (18%, group 3), 3 lesions with a cutting balloon (9%, group 4), and 10 lesions with placement of a drug eluting stent (31%, group 5). During follow-up, overall 12 lesions (36%) developed reoccurrence of instent restenosis: n=5 in group 1 (reoccurrence rate 71%), n=3 in group 2 (43%), n=1 in group3 (17%), 3 in group 4 (100%), and n=0 in group 5 (0%). Treatment with a cutting balloon was the only significant predictor of restenosis (hazard ratio 32.3 (95% CI, 3.3-315.0); P<0.001). CONCLUSION: Treatment of at least second renal artery instent restenosis is feasible and safe. Balloon angioplasty and the implantation of a bare metal stent, a covered stent, or a drug eluting stent seemed to offer favorable long-term patency, whereas cutting balloon angioplasty resulted in a very high rate of restenoses and should therefore be discouraged for this indication.