Initial experience with the novel 6 Fr-compatible system for debulking de novo coronary arterial lesions.

The purpose of this study was to determine the efficacy of a novel system for debulking of de novo native coronary arterial lesions. The Helixciser De Novo system is a novel 6 Fr-compatible catheter with a cutter encased in a slotted-orifice housing to excise atheromatous plaque. The cutter rotates at 15,000 rpm, debulking the plaque as it tracks through the lesion over a straight wire or a self-expanding nitinol helical-shaped wire. The tissue is aspirated via an Archimedes screw pump to vacuum collection chamber. The device was evaluated in a porcine toxic coronary stent model of chronic occlusion and in five patients with focal de novo native coronary arterial lesions. Procedural variables along with outcomes were reviewed. Quantitative angiography (QCA) and volumetric intravascular ultrasound (IVUS) analysis were performed. In a porcine model of chronic occlusion, QCA demonstrated pretreatment minimal lumen diameter (MLD) increased from 0.77 +/- 0.59 to 1.88 +/- 0.25 mm postdebulking. IVUS analysis demonstrated pretreatment lumen volume (LV) increased from 15.8 +/- 22.2 to 46.4 +/- 28.9 mm(3) postdebulking. In human clinical feasibility cases, QCA demonstrated pretreatment MLD increased from 0.96 +/- 0.40 to 2.04 +/- 0.19 mm postdebulking. IVUS analysis demonstrated pretreatment LV increased from 38.40 +/- 12.78 to 52.05 +/- 15.68 mm(3) postdebulking. Preliminary results document the feasibility of Helixcision De Novo for treatment of focal de novo native coronary arterial lesions. Quantitative angiographic and IVUS analysis indicate that this system can effectively debulk plaque from selected noncalcified atherosclerotic lesions and thus may represent an alternative treatment strategy for coronary artery disease.     

Comparison of acute elastic recoil after directional coronary atherectomy versus standard balloon angioplasty.

We evaluated intraprocedural "elastic recoil" in 25 patients (22 men and 3 women) undergoing directional coronary atherectomy (DCA) of left anterior descending stenoses, and compared these with 25 temporally-matched (14 men and 11 women) patients having balloon angioplasties (PTCA). Quantitative arteriography was performed using the Coronary Measurement System (Leiden, The Netherlands), with "elastic recoil" defined as the difference in maximum device or balloon size minus residual minimum diameter. In addition, we determined the effects of relative device size, specific anatomic location (proximal/mid artery), lesion length, eccentricity (symmetry index), and dystrophic calcification on acute "recoil" severity after both procedures. Although initial coronary stenoses were similar (minimum stenotic diameter, DCA = 0.59 +/- 0.20 mm versus PTCA = 0.55 +/- 0.23 mm, p = NS), less "elastic recoil" was observed after atherectomy (DCA = 0.83 +/- 0.57 mm versus PTCA = 1.26 +/- 0.56 mm, p < 0.01), and this was confirmed by absolute recoil/maximum device size ratios (DCA = 23.5 +/- 16.0% versus PTCA = 41.6 +/- 13.8%, p < 0.01). Acute "elastic recoil" was also influenced by maximum device size/"normal" coronary artery ratios [(ratio < 0.9, DCA = 0.26 +/- 0.10 mm versus PTCA = 0.84 +/- 0.13 mm, p < 0.01); (ratio 0.9 to 1.1, DCA = 0.69 +/- 0.41 mm versus PTCA 0.75 +/- 0.32 mm, p = NS); (ratio > 1.1, DCA = 1.09 +/- 0.64 mm versus PTCA = 1.59 +/- 0.48 mm, p < 0.05)].(ABSTRACT TRUNCATED AT 250 WORDS)     

Pullback atherectomy. An alternative procedure in the treatment of coronary stenosis and in-stent restenosis

Optimized directional coronary atherectomy (DCA) has shown significantly superior acute and long-term results compared to conventional balloon angioplasty (BA). Nevertheless DCA has remained a niche application due to specific procedural aspects. The pullback atherectomy catheter (PAC), developed to retrieve atheromatous plaque material, is an alternative debulking device. We report on clinical and angiographic experience in 55 consecutive patients, in whom de novo lesions (35 pts) as well as instent restenoses (17 pts) were treated. The minimal luminal diameter (MLD, mm) rose after PAC and additional BA from 1.06 +/- 0.53 to 2.68 +/- 0.48 and from 1.10 +/- 0.48 to 2.55 +/- 0.49 mm, respectively. A stenosis reduction from 69 +/- 13 to 19 +/- 16 and from 64 +/- 15 to 16 +/- 10%, resp., could be documented. After 3-6 months a complete angiographic follow-up showed MLD values of 2.01 +/- 0.69 and 1.88 +/- 0.61 mm. Nine of 35 (26%) vs. 5 of 17 (29%) pts developed significant restenosis at the treated site (diameter stenoses > 50%). Stent implantation was necessary to achieve an optimal acute angiographic result or due to dissection in 17 vs. 5 pts. Major cardiac events did not occur; however, two restenosed coilstents were removed by PAC. With the pullback atherectomy catheter, a safe and effective alternative device is available for the treatment of coronary lesions and also of in-stent restenosis. Promising short and acceptable long-term results are comparable to those of other debulking procedures.     

Impact of intravascular ultrasound guidance on directional coronary atherectomy

In contrast to the luminogram of coronary angiography, intravascular ultrasound (IVUS) has proven to accurately assess both coronary lumen and vessel morphology due to its 360 degrees imaging capacity. Directional coronary atherectomy (DCA) improves the coronary lumen by removing plaque mass rather than stretching the vessel and compressing the plaque as with conventional percutaneous transluminal coronary angioplasty. In an attempt to optimize the procedural result of DCA we prospectively investigated the impact of IVUS guidance in a head to head comparison to on-line quantitative coronary angiography (QCA) on the result of DCA. In 16 consecutive patients IVUS demonstrated significant residual plaque mass after DCA irrespective of a satisfactory angiographic result. After a mean of 9 +/- 2 cuts luminal improvement was obtained with an area stenosis by angiography of 39 +/- 17% and by IVUS of 50 +/- 10% (p < 0.05), a diameter stenosis by angiography of 23 +/- 10% and IVUS of 35 +/- 14% (p < 0.05) and finally a minimal lumen diameter (MLD) by angiography of 2.9 +/- 0.5 mm and by IVUS of 2.3 +/- 0.5 mm (p < 0.005). After both on-line QCA and IVUS measurements a second series of 7 +/- 2 cuts were initiated to debulk more atheroma and improve stenosis dimensions. After additional cuts IVUS revealed further luminal improvement with an area stenosis by angiography of 25 +/- 16% and IVUS of 21 +/- 18% (n.s.), a diameter stenosis by angiography of 16 +/- 11% and by IVUS of 13 +/- 19% (n.s.) and finally a MLD by angiography of 3.1 +/- 0.5 mm and by IVUS of 2.8 +/- 0.3 mm (p < 0.05). Intraprocedural use of IVUS is superior to on-line QCA to assess the immediate result of DCA. IVUS-guided DCA results in more effective atheroma debulking than luminographic evaluation. Results of larger follow-up studies are needed to substantiate the intraprocedural advantage of IVUS with DCA.     

Directional coronary atherectomy in intermediate sized vessels: final results of the intermediate vessel atherectomy trial (IVAT).

Revascularization options for intermediate sized vessels (2.5-2.9 mm) have historically been limited. IVAT is a pilot study to assess the efficacy and safety of debulking intermediate sized vessels using directional coronary atherectomy (DCA). Between March 1996 and June 1997, 50 patients were enrolled at seven hospitals in the United States. Of those patients, 70% presented with unstable angina and 52% had single vessel disease. Of the lesions treated, 96% were de novo. Adjunctive PTCA after DCA was performed in 90% of cases at the discretion of the investigator to maximize luminal diameter. The GTO DCA device was used in 90% of cases. Procedural success (residual stenosis <50% without major complications) was 94%. Stents were placed in 12% of patients. The only complications were three non-Q wave MIs. Mean reference vessel diameter increased from 2.49 mm pre-procedure to 2.57 mm after DCA and 2.61 post-procedure; mean MLD increased from 0.76 mm to 2.03 mm to 2.31 mm; and mean stenosis decreased from 70% to 21% post DCA and to 11% post procedure. At six months follow-up, 18.0% of target lesions required revascularization. Total revascularization, including non-target vessels, was 32%. These results suggest that DCA has a high procedural success rate and a low target lesion revascularization rate in intermediate sized vessels.     

Effective plaque removal with a new 8 French-compatible atherectomy catheter.

The purpose of this study was to evaluate the safety and efficacy of the new 8 Fr guide catheter-compatible Flexicut directional atherectomy device and to compare it with the conventional Atherocath GTO catheter. The 6 Fr Flexicut catheter has a larger cutting window and a titanium nitride-coated cutter to effect more tissue removal as well as treat mildly calcified lesions. A group of 143 lesions in 117 consecutive patients treated with the Flexicut catheter in four centers were compared with a control group of 277 lesions in 212 consecutive patients treated with the GTO device. Postatherectomy luminal diameters were larger (2.92 +/- 0.79 vs. 2.52 +/- 0.64 mm; P < 0.0001), with more luminal gain (relative gain: 0.58 +/- 0.24 vs. 0.48 +/- 0.25; P = 0.0007) using fewer directional coronary atherectomy (DCA) cuts (12 +/- 7 vs. 16 +/- 9; P = 0.0001) in the Flexicut group. A residual diameter stenosis < 20% immediately after DCA was obtained in 77% of the lesions in the Flexicut group vs. 45% in the GTO group (P < 0.0001). Histology in the former group revealed large calcium speckles in the retrieved specimens. In the Flexicut group, there was a lower incidence of access site complications and damage to the coronary ostium (2.5% vs. 7.5%; P = 0.08). The new Flexicut catheter is more effective than the conventional GTO catheter with a trend for reduced guiding catheter-related complications.     

Early Changes in Minimal Luminal Diameter After Balloon Angioplasty and Directional Coronary Atherectomy

Early elastic recoil has been implicated in the pathophysiology of restenosis after balloon coronary angioplasty (PTCA). Directional atherectomy (DCA) may significantly attenuate this vessel wall reaction by altering the vessel wall architecture, specifically by removing or injuring the medial smooth muscle cells. We compared the magnitude of early changes in minimal lumen diameter (MLD) after DCA followed by adjunctive PTCA (group I) in comparison to PTCA alone (group II). In two groups of 30 lesions, matched for vessel size and location, group I cases showed significantly less recoil than group II cases, as assessed by routinely performed 15 minute post-procedure angiograms: mean changes in post-procedure MLD +0.06mm (increase) vs. -0.31mm (decrease) respectively, p = 0.02. In a histopathologic substudy of the DCA treated patients, those without early recoil had significantly higher incidence of media removal compared to patients with recoil (50% vs. 7%, p = 0.03). Therefore, early changes in MLD, presumably related to elastic recoil, are less with DCA and adjunct PTCA in comparison to PTCA alone. Attenuation of early recoil may be an additional mechanism accounting for the acute lumen gain achieved with this technique.     

The AST petal dedicated bifurcation stent: first-in-human experience.

The aim of this first-in-human study was to evaluate the feasibility and safety of the novel AST petal side-access bifurcation stent. Outcomes following percutaneous coronary intervention for bifurcations remain inferior to those of nonbifurcated lesions. Even with drug-eluting stents, restenosis occurs especially at the side-branch (SB) ostium. The petal stent uniquely deploys strut elements into the SB, supporting the ostium and carina. The primary endpoint of this 13-patient prospective registry was in-hospital major adverse cardiac events (MACE). Secondary end points included acute minimum lumen diameter (MLD) at the SB ostium, lesion success, device success, procedural success, 30-day MACE, and 4-month SB ostial MLD. The study lesion was successfully treated in 13 patients with the study stent being successfully implanted in 12. Target lesions were left anterior descending coronary artery in nine subjects, left circumflex in three, and right coronary artery in one. In-hospital MACE were limited to two non-Q-wave myocardial infarctions. In-stent main branch MLD increased from a mean of 0.63 +/- 0.45 mm to 2.61 +/- 0.47 mm at the index procedure and for this initial bare metal version of the stent, 4-month mean MLD measured 1.02 +/- 0.42 mm and there was target vessel revascularization on two patients. The feasibility of safely deploying this first-generation petal stent was demonstrated in selected patients with challenging coronary bifurcation lesions. It is a promising platform for drug delivery, with unique scaffolding of the side-branch ostium.     

A porcine coronary stent model of increased neointima formation in the left anterior descending coronary artery

BACKGROUND: Clinical trials suggest an increased frequency of restenosis after coronary intervention in left anterior descending (LAD) compared to the left circumflex or right coronary arteries. Experimental studies correlate stent-induced arterial injury and the extent of neointima formation. This study investigates whether the coronary artery affects the relationship between arterial injury and neointima hyperplasia in the porcine stent model. METHODS: Non-lipemic farm pigs underwent stent placement in the LAD (n = 26) and the right coronary artery (RCA; n = 30). Quantitative coronary angiography (QCA) was performed before and after stent placement, and at follow-up; quantitative histomorphometry and injury score were analyzed at 30-day follow-up. RESULTS: Initial procedure balloon/artery ratios (LAD 1.17 +/- 0.11 vs RCA 1.17 +/- 0.09, P = NS), and minimal stent lumen diameters (MLD; LAD 2.91 +/- 0.31 vs RCA: 2.93 +/- 0.28 mm, P = NS) were similar suggesting no difference in deployment technique. At follow-up there was more restenosis in the LAD (diameter stenosis: 55.0 +/- 26.4% vs 37.3 +/- 18.1%, and MLD: 1.24 +/- 0.78 mm vs. 1.71 +/- 0.57 mm, P < 0.05 for both comparisons). No differences were seen for injury score (1.09 +/- 0.51 vs 1.01 +/- 0.57; LAD vs RCA) or stent area (6.13 +/- 0.99 vs 6.55 +/- 1.42 mm2). Histomorphometry demonstrated smaller lumen area (2.15 +/- 0.94 vs 2.96 +/- 1.29 mm2) and thicker neointima (0.63 +/- 0.25 vs 0.51 +/- 0.17 mm; all P < 0.05) in the LAD. Multiple linear regression analysis identified the LAD as an independent predictive factor for increased neointima formation. CONCLUSIONS: These observations establish an animal model that is consistent with clinical experience showing that restenosis after stenting is more common in the LAD. The findings may be useful for understanding and developing systemic and local antirestenotic strategies.     

Low power ultrasound delivered through a PTCA-like guidewire: preclinical feasibility and safety of a novel technology for intracoronary thrombolysis

BACKGROUND: Low power ultrasound delivered through an angioplasty-like guidewire may be effective for intracoronary thrombolysis. We evaluated the preclinical feasibility and safety of such wire. METHODS AND RESULTS: In 15 anesthetized Yucatan minipigs, the ultrasonic wire was advanced percutaneously into all three coronaries. Each coronary was randomized to long activation (6 minutes), short activation (3 minutes), or control (3 minutes indwelling, no activation). The energy delivered was 0.14 +/- 0.01 W/cm of active length (20 kHz). No changes in heart rate, rhythm, or arterial pressure occurred during wire positioning or activation. Mean lumen diameter (MLD) by quantitative angiography was not significantly different pre- and postintervention (2.36 +/- 0.12 mm vs 2.36 +/- 0.11 mm for long activation, P = 0.96; 2.33 +/- 0.15 mm vs 2.34 +/- 0.14 mm for short activation, P = 0.54; 2.30 +/- 0.12 mm vs 2.33 +/- 0.12 mm for control, P = 0.21). There were no angiographic stenoses at 60 or 90 days follow-up. Compared with baseline, MLD at follow-up increased in all the three groups (2.40 +/- 0.13 mm vs 2.53 +/- 0.11 mm, P = 0.004 for long activation; 2.37 +/- 0.17 mm vs 2.52 +/- 0.14 mm, P = 0.023 for short activation; 2.20 +/- 0.12 mm vs 2.33 +/- 0.11 mm, P = 0.001 for the control group). By histology, there were no clinically significant pathologic changes in coronary morphology. CONCLUSION: Use of a transverse cavitation therapeutic wire is feasible and well tolerated acutely in the normal porcine coronary. At 60 and 90 days, no angiographically apparent damage, no clinically significant pathologic changes, and no adverse events were seen. This technology may be safely used during percutaneous coronary intervention. Further studies are justified to evaluate its efficacy for intracoronary thrombus ablation.     

Acute outcome of directional coronary atherectomy vs standard balloon angioplasty in de novo left anterior descending stenoses.

To assess the immediate outcome of directional coronary atherectomy (DCA) versus standard balloon angioplasty (PTCA) in de novo left anterior descending coronary stenoses, 25 consecutive atherectomies (22 men, 3 women) performed at The Toronto Hospital, between July 1990 and March 1991 were compared with 25 (14 men, 11 women) temporally matched successful angioplasties. Coronary stenoses were analyzed by quantitative arteriography, using the Coronary Measurement System (Leiden, The Netherlands), with estimation of transstenotic hemodynamics by fluid dynamic equations. Before and after procedure qualitative blood flow (TIMI criteria) was also evaluated, as was intimal haziness and coronary dissection. In comparison to PTCA, coronary atherectomy produced less residual minimum stenotic diameter (DCA, 2.75 +/- 0.55 vs PTCA, 1.70 +/- 0.44 mm, p < 0.001), and relative percent diameter stenosis (DCA, 17.9 +/- 10.7 vs PTCA, 34.4 +/- 10.7 percent, p < 0.001), with less transstenotic obstructive gradient (DCA, 0.2 +/- 0.2 vs PTCA, 1.0 +/- 1.5 mm Hg, p < 0.05), and greater estimated stenotic flow reserve (DCA, 4.86 +/- 0.15 vs PTCA, 4.50 +/- 0.48 x baseline, p < 0.05). Coronary atherectomy "normalized" TIMI flow patterns in virtually all patients (DCA, 2.96 +/- 0.20 vs PTCA, 2.72 +/- 0.45, p < 0.05), while creating less intimal haziness (DCA, 10/25 [40 percent] vs PTCA, 23/25 [92 percent], p < 0.01), and coronary dissection (DCA, 6/25 [24 percent] vs PTCA, 16/25 [64 percent], p < 0.05). Therefore, when compared with standard balloon angioplasty, DCA produces less residual stenosis, better transstenotic hemodynamics, while decreasing the frequency of coronary artery damage, in de novo left anterior descending stenoses.     

Six-month outcome after excimer laser coronary angioplasty for diffuse in-stent restenosis in native coronary arteries

This study evaluated the intermediate-term follow-up after excimer laser coronary angioplasty (ELCA) and adjunctive percutaneous transluminal coronary angioplasty (PTCA) in patients with diffuse in-stent restenosis (lesion length >10 mm). Clinical and angiographic follow-up were performed at 6 months. Quantitative coronary angiography performed at 3 stages-during stent implantation, before and after ELCA + PTCA, and at follow-up-included measurements of the minimum lumen diameter (MLD) and percent diameter stenosis (DS). Sixteen consecutive patients were included. The (median + range) stent length was 36 mm (range 15 to 105), with a restenotic lesion length of 32 mm (range 10 to 90). After ELCA + PTCA, the MLD increased from 0.60 +/- 0.41 to 2.28 +/- 0.50 mm, whereas the DS decreased from 76 +/- 16% to 22 +/- 8%. Despite adjunctive high-pressure PTCA, the MLD after ELCA + PTCA remained smaller than the MLD after initial stent implantation, (2.28 +/- 0. 50 mm vs 2.67 +/- 0.32 mm, p = 0.014). Adverse events included ELCA-related acute coronary occlusion in 4 patients and a per-procedural intracerebral hematoma in 1. At 6 months, there was recurrence of angina in all patients. Angiographic follow-up was completed in 13 patients (87%), showing a reocclusion in 6 (46%), a >50% DS in 6 (MLD 1.03 +/- 0.87 mm, DS 68 +/- 24%), and a distal de novo lesion in 1. Despite satisfactory acute angiographic results, the recurrence of significant restenosis in all patients suggests that ELCA + PTCA is not a suitable stand-alone therapy for diffuse in-stent restenosis of long stented segments.     

Treatment of in-stent restenosis with excimer laser coronary angioplasty

Diffuse in-stent restenosis remains an important problem in percutaneous transluminal coronary angioplasty (PTCA). In this trial, we studied the early and mid-term outcomes of excimer laser coronary angioplasty (ELCA) on diffuse in-stent restenosis. ELCA was performed in 23 patients (19 males). The mean length of the lesions was 14.3 +/- 3 mm and the mean age was 58 +/- 7 years. The minimal lumen diameter (MLD) was measured by on-line quantitative coronary angiography. Before the procedure, MLD was 0.9 +/- 0.4. The Q/non-Q-wave myocardial infarction (MI), coronary artery bypass graft (CABG), PTCA, and mortality were recorded during the procedure and at 6 months follow up. The fluence of laser emission was 45 mj/m2 and the repetition rate was 25 pulses per second. Adjunctive balloon angioplasty was performed in all of the cases at a mean 7 +/- 2 atm pressure. The procedure was successfully performed in all of the cases. Type-B dissection developed, after ELCA in 1 patient (4%). Perforation, death, cerebrovascular accidents, emergency CABG, PTCA or Q/non-Q wave myocardial infarction were not observed. MLD was 0.9 +/- 0.4 mm before ELCA, 1.8 +/- 0.9 mm (P<0.05) after ELCA, and 3.1 +/- 0.7 mm after PTCA. At 6 months follow up, there were 2 (8.7%) Q-wave myocardial infarctions and 2 (8.7%) recurrent anginal pain cases. Control angiography was obtained in 20 cases (87%). Control angiography was not accepted by 3 patients. Their maximal exercise test was negative. Angiographic restenosis was observed in 6 cases (30%). The rate of target lesion revascularization (TLR) was 5 of 23 (22%) in the patients treated with ELCA. It is concluded, ELCA is a safe and efficient debulking technology for treating diffuse in-stent restenosis.     

Histopathological findings of new in-stent lesions developed beyond five years.

We analyzed 14 cases of new lesions inside implanted bare-metal stents. In every case, there was no angiographic restenosis within 3 years, but a new lesion was observed inside a stented segment at long-term follow-up (>5 years). Fourteen cases were evaluated: 9 with Wiktor stents, 2 with Palmaz-Schatz stents, and 3 with ACS Multilink stents. The interval from stent implantation to follow-up angiography was 63-147 months (89 +/- 23). Thirteen lesions were treated by percutaneous coronary intervention (PCI) and stenotic tissue was obtained by directional coronary atherectomy (DCA) in 10 cases. All retrieved samples were composed of newly developed atherosclerosis facing the healed neointimal layer, and four samples showed histopathological findings of acute coronary syndrome. Stent struts were retrieved in four cases and no inflammation was observed surrounding them. Qualitative and quantitative analysis of stent struts was performed in two cases that showed no metal corrosion. These findings suggest that new atherosclerotic progression occurred inside the implanted stent without peristrut inflammation.     

Is Direct Stent Implantation Without Predilatation Safe? Acute and Long‐Term Outcome

Direct stenting could potentially lead to a reduction in dissections, time, and restenosis at 6-month follow-up. Using the premounted Palmaz-Schatz Crown stent elective stenting was performed without predilatation in 61 consecutive patients who were compared with a control group of provisional stenting. All patients underwent clinical and angiographic follow-up at 6 months. Direct stenting was successful in 81% of patients. In 16% of the patients predilatation was needed. In 3% the stent could not be implanted despite predilatation. Stent dislodgment occurred in 2% of patients, without embolization. Six-month angiographic follow-up was performed in 51 (84%) of 61 patients. In the direct stenting group the mean preprocedural minimal luminal diameter (MLD) increased from 0.96 +/- 0.47 to 3.09 +/- 0.54 mm directly after the procedure. At 6-month follow-up the MLD measured 2.32 +/- 0.79 mm. In the provisional stenting group the mean MLD increased from 0.92 +/- 0.51 to 2.44 +/- 0.58 mm and was 1.84 +/- 0.70 mm at 6-month follow-up. Restenosis, defined as a diameter stenosis > 50%, occurred in 8% of the direct stenting group compared with 28% in the provisional stenting group (P < 0.001). Direct coronary stent implantation can be attempted safely and efficaciously. The risk of stent loss is low. The initial and long-term angiographic results are significantly better as compared with provisional stenting. The risk of restenosis is significantly lower.     

Long-term effects of novel biolimus eluting DEVAX AXXESS plus nitinol self-expanding stent in a porcine coronary model.

OBJECTIVE: The purpose of this study was to evaluate the long-term effects of the DEVAX AXXESS biolimus eluting stent (BES) in a porcine coronary model, compared with those of bare metal stent (BMS) and polymer only stent (POS) controls. BACKGROUND: Excessive neointimal growth has been identified as a major cause of late failure of percutaneous coronary interventions. The effect of drug eluting from self-expanding stents for prevention of neointimal hyperplasia has not been studied before. The DEVAX AXXESS is a self-expanding nickel titanium stent, coated with antiproliferative compound-biolimus. METHODS: Twenty juvenile farm swine, 25-35 kg in weight, 3-6 months in age were used. Each animal received a stent to the left anterior descending artery, left circumflex or right coronary arteries as permitted per anatomy. The chronic vascular response after BES implantation was compared with that after BMS and POS implantation at 28, 90, and 180 days follow-up. RESULTS: The 28-day outcome by quantitative coronary angiography (QCA) showed significant increase in minimal luminal diameter (MLD) in the BES (MLD: 2.90 +/- 0.97, 2.39 +/- 0.90, 1.59 +/- 0.91; P = 0.009) compared with BMS and POS, respectively. By histomorphometric analysis, there was also a corresponding significant reduction in neointimal tissue proliferation in the BES (average neointimal area: 2.78 +/- 0.07, 5.46 +/- 0.66, 8.42 +/- 0.85; P = 0.002) compared with that in BMS and POS controls, respectively at 28-days follow-up. At 90 and 180 days, the mean neointimal area was not significantly different between the BES and the controls. CONCLUSIONS: BES favorably modulates the neointimal tissue formation for 28 days, in the porcine coronary model. Long-term inhibition of neointimal hyperplasia is not sustained most likely because of the delayed cellular proliferation and inflammation in the vessel wall.     

Stenting after directional coronary atherectomy compared with directional coronary atherectomy alone and stenting alone: a serial intravascular ultrasound study.

BACKGROUND: Directional coronary atherectomy prior to stent implantation (DCA-stent) is expected to be an effective approach to reduce restenosis. The purpose of this study was to determine whether DCA-stent has advantages over DCA alone or stenting alone using serial intravascular ultrasound (IVUS). METHODS AND RESULTS: Serial (pre-, post- and follow-up) IVUS was performed in 187 native coronary lesions treated with each of the 3 strategies. External elastic membrane cross-sectional area (CSA), lumen CSA and plaque CSA were measured. Baseline characteristics were similar. Postprocedural lumen CSA was largest after DCA-stent (11.2+/-2.7 mm2) and DCA (10.8+/-2.5 mm2) than stenting alone (9.0+/-2.9 mm2) (p<0.0005). Follow-up lumen loss was similar. As a result, follow-up lumen CSA was largest after DCA-stent (DCA-stent: 9.1+/-3.4 mm2, DCA: 7.8+/-4.2 mm2, stent: 6.3+/-2.6 mm2, p<0.0005). There was a trend toward a lower rate of restenosis with DCA-stent (DCA-stent, 12.5%; DCA, 18.3%; stent, 18.8%; p=0.57). CONCLUSIONS: DCA-stent is superior to both DCA alone and stent alone in terms of the ability to gain a larger lumen as assessed by IVUS.     

Influence of residual stenosis in determining restenosis after cutting balloon angioplasty.

The cutting balloon is a new device for coronary angioplasty, which, by the combination of incision and dilatation of the plaque, is believed to minimize arterial wall trauma, the neoproliferative response, and subsequent restenosis. In this study, we sought to determine predictors of the restenosis using this technique. Seventy-seven patients underwent successful coronary angioplasty with cutting balloon alone. In 67 of these patients (87%), we performed a control angiogram at 6-month follow-up. Pre-, post-, and late angiographic results were evaluated by quantitative coronary analysis. Clinical and angiographic variables were correlated with restenosis as a binary variable and a continuous variable (late loss and late minimum luminal diameter). Univariate analysis showed that the immediate postprocedure minimum luminal diameter (MLD) was smaller in the restenotic group (defined as MLD > 50% by quantitative coronary angiography) than in the nonrestenotic group (1.90 +/- 0.47 mm vs. 2.19 +/- 0.56 mm, P < 0.05). In addition, the immediate percentage of stenosis was higher in the restenotic group than in the nonrestenotic group (37% +/- 10% vs. 27% +/- 11%, P < 0. 003). Multivariate analysis identified the immediate postcutting balloon percentage of stenosis as an independent determinant of binary restenosis (P < 0.008). When restenosis was defined as a continuous variable, the immediate postprocedure MLD was an independent predictor of late loss (P < 0.02) and of late MLD (P < 0. 0002). No clinical, preprocedure angiographic, or technical variables tested were associated with restenosis. The degree of postprocedural residual stenosis after cutting balloon angioplasty is predictive of late restenosis.     

Long-term follow-up of primary stenting with coil stent in acute myocardial infarction

The authors evaluated clinical and angiographic outcomes for 1 year after primary stenting using coil stent for acute myocardial infarction. Twenty-eight patients underwent primary stenting with coil stent. Follow-up coronary arteriography at 3 months and 1 year was planned in all patients. Procedural success was achieved in 96%. There was no acute or subacute thrombosis. Minimal lumen diameter (MLD) was increased from 0.08 +/- 0.19 to 2.73 +/- 0.49 mm after stenting. MLD had decreased significantly for 3 months (MLD at 3 months: 2.03 +/- 0.86 mm, p = 0.001). On the other hand, MLD did not differ between 3-month; and 1-year follow-up (MLD at 1 year: 2.26 +/- 0.73 mm, p = NS). Only one patient manifested reocclusion at 3-month follow-up. The cumulative restenosis rate and target lesion revascularization rate at 1-year follow-up were 25.9% (7/27) and 11.1% (3/27). Primary stenting using coil stent is safe and feasible in patients with acute myocardial infarction and may improve clinical outcome and decrease restenosis and target lesion revascularization rate.     

High-speed rotational atherectomy and coronary stenting: QCA and QCU analysis.

To evaluate the acute effect of pretreatment with high-speed rotational atherectomy (HSRA) on stent deployment (rotastenting), we studied 33 patients with rotastenting of 40 segments, 34 patients with 40 coronary segments treated with Palmaz-Schatz stenting alone, and 34 patients with 40 segments treated with HSRA. The HSRA- and stent-alone patient groups were selected retrospectively by matching the quantitative coronary angiography (QCA) reference diameter (D ref). QCA revealed similar baseline percent of stenosis (85.3% +/- 12.4%), minimal luminal diameter (MLD), and D ref. The percent area expansion was calculated as a ratio between the minimal intrastent area and the reference area measured by intracoronary ultrasound. The rotastent group was characterized by more frequent calcification compared to HSRA and stent groups (67.5% vs. 20% and 12.5%; P < 0.01). Lesion length determined by QCA was longer both in the HSRA and the rotastent groups vs. the stent-alone group (21.1 +/- 12.3 and 20.9 +/- 4.3 vs. 17.0 +/- 7.7 mm; P < 0.05). In this small study, there was no difference demonstrated between final MLD in the rotastent and stent-alone groups. However, a smaller MLD was achieved in the HSRA group (3.0 +/- 0.7 vs. 3.1 +/- 0.5 vs. 2.5 +/- 0.7 mm, respectively; P < 0.01). The degree of stent expansion was higher in the rotastent group compared to the stent-alone group (91.9% +/- 4.4% vs. 79.7% +/- 3.4%; P < 0.03) and the % residual area of plaque was less for the rotastent group than for the stent-alone group (12.1% +/- 13.2% vs. 21.1% +/- 17.5%; P = 0.03). These data suggest that antecedent HSRA atheroma debulking using HSRA results in improved intravascular stent expansion and reduction in residual plaque, facilitating optimal stent deployment.