Favorable strategy for the ostial lesion of the left anterior descending coronary artery: Influence on narrowing of circumflex coronary artery

We examined the effectiveness of Palmaz-Schatz (P-S) stent and directional coronary atherectomy (DCA) in ostial lesions of left anterior descending arteries (LAD). The P-S stent was implanted in 11 cases at LAD ostial lesions, and DCA was performed in 13 cases. Percent stenosis and vessel diameter at the target site and the ostium of the circumflex coronary artery (LCX) were measured before and after the procedure. The initial success rate was 100% in both groups. No major complication occurred. LAD ostial lesions were improved from 81.3 ± 3.4% to −8.1 ± 5.7% by P-S stent and from 82.8 ± 2.6% to −2.7 ± 3.9% by DCA. LCX ostial vessel diameter was not changed by DCA (from 3.0 ± 0.2 mm to 3.1 ± 0.3 mm); however, it was significantly decreased by P-S stent (from 2.9 ± 0.2 mm to 2.6 ± 0.2 mm, P < 0.01). When the angle of LAD and LCX was ≦80° from the view of RAO 30° and Caudal 30°, the LCX ostium was significantly narrowed by stenting at LAD ostium (P < 0.01). These findings indicate that both the P-S stent and DCA are effective and safe therapies for LAD ostial lesions in cases with LAD-LCX angle >80°. In cases with LAD-LCX angle ≦80°, however, DCA is a favored therapy rather than P-S stenting to avoid narrowing of the LCX ostium. Cathet. Cardiovasc. Diagn. 43:95–100, 1998. © 1998 Wiley-Liss, Inc.     

Intracoronary ultrasound before coronary interventions: A prospective comparison of two different catheters

Intravascular ultrasound (IVUS) provides unique information about the coronary arterial wall that can be used to guide transcatheter therapy. In this prospective study, two different IVUS systems were compared with respect to feasibility of imaging before intervention and angiographic changes induced by the simple advancement of the catheter across the lesion. Eighty-five patients (mean age 59 ± 10 yr, 11 female) were studied with IVUS before intervention. In 34 patients, a 4.8F (1.6-mm) IVUS catheter was used (Group I), whereas in the remaining 51 patients a 3.5F (1.2-mm) IVUS catheter was used (Group II). Quantitative angiography was performed before and after the IVUS study to determine potential changes in lumen diameter. Clinical and angiographic characteristics were similar in the two groups. A successful IVUS interrogation of the target lesion was obtained more frequently in Group II (45/51 (88%) vs. 19/34 (56%) patients, P < 0.01). After the IVUS study, a change in minimal lumen diameter was seen in Group I (baseline 0.84 ± 0.2 vs. Final 1.17 ± 0.2 mm, P < 0.001) and Group II patients (baseline 0.80 ± 0.3 vs. final 1.03 ± 0.4 mm, P < 0.01). In the 64 lesions successfully crossed, the absolute gain in lumen diameter was significantly higher in Group I (0.40 + 0.2 vs. 0.23 ± 0.2 mm, P < 0.05). In addition, an inverse correlation was found between baseline minimal lumen diameter and the absolute lumen gain induced by the IVUS study in Group I (r = −0.47, P < 0.05) but not in Group II patients (r = −0.16, NS). Neither angiographic nor echogenic lesion characteristics were associated with the change in lumen diameter. When multivariate analysis was applied, catheter size was the only independent predictor of lumen gain induced by IVUS after adjustment. Thus, the advancement of IVUS catheters across severe coronary lesions induces significant angiographic changes consistent with plaque remodeling and a Dotter effect. The use of smaller catheters not only allows a higher number of lesions to be studied before intervention, but also lessens the mechanical disruption of the plaque, yielding a more accurate and veracious picture of baseline plaque characteristics. Cathet Cardiovasc Diagn 40:33–39, 1997. © 1997 Wiley-Liss, Inc.     

Randomized comparison of debulking followed by stenting versus stenting alone for ostial left anterior descending artery stenosis: intravascular ultrasound guidance

Background

Although directional coronary atherectomy (DCA) before stenting has the advantage of combining substantial removal of atheromatous plaque and prevention of elastic recoil, there has been no randomized study to investigate its efficacy in ostial left anterior descending artery (LAD) lesions. This study was aimed to evaluate the effect of DCA followed by stenting on ostial LAD stenosis under the guidance of intravascular ultrasound (IVUS).

Methods

Eighty-six patients with ostial LAD stenoses were randomly assigned to DCA followed by stenting (group I) or stenting alone (group II). Aggressive DCA or optimal stenting was performed in both groups under the guidance of IVUS. The primary end point was angiographic restenosis at 6 months.

Results

Baseline clinical and angiographic characteristics were similar between the 2 groups. The postprocedural minimal lumen diameter was larger in group I than group II (4.0 ± 0.4 mm vs. 3.5 ± 0.5 mm, P < .001). However, the angiographic restenosis rates were not significantly different between the 2 groups (9/32 [28.1%] in group I vs. 11/30 [36.7%] in group II, P = .472). The postprocedural IVUS stent area was the only independent determinant of restenosis by multivariate analysis (odds ratio .61, 95% CI 0.41-0.92, P = .018).

Conclusions

DCA followed by stenting achieved greater lumen gain than stenting alone for ostial LAD stenosis. However, DCA did not improve angiographic restenosis.     

Stenting alone versus debulking and debulking plus stent in branch ostial lesions of native coronary arteries

Angioplasty of branch ostial stenosis is associated with a high complication and restenosis rate. Previous investigations have demonstrated various treatments. However, the ideal strategy for treating branch ostial lesion remains uncertain. This investigation attempted to compare the acute, late results of stenting alone and debulking-based strategies in branch ostial lesions of native coronary arteries. Notably, various debulking strategies exist. This investigation also analyzed the acute and long-term results of the different treatments. In this study, we examined 86 patients with angina pectoris or exercise-induced ischemia and successful angioplasty of branch ostial lesions in native coronary arteries. The lesions were divided into two groups based on the angioplasty device used: group I (debulking devices, n = 44) and group II (stenting alone, n = 42). Procedural success and in-hospital complications were similar in both groups (P not significant). Following intervention, group I patients tended to show a smaller area of stenosis (42.3% ± 9.9% vs 48.2% ± 6.2%, P = 0.05) and a smaller plaque-media cross-sectional area (6.05 ± 1.87 vs 7.07 ± 1.79mm², P = 0.01) than group II. Furthermore, at 3 months follow-up, group I exhibited a larger minimal lumen diameter (MLD) (2.30 ± 0.91 vs 1.86 ± 0.80mm, P = 0.03) than group II. Regarding the angiographic and clinical outcomes, group I displayed a restenosis rate of 32% (14/44), compared with 41% (17/42) in group II (P = 0.40). Even during the 6-month follow-up, group I had a lower cumulative restenosis rate of 40% (17/43), compared with 60% (22/37) in group II (P = 0.04). The minimal luminal diameter of the ostium had not changed after directional coronary atherectomy or at follow-up. In contrast, MLD of another ostium was significantly reduced during stenting alone and at follow-up (P < 0.01). When subgroups were studied, a debulking followed by stent group achieved a larger acute lumen gain than a debulking alone group (2.57 ± 0.59 vs 2.32 ± 0.55mm, P = 0.04). The optimal debulking plus stent subgroup had a restenosis rate of 9% (1/11) compared with 33% (6/18) in the optimal debulking alone group (P = 0.05). The optimal debulking plus stent group also had a lower cumulative restenosis rate at 6 months than the optimal debulking alone group (9% vs 44%, P = 0.04). Guided by intravascular ultrasound, atherectomy-based intervention appears superior to stenting alone for treating branch ostial lesions. Directional coronary atherectomy did not cause the narrowing of another ostium. However, optimal debulking followed by stenting minimized the restenosis and target lesion revascularization rates.     

Directional coronary atherectomy for lesions of the proximal left anterior descending artery: initial clinical results, complications and histopathological findings

Background: Directional coronary atherectomy is a percutaneous technique which extends the role of balloon angioplasty to bulky eccentric coronary lesions. Aims: To report the early experience, clinical results, complications and histopathological findings of directional coronary atherectomy (DCA) in proximal left anterior descending artery (LAD) stenosis. Methods: Study of 25 lesions in 24 patients on whom directional atherectomy was performed on the proximal LAD artery with the Simpson coronary atherectomy device. Results: Twenty-five procedures were performed on 24 patients with stenosis in the proximal LAD artery. There were 21 males and three females with a mean age of 56.5 years. Sixteen patients presented with stable angina and eight with unstable angina. Eight patients had previous myocardial infarction (MI). Angiographic success was obtained in 24 of 25 lesions (96%). The mean lesion length was 13.1 ± 3.7 mm and the mean LAD artery diameter was 3.6 ± 0.5 mm. Minimal luminal diameter improved from 0.9 ± 0.4 mm to 3.0 ± 0.5 mm and the percentage diameter stenosis reduced from 75 ± 12% to 16 ± 9%. Complications included acute occlusion in one patient, non-Q MI in three patients, local vascular complications in one patient and side-branch loss in one patient. Histology demonstrated fibrous cap of atherosclerotic plaque in 100%, media and internal elastic lamina in 28% and intimal hyperplasia in 100% of restenotic lesions and 27% of native lesions. Restenosis rates in angiographically restudied patients was 27%. The mean minimal luminal diameter at follow-up was 2.3 ± 0.9 mm and the mean percentage diameter stenosis was 35 ±21%. Conclusion: From this initial study, we conclude that DCA is an effective and safe procedure for the treatment of large proximal LAD lesions. DCA provides a large luminal diameter and a ‘smoother’ angiographic appearance compared to coronary angioplasty. Acute complication rates are low and restenosis rates were comparable with percutaneous transluminal coronary balloon angioplasty.     

Influence of expanded balloon diameter on palmaz-schatz stent recoil

After successful stent implantation, the residual luminal diameter of the stented vessel is usually smaller than the maximal stent-expanded balloon diameter. The goal of this study was to determine whether immediate vessel diameter recoil after Palmaz-Schatz stenting is affected by the final expanding balloon diameter used during stent deployment. Single Palmaz-Schatz balloon expandable stents were successfully placed in 108 stenotic lesions. There were 68 patients with 75 saphenous vein graft (SVG) and 30 patients with 33 native coronary artery lesions, including 26 restenotic and 82 de novo occlusive (>50% diameter stenosis) lesions. Quantitative coronary angiography was used for the assessment of stent recoil, defined as the difference between the minimal diameter of the fully expanded balloon and the postprocedure minimal lumen diameter divided by minimal diameter of the fully expanded balloon. A strong correlation (r = 0.94) was found between the minimal diameter of the fully expanded balloon and poststenting minimal lumen diameter. Immediate recoil was 11.3 ± 7.5%, responsible on an average for 0.4 ± 0.2-mm acute lumen loss. Recoil was less in SVG than in coronary arteries (9.7 ± 6.6% vs. 14.0 ± 7.8%; P = 0.004, and 0.3 ± 0.2 vs. 0.4 ± 0.2 mm; p = 0.01). Lesions were divided into four subgroups, based on the final stent expanding balloon diameter: (1) ?3.0 mm (n = 33); (2) >3 ± 3.5 mm (n = 43); (3) >3.5 ± 4 mm (n = 23); and (4) >4 mm (n = 9). For the four subgroups, the percentage recoil values were 15.0 ± 5.7, 10.4 ± 8.2, 9.0 ± 5.4, and 4.7 ± 2.0, respectively (P <0.001). Mean values of diameter stenosis, lesion length, maximal balloon pressure, balloon-to-artery ratio, relative vessel stretch, and absolute recoil were not statistically different. Immediate vascular recoil in single implanted Palmaz-Schatz stent is a function of the final expanding balloon diameter, with recoil larger at small-balloon diameters and almost eliminated at large inflation diameters. This finding could contribute to less acute gain, increased restenosis, and higher stent thrombosis rates after stenting vessels of <3-mm diameter. © 1995 Wiley-Liss, Inc.     

Comparison of quantitative coronary angiographic results after directional coronary atherectomy and balloon angioplasty of protected left main coronary stenosis

We compared the angiographic and clinical outcomes after directional coronary atherectomy (DCA, 13 patients) with those after conventional balloon angioplasty (BA, 21 patients) in patients with protected left main coronary artery stenosis. The initial success rate was 100% in the DCA group and 81% (17 of 21) in the BA group. Restenosis was present in 2 of 11 patients in the DCA group and 9 of 16 patients in the BA group (18% vs. 56%, P < 0.05). DCA and BA improved a minimal lumen diameter. The initial gain after DCA was greater than that after BA. At follow-up, the minimal lumen diameter was larger and the percentage diameter stenosis was smaller in the DCA group than in the BA group. The late loss and loss index were equivalent in both groups. Compared with conventional BA, DCA in protected left main coronary artery stenosis is associated with a higher angiographic success rate and provides a wider luminal diameter with reduced incidence of restenosis. Cathet. Cardiovasc. Diagn. 44:138–141, 1998. © 1998 Wiley-Liss, Inc.     

Feasibility of intravascular ultrasound studies: Predictors of imaging success before coronary interventions

Background: Intravascular ultrasound (IVUS) is currently used to study lesions during transcatheter coronary therapy. However, before dilation some lesions cannot be reached or crossed with the imaging catheter. Hypothesis: This study seeks to elucidate which factors determine the feasibility of IVUS examination before coronary interventions. Methods: Accordingly, 100 consecutive patients undergoing IVUS examination before coronary angioplasty were prospectively studied. The clinical and angiographic characteristics of 77 patients with a successful IVUS study (Group A) were compared with those of 23 patients in whom IVUS was attempted but the target lesion could not be interrogated (Group B). The echogenic characteristics of the target lesion [before (n = 77) or after intervention (in 18 patients in Group B)] were also studied. Results: Patients in Group B were significantly older (62 ± 7 vs. 57 ± 10 years, p < 0.05) and more frequently had stable angina [8 (35%) vs. 9 (11%), p < 0.05]. The distribution of lesions within the coronary tree and angiographic lesion characteristics including length, eccentricity, calcification, bend location, and the American College of Cardiology/American Heart Association classification were similar in both groups. However, proximal tortuosities (>45° at end diastole) were more frequently found in Group B [20 (87%) vs. 47 (61%), p < 0.05]. In addition, by quantitative angiography, patients in Group B had smaller arteries (reference diameter 2.8 ± 0.4 vs. 3.1 ± 0.4 mm, p < 0.05) and more severe lesions (minimal lumen diameter 0.46 ± 0.24 vs. 0.65 ± 0.34 mm, p < 0.05). On IVUS, calcified lesions were more frequently visualized in Group B (61 vs. 38%, p < 0.05). On multivariate analysis, catheter size, baseline minimal lumen diameter, angiographic proximal tortuosities, and lesion calcification on imaging were independent predictors of the feasibility of IVUS studies. Conclusions: Unsuccessful IVUS studies before intervention occur more frequently (1) in vessels with proximal tortuosities or severe lumen narrowing, (2) in lesions that are calcified on IVUS, and (3) when large imaging catheters are used.     

Early clinical experience with the implantation of a novel synthetic coronary stent graft

Coating stents with autologous venous grafts has been suggested to prevent problems associated with conventional stenting, but the need for surgical vessel harvest hampered broad application. A novel synthetic coronary stent graft (CSG) overcomes this limitation by a synthetic membrane, fixed between two thin metallic stents. We successfully implanted 21 CSGs in 18 patients for treatment of acute coronary rupture, thrombus-containing lesions, and lesions with plaque rupture or adjacent pseudoaneurysm. Substantial residual angiographic diameter stenoses were seen in seven CSGs (25% ± 10% vs. 8% ± 6%; P < 0.01), which were implanted with relatively small balloon catheters (balloon-to-artery ratio 1.00 ± 0.09 vs. 1.24 ± 0.18; P = 0.01) and required postdilatation. Overall, the largest balloon catheter applied measured 4.0 ± 0.7 mm (balloon-to-artery ratio 1.21 ± 0.20) and the inflation pressure was 16 ± 3 atm. Final intravascular ultrasound imaging demonstrated adequate and symmetrical expansion of the CSG (≥85% ± 15% of the reference lumen). Elective implantation was associated with two small non–Q-wave myocardial infarctions, resulting from unavoidable occlusions of side branches. Thus, implantation of CSG is feasible and safe. Adequate expansion can be achieved by the use of relatively large low-compliant balloon catheters inflated with high pressure. Cathet. Cardiovasc. Intervent. 47:496–503, 1999. © 1999 Wiley-Liss, Inc.     

Lower restenosis rate with stenting following aggressive versus less aggressive rotational atherectomy

The present study evaluated the acute and follow-up results of stenting following aggressive rotational atherectomy compared with stenting following less aggressive rotational atherectomy. Recent work has demonstrated that stenting following rotational atherectomy is a promising strategy for complex and calcified lesions. However, there is little information available regarding the optimal procedural technique of rotational atherectomy to be employed before stent implantation. Between May 1995 and February 1997, 162 lesions in 126 patients were stented following rotational atherectomy because of the presence of severe calcification on fluoroscopy or intravascular ultrasound (95%). The lesions were divided as to whether aggressive rotational atherectomy was performed or not. Aggressive rotational atherectomy, defined as the use of a final burr size ≥2.25 mm and/or final burr/vessel ratio ≥0.8, was performed in 56 lesions. A less aggressive rotational atherectomy strategy was performed in 106 lesions. Procedural Q-wave (8.9% vs. 1.9%, P < 0.05) and non–Q-wave (11% vs. 1.9%, P < 0.05) myocardial infarctions were observed more frequently after aggressive rotational atherectomy; there was no significant difference in the incidence of other procedural complications. Although there was no significant difference in minimal lumen diameter after the procedure (3.11 ± 0.68 vs. 2.99 ± 0.48 mm, NS), at follow-up a greater minimal lumen diameter was observed in the lesions treated with aggressive rotational atherectomy compared to those treated with less aggressive rotational atherectomy (2.12 ± 1.31 vs. 1.56 ± 0.89 mm, P < 0.01). Restenosis rates were 50.0% in the lesions treated without aggressive rotational atherectomy and 30.9% in those treated with aggressive rotational atherectomy (P < 0.05). There was no significant difference in the incidence of restenosis with a focal pattern between the two groups (25.0% vs. 21.4%, NS). In contrast, restenosis with a diffuse pattern was lower in lesions treated with aggressive rotational atherectomy than in those without aggressive rotational atherectomy (9.5% vs. 25.0%, P < 0.05). Aggressive rotational atherectomy followed by stenting is a promising strategy to reduce the restenosis rate in calcified lesions. However, the aggressive strategy is associated with an increased risk of procedural myocardial infarction. Cathet. Cardiovasc. Intervent. 46:406–414, 1999. © 1999 Wiley-Liss, Inc.     

Comparative analysis of saphenous vein bypass vs. native coronary artery balloon angioplasty: Technical differences and angiographic response

To evaluate technical differences and angiographic response of saphenous vein bypass graft angioplasty in comparison to native coronary arteries, we retrospectively analyzed 54 patients undergoing this procedure at The Toronto Hospital between February 1988 and May 1993. These subjects were temporally matched to a cohort of successful native coronary angioplasties, with comparison of technical parameters, pre-existing qualitative/quantitative (Cardiac Measurement System) stenotic morphology, and angiographic response; including changes in minimum lumen diameter. Saphenous bypass graft angioplasty utilized larger balloons (CABG, 3.27 ± 0.65 vs. native, 2.90 ± 0.37 mm, P < .05), and higher inflation pressures (CABG, 10.1 ±3.7 vs. native, 8.8 ± 2.5 atm, P < .05), although in a relative sense, balloon/artery ratios were similar (CABG, 1.09 ± 0.20 vs. native, 1.03 ± 0.15, pNS). Pre-procedural bypass graft lesions were more complex, with more frequent ACC/AHA type B₁ lesions [CABG, 24/54 (44%) vs. native, 16/54 (30%), P < .05] and luminal thrombus [CABG, 17/54 (31%) vs. native, 6/54(11%), P < .05]. Quantitative angiography revealed larger “reference” diameters within saphenous veins (CABG, 3.41 ± 0.76 vs. native, 3.04 ± 0.51 mm, P < .05), although minimum lumen diameter was less severe (CABG, 0.83 ± 0.41 vs. native, 0.77 ± 0.36, P < .05). In terms of balloon angioplasty response, greater improvemnet in luminal diameter was seen in bypass graft lesions (CABG, 1.55 ± 0.53 vs. native, 1.32 ± 0.44 mm, P < .05), with the largest changes within the “body” of the saphenous vein (ostial, 1.53 ± 0.37; body, 1.68 ± 0.50; anastomosis, 1.37 ± 0.57 mm). In conclusion, technical differences do exist during the performance of balloon angioplasty in degenerative saphenous vein bypass grafts, often dictated by morphologically complex lesions. Bypass grafts demonstrate a larger intrinsic lumen, although preexisting stenoses tend to be less severe, with greater improvement in minimum lumen diameter. Some of these differences may be attributable to intrinsic differences in the compliance characteristics of saphenous vein bypass grafts and to differing characteristics of the relatively accelerated atherosclerosis.     

Final results of the STent versus directional coronary Atherectomy Randomized Trial (START)

OBJECTIVES: This study was designed to compare primary stenting with optimal directional coronary atherectomy (DCA). BACKGROUND: No previous prospective randomized trial comparing stenting and DCA has been performed. METHODS: One hundred and twenty-two lesions suitable for both Palmaz-Schatz stenting and DCA were randomly assigned to stent (62 lesions) or DCA (60 lesions) arm. Single or multiple stents were implanted with high-pressure dilation in the stent arm. Aggressive debulking using intravascular ultrasound (IVUS) was performed in the DCA arm. Serial quantitative angiography and IVUS were performed preprocedure, postprocedure and at six months. The primary end point was restenosis, defined as > or =50% diameter stenosis at six months. Clinical event rates at one year were also assessed. RESULTS: Baseline characteristics were similar. Procedural success was achieved in all lesions. Although the postprocedural lumen diameter was similar (2.79 vs. 2.90 mm, stent vs. DCA), the follow-up lumen diameter was significantly smaller (1.89 vs. 2.18 mm; p = 0.023) in the stent arm. The IVUS revealed that intimal proliferation was significantly larger in the stent arm than in the DCA arm (3.1 vs. 1.1 mm ; p < 0.0001), which accounted for the significantly smaller follow-up lumen area of the stent arm (5.3 vs. 7.0 mm2; p = 0.030). Restenosis was significantly lower (32.8% vs. 15.8%; p = 0.032), and target vessel failure at one year tended to be lower in the DCA arm (33.9% vs. 18.3%; p = 0.056). CONCLUSIONS: These results suggest that aggressive DCA may provide superior angiographic and clinical outcomes to primary stenting.     

Assessment of the results of percutaneous transluminal coronary angioplasty using an integrated ultrasound imaging-angioplasty Catheter

To evaluate the results percutaneous transluminal coronary angioplasty (PTCA), intra-vascular ultrasound imaging was performed in 32 proximal coronary arterial segments and in 16 atherosclerotic lesions after PTCA in 13 patients using a 5 Fr balloon catheter with an ultrasound transducer mounted just proximal to the balloon. Simultaneous angiographic measurements of vessel diameter were also performed using electronic calipers from contrast cine angiograms. There was good correlation between ultrasound and angiographic minimum luminal diameters of the normal proximal vessel (y = 0.59x + 1.49, r = 0.70, P<0.01, n = 32). However, the luminal diameter measured by intravascular ultrasound was significantly greater than when measured by contrast angiography (2.81±0.10 vs. 2.34±0.12mm, n = 16, P<0.001, mean ±SEM). Post-PTCA, there was good correlation between ultrasound and angiographic minimum luminal diameters of the lesion (y = 0.62x + 1.42, r=0.76, P<0.001, n = 16), but again luminal diameters were significantly greater when measured by intravascular ultrasound compared to contrast angiography (2.61±0.08 vs. 1.89 ± 0.10mm, n = 16, P<0.001). Furthermore, residual stenosis was significantly less when determined by intravascular ultrasound than by contrast angiography (7.3±2.0 vs. 18.1 ± 2.1%, n = 16, P<0.001). Intravascular ultrasound was able to detect coronary calcification that was not evident by contrast coronary angiography in 8 of 16 lesions. Post-PTCA, dissection was evident in four lesions by ultrasound, whereas dissection was appreciated in only three lesions by contrast angiography. We conclude that intravascular ultrasound can accurately measure the luminal diameter of coronary arteries both before and after PTCA and reveals more information about the lesion characteristics than does conventional contrast angiography.     

Debulking and stenting versus debulking only of coronary artery disease in patients treated with cilostazol (final results of ESPRIT)

Stenting inhibits vascular constrictive remodeling after directional coronary atherectomy (DCA). Cilostazol has been reported to control neointimal proliferation after stenting. This study's aim was to examine the effect of debulking and stenting with antirestenotic medication on restenosis. After optimal DCA, 117 lesions were randomly assigned to either the DCA with stent (DCA-stent) (58 lesions) group or the DCA only (59 lesions) group. Multilink stents were implanted in the DCA-stent group. Cilostazol (200 mg/day) without aspirin was administered to both groups for 6 months. Ticlopidine (200 mg/day) was given to the DCA-stent group for 1 month. Serial quantitative angiography and intravascular ultrasound (IVUS) were performed at the time of the procedure and at 6-month follow-up. The primary end point was 6-month angiographic restenosis. Clinical event rates at 1 year were also assessed. Baseline characteristics were similar. All procedures were successful. No adverse effects to cilostazol were observed. Postprocedural lumen diameter was significantly larger (3.27 vs 2.92 mm; p <0.0001) in the DCA-stent group. However, the follow-up lumen diameter was not significantly different (2.53 vs 2.41 mm, DCA-stent vs DCA). IVUS revealed that intimal proliferation was significantly larger in the DCA-stent group (4.2 vs 1.5 mm(2); p <0.0001), which accounted for the similar follow-up lumen area (6.5 vs 7.1 mm(2)). The restenosis rate was low in both groups (5.4% vs 8.9%), and the difference was not significant. Clinical event rates at 1 year were also not significantly different. These results suggest that optimal lesion debulking by DCA does not always need adjunctive stenting if cilostazol is administered.     

Impact of post-dilatation with a focal expanding balloon for optimization of intracoronary stenting

Optimal stenting frequently requires additional stent post-dilatation following initial stent deployment. Stent post-dilatation using a focal expanding balloon (FB) that grows 0.5 mm larger centrally may achieve a larger final stent lumen with fewer stent edge injuries as compared to use of a conventional unidiameter balloon (UB). In the present prospective study, of 128 stented lesions in 122 patients, 63 lesions had stents dilated with FB (Group F), while 65 lesions had stents dilated with UB (Group U). All balloons for stent post-dilatation were half-sized up to reference diameter by on-line quantitative coronary analysis. There were no differences in the reference diameter, pre-procedural minimal lumen diameter (MLD), balloon/artery ratio, and final balloon pressure between the two groups. Post-procedural MLD in Group F was significantly larger than that in Group U (3.03 ± 0.43 vs 2.80 ± 0.47 mm, P < 0.001). Stent edge injury occurred in 4 patients, and stent thrombosis in 2 patients in Group U, but not in Group F. Minimal lumen diameter at 6 months in Group F was significantly larger than that in Group U (2.05 ± 0.63 vs 1.82 ± 0.66 mm, P < 0.05), and incidence of restenosis was significantly lower in Group F than Group U (9% vs 22%, P < 0.05). By using a focal expanding balloon for stent optimization, a larger stent lumen can be obtained safely, and subsequent incidence of restenosis can be reduced.     

Inter-Series differences in the restenosis rate of palmaz-schatz coronary stent placement: Differences in demographics and post-procedure lumen diameter

Restenosis rates following Palmaz-Schatz stenting vary between 13 and 36%. To determine whether the nearly three-fold interseries difference in restenosis rates reflects systematic factors (demographic and procedural variables such as post-treatment lumen diameter) rather than random variation, we pooled 486 lesions treated with the Palmaz-Schatz coronary stent in the U.S. Multicenter Registry (n = 259) with the single-center Beth Israel Hospital experience (n = 227) and analyzed the combined series using a continuous geometric model of restenosis. A greater proportion of lesions (66 vs. 50%; P < 0.001) in the Multicenter cohort represented restenosis after a prior intervention. The Multicenter experience also showed a smaller minimum lumen diameter following stent placement (2.61 vs. 3.43 mm; P < 0.001), higher post-stent percent stenosis (16 vs. –2%; P < 0.001), and less acute gain (1.79 vs. 2.67 mm; P < 0.001) than lesions treated in the Beth Israel cohort. At 6-month follow-up, the angiographic restenosis rate (≥ 50% diameter stenosis) was significantly higher in the Multicenter group (35 vs. 27%; P = 0.05), despite the development of less absolute late loss (0.96 vs. 1.32 mm; P < 0.001). Multivariable modeling, however, showed that the only independent predictors of restenosis were a post-procedure lumen diameter < 2.80 mm (odds ratio = 1.57; P = 0.04), diabetes mellitus (odds ratio = 3.55; P < 0.001), and prior restenosis (odds ratio = 1.84; P = 0.008). Since center (Beth Israel vs. Multicenter) was eliminated from the multivariable model after inclusion of these variables, the observed higher restenosis rate in the Multicenter series of Palmaz-Schatz coronary stents can thus be explained in part by differences in demographics (more previously treated lesions) and procedural details (a smaller posttreatment lumen diameter). Since post-procedure lumen diameter is a strong predictor of freedom from restenosis in the pooled experience, the probability of restenosis within a Palmaz-Schatz stent can be decreased by obtaining a large post-procedure lumen diameter.     

Fate of lumen size in distal coronary segment following successful chronic total occlusion recanalization

BackgroundRestoration of anterograde blood flow leads to alterations in vascular wall stress that may influence lumen size distal to chronic total occlusion (CTO) lesions. We sought to assess changes in lumen diameter of segments distal to the stent segment of successfully recanalized CTO.MethodsWe analyzed 507 consecutive CTO cases with stent implantation that underwent follow-up angiography at a single high-volume center (mean follow-up of 13.5 months). Segments ≤40 mm distal to the stent edge were analyzed using quantitative coronary angiography.ResultsAt follow-up, lumen diameters significantly increased; diameter changes of 0.26 ± 0.47 (percent diameter change of 18.2%) at 5 mm distal, mean lumen diameter changes of 0.23 ± 0.35 (14.3%) and minimal lumen diameter changes of 0.22 ± 0.80 (24.7%) (all p < 0.001). Lumen enlargement was similar between visually shrunken and stenosed vessels (degree of stenosis ≥20% with luminal irregularities) distal to stents; 5 mm distal (0.32 ± 0.48 vs. 0.30 ± 0.48, p = 0.76), mean lumen diameter changes (0.26 ± 0.37mm vs. 0.26±0.33 mm, p = 0.94), minimal lumen diameter changes (0.28 ± 0.43 mm vs. 0.22 ± 1.30 mm, p = 0.48). There was no association between degree of in-stent narrowing and changes in distal lumen diameter (Spearman r = ?0.02, p = 0.59). Multivariate logistic regression for the predictors of greater lumen enlargement indicated that patients with left ventricle dysfunction (ejection fraction ≤45%) had greater enlargement [odds ratio (OR): 2.53, 95% confidence interval (CI): 1.23–5.23, p = 0.01]. Conversely, a low hematocrit (male <40%, and female <35%) was associated with attenuated lumen enlargement (OR: 0.68 95% CI: 0.47–0.98; p = 0.04).ConclusionsLumen diameter distal to CTO lesions significantly increased following successful revascularization, regardless of diseased status of the distal bed or degree of in-stent narrowing. These findings implicate appropriate determination of stent size, stent coverage length, as well as management strategies of distal vessels.     

Primary stenting of de novo lesions in small coronary arteries: A prospective,pilot study

Technical advancement and new anti-thrombotic regimens have recently shown so much improvement in the results of coronary stenting that the conventional contra-indication for stenting in small coronary arteries (<3 mm) needs to be revised. We undertook a prospective pilot study of elective Palmaz-Schatz stenting in de novo lesions located in coronary arteries of less than 3 mm diameter. Fifty consecutive patients (63 ± 9 years) with stable (n = 38) and unstable angina (n = 12) were included. Philips-DCI quantitative coronary analysis was used to measure reference diameter, minimal lumen diameter and percent diameter stenosis before PTCA, after stenting and at 6-month angiographic follow-up study. All measurements were performed after intracoronary injection of nitroglycerin (300 μg). All patients received ticlopidine (250 mg/day) and aspirin (100 mg/day). The mean lesion length was 9 ± 3 mm. The balloon size used for stent delivery was 2.75 mm in 30 patients and 2.5 mm in 20 patients and the mean balloon inflation pressure used for stent deployment was 12 ± 2 atm. All stents were deployed successfully. In-hospital complications occurred in two patients, diagonal branch occlusion at day 2 requiring emergency PTCA in one and a hematoma at the femoral puncture site requiring surgery in the other. Major adverse cardiac event (MACE) rate remained 2% (nonfatal infarct in one). Follow-up angiography (n = 46, 92%) at 6 ± 3 months showed a 30% restenosis rate. Target vessel revascularization (TVR) rate was 13%. We conclude that elective stenting in small coronary arteries is feasible and involves an acceptable risk of restenosis. Cathet. Cardiovasc. Diagn. 45:235–238, 1998. © 1998 Wiley-Liss, Inc.     

Incidence and predictors of late total occlusion following coronary stenting

To determine the incidence and predictors of total occlusion in‐stent restenosis, we reviewed three randomized stent vs. stent trials and one stent registry, which provided 955 coronary artery lesions with 6‐month angiographic follow‐up. Fifteen (1.6%) of the 955 stented lesions were totally occluded at 6‐month follow‐up. Most patients with total occlusion presented with recurrent angina at the time of repeat angiography (60.0%) while no patient presented with an acute ST segment elevation myocardial infarction. The univariate predictors of total occlusion following elective coronary stenting included stenting for restenosis after a previous percutaneous intervention (P = 0.001), longer stent length (P < 0.001), longer lesion length (P < 0.001), smaller reference vessel diameter (P = 0.022), smaller preprocedure minimum lumen diameter (MLD; P = 0.004), and smaller postprocedure MLD (P = 0.036). Stepwise multiple logistic regression analysis demonstrated that stenting for restenotic lesions (P = 0.004), longer stent length (P < 0.001), and smaller preprocedure MLD (P = 0.012) were independent predictors of total occlusion following coronary stenting. Catheter Cardiovasc Interv 2003;60:344‐351. © 2003 Wiley‐Liss, Inc.     

Immediate and mid-term results after multilink stent implantation in native coronary arteries

Different stent designs have widely disparate characteristics that may exert a positive or negative impact on their early and mid-term outcomes. The MultiLink stent (Guidant/Advanced Cardiovascular Systems, Santa Clara, CA) is a new coronary stent with only very limited data. In this report, we examined the results of 50 consecutive patients treated with 57 premounted sheathless MultiLink stents in 53 native coronary arteries with reference diameter ≥2.7 mm. Successful stenting was achieved in 98% of patients, resulting in an improvement in diameter stenosis from 91% ± 11% to 1% ± 3% (P = 0.0001). At 1 month, there was no death, myocardial infarction, or stent thrombosis. Angiographic restudy at a mean of 5.0 ± 1.8 months in 94% of patients revealed an in-stent restenosis rate of 20.7%. The restenosis rates for diabetic patients (vs. nondiabetic patients), type C lesions (vs. type A/B1 lesions), and the use of 35-mm-long stents (vs. 15-mm-long stents) were 45.4% (14.3%), 56% (≤11%), and 80% (8.8%), respectively (P < 0.05). In conclusion, the present study demonstrates that the MultiLink stent has an excellent performance profile, is associated with a low risk of stent thrombosis in native coronary vessels, and yields a favorable restenosis rate, particularly after the use of short (15 mm) stents to treat simple lesions. Cathet. Cardiovasc. Intervent. 47:23–27, 1999. © 1999 Wiley-Liss, Inc.