Effect of technique on outcomes following bioresorbable vascular scaffold implantation: analysis from the ABSORB trials

BACKGROUND: Procedural technique may affect clinical outcomes after bioresorbable vascular scaffold (BVS) implantation. Prior studies suggesting such a relationship have not adjusted for baseline patient and lesion characteristics that may have influenced operator choice of technique and outcomes. OBJECTIVES: This study sought to determine whether target lesion failure (TLF) (cardiac death, target-vessel myocardial infarction, or ischemia-driven target lesion revascularization) and scaffold thrombosis (ScT) rates within 3 years of BVS implantation are affected by operator technique (vessel size selection and pre- and post-dilation parameters). METHODS: TLF and ScT rates were determined in 2,973 patients with 3,149 BVS-treated coronary artery lesions from 5 prospective studies (ABSORB II, ABSORB China, ABSORB Japan, ABSORB III, and ABSORB Extend). Outcomes through 3 years (and between 0 to 1 and 1 to 3 years) were assessed according to pre-specified definitions of optimal technique (pre-dilation, vessel sizing, and post-dilation). Multivariable analysis was used to adjust for differences in up to 18 patient and lesion characteristics...

2-year follow-up of Nevo RES-elution I, a randomisedmulticentre comparison of the Nevo Sirolimus-eluting coronarystent system using RES technology with the Taxus LibertéPaclitaxel-eluting stent

Aims: The NEVO™ sirolimus eluting coronary stent is designed to improvelong-term PCI safety by combining sirolimus release from reservoirs withbioabsorbable polymer to reduce spatial and temporal polymer exposure.Absorption of drug and polymer within approximately three months limits theduration of vessel wall exposure to the polymer. Thereafter, only a biologically inertbare-metal platform remains. The NEVO™ stent was first evaluated in the multicenterrandomised NEVO RES-Elution I trial which demonstrated its superiority tothe TAXUS Liberté Paclitaxel - eluting stent.

Randomized, double-blind, multicenter study of the Endeavor zotarolimus-eluting phosphorylcholine-encapsulated stent for treatment of native coronary artery lesions. Clinical and angiographic results of the ENDEAVOR II Trial.

AIM: The use of the Endeavor stent might reduce restenosis and stent thrombosis at 9 months. METHODS: Patients (n =1,197) treated for single coronary artery stenosis were enrolled in a prospective, randomized, double-blind study and randomly assigned to receive the Endeavor zotarolimus-eluting phosphorylcholine polymer-coated stent (n= 598) or the same bare metal stent but without the drug or the polymer coating (n=599). RESULTS: The 2 groups were well matched in baseline characteristics. Diabetes was present in 20.1% of patients; the mean reference vessel diameter was 2.75 mm; and the mean lesion length was 14.2 mm. The primary end point of target vessel failure at 9 months was reduced from 15.1% with the bare metal stent to 7.9% with the Endeavor (P=0.0001), and the rate of major adverse cardiac events was reduced from 14.4% with the bare metal stent to 7.3% with the Endeavor (P=0.0001). Target lesion revascularization was 4.6% with Endeavor compared with 11.8% with the bare metal stent (P=0.0001). The rate of stent thrombosis was 0.5% with the Endeavor, which was not significantly different from 1.2% with the bare metal stent. In 531 patients submitted to angiographic follow-up, late loss was reduced from 1.03+/-0.58 to 0.61+/-0.46 (P<0.001) in stent and from 0.72+/-0.61 to 0.36+/-0.46 (P<0.001) in segment. The rate of in-segment restenosis was reduced from 35% to 13.2% with Endeavor (P<0.0001). There was no excessive edge stenosis, aneurysm formation, or late acquired malposition by intravascular ultrasound imaging. Differences in clinical outcome were maintained at 12 and 24 months (P<0.0001). CONCLUSIONS: Compared with bare metal stents, the Endeavor stent is safe and reduces the rates of clinical and angiographic restenosis at 9, 12, and 24 months.

Lack of association between baseline plasma homocysteine concentrations and restenosis rates after a first elective percutaneous coronary intervention without stenting.

OBJECTIVE: To evaluate the association between baseline homocysteine concentrations and restenosis rates in patients electively undergoing their first percutaneous coronary intervention (PCI) without stenting. DESIGN: Prospective, single centre, observational study. SETTING AND PATIENTS: Patients electively undergoing their first PCI without stenting at a tertiary referral centre between 1990 and 1998. METHODS: Blood samples were collected from all patients at baseline and assayed to determine the patients' homocysteine concentrations. Patients whose PCI was successful underwent repeat angiography at a median of 6.4 (interquartile range 6-6.8) months. Their baseline and follow up angiograms were compared by quantitative coronary angiography to assess the incidence of restenosis. For the analysis, the patients were divided into two groups based on whether their baseline homocysteine concentrations were above or below the median value. These two groups were compared to determine whether there was any association between their baseline homocysteine concentrations and the incidence of restenosis at six months. RESULTS: 134 patients had a successful first PCI without stenting (involving 200 lesions). At six month angiography, restenosis was observed in 33 patients (49.3%) with baseline homocysteine concentrations above the median value and in 31 patients (46.3%) with concentrations below the median value (p = 0.74). There was no difference in the percentage of lesions developing restenosis (38 (39.6%) v 40 (38.5%), respectively, p = 0.87) or late lumen loss (0.40 mm v 0.31 mm, respectively, p = 0.24). On multivariable analysis, there was no association between homocysteine concentrations and late lumen loss (r = -0.11, p = 0.11) or the percentage diameter stenosis at follow up (r = -0.07, p = 0.32). CONCLUSION: Baseline homocysteine concentrations were not associated with six month restenosis rates in patients electively undergoing their first PCI without stenting.

Clinical and angiographic factors associated with asymptomatic restenosis after percutaneous coronary intervention.

BACKGROUND: Angiographic restenosis after percutaneous coronary interventional procedures is more common than recurrent angina. Clinical and angiographic factors associated with asymptomatic versus symptomatic restenosis after percutaneous coronary intervention were compared. METHODS AND RESULTS: All patients with angiographic restenosis from the BENESTENT I, BENESTENT II pilot, BENESTENT II, MUSIC, WEST 1, DUET, FINESS 2, FLARE, SOPHOS, and ROSE studies were analyzed. Multivariate analysis evaluated 46 clinical and angiographic variables, comparing those with and without angina. The 10 studies recruited 2690 patients who underwent percutaneous revascularization and 6-month follow-up angiography (86% of those eligible). Restenosis (>/=50% diameter stenosis) occurred in 607 patients and was clinically silent in 335 (55%). Male sex (P=0.008), absence of antianginal therapy with nitrates (P=0.0002) and calcium channel blockers (P=0.02) at 6 months, greater reference diameter after the procedure (P=0.04), greater reference diameter at follow-up (P=0.004), and lesser lesion severity (percent stenosis) at 6 months (P=0.0004) were univariate predictors of asymptomatic restenosis. By multivariate analysis, only male sex (P=0.04), greater reference diameter at follow-up (P=0.002), and lesser lesion severity at 6 months (P=0.0001) were associated with restenosis without angina. CONCLUSIONS: Approximately half of patients with angiographic restenosis have no symptoms. The only multivariate predictors of silent restenosis at 6 months were male sex, greater reference diameter at follow-up, and lesser lesion severity on follow-up angiography.

5 French guide catheters for percutaneous coronary intervention: a feasibility study in 100 consecutive patients.

Percutaneous coronary intervention using smaller-diameter guide catheters may have a favorable impact on groin complications, mobilization time, hospital stay, and contrast use. This prospective registry study assessed the feasibility of routine stent delivery through 5 Fr guide catheters. Of the 100 consecutive patients, 5 Fr guided intervention was attempted in 84 and was successful in all but 2 patients who had chronic complete occlusions. Reasons for not selecting a 5 Fr guide were planned kissing balloons (eight), directional coronary atherectomy (one), and no suitable 5 Fr guide in stock (seven). There was no stent dislodgment, need to change to a larger-caliber guide, or inadequate contrast opacification. When necessary, guide support was achieved by deep-vessel intubation, which was not associated with vascular damage. The only adverse sequelae were non-Q-wave myocardial infarctions in two patients. Coronary artery stenting using 5 Fr guide catheters is feasible and applicable to most patients.

Coronary angioplasty in New Zealand 1995-1998: a report from the National Coronary Angioplasty Registry.

AIMS: To report coronary angioplasty data collected by the New Zealand Coronary Angioplasty Registry from 1995-1998. METHOD: Information on all patients undergoing attempted coronary angioplasty in eight New Zealand institutions was recorded on datasheets at the time of, or soon after, the procedure. These were forwarded to the registry at Green Lane Hospital. RESULTS: Over the four-year period, 8395 angioplasty procedures were performed by 26 cardiologists in eight coronary interventional facilities, with a procedural success rate of 94%. Procedural numbers grew steadily, with 55% more coronary angioplasties performed in 1998 than in 1995 (p = 0.02). The New Zealand national angioplasty rate, which rose from 459/million population in 1995 to 684/million in 1998, remains lower than that of Australia and Western European countries. Excluding those that underwent angioplasty for acute myocardial infarction, the number of peri-procedural deaths was similar, with six in 1995 and four in 1998 (p = 0.30), and the requirement for emergency bypass surgery fell from 22 cases in 1995 to three in 1998 (p < 0.001). The use of stents increased dramatically, with 85% of patients receiving a stent in 1998, compared with 23% in 1995 (370% increase, p < 0.001). This was associated with a reduction in the number of patients requiring repeat percutaneous interventions for restenosis (10.7% in 1995 to 6.4% in 1998, p < 0.001). CONCLUSION: There has been a steady growth in the numbers of patients with coronary artery disease treated by coronary angioplasty, and in the number treated by intracoronary stents from 1995 to 1998. The need for urgent coronary bypass surgery has fallen. Continued submission of complete and accurate data to the coronary angioplasty registry is vital for ongoing audit.

A randomized study of direct coronary stent delivery compared with stenting after predilatation: the NIR future trial. On behalf of the NIR Future Trial Investigators.

This randomized trial compared a strategy of direct stenting without predilatation (n = 39) with conventional stenting with predilatation (n = 42) in patients with suitable lesions in native vessels > or = 2. 5-mm diameter to be covered by either a 9- or 16-mm-length NIR Primo stent. Equipment cost [mean (median) +/- SD] was less in those with direct stenting [$1,199 (979) +/- 526] than in those with predilatation [$1,455 (1,285) +/- 401, P < 0.001]. There was no significant difference in contrast use or fluoroscopy time. Procedural time was shorter in the direct stenting group. The clinical outcome at 1 month was satisfactory in both groups. In selected patients, a strategy of direct stenting is feasible, costs less, and is quicker to perform than the conventional strategy of stenting following predilatation.

Stent longitudinal flexibility: a comparison of 13 stent designs before and after balloon expansion.

Longitudinal flexibility is an important property of coronary stents, facilitating delivery and allowing the expanded stent to conform to vessel contour. Subjective descriptions of flexibility abound, but there are few independent quantitative data to aid stent selection. A three-point bend test was employed to measure stiffness, the reciprocal of flexibility, for 13 stent designs in the unexpanded (bare) state, then after expansion with a 3.5-mm balloon. For eight of the designs, stiffness of the proprietary stent/balloon delivery system was also measured. In the unexpanded state, there was a wide spread of stiffness, which ranged from 0.5+/-0.2 to 91.5+/-10.0 g force/mm, depending on design. Stiffness was least for the coil (Wiktor and Crossflex) and hybrid (AVE GFX and Bard XT) designs. The MultiLink was the most flexible and the Crown the stiffest of the slotted tube designs. All stents became stiffer upon expansion. For most manufacturer-mounted stents, the delivery balloon was the main determinant of stent/balloon delivery system stiffness. Manufacturer-mounted stent profile ranged from 1.15+/-0.11 mm for the Jostent to 1.53 +/- 0.05 mm for the MultiLink system. Independent quantitative assessment of characteristics such as flexibility and profile should aid rational comparison of stent designs.

Gelfoam embolization of a distal coronary artery guidewire perforation.

A guidewire-induced distal coronary artery perforation presenting with cardiac tamponade was occluded by distal Gelfoam embolization via an infusion catheter. This extends the treatment options for this rare complication of coronary interventional procedures. Cathet. Cardiovasc. Intervent. 49:214-217, 2000.

Does angiography six months after coronary intervention influence management and outcome? Benestent II Investigators.

OBJECTIVES: This study was performed to assess whether angiography six months after coronary balloon angioplasty or stent implantation has an influence on clinical management and one-year outcome. BACKGROUND: The Benestent II study randomized 827 patients to balloon angioplasty or stent implantation. A subrandomization was undertaken allocating patients to six-month clinical follow-up (CF) or clinical and angiographic follow-up (AF). METHODS: Seven hundred and six patients (349 CF and 357 AF) had no intercurrent angiography, so that restenosis and disease progression elsewhere remained unknown until the time of six-month follow-up. These two groups, which were well matched at enrolment, were compared with respect to symptoms, medication and major cardiac events defined as death, myocardial infarction and need for revascularization at six and 12 months. RESULTS: At six-month follow-up, 53 (15%) of the CF and 76 (21%) of the AF patients had stable angina (p = 0.041), while 5 (1%) and 4 (1%) had symptoms of unstable angina. At 12-month follow-up, 44 (13%) patients in both groups had stable angina, and only 1 patient in the CF group had unstable angina. Seventy-seven patients (27 CF and 50 AF; p < 0.01) had major cardiac events between 6 and 12 months. Of the 349 patients in the CF group, 21 underwent repeat percutaneous transluminal coronary angioplasty or coronary artery bypass graft surgery between 6 and 12 months, compared with 44 of the 357 patients in the AF group (relative risk 2.05 [1.24 to 3.37], p = 0.003). CONCLUSIONS: Patients who had AF six months after balloon angioplasty or stent implantation experienced more repeat revascularization procedures than those who had CF. They also had significantly more angina at six-month follow-up but this may be due to bias.

Preliminary experience with the V-flex plus coronary stent: immediate and one-month clinical outcome.

Procedural and 1-month outcome data following implantation of the V-Flex Plus stent in our first 54 consecutive patients (35 male; mean age, 62 years) are described. Sixty-four stents were implanted for 60 mainly complex lesions; 48% were left anterior descending; 20%, circumflex; 27%, right coronary artery; and 5%, saphenous vein graft. The Indication for stenting was elective in half of the patients and for a suboptimal result or as a bailout procedure in the other half. The stents were deployed at a mean of 12 atm (range, 6-18) and postdilatated to a mean of 15 atm (range, 8-20). Pre- and postdilatation balloon sizes were 2.96 +/- 0.57 mm and 3.16 +/- 0.34 mm, respectively. The procedural success rate was 98%. There were no deaths or Q-wave myocardial infarctions. One patient suffered a non-Q-wave myocardial infarction and another developed a femoral false aneurysm. At 1-month follow-up, there were no additional events, in particular no revascularization procedures. Eighty-nine percent of patients were free of angina. Implantation of the V-Flex Plus stent is safe and effective with an excellent early success rate comparable to that of published randomized trials and registries of carefully selected patients.

Stent deformation following simulated side-branch dilatation: a comparison of five stent designs.

We aimed to determine the effects of simulated stent side-branch dilatation and subsequent redilatation of the central lumen. Following coronary stent implantation it may be necessary to dilate through the side of a stent to maintain branch patency. Branch dilatation through the side of 3.5-mm-diameter stents (AVE GFX, beStent, Crown, MultiLink, and NIR) was simulated in a plexiglass phantom using 2.5-, 3.0-, 3.5-, and 4.0-mm balloons. In further experiments, the main lumen was redilated with a 3.5-mm balloon after 3.0-mm side-branch dilatation. Thereafter, a 3.5-mm central and a 3.0-mm side-branch balloon were simultaneously inflated ("kissing balloons"). The larger the balloon size used for side-branch dilatation, the greater the distortion of the stent immediately distal to the side-branch, which for a 4.0-mm balloon ranged from 36% +/- 2% (Crown) to 65% +/- 6% (NIR). Central lumen redilatation or kissing balloons abolished this stenosis with little reduction of the side-lumen diameter. The main stent lumen compromise caused by side-branch dilatation can be abolished by main-lumen redilatation or by kissing balloons.

Randomised comparison of implantation of heparin-coated stents with balloon angioplasty in selected patients with coronary artery disease (Benestent II)

BACKGROUND: The multicentre, randomised Benestent-II study investigated a strategy of implantation of a heparin-coated Palmar-Schatz stent plus antiplatelet drugs compared with the use of balloon angioplasty in selected patients with stable or stabilised unstable angina, with one or more de-novo lesions, less than 18 mm long, in vessels of diameter 3 mm or more. METHODS: 827 patients were randomly assigned stent implantation (414 patients) or standard balloon angioplasty (413 patients). The primary clinical endpoint was event-free survival at 6 months, including death, myocardial infarction, and the need for revascularisation. The secondary endpoints were the restenosis rate at 6 months and the cost-effectiveness at 12 months. There was also one-to-one subrandomisation to either clinical and angiographic follow-up or clinical follow-up alone. Analyses were by intention to treat. FINDINGS: Four patients (one stent group, three angioplasty group) were excluded from analysis since no lesion was found. At 6 months, a primary clinical endpoint had occurred in 53 (12.8%) of 413 patients in the stent group and 79 (19.3%) of 410 in the angioplasty group (p=0.013). This significant difference in clinical outcome was maintained at 12 months. In the subgroup assigned angiographic follow-up, the mean minimum lumen diameter was greater in the stent group than in the balloon-angioplasty group, (1.89 [SD 0.65] vs 1.66 [0.57] mm, p=0.0002), which corresponds to restenosis rates (diameter stenosis > or =50%) of 16% and 31% (p=0.0008). In the group assigned clinical follow-up alone, event-free survival rate at 12 months was higher in the stent group than the balloon-angioplasty group (0.89 vs 0.79, p=0.004) at a cost of an additional 2085 Dutch guilders (US$1020) per patient. INTERPRETATION: Over 12-month follow-up, a strategy of elective stenting with heparin-coated stents is more effective but also more costly than balloon angioplasty.

Results of percutaneous coronary angioplasty in patients <40 years of age.

This study examined factors influencing the outcome of percutaneous transluminal coronary angioplasty (PTCA) in patients <40 years of age. We followed 86 patients (mean age 37 years) treated from 1982 to 1994. The primary procedural success was 90%. At follow-up of 83 patients (97%) at a mean of 48 +/- 33 months (range 5 to 147), there had been 3 late deaths. Actuarial survival at 5 and 10 years was 95% and 91%, respectively. At review only 5% of patients had class III angina and no patient had class IV angina. Repeat revascularization (PTCA alone in 21 [25%], surgery in 8 [10%], or both in 10 [12%] patients) was performed for restenosis in 29 patients (35%) and for disease progression at other sites in 10 patients (12%). On multivariate analysis, a history of diabetes mellitus (p <0.02) was the only factor associated with death or a subsequent cardiovascular event (myocardial infarction, stroke, or hospital admission with unstable angina). At follow-up, 20 patients (24%) still smoked, 64 (77%) had a total cholesterol level > or = 200 mg/dl, 20 (24%) had a body mass index > or = 30, and 15 (18%) were not taking aspirin. In conclusion, PTCA in adults <40 years of age has excellent early results with a low morbidity and mortality. The medium-term prognosis and control of symptoms was good, although by 5 years, further revascularization was required in almost half of the patients.

Introduction of the Multilink stent into routine angioplasty practice: early angiographic and clinical outcome.

To assess the early outcome of implantation of the Multilink stent in everyday angioplasty practice, we prospectively collected procedural and 1-mo follow-up data on the first 126 patients (93 male, mean age 61+/-9 yr) in 3 centers. One hundred and seventy-four stents were implanted for 134 lesions: left anterior descending artery in 46%, circumflex in 20%, right coronary artery in 31%, and protected left main in 3%. The indication was elective in 56%, a suboptimal result in 43%, and bailout in 1%. Stents were deployed at 10.8+/-1.9 atmospheres and postdilated to 15.7+/-2.4 atmospheres. There were 115 patients who received ticlopidine and aspirin, 10 received aspirin alone, and 1 received warfarin and aspirin following the procedure. The reference diameter increased from 3.02+/-0.44 mm pre- to 3.13+/-0.43 mm postprocedure, with the minimal luminal diameter increasing from 0.82+/-0.47 to 2.86+/-0.45 mm (diameter stenosis 73% pre- and 9% postprocedure). The procedural success rate was 93.7%. There were no deaths, 1 (0.8%) Q- and 5 (4.0%) non-Q-wave myocardial infarctions, 3 (2.4%) emergency bypass operations, and 1 (0.8%) repeat angioplasty during the hospital admission (median stay, 1 day). There were 2 (1.6%) cases of subacute stent thrombosis. At 1-mo follow-up there were no additional events, with 88% of patients remaining free of angina. Implantation of the Multilink stent is safe and effective in everyday angioplasty practice, with a complication rate comparable to those of published trials of carefully selected patients.