Smaller Reference Diameter Research Articles

Efficacy of Low-Pressure Inflation of Oversized Drug-Coated Balloon for Coronary Artery Disease.

Objectives This study sought to assess the efficacy of oversized drug-coated balloon (DCB) inflation at low pressure for the prevention of acute dissections and late restenosis. Background The major limitation of DCB coronary angioplasty is the occurrence of severe dissection after inflation of DCB. Methods Between 2014 and 2018, 273 consecutive patients were retrospectively studied. 191 lesions (154 patients) treated by oversized DCB inflation at low pressure (<4 atm, 2.4 ± 1.2 atm, DCB/artery ratio 1.14 ± 0.22; LP group) were compared with 135 lesions (119 patients) treated by the standard DCB technique (7.1 ± 2.2 atm, DCB/artery ratio 1.03 ± 0.16; SP group). Results Although the lesions in the LP group were more complex than those in the SP group (smaller reference diameter (2.38 mm vs. 2.57 mm, P=0.011), longer lesions (11.7 mm vs. 10.5 mm, P=0.10), and more frequent use of rotational atherectomy (45.0% vs. 28.1%, P=0.003), there was no significant difference in the NHLBI type of dissections between the two groups (11.5%, 12.0%, 5.2% vs. 12.6%, 12.6%, 2.2% in type A, B, and C, P=0.61), and no bailout stenting was required. In 125 well-matched lesion pairs after propensity score analysis, the cumulative incidence of target lesion revascularization at 3 years was 4.5% vs. 7.0%, respectively (P=0.60). Late lumen loss (−0.00 mm vs. −0.01 mm, P=0.94) and restenosis rates (7.4% vs. 7.1%, P=1.0) were similar in both of the groups. Conclusion The application of oversized DCB at low pressure is effective and feasible for preventing late restenosis comparative to the standard technique of DCB.

P3578Determinants of visual-functional mismatches as assessed by coronary angiography and 3-D angiography-based quantitative flow ratio

Abstract Background Quantitative flow ratio (QFR) is a novel three-dimensional quantitative coronary angiography (QCA)-based computational index that can estimate fractional flow reserve (FFR) without pharmacologically induced hyperemia or the use of a pressure wire. Purpose We aimed to evaluate the determinants of visual-functional mismatches between conventional two-dimensional QCA and QFR. Methods A total of 504 de novo intermediate-to-severe lesions from 504 patients with stable angina who underwent angiographical and physiological assessments were analyzed. All lesions were divided into four groups based on the significance of visual (QCA-diameter stenosis [DS] &gt;50% and ≤50%) and functional (QFR &lt;0.80 and ≥0.80) stenosis severity. Patient characteristics, angiographic findings, QFR computations, and physiological indices were compared among the four groups. Results Among 504 lesions, 153 lesions (30.4%) showed concordantly negative (DS ≤50% and QFR &gt;0.80) and 170 lesions (33.7%) showed concordantly positive (DS &gt;50% and QFR ≤0.80) visual and functional assessments. Among 181 lesions (35.9%) with discordant results, 75 lesions (14.9%) showed a mismatch (DS &gt;50% and QFR &gt;0.80) and 106 lesions (21.0%) showed a reverse mismatch (DS ≤50% and QFR ≤0.80), respectively. Reverse mismatch was associated with smaller reference diameter (odds ratio [OR] 0.561; P=0.036), greater DS (OR 1.039, P=0.013), lower coronary flow reserve (CFR) (OR 0.571, P&lt;0.001, non-diabetes mellitus (OR 2.141, P=0.013) and lower ejection fraction (OR 0.961, P=0.011). Mismatch was associated with smaller DS (OR 0.914, P&lt;0.001), shorter lesion length (OR 0.894, P=0.001), higher CFR (OR 1,633, P&lt;0.001), and lower estimated glomerular filtration rate (OR, 0.968, P=0.001). Lesion location and the index of microcirculatory resistance was not associated with the prevalence of reverse mismatch or mismatch. Conclusions There was a high prevalence of visual-functional mismatches between QCA-DS and QFR, and CFR was an important functional factor of mismatches. Our results suggested the difference between predictors of reported visual-functional mismatches of QCA/FFR and those of QCA/QFR.

Angiographic features of patients with coronary plaque erosion

BackgroundAlthough an in vivo diagnosis of coronary plaque erosion has become possible by optical coherence tomography (OCT), angiographic characteristics of erosion have not been studied. The aim of this study was to investigate the angiographic features of plaque erosion in patients with non-ST elevation acute coronary syndromes (NSTE-ACS). MethodsPatients with NSTE-ACS who underwent OCT of the culprit lesion were collected at 11 institutions from 6 countries. Patients were classified as erosion or non-erosion based on OCT images. Angiographic features of both groups were compared. ResultsAmong 494 cases with NSTE-ACS, 242 had plaque erosion and 252 had non-erosion. Compared to non-erosion group, erosion patients had less multivessel disease (28.5% vs. 49.6%, p < 0.001), lower Jeopardy score (4.2 vs. 5.0, p < 0.001), lower Gensini score (21.3 vs. 25.6, p = 0.014), and lower Syntax score (8.9 vs. 11.5, p < 0.001). With regard to the culprit lesion morphology, plaque erosion group had smaller reference diameter (2.8 mm vs. 3.0 mm, p = 0.032), less frequent type B2/C lesions (51.2% vs. 71.8%, p < 0.001), and lower prevalence of calcification (4.1% vs. 13.9%, p < 0.001) and thrombus (16.5% vs. 28.2%, p = 0.002). In the mid left anterior descending artery (LAD), erosion was significantly more frequent than non-erosion (30.2% vs. 21.8%, p = 0.034). ConclusionsPatients with NSTE-ACS caused by plaque erosion have less complex angiographic features both at the 3-vessel level and at the culprit lesion level. Plaque erosion was frequently found in the mid LAD.

Novel predictors of late lumen enlargement in distal reference segments after successful recanalization of coronary chronic total occlusion.

Although successful recanalization of coronary chronic total occlusion (CTO) can induce subsequent positive vascular remodeling in the distal segment, the predictors are not fully understood. The aim of this study was to investigate the extent and predictors related to luminal gain after successful CTO recanalization. A total of 134 patients who underwent intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) for CTO and follow-up angiography were included. Angiographic parameters were assessed qualitatively and quantitatively at baseline and follow-up. Gray-scale IVUS images during the PCI procedure were also analyzed. Lumen diameter (LD) at distal reference on the post-PCI angiogram was compared with corresponding LD at follow-up coronary angiography. At the mean follow-up of 10.0 ± 2.7 months, LD at distal reference was significantly increased by 15.9% from baseline to follow-up (2.06 ± 0.62 vs. 2.30 ± 0.55 mm, p < 0.001). Univariable analysis indicated that the left anterior descending artery (LAD), no moderate or severe calcification, presence of peri-medial high-echoic band on IVUS, and impairment of final coronary flow and small distal reference diameter at baseline were associated with greater late lumen enlargement. Multivariable analysis showed the LAD, no moderate or severe calcification, and small LD at distal reference as independent predictors of greater late lumen enlargement. The segment distal to recanalized CTO showed significant late lumen enlargement, especially in the cases with small distal reference, in the LAD, and without moderate or severe calcification.

Influence of visual-functional mismatch on coronary flow profiles after percutaneous coronary intervention: a propensity score-matched analysis.

The aims of this study are to clarify whether discrepancies between angiographic and fractional flow reserve (FFR) measurements (visual-functional mismatch) influence coronary flow profiles after percutaneous coronary intervention. While current guidelines FFR-guided revascularization, clinical practice most commonly relies on angiographic evaluation, which may under- or over-estimate the functional relevance of the lesion. Our retrospective analysis involved 274 vessels from 264 patients with stable angina pectoris who underwent FFR, index of microvascular resistance, and coronary flow reserve (CFR) measurements before and after PCI. Visual-functional concordance and discordance (reverse mismatch) were defined as angiographic stenosis > 50% with FFR ≤ 0.80 and angiographic stenosis ≤ 50% with FFR ≤ 0.80, respectively. Propensity score-matched cohort included 132 lesions (66 lesions: concordant findings, 66 lesions: reverse mismatch). The change in coronary flow profiles after PCI was assessed in terms of FFR, CFR, index of microvascular resistance (IMR), and mean transit time (Tmn). Compared with concordant territories, reverse mismatch territories were associated with lower pre-PCI IMR, higher pre-PCI CFR, greater minimum lumen diameter and smaller reference diameter (all comparisons, P < 0.05). After propensity score matching, the prevalence and extent of coronary flow improvement after PCI, evaluated by CFR and Tmn, were both remained significantly greater in concordant territories (all comparisons, P < 0.05). The prevalence and extent of coronary flow improvement after PCI assessed by the physiologic indices was significantly greater in visual-functional concordant lesions, suggesting that these coronary physiologic changes were associated with discrepancy between angiographic measurements.

Clinical and angiographic predictors of haemodynamically significant angiographic lesions: development and validation of a risk score to predict positive fractional flow reserve.

Coronary revascularisation based upon physiological evaluation of lesions improves clinical outcomes. Angiographic or visual stenosis assessment alone is insufficient in predicting haemodynamic stenosis severity by fractional flow reserve (FFR) and therefore cannot be used to guide revascularisation, particularly in the lesion subset <70%. Accordingly, we sought to identify independent determinants of angiographic intermediate lesions with haemodynamic significance. We assessed consecutive intermediate lesions for patients from January 2014 to April 2015 at our institution. Independent predictors of FFR positivity (FFR ≤0.8) were identified and a scoring system formulated. Of 1,023 consecutive lesions (883 patients), 314 (31%) were haemodynamically significant. Characteristics associated with FFR ≤0.8 include male gender, higher SYNTAX score, lesions ≥20 mm, stenosis >50%, bifurcation, calcification, absence of tortuosity and smaller reference diameter. A user-friendly integer score was developed with the five variables demonstrating the strongest association. On prospective validation (in 279 distinct lesions), the increasing value of the score correlated well with increasing haemodynamic significance (C-statistic 0.85). We identified several clinical and angiographic characteristics and formulated a scoring system to guide the approach to intermediate lesions. This may translate into cost savings. Larger studies with prospective validation are required to confirm our results.

Angiographic Dissection Patterns and Patency Outcomes After Balloon Angioplasty for Superficial Femoral Artery Disease

Purpose: To investigate the angiographic dissection patterns after balloon angioplasty for superficial femoral artery (SFA) lesions, the clinical outcome associated with each dissection pattern, and the predictive factors for severe dissection. Methods: A retrospective, multicenter analysis examined 621 patients (mean age 72.8±9.5 years; 414 men) with 748 symptomatic de novo SFA lesions treated with endovascular therapy. Vessel dissection after the initial balloon angioplasty procedure was graded into 7 types according to a modified version of the coronary artery classification types A to F. Severe vessel dissection patterns were defined as type C or higher. Nitinol stent implantation was performed in 555 (74.2%) lesions for residual stenosis >30% or flow-limiting dissection; 193 lesions (25.8%) were treated with balloon angioplasty only. To determine the clinical outcomes associated with each dissection pattern and identify predictive factors for severe dissection, 2-year follow-up data for the 193 lesions treated with balloon angioplasty only were analyzed for primary patency and clinically driven target lesion revascularization (TLR). Results: No dissection was found in 16% (120/748) of lesions, and types A and B dissections were seen in 19% (142/748) and 23% (172/748), respectively. Dissection grades above type C were observed in 42% of cases, most frequently type D (180/748, 24%) and less often type C (37/748, 5%), type E (67/748, 9%), and type F (30/748, 4%). The bailout stent implantation rate increased according to dissection severity. At up to 2 years, the severe dissection group (types C–F) showed a significantly lower patency rate (p<0.001) and higher clinically driven TLR (p<0.001) compared to the nonsevere group (no dissection and types A and B dissections). Severe dissection was a significant risk factor for restenosis, which rose progressively from types C to F. Multivariate analysis identified a small reference vessel diameter <5 mm (p=0.001), lesion length >15 cm (p=0.001), and chronic total occlusion (p<0.001) as independent predictors of severe dissection. In subgroup analysis, vessels with a small reference diameter and TASC II C and D lesions had a higher prevalence of severe dissection. Conclusion: Severe dissection was found in 42% of cases after PTA. A small vessel diameter and/or TASC II C/D lesions were related to a high incidence of dissection. Severe dissection during procedures employing balloon angioplasty only could affect long-term patency.

Predictors for Side Branch Failure During Provisional Strategy of Coronary Intervention for Bifurcation Lesions (from the Korean Bifurcation Registry)

The most favored strategy for bifurcation lesion is stenting main vessel with provisional side branch (SB) stenting. This study was performed to elucidate predictors for SB failure during this provisional strategy. The study population was patients from 16 centers in Korea who underwent drug-eluting stent implantation for bifurcation lesions with provisional strategy (1,219 patients and 1,236 lesions). On multivariate analysis, the independent predictors for SB jailing after main vessel stenting were SB calcification, large SB reference diameter, severe stenosis of SB, and not taking clopidogrel. Regarding SB compromise, however, the independent predictors were true bifurcation lesion and small SB reference diameter, whereas possible predictors were parent vessel thrombus and parent vessel total occlusion. In addition, SB predilation helps us to get favorable SB outcome. The diameter of SB ostium after main vessel stenting became similar between severe SB lesions treated with predilation and mild SB lesions not treated with predilation. In conclusion, SB calcification, less clopidogrel use, large SB reference diameter, and high SB diameter stenosis are independent predictors for SB jailing, and true bifurcation and small SB reference diameter are independent predictors for SB compromise after main vessel stenting.

Comparison of the Predictors of Coronary Restenosis after Drug-Eluting Stent Implantation in Diabetic and Nondiabetic Patients

Background and Objectives: Coronary restenosis after drug-eluting stent (DES) implantation occurs more frequently in diabetic patients than in nondiabetic patients. We compared the parameters influencing the likelihood of restenosis after DES implantation in diabetic and nondiabetic patients. Subjects and Methods: Patients who underwent DES implantation (619 patients with 917 lesions, 211 diabetics and 408 nondiabetics), followed by 8 months coronary angiogram, were retrospectively identified using the percutaneous coronary intervention database and included in the present study [AH1]. Predictors of restenosis were identified by multivariate logistic regression analyses. Results: The baseline characteristics of the patients, such as sex, body mass index, hypertension, hyperlipidemia, and smoking status, were similar between the diabetic and nondiabetic patients. Restenosis (>50% of the diameter stenosis) occurred in 32 of 408 (7.8%) nondiabetic patients and in 32 (15.2%) of 211 diabetic patients (p<0.001). The use of a paclitaxel-eluting stent (PES), a higher level of C-reactive protein (CRP), longer stent length, smaller reference diameter (RD) before DES implantation, smaller RD and minimal lumen diameter after DES implantation were common predictors of restenosis in both the diabetic and nondiabetic patients after multivariate analyses. Current smoking status [odds ratio (OR)=3.213, 95% confidence interval (CI) 1.458 to 7.080 p=0.004] and right coronary lesions (OR=2.444, 95% CI 1.048 to 5.703, p=0.039) were predictors of restenosis in the diabetic patients, while higher body mass index (OR=1.322, 95% CI 1.054 to 1.659, p=0.016) and A-type lesions (OR=0.108, 95% CI 0.022 to 0.530, p=0.006) were predictors of restenosis in the nondiabetic patients. Conclusion: The use of PESs and higher levels of CRP were associated with restenosis regardless of the presence of diabetes. Moreover, small baseline and post-PCI reference diameter and longer stent length remained significant angiographic predictors of restenosis in both diabetic and nondiabetic patients, even in the era of DES implantation. (Korean Circ J 2007;37:530-537)

A Prospective Registry to Evaluate Sirolimus-Eluting Stents Implanted at Coronary Bifurcation Lesions Using the “Crush Technique”

The "crush technique" has been proposed as an alternative approach to treat bifurcation lesions because of its predictability and high procedural success rate. However, few data are available regarding its safety and long-term efficacy. We report the long-term clinical outcomes of patients with coronary bifurcation lesions treated with sirolimus-eluting stents using the crush technique. From April 2003 to May 2004, 120 patients with coronary bifurcation lesions were treated with sirolimus-eluting stents using the crush technique. Six months of clinical follow-up was completed in 95.8% of patients. Mean patient age was 64 years; 36% had diabetes mellitus, and the left anterior descending artery/diagonal was the most frequent bifurcation location (69%). Final kissing balloon inflation was performed in 87.5% of patients. Compared with the main vessel, side branch lesions were shorter, with a smaller reference diameter and final in-stent minimum lumen diameter. Procedural success was achieved in 97.5%. At 30 days of follow-up, 1 patient had died of noncardiac causes and 2 patients (1.7%) had subacute stent thrombosis. At 6 months of follow-up, target lesion revascularization was required in 13 patients (11.3%), all of whom had focal restenosis predominantly at the side branch ostium. In conclusion, the crush technique with final kissing balloon inflation can be safely used by experienced operators to treat highly complex bifurcation lesions with sirolimus-eluting stents. The safety profile of this technique is similar to that of other bifurcation stenting techniques reported thus far. Nonetheless, despite the excellent patency rates of the main vessel, the need for revascularization at the ostium of the side branch was not fully eliminated.

Latin American randomized trial of balloon angioplasty versus coronary stenting in diabetic patients with small vessel reference size (Latin American Small Vessel [LASMAL II] Trial): Immediate and long-term results

Percutaneous coronary interventions (PCIs) in diabetic patients with small reference diameter vessels remain an important challenge in interventional cardiology because it is associated with increased complications and restenosis rates. Plain old balloon angioplasty (POBA) has limited efficacy in patients with lesions in small vessels. Although coronary stenting (stent) has been demonstrated to improve both immediate and long-term results after coronary intervention, small reference diameter is a strong predictor of restenosis after stent implantation. Thus, the question of how to best treat diabetic patients with lesions in small reference diameter remains unanswered. The purpose of this international and multicenter study was to compare the incidence of angiographic restenosis between percutaneous transluminal coronary angioplasty (PTCA) and stent in diabetic patients undergoing PCI of small reference diameter vessels using a specially designed phosphoryl choline (PC)-coated stent for small vessels. The patient population comprised of 220 diabetic patients with lesions in small reference diameter (< 2.9 mm but > 2.0 mm) that were randomized into two different PCI strategies: PTCA with provisional stenting (n = 109) versus stent (n = 111). In the PTCA arm, 26 patients (24%) crossed over to stent during the initial procedure; glycoproteins IIb to IIIa was used in 40.5% of patients in both groups. During initial procedure and at 30 days, both strategies of revascularitation had similar clinical success and acute complications. During long-term follow-up, even though requirements of target vessel revascularization and incidence of major adverse cardiovascular event were similar with both techniques, angiographic binary restenosis (45% with PTCA and 28% with stents, P = .047), net gain (0.74 mm with POBA and 0.94 mm with stents, P = .008), and freedom from target vessel failure (66% with POBA and 81.2% with stents, P = .013) were significantly improved when diabetic patients were initially treated with stent therapy. In summary, in diabetic patients with small coronary arteries, the use of a coronary PC coated stent as a primary device during percutaneous interventions was associated with better angiographic and long-term outcome.

Latin American randomized trial of balloon angioplasty vs coronary stenting for small vessels (LASMAL): Immediate and long-term results

Purpose To assess the potential role of coronary stent to improved acute success and reduce late restenosis in lesions with reference diameter <2.9 mm using a bare metal stent specifically designed for small coronary vessels. There is controversy on the results among previous studies comparing bare metal stent implantation with conventional balloon percutaneous transluminal coronary angioplasty (PTCA). Differences in baseline characteristics, inclusion and exclusion criteria, and stent design may account for these discrepancies. Methods The population of this multicenter, multinational randomized study (LASMAL) consisted of 246 patients undergoing percutaneous coronary intervention of small vessel reference diameter. They were randomized into 2 strategies of percutaneous revascularization: elective primary stent (n = 124) or conventional balloon PTCA with provisional stenting (n = 122) in the presence of acute, threatened closure or flow-limiting dissections. Results The clinical success rate was significantly better for the stent group (98.3% vs 91.8%; P = 0.038). At 30 days follow-up, requirements of target vessel revascularization (TVR) (6.6% vs 0.8%; P = 0.018) and incidence of major adverse cardiac and cerebrovascular events (MACCE) (9.8% vs 2.4%; P = 0.01) was significantly lower in the stent strategy. Postpercutaneous coronary intervention minimal luminal diameter (MLD) was significantly larger in the stent group (2.3 ± 0.2 mm vs 2.2 ± 0.2 mm; P = 0.003). At follow-up, MLD in the stent group was larger than with PTCA (1.7 ± 0.7 mm vs 1.5 ± 0.7 mm, respectively; P = 0.035). Net gain was also significantly better with stent strategy (1.1 ± 0.7 mm vs 0.8 ± 0.7 mm, respectively; P = 0.002). Stenting resulted in a significant lower angiographic binary restenosis (20% vs 31%; P = 0.02) than PTCA. Furthermore, patients treated with stent were more frequently free from MACCE at 9-month follow-up (death, acute myocardial infarction [AMI], stroke, repeat revascularization procedures) than those treated initially with PTCA (82.2% vs 72% of PTCA, P = 0.046). Conclusions The use of a specifically designed bare metal coronary phosphoril choline-coated stent as primary device during percutaneous interventions in small coronary arteries was associated with high procedural success and low in-hospital and 30-day follow-up complications. At long-term follow-up, patients initially treated with stents had lower angiographic restenosis rate and were more frequently free from major adverse cardiac events.

Determination of vessel size: a putative framework to assess clinical outcome

Background Unknown is the predictive value of the coronary artery diameter without the administration of vasomotor stimuli. A small reference diameter of the target vessel has been demonstrated to be an adverse prognostic factor in patients undergoing revascularisation. The present study investigated the prognostic value of the proximal non-stenotic left anterior descending coronary artery (LAD) diameter in patients referred for a first diagnostic angiogram without a previous revascularisation. Methods A total of 277 patients (mean age 57 year, 61% male) were eligible for analysis. The proximal non-stenotic diameter of the LAD was measured by quantitative coronary angiography without prior nitrate infusion. We defined a small LAD as a diameter ≤2.5 mm. Cardiovascular events were defined as cardiac death, myocardial infarction, and hospitalizations for unstable angina. Results During a median follow-up of 47 months, 24 major cardiac events occurred. The cumulative survival for patients with a small LAD was significantly lower, than for patients with a large LAD (hazard ratio 2.51; 95% confidence interval 1.11–5.66, p=0.03). In the multivariate analysis, a LAD diameter ≤2.5 mm remained a significant predictor of cardiovascular events after adjustment for age, gender, and the presence of significant coronary artery disease (hazard ratio 2.32; 95% confidence interval 1.01–5.34, p=0.048). Conclusion In patients referred for a first diagnostic angiogram without a previous revascularisation, the diameter of the proximal non-stenotic LAD is an independent predictor of cardiovascular events.

Predictors of angiographic restenosis after coronary intervention in patients with diabetes mellitus

Background Patients with diabetes mellitus are particularly prone to restenosis after percutaneous coronary intervention. An exploratory, nested, case-control study was undertaken to identify clinical, lesional, and procedural predictors of angiographic restenosis in these patients. Methods Seventy-five patients with diabetes mellitus with 86 coronary lesions were selected from a larger population of 217 patients who had undergone 6-month angiographic follow-up after a first, successful balloon angioplasty (PTCA) or stent implantation procedure. Data collection was by patient interview and review of hospital database and other medical records. All angiograms were analyzed with quantitative coronary angiography, and restenosis was defined as a ≥50% diameter reduction at the treated site. A multivariate analysis of 10 prespecified explanatory variables, derived from a literature review, was performed on a per-lesion basis. Results There were 45 patients (53 lesions) with restenosis and 30 patients (33 lesions) without restenosis. Univariate predictors of binary restenosis were periprocedural glycosylated hemoglobin level, vessel reference diameter, PTCA, and larger final balloon size to reference artery diameter ratio. Multiple logistic regression identified poor glycemic control (odds ratio [OR] 3.03, 95% CI 1.06–8.65, P = .038), small vessel reference diameter (OR 3.41, 95% CI 1.17–9.95, P = .025), and mode of intervention (OR 3.12, 95% CI 1.08–9.00, P = .036) as independent risk factors. Vessel reference diameter appeared to be an important effect modifier of the association between type of intervention and angiographic outcome, with stenting no longer superior to PTCA in patients with diabetes mellitus who had vessels <2.87 mm in diameter ( P = .054). Conclusion Poor glycemic control, vessel size, and PTCA were independent predictors of restenosis in patients with diabetes mellitus. It is possible that improved periprocedural glycemic control, in addition to stenting, may reduce the restenosis rate in these patients.

P2222 Efficacy of vascular brachytherapy with beta-radiation in longer lesions and smaller reference diameter vessels

P2222 Efficacy of vascular brachytherapy with beta-radiation in longer lesions and smaller reference diameter vessels

A multicenter European REgistry of intraluminal coronary beta brachytherapy using the NOvoste system

While intravascular brachytherapy (VBT) is now an established mode of therapy to prevent restenosis following percutaneous intervention (PCI), there are only very few data available concerning its use outside the framework of randomized controlled trials. The RENO registry was therefore designed to assess feasibility, safety and effectiveness of VBT in routine clinical practice, as well as to determine the predictors of major adverse cardiac events (MACE) following the procedure. Between April 1999 and September 2000, 1098 consecutive patients treated in 46 European centres by intraluminal irradiation using a Sr/Y90 source train (BetaCath™, Novoste, GA) were included in RENO, and follow-up data were obtained for 98.8 % of them after 6.3 ± 2.4 months. 840 (76.5 %) patients were males, and mean age was 62.0 ± 10.2 years. 271 (26.9 %) had unstable angina, and 256 (23.5 %) were diabetics. 913 lesions (77.7 %) were in-stent restenosis, 208 (17.7 %) de novo lesions and 48 (4.1 %) non-stented restenotic lesions. Mean estimated reference diameter was 3.2 ± 0.5 mm and mean estimated lesion length was 19.0 ± 11.8 mm. The prescribed radiation dose was 18.8 ± 3.2 Gy. Multivessel irradiation was done in 6.2% of cases, and a new stent was implanted in 29.6 % of cases. Most patients received 6 or 12 months of combined aspirin and thienopyridin treatment after the procedure. Technical success was obtained in 95.9 % of treated lesions, and the in-hospital MACE rate was 1.8 %. At follow-up, the MACE rate was 18.7 % (1.9 % death of all causes, 2.6 % AMI, 13.3 % TVR by PCI and 3.3 % TVR by CABG). Using multivariate analysis, 7 independent significant predictors of MACE at follow-up could be identified. These were younger patient age, unstable angina, target lesion in a saphenous vein graft, longer lesion length, smaller reference diameter, failure to use a cutting balloon and implantation of a new stent at the time of VBT. The major current application of VBT is the treatment of in-stent restenosis. The good results of VBT observed in recent randomized controlled trials can be reproduced in clinical practice.

Implications of small reference vessel diameter in patients undergoing percutaneous coronary revascularization

OBJECTIVESThe purpose of this study was to determine whether small reference diameter of the culprit coronary artery influences the outcome of an attempted percutaneous revascularization procedure in the current era of interventional cardiology.BACKGROUNDAlthough the interventional strategy is largely determined by the size of the culprit coronary artery, earlier quantitative studies have not shown a worse acute outcome for small reference vessel diameter (≤2.5 mm).METHODSA total of 2,306 patients undergoing percutaneous coronary revascularization was divided in groups with reference diameters ≤2.5 mm (n = 813) or >2.5 mm (n = 1,493). Success and in-hospital major adverse cardiac event (death, Q-wave myocardial infarction and emergency coronary artery bypass graft) rates between both groups were compared.RESULTSPatients with lesions in small vessels were older and presented more frequently with female gender, diabetes mellitus, heart failure, peripheral vascular, multivessel coronary disease and American Heart Association/American College of Cardiology (AHA/ACC) lesion type C (p ≤ 0.01, each). Further, utilization of interventional devices differed markedly. In contrast to stents (18.5% vs. 41.9%) and directional atherectomy (3.7% vs. 13.5%), conventional balloon angioplasty (73% vs. 50%) and rotational atherectomy (16.1% vs. 8.3%) were used more often in smaller vessels (p ≤ 0.0001, each). Success rate was lower in the small vessel group (92% vs. 95%; p = 0.006). Major adverse cardiac events occurred more frequently in small than large vessels (univariate 3.4% vs. 2.0%, p = 0.03; multivariate odds ratio 2.1, p = 0.02), particularly when proximal coronary segments were compared.CONCLUSIONSLesions in vessels with small reference diameter represent a distinct group with respect to clinical and morphologic characteristics as well as device utilization. These lesions have lower chances of successful percutaneous intervention and carry relatively higher risks, specifically when located in proximal coronary segments.

Predictors of restenosis after coronary stent implantation.

We sought to determine predictors of restenosis after coronary stenting (CS) in a consecutive series of patients. Although stenting in highly selected patient groups reduces restenosis, the results of stenting in a heterogeneous patient group and the effects of clinical and procedural factors on stent restenosis are currently unclear. We analyzed the 6-month angiographic outcome of 500 lesions in 463 consecutive patients undergoing successful CS. Clinical, qualitative and quantitative angiographic variables were correlated with restenosis assessed as both a binary and a continuous variable. Restenosis, defined as the presence of >50% diameter stenosis in the dilated segment, was present in 105 (26%) of the 405 lesions with angiographic follow-up. The mean late lumen loss during the follow-up period was 0.79+/-0.64 mm. Implantation of multiple stents (p < 0.0001) and a high acute gain (p < 0.0002) were independently associated with a higher late lumen loss. In contrast, the use of high inflation pressure (p < 0.02) and Palmaz-Schatz stents (p < 0.005) was independently associated with a lower late lumen loss. When restenosis was defined as a qualitative variable, implantation of multiple stents (p < 0.001), stenosis length (p < 0.01), small reference diameter (p < 0.02) and stent type other than Palmaz-Schatz (p < 0.01) were independent predictors of restenosis. None of the clinical variables tested was associated with restenosis. Coronary stenting in an unselected patient group is associated with an acceptable restenosis rate. Although some risk factors were identified, the risk of restenosis was not related to most of the variables tested. This suggests that the superiority of CS over balloon angioplasty, in terms of restenosis, might also apply to subgroups of patients that were not included in the recent randomized studies.

Restenosis After Delayed Coronary Angioplasty of the Culprit Vessel in Patients With a Recent Myocardial Infarction Treated by Thrombolysis

Clinical follow-up after percutaneous transluminal coronary angioplasty (PTCA) of an infarct-related lesion has demonstrated a low incidence of recurrent symptoms and repeated revascularization. In the absence of systematic angiographic follow-up, this low rate of clinical restenosis may reflect either a truly lower incidence of anatomic restenosis or the lack of recurrent symptoms in patients with extensive infarction in the territory of the restenotic vessel. We studied 300 consecutive patients who, after a thrombolysis for myocardial infarction, underwent delayed (10.5 +/- 6 days after the myocardial infarction) PTCA of the infarct-related lesion. Procedural success was obtained in 253 patients (84%), and angiographic follow-up was performed in 205 of this group (81%) at a mean of 7.3 +/- 1.9 months. Restenosis (defined as the recurrence of > 50% stenosis) was present in 105 patients (51%). Only 34 of the 105 patients (32%) with angiographic restenosis were symptomatic; the other 68% had clinically silent restenosis. Of these 105 patients, 27 (13% of the total population undergoing follow-up angiography) had reocclusion at the dilated site at follow-up. The severity of the stenosis at follow-up and the late loss in minimal lumen diameter followed a nearly Gaussian distribution if the lesions that were totally occluded at follow-up were excluded. By multivariate analysis, two independent predictors of reocclusion were identified: a small reference diameter (P < .0005) and the presence of collateral vessels before the procedure (P < .01). Only one factor was associated with restenosis in the 178 patients who did not have reocclusion at follow-up; a Thrombolysis in Myocardial Infarction grade < or = 2 before the procedure (P < .0001). At follow-up, there was a significantly (P < .01) higher ejection fraction in patients without restenosis (56.1 +/- 13.4%) and in patients with restenosis without total occlusion (56.0 +/- 13.8%) than in patients with reocclusion (46.4 +/- 13.0%). Despite a satisfactory clinical outcome, delayed PTCA of an infarct-related lesion is associated with a high rate of angiographic recurrence. Two distinct mechanisms account for recurrent stenosis: progressive luminal renarrowing as documented after angioplasty of stable lesions and reocclusion of the infarct-related lesion. Only reocclusion is associated with a deterioration in left ventricular function at follow-up.