Minimal Luminal Diameter Research Articles

Three-dimensional and two-dimensional quantitative coronary angiography, and their prediction of reduced fractional flow reserve

We investigated whether three-dimensional (3D) and two-dimensional quantitative coronary angiography (2D-QCA) measurements differed in their accuracy in predicting reduced fractional flow reserve (FFR), and how this varied with stenosis severity and the FFR cut-off used. Three-dimensional and 2D-QCA were compared in their measurements of minimum luminal area (MLA), percentage area stenosis, lesion length, minimum luminal diameter (MLD) and percentage diameter stenosis, and in their prediction of functionally significant FFR. In total, 63 target lesions were interrogated in 63 patients undergoing elective percutaneous coronary intervention. Of all measurements of lesion severity obtained by 3D-QCA, MLA best correlated with FFR (R = 0.63, P < 0.001), and was the most accurate predictor of FFR < 0.75 (C statistic 0.86, P < 0.001). Of 2D-QCA measurements, MLD correlated best with FFR (R = 0.58, P < 0.001), and best predicted FFR < 0.75 (C statistic 0.80, P < 0.001). Overall, 3D-QCA showed a non-significant trend towards more accurate prediction of FFR than 2D-QCA, especially in intermediate lesions. The relationship between FFR and apparent stenosis severity was found to be curvilinear. Both 3D- and 2D-QCA were less accurate in intermediate lesions, and in predicting FFR ≤ 0.80 than in predicting FFR <0.75. The accuracy of QCA in predicting functionally significant FFR is limited and is dependent on FFR cut-off used and lesion severity. Where FFR is not available or contraindicated, 3D-QCA may assist in the evaluation of coronary lesions of intermediate severity.

Prognostic value of non-invasive coronary computed tomography angiography: where are we now?

Coronary computed tomography angiography (CCTA) has become a robust non-invasive method in recent years for evaluating coronary atherosclerosis [1]. High quality CCTA (64 slice and higher) is currently probably the most sensitive non-invasive modality for diagnosing obstructive and non-obstructive coronary artery disease (CAD), with high negative predictive value [1, 2]. This is not surprising considering that CCTA examines coronary anatomy (or minimal luminal diameter), while other non-invasive methods invoking physiologic stress (such as myocardial perfusion imaging or stress echocardiography) evaluate the physiologic consequences of coronary arterial narrowing, i.e. myocardial ischemia. Regarding prognosis, however, the degree of inducible myocardial ischemia or the presence of extensive myocardial fibrosis and reduced left ventricular function as assessed by physiologic testing are indeed established powerful predictors of adverse cardiac events [3–7]. For this reason, physiologic assessment of myocardial ischemia and left ventricular contractile function have become the most commonly used methods for risk stratification in patients with known or suspected CAD. The prognostic value of conventional coronary angiography, which clearly delineates the severity and extent of obstructive CAD, is well established. High risk coronary anatomy (triple vessel CAD, narrowing of the left main coronary artery) is clearly associated with poorer outcome [8–10], while normal coronary anatomy is associated with an excellent prognosis [11]. Thus, the anatomy-based approach is a well established method for risk stratification of patients, especially those who are symptomatic. Nonetheless, despite many reports demonstrating the prognostic value of coronary calcifications found on nonenhanced scans [12], until very recently the prognostic value of (contrast enhanced) CCTA was unclear. The introduction of 64-slice CCTA during 2004 allowed better assessment of coronary atherosclerosis with more reliable results [13]. In recent years, several papers reported mid-term outcome of patients undergoing 64-slice CCTA. Since most of these outcome studies were a single center experience and usually based on a scanner from a single vendor, it was indeed logical to combine the results of those studies to better appreciate the prognostic usefulness of CCTA. In this issue of the journal, Abdulla and colleagues [14] report a meta-analysis of 10 relatively large studies (range 100–2,076 patients/study) evaluating the prognostic value of 64-slice CCTA. The combined end point of cardiac death, myocardial infarction and coronary revascularization (MACE) was evaluated in Editorial comment to the article by Abdullah et al. doi:10.1007/s10554-010-9652-x.

Predictors of embolization during protected renal artery angioplasty and stenting: Role of antiplatelet therapy

The objective of this study was to identify the predictors of distal embolization (DE) during protected renal artery angioplasty and stenting. DE may contribute to worsening renal function after renal artery stenting. The factors associated with DE, rates of platelet-rich emboli, and treatments that may prevent DE during renal stenting have not been evaluated. The current study evaluated patients randomized to receive an embolic protection device (EPD) in the RESIST trial. Forty-two patients were identified for inclusion in this study. These patients were further randomized to abciximab (N = 22) or placebo (N = 20). Modification in Diet in Renal Disease glomerular filtration rate (GFR) was used as the primary measure of renal function. Creatinine was measured by a modified Jaffe reaction using the IDMS-traceable assay. The primary endpoint was capture of platelet rich emboli in the angioguard basket. DE occurred in 15/42 (35%) of the patients and platelet rich DE in 10 (24%) of the patients who received an EPD. Of the angiographic characteristics only lesion length was significantly higher in patients with DE (16 +/- 7 mm vs. 10 +/- 5 mm, P = 0.04). Preprocedural abciximab reduced DE from 42 to 8% (P = 0.02). The rate of platelet rich emboli was 50% with neither abciximab nor a thienopyridine, 36% with thienopyridine only, 15% abciximab only, and 0% in patients who received both a thienopyridine and abciximab. Only Abciximab use was associated with improved renal function at 1-month, thienopyridine was not. Angiographic characteristics including percent stenosis, minimal luminal diameter (MLD), reference diameter, change in MLD, contrast volume, and procedure time were not predictors of DE during renal stenting. Capture of DE and specifically platelet DE are common during protected renal stenting using a filter-type EPD. Abciximab use, and potentially combined thienopyridine and abciximab use, decreased the rate of platelet rich DE; however, only abciximab improved renal function at 1-month.

Comparison of sirolimus-eluting and bare metal stent for treatment of patients with total coronary occlusions: results of the GISSOC II-GISE multicentre randomized trial

Percutaneous coronary intervention with bare metal stent (BMS) in chronic total coronary occlusions (CTOs) is associated with a higher rate of angiographic restenosis and reocclusion than that observed in subtotal stenoses. Preliminary reports have suggested a better performance of drug-eluting stents in CTO. In this multicentre, randomized trial, we compared the mid-term angiographic and clinical outcome of sirolimus-eluting stent (SES) or BMS implantation after successful recanalization of CTO. Patients with CTO older than 1 month, after successful recanalization, were randomized to implantation of SES (78 patients) or BMS (74 patients) in 13 Italian centres. Clopidogrel therapy was prescribed for 6 months. The primary endpoint was in-segment minimal luminal diameter (MLD) at 8-month follow-up. Secondary clinical endpoints included death, myocardial infarction (MI), target lesion revascularization (TLR), and target vessel revascularization (TVR) at 24 months. Patients treated with SES showed, at in-segment analysis, a larger MLD (1.98 +/- 0.57 vs. 0.98 +/- 0.80 mm, P < 0.001), a lower late luminal loss (-0.06 +/- 0.49 vs. 1.11 +/- 0.79 mm, P < 0.001), and lower restenosis (9.8 vs. 67.7%, P < 0.001) and reocclusion (0 vs. 17%, P = 0.001) rates. At 24-month follow-up, patients in the SES group experienced fewer major adverse cardiac events (50.0 vs. 17.6%, P < 0.001) mainly due to a lower rate of both TLR (44.9 vs. 8.1%, P < 0.001) and TVR (44.9 vs. 14.9%, P < 0.001). In CTO, SES is markedly superior to BMS in terms of restenosis and reocclusion rate, and incidence of repeat revascularization at 24 months. Clinicaltrials.gov identifier: NCT00220558.

Three‐Dimensional Vessel Analyses Provide More Accurate Length Estimations than the Gold Standard QCA

The aim of this study was to compare lesion dimensions as determined by a three-dimensional quantitative coronary angiographic (QCA) system to that of a validated two-dimensional QCA system. In an era of drug-eluting stents, device sizing has become an important clinical application of online QCA. The CardiOp-B system integrates two standard angiographic projections to provide a three-dimensional reconstruction of the arterial segment of interest. Phase 1 - 47 stenoses from consecutive coronary angiograms were assessed in two projections with both systems providing two data sets for the CMS-Medis system and a single data set for CardiOp-B. Phase 2--a perspex phantom with a known lesion length, was analyzed at increasing degrees of foreshortening with acceptance criteria set at 5% from the absolute value. Phase 1 demonstrated an adequate correlation between the CardiOp-B and Medis systems when minimal luminal diameter was measured in the optimal view (1.32 +/- 0.47 mm vs 1.42 +/- 0.49 mm respectively; r = 0.82). A stronger correlation was noted when length was measured (25.27 +/- 10.76 mm and 21.32 +/- 8.08 mm, respectively; r = 0.95); however CardiOp-B provided a consistently longer length (P < 0.0001). On phantom length measurements the mean accuracy result for the CardiOp-B system was -1.3%. This compared favorably with the two-dimensional system where all measures performed at greater than 20 degrees of for shortening were beyond the 5% criteria from the known length. Three-dimensional QCA provides accurate and precise vessel diameter assessments. Length assessments are consistently longer than two-dimensional measures and are significantly less affected by foreshortened projections.

Does “late catch-up” exist in drug-eluting stents: Insights from a serial quantitative coronary angiography analysis of sirolimus versus paclitaxel-eluting stents

Recent studies have suggested the possibility of late catch-up after drug-eluting stent implantation. There are limited data on whether late catch-up exists in sirolimus-eluting stents (SESs) and paclitaxel-eluting stents (PESs). Consecutive patients were routinely recommended 2 serial angiographic follow-ups (at 6-9 and 18-24 months post-percutaneous coronary intervention). A serial quantitative coronary angiographic analysis was performed in lesions not receiving target lesion revascularization at first follow-up. Early luminal loss (LL) was defined as the difference in minimal luminal diameter between the first angiographic follow-up and immediate post-percutaneous coronary intervention, and delayed LL was defined as the difference in minimal luminal diameter between the second and first angiographic follow-up. Four hundred twelve lesions in the main cohort (PES 128, SES 284) and 47 lesions in the secondary hybrid cohort (PES 23, SES 24), which received serial angiographic follow-ups without target lesion revascularization, were included. In the main cohort, early LL was higher in PES compared with SES (0.56 vs 0.20 mm, P < .01), whereas delayed LL occurring after the first angiographic follow-up was higher in SES (0.10 vs 0.28 mm, P < .01), suggesting more prominent late catch-up in SES. Early LL showed better correlation with total LL (correlation coefficient 0.82 vs 0.30) in PES, whereas delayed LL showed better correlation with total LL (correlation coefficient 0.42 vs 0.91) in SES. Such observations were reproducible in the hybrid cohort, where both SES and PES were implanted at index procedure. Late catch-up occurs in both PES and SES with greater delayed late loss in SES. Our data suggest that the process of neointima formation after SES and PES implantation may follow a slightly different timeline.

True coronary bifurcation lesions: meta-analysis and review of literature

Percutaneous intervention of true coronary bifurcation lesions is challenging. Based on the results of randomized trials and registry data, the approach of stenting of main vessel only with balloon dilatation of the side branch has become the default approach for false bifurcation lesions except when a complication occurs or in cases of suboptimal result. However, the optimal stenting strategy for true coronary bifurcation lesions - to stent or not to stent the side branch - is still a matter of debate. The purpose of this study was, therefore, to compare the clinical and angiographic outcomes of the double stent technique (stenting of the main branch and side branch) over the single stent technique (stenting of main vessel only with balloon dilatation of the side branch) for treatment of true coronary bifurcation lesions, with drug-eluting stents (DES). Comparative studies published between January 2000 and February 2009 of the double stent technique vs. single stent technique with DES for true coronary bifurcations were identified using an electronic search and reviewed using a random effects model. The primary endpoints of our study were side-branch and main-branch restenoses, all-cause mortality, myocardial infarction (MI) and target lesion revascularization (TLR) at longest available follow-up. The secondary endpoints of our analysis were postprocedural minimal luminal diameter (MLD) of the side branch and main branch, follow-up MLD of side branch and main branch and stent thrombosis. Heterogeneity was assessed and sensitivity analysis was performed to test the robustness of the overall summary odds ratios (ORs). Five studies comprising 1145 patients (616 single stent and 529 double stent) were included in the analysis. Three studies were randomized comparisons between the two techniques for true coronary bifurcation lesions. Incomplete reporting of data in the primary studies was common. The lengths of clinical and angiographic follow-up ranged between 6 and 12 months and 6 and 7 months, respectively. Postprocedural MLD of the side branch was significantly smaller in the single stent group [standardized mean difference (SMD) -0.71, 95% CI -0.88 to -0.54, P < 0.000, I2 = 0%]. The odds of side-branch restenosis (OR 1.11, 95% CI 0.47-2.67, P = 0.81, I2 = 76%), main-branch restenois (OR 0.88, 95% CI 0.56-1.39, P = 0.58, I = 0%), all-cause mortality (OR 0.52, 95% CI 0.11-2.45, P = 0.41, I2 = 0%), MI (OR 0.92, 95% CI 0.34-2.54, P = 0.87, I = 49%) and TLR (OR 0.87, 95% CI 0.46-1.65, P = 0.68, I2 = 0%) were similar between the two groups. Postprocedural MLD of the main branch [standardized mean difference (SMD) -0.08, 95% CI -0.42 to -0.26, P < 0.65, I2 = 67%], follow-up MLD of side branch (SMD -0.19, 95% CI -0.40 to 0.01, P < 0.31, I2 = 15%) and main branch MLD (SMD 0.17, 95% CI -0.18 to 0.542, P < 0.35, I2 = 65%) were also similar between the two groups. In patients undergoing percutaneous coronary intervention (PCI) for true coronary bifurcations, there is no added advantage of stenting both branches as compared with a conventional one-stent strategy. The results, however, need to be interpreted considering the poor study methods and/or poor quality of reporting in publications. We propose to move forward and consider the conduct of more systematic, well-designed and scientific trials to investigate the treatment of true coronary bifurcation lesions.

Late Progression After Sirolimus-Eluting Stent Implantation for de Novo Lesions - Comparison With Bare Metal Stent Implantation -

In previous studies, the minimal luminal diameter (MLD) of lesions treated with a bare metal stent (BMS) was shown to improve from 6 months to 3 years. However, the long-term response to a sirolimus-eluting stent (SES) implantation remains unclear. To evaluate 6-month, 12-month and 3-year outcomes, clinical and angiographic follow-up data were analyzed for 367 consecutive patients (506 de novo lesions) who underwent successful SES implantation compared to follow-up data for 617 consecutive patients (802 de novo lesions) who underwent BMS implantation. Clinical follow-up information was obtained for 363 SES-treated patients (98.9%) and 581 BMS-treated patients (94.2%) at 1 year, and 334 SES-treated patients (91.0%) and 566 BMS-treated patients (91.7%) at 3 years. At 3 years, there were no significant differences in the cumulative cardiac death and myocardial infarction. Target lesion revascularization (TLR) rates were significantly higher in BMS-treated patients than in SES-treated patients. In BMS-treated patients, most TLR was performed within 450 days, however, after 450 days, the TLR rate was significantly lower than that for the SES-treated patients. In quantitative coronary angiographic data, among lesions that required no revascularization at the initial 12-month follow up, MLD increased significantly from the 12-month to the 3-year follow-up angiography in BMS-treated lesions. However, MLD decreased significantly in SES-treated lesions. From a 12-month follow-up to a 3-year follow-up, stenosis in BMS-treated lesions regressed, but stenosis in SES-treated lesions progressed. And late TLR was more frequently required in the SES-treated patients.

Modelo experimental de reestenose intrastent em artérias coronárias de suínos: efeito do implante de stent sobredimensionado

INTRODUÇÃO: Há múltiplos modelos experimentais em animais, entretanto o modelo suíno é o que apresenta características anatômicas e funcionais mais próximas às humanas. Assim sendo, este trabalho foi realizado com o objetivo de desenvolver e implementar um protocolo experimental de indução de hiperproliferação neointimal em suínos, visando à criação de técnicas de lesão vascular simulando a reestenose. MÉTODO: De agosto de 2006 a março de 2009, 69 suínos jovens da raça Large White foram submetidos a cinecoronariografia seguida de lesão vascular com implante de 102 stents sobredimensionados, guiados por ultrassom intracoronário. Em 28 dias foi realizado reestudo com nova cinecoronariografia e ultrassom intracoronário. RESULTADOS: O diâmetro luminal mínimo e a área luminal mínima imediatamente após o implante de stent no grupo stent sobredimensionado foram maiores em comparação ao grupo controle (3,5 ± 0,3 mm vs. 3 ± 0,2 mm, P < 0,0001 e 40,7 ± 0,3 mm² vs. 30,2 ± 0,2 mm², P < 0,0001). A taxa de reestenose binária no grupo submetido a implante de stent sobredimensionado foi de 92% (69/75 stents), enquanto no grupo controle foi de 12% (3/25 stents), com diferença estatisticamente significante (P < 0,0001). O volume de hiperplasia neointimal foi maior no grupo submetido a implante de stent sobredimensionado, em comparação ao grupo controle (5,9 ± 0,8 mm³/mm de stent vs. 1,8 ± 0,7 mm³/mm de stent; P < 0,0001). CONCLUSÃO: O modelo experimental proposto de indução de proliferação neointimal em suínos é eficaz na indução de hiperplasia intrastent, portanto pode ser utilizado tanto para o estudo dos mecanismos fisiopatológicos da reestenose intrastent quanto para aplicações terapêuticas, como testes de novos fármacos, novos dispositivos e novos stents farmacológicos para prevenção e tratamento da reestenose intrastent.

Impact of Stent Design on In-Stent Stenosis in a Rabbit Iliac Artery Model

The purpose of this study was to evaluate the impact of stent design on in-stent stenosis in rabbit iliac arteries. Four different types of stent were implanted in rabbit iliac arteries, being different in stent design (crown or wave) and strut thickness (50 or 100 microm). Ten stents of each type were implanted. Each animal received one crown and one wave stent with the same strut thickness. Follow-up was either 12 weeks (n = 10 rabbits) or 24 weeks (n = 10 rabbits). Primary study end points were angiographic and microscopic in-stent stenosis. Secondary study end points were vessel injury, vascular inflammation, and stent endothelialization. Average stent diameter, relative stent overdilation, average and minimal luminal diameter, and relative average and maximum luminal loss were not significantly different. However, a trend to higher relative stent overdilation was recognized in crown stents compared to wave stents. A trend toward higher average and minimal luminal diameter and lower relative average and maximum luminal loss was recognized in crown stents compared to wave stents with a strut thickness of 100 microm. Neointimal height, relative luminal area stenosis, injury score, inflammation score, and endothelialization score were not significantly different. However, a trend toward higher neointimal height was recognized in crown stents compared to wave stents with a strut thickness of 50 microm and a follow-up of 24 weeks. In conclusion, in this study, crown stents seem to trigger neointima. However, the optimized radial force might equalize the theoretically higher tendency for restenosis in crown stents. In this context, also more favorable positive remodeling in crown stents could be important.

Late loss in a disappearing frame of reference: is it still applicable to fully absorbable scaffolds?

Bioabsorbable stents are an important advancement in stent technology providing a temporary scaffold and may be augmented with drugs to suppress neointimal hyperplasia.Though changes are being made to the design of the stents, to ensure similar rates of acute recoil, residual stenosis postintervention remains higher when compared to contemporary durable stents. In order to achieve similar clinical restenosis outcomes, bioabsorbable stents must first show similar MLD or percent diameter stenosis at follow-up to drug-eluting stents.While variable different acute gain and post-procedure MLD for bioabsorbable stents make late lumen loss a poor marker for restenosis probability by itself, late loss can be an informative metric for neointimal hyperplasia over time in these stents.Metrics which are independent of acute gain such as minimal luminal diameter and percentage diameter stenosis may make better surrogates for restenosis (Table 1). Moreover, remodelling over time requires measurement of the vessel and lumen diameters in later follow-up. Since the natural history of the vascular response to bioabsorbable stents is in its infancy of investigation, follow-up of these stents at least beyond the duration of polymer is prudent. Finally, given a disappearing frame of reference, both careful angiographic and intravascular ultrasound assessments are helpful to delineate the varying contributions of recoil, remodelling, and neointima formation.

Paclitaxel-induced Arterial Wall Toxicity and Inflammation: Part 2—Long-term Tissue Response in a Minipig Model

In part 1 of the present study, the authors demonstrated that coronary paclitaxel uptake from drug eluting stents (DESs) was not dependent on exposure time and dose. In this second part, the effect of the different paclitaxel dose densities on long-term biologic behavior was evaluated. In 40 minipigs, (with 4- and 12-week follow-up), identical stents with the same three paclitaxel dose densities as in part 1 were implanted in the right coronary artery. Minipigs implanted with Polyzene-F nanocoated stents served as the control group. Quantitative angiography measuring average luminal diameter (from three in-stent reference points), minimal luminal diameter (from the point of maximum in-stent stenosis), average late loss, maximum late loss, and binary stenosis rate was performed, as was microscopy to determine neointimal thickening, injury score, and inflammation. All three DESs were associated with a high average late loss, binary stenosis rate, and neointimal thickening, without significant differences. Drug-free stents had significantly less late in-stent stenosis: there was an average late loss of 0.3 mm +/- 0.3 in drug-free stents versus 0.8 mm +/- 0.2 in intermediate-dose stents and 1.5 mm +/- 0.6 in high-dose stents (P = .04). DES-associated inflammation was high in all DESs and six times higher as in the drug-free stents (Kornowski scores of 0.2 +/- 0.1 in drug-free stents, 1.3 +/- 0.9 in low-dose stents, 1.7 +/- 0.8 in intermediate-dose stents, and 1.3 +/- 1.0 in high-dose stents; P = .04). It worsened with time in all DESs, as did late in-stent stenosis. The extensive and long-term retention of paclitaxel even in a low-dose formulation, at least according to the present labeling of DESs, might be associated with negative long-term results with regard to inflammation and late in-stent stenosis.

Accuracy of Computed Tomographic Angiography for Stenosis Quantification Using Quantitative Coronary Angiography or Intravascular Ultrasound as the Gold Standard

Computed tomographic angiography (CTA) is considered to have limited accuracy for quantifying exact percent diameter stenosis in coronary arteries. However, most studies evaluating CTA use quantitative coronary angiography (QCA) as the gold standard, a technique with its own limitations. We sought to determine whether CTA measurements of stenosis severity correlate better with intravascular ultrasound (IVUS) than with QCA. Luminal dimensions of 67 de novo coronary lesions were measured by CTA, IVUS, and QCA. IVUS was performed when lesion severity by angiography was equivocal. Mean percent diameter stenosis by QCA was 51 +/- 9.8% and mean IVUS minimal luminal area was 3.8 +/- 1.8 mm(2). There was a moderate correlation between CTA minimal luminal area and IVUS minimal luminal area (r(2) = 0.41, p <0.001), but no relation between CTA and QCA measurements of minimal luminal diameter (r(2) = 0.01, p = 0.57) or diameter stenosis (r(2) = 0.02, p = 0.31). There was also no relation between IVUS minimal luminal area and QCA diameter stenosis (r(2) = 0.01, p = 0.50). When lesions with moderate or severe calcification were excluded, the correlation between CTA minimal luminal area and IVUS minimal luminal area was good (r(2) = 0.68, p <0.001). In conclusion, in this cohort of patients with intermediate-grade lesions on cardiac catheterization, absolute measurements of stenosis severity on CTA correlated with IVUS but not with QCA. Our findings suggest that limitations of quantitative coronary angiography as a gold standard need to be considered in studies evaluating the accuracy of coronary CTA.

Carotid Duplex Ultrasound Velocity Measurements Versus Intravascular Ultrasound in Detecting Carotid In-Stent Restenosis

Duplex ultrasonography criteria for assessing the severity of carotid artery (CA) in-stent restenosis are not well established. We analyzed 39 patients (40 CAs) who underwent CA stenting with baseline and 6-month follow-up carotid duplex ultrasonography and intravascular ultrasound. Intravascular ultrasound measurements included minimum luminal diameter, percent diameter, and lumen area stenosis. Duplex ultrasonography measurements included peak systolic velocity (PSV), percentage change in PSV, end-diastolic velocity (EDV), and internal-to-common CA PSV ratio (ICA/CCA). Receiver operating characteristic curves assessed each duplex measurement to detect >or=50% diameter, >or=75% lumen area stenosis, and minimum luminal diameter <3 mm at follow-up. At 6-month intravascular ultrasound follow-up, >or=50% diameter and >or=75% lumen area CA in-stent restenosis occurred in 20% and 25%, respectively; minimum luminal diameter <3 cm occurred in 48%. Area under receiver operating characteristic curves for PSV, EDV, and ICA/CCA were 0.85, 0.96, and 0.89 for >or=50% diameter stenosis and 0.89, 0.93, and 0.88 for >or=75% lumen area stenosis, respectively. Optimal PSV, EDV, and ICA/CCA criteria to detect >or=50% diameter and >or=75% lumen area CA in-stent restenosis were greater compared with those for native CA. A >98% increase in PSV had the highest specificity, whereas the combination of EDV >41 cm/s and ICA/CCA >2 had the highest sensitivity in detecting >or=75% lumen area CA in-stent restenosis. PSV, EDV, and ICA/CCA PSV ratio were good discriminators for detecting significant diameter and lumen area greater compared with those for native CA. The combination of duplex velocity criteria increases diagnostic accuracy.

Two-Year Clinical, Angiographic, and Intravascular Ultrasound Follow-Up of the XIENCE V Everolimus-Eluting Stent in the Treatment of Patients With De Novo Native Coronary Artery Lesions: The SPIRIT II Trial

Two-Year Clinical, Angiographic, and Intravascular Ultrasound Follow-Up of the XIENCE V Everolimus-Eluting Stent in the Treatment of Patients With De Novo Native Coronary Artery Lesions: The SPIRIT II Trial

Triple antiplatelet therapy vs. dual antiplatelet therapy in patients undergoing percutaneous coronary intervention: an evidence‐based approach to answering a clinical query

Outcomes of patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DES) and bare metal stents (BMS) have not been evaluated separately for specific dual and triple antiplatelet agent use. The purpose of this meta-analysis was to determine whether triple antiplatelet therapy (combination of clopidogrel, aspirin and cilostazol) has any advantage in efficacy compared with standard dual antiplatelet therapy (aspirin and clopidogrel) in patients undergoing PCI. Electronic and printed sources were searched till May 2008 for randomized controlled clinical trials (RCTs) of cilostazol in combination with aspirin and clopidogrel. Pooled weighted mean difference (WMD) and pooled odds ratio (OR) with 95% confidence intervals (CIs) were calculated. A total of four RCTs including 1457 patients with a median follow-up period of 6-9 months were included in the analysis. The rates of major adverse cardiac and/or cerebrovascular events (MACE/MACCE), stent thrombosis and bleeding were not significantly different between triple and dual antiplatelet therapy groups. Pooled analysis showed that cilostazol was associated with significantly decreased incidence of in segment restenosis (ISR) (OR 0.51, 95% CI 0.38, 0.68; P < 0.00001), increased minimum luminal diameter (MLD) (WMD 0.16, 95% CI 0.10, 0.22; P < 0.00001) for both DES and BMS and also individually. However, the rates of target vessel revascularization (OR 0.45, 95% CI 0.25, 0.83; P = 0.01 and late lumen loss (pooled WMD 0.14, 95% CI 0.2, 0.07; P = 0.001) were decreased significantly only in the DES group receiving triple therapy. Cilostazol appears to be effective in reducing the rates of ISR without any significant benefit for MACE/MACCE.

Comparison between Three‐Dimensional Angiographic Reconstruction and Intravascular Ultrasound Imaging for the Measurement of Cross‐Sectional Luminal Dimensions in Intermediate Coronary Lesions

Intravascular ultrasound (IVUS) has enabled the measurement of minimal luminal area of coronary stenoses. We evaluated the hypothesis that angiographic three-dimensional reconstruction of luminal dimensions may be able to provide similar measurements to IVUS in intermediate coronary lesions. We retrospectively enrolled patients undergoing invasive coronary angiography and IVUS for the assessment of angiographically intermediate coronary lesions (50-70%) at a high-volume tertiary care hospital between July 1, 2006, and May 20, 2008. IVUS (Boston Scientific, Natick Massachusetts, USA) minimal cross-sectional area (CSA) and minimal luminal diameters (MLD) were compared with the measurements obtained using a sophisticated three-dimensional angiographic reconstruction software (CardiOP-B, Paieon, Inc., Rosh Ha'ayin, Israel), with orthogonal angiographic views used to reconstruct and calculate lesion dimensions. Data were obtained from 34 patients with 35 lesions. The lesions were assessed in the left main (n = 2), left anterior descending artery (n = 15), left circumflex/marginal artery (n = 7), and right coronary artery (n = 11). Using IVUS, the mean minimal CSA was 3.78 +/- 1.60 mm(2), and MLD was 1.88 +/- 0.43 mm. Three-dimensional reconstruction measurements of minimal CSA (3.42 +/- 1.66 mm(2)) highly correlated in a linear fashion with the measurements by IVUS (R = 0.88, P < 0.0001). A three-dimensional angiographic measurement of coronary minimal CSA is highly correlated with the measurements using IVUS. This new software technology may be a promising imaging modality to measure CSAs in coronary lesions.

Prevalence of significant peripheral artery disease in patients evaluated for percutaneous aortic valve insertion: Preprocedural assessment with multidetector computed tomography

Percutaneous aortic valve insertion is an emerging treatment option for selected patients with severe aortic stenosis and may be done from a transfemoral or transapical approach. Concomitant atherosclerotic peripheral artery disease limits transfemoral access. We evaluated the potential role of multidetector computed tomography in preoperative assessment of vascular anatomy. Consecutive patients with severe aortic stenosis were included. Contrast-enhanced computed tomographic angiography of the thoracic and abdominal aorta and iliofemoral arteries was performed. Criteria of unfavorable iliofemoral anatomy were defined as a minimal luminal diameter of the common iliac, external iliac, or common femoral arteries of less than 8 mm, presence of greater than 60% circumferential calcification at the external-internal iliac bifurcation, and severe angulation between the common and external iliac arteries (< 90 degrees ). The prevalence of these criteria was evaluated and infrarenal aortic and iliofemoral arterial anatomy was compared in the groups with and without peripheral artery disease for any of these criteria. One hundred patients (79 +/- 9 years, 59% male) were included. A total of 35 (35%) patients had at least one criterion of unsuitable iliofemoral anatomy, including 27 patients with small minimal luminal diameter (<8 mm), 12 patients with severe circumferential calcification at the iliac bifurcation (>60%), and 4 with severe angulation of the iliac arteries (<90 degrees ). Significant atherosclerotic peripheral artery disease is common in the high-risk patient population currently evaluated for percutaneous aortic valve insertion. Computed tomography allows identification of patients with iliofemoral anatomy unfavorable for the transfemoral approach to percutaneous aortic valve insertion.

Baseline Fractional Flow Reserve and Stent Diameter Predict Optimal Post-Stent Fractional Flow Reserve and Major Adverse Cardiac Events After Bare-Metal Stent Deployment

We sought to identify baseline clinical, angiographic, and hemodynamic variables associated with optimal bare-metal stent (BMS) deployment, allowing selection of patients for treatment with BMS. Patients with fractional flow reserve (FFR) >0.90 after BMS have low (<6%) major adverse cardiac event rates (MACE). We hypothesized that baseline variables can predict post-stent FFR >0.90 and MACE after BMS. In 586 patients from the multicenter post-BMS FFR registry, we developed multivariable logistic regression models to identify clinical, angiographic, and hemodynamic variables associated with post-stent FFR >or=0.90 and 6-month MACE. After adjusting for potential confounders, baseline FFR (odds ratio [OR]: 5.0) and stent diameter (OR: 2.5 per millimeter) were predictive of post-stent FFR >0.90. Lower FFR (OR: 7.8); smaller stent diameter (OR: 3.7 per millimeter); longer stent length (OR: 1.0 per millimeter); and larger minimal luminal diameter (OR: 2.2 per millimeter) were predictors of MACE. In patients receiving 3-mm diameter stents, baseline FFR >0.70 yielded significantly higher likelihood of achieving post-stent FFR >0.90 than baseline FFR <or=0.70 (77% vs. 63%, p < 0.05); and in patients receiving <3-mm diameter stents, baseline FFR <0.50 was associated with higher MACE than FFR 0.50 to 0.70, and FFR >0.70 (40% vs. 15% vs. 13%, p < 0.05). In patients receiving BMS, baseline FFR and stent diameter are predictors of post-stent FFR >0.90; and baseline FFR, stent diameter, stent length, and minimal luminal diameter are predictors of MACE. These variables may allow selection of patients who will have excellent results with BMS.

Severity of Coronary Arterial Stenoses Responsible for Acute Coronary Syndromes

Acute myocardial infarctions were generally believed to result from plaque rupture and thrombosis at the site of a "mild to moderate" coronary stenosis. To assess the severity of coronary stenoses that predisposed to acute coronary syndrome, the 317 patients prospectively included were (1) 102 patients with acute ST-elevation myocardial infarction (STEMI) referred for primary percutaneous coronary intervention (PCI), (2) 135 patients with non-STEMI or unstable angina pectoris (UAP) referred for semiurgent PCI, and (3) 80 patients with stable angina pectoris (SAP) admitted for elective PCI. Patients with STEMI were included if thrombus aspiration could restore normal antegrade coronary blood flow. After aspiration (but before PCI), a high-quality angiogram was obtained and the reference diameter, minimal luminal diameter, and percentage of diameter stenosis of the culprit lesion were quantified. In patients with non-STEMI/UAP and SAP, aspiration was not performed. Average diameter of stenosis was similar in patients with STEMI and those with SAP (66 +/- 12% vs 65 +/- 10%, respectively; p = NS), but was slightly larger in patients with non-STEMI/UAP (71 +/- 12%; p <0.05 vs both STEMI and SAP). In patients with STEMI, only 11% of culprit stenoses were found to have diameter stenosis <50% after removal of the thrombus. In conclusion, most STEMIs occurred at the site of severe coronary stenosis. Diameter stenosis severity was <50% in a minority of cases.