Computed tomographic angiography in coronary artery disease.

Coronary computed tomographic angiography (CCTA) is becoming the first-line investigation for establishing the presence of coronary artery disease and, with fractional flow reserve (FFRCT), its haemodynamic significance. In patients without significant epicardial obstruction, its role is either to rule out atherosclerosis or to detect subclinical plaque that should be monitored for plaque progression/regression following prevention therapy and provide risk classification. Ischaemic non-obstructive coronary arteries are also expected to be assessed by non-invasive imaging, including CCTA. In patients with significant epicardial obstruction, CCTA can assist in planning revascularisation by determining the disease complexity, vessel size, lesion length and tissue composition of the atherosclerotic plaque, as well as the best fluoroscopic viewing angle; it may also help in selecting adjunctive percutaneous devices (e.g., rotational atherectomy) and in determining the best landing zone for stents or bypass grafts.

Estudio comparativo de la cobertura neointimal entre los stents con recubrimiento de titanio-óxido nítrico y los liberadores de everolimus en el sindrome coronario agudo / Comparative study of neointimal coverage between titanium-nitric oxide-coated and everolimus-eluting stents in acute coronary syndromes

Introducción y objetivos Evaluar mediante tomografía de coherencia óptica (OCT) el proceso de cicatrización neointimal tras el implante de stents de cromo cobalto con recubrimiento de titanio-óxido nítrico (TiNO) y de stents de platino-cromo liberadores de everolimus (SLE) con polímero biodegradable en pacientes con síndrome coronario agudo. Métodos Los pacientes fueron aleatorizados (1:1) para recibir el stent TiNO o SLE. Se obtuvieron imágenes de OCT a los 30 días (cohorte A, n=52) y a los 6 meses (cohorte B, n=30) de seguimiento. El objetivo primario del estudio fue el porcentaje de struts no cubiertos por paciente. Resultados En la cohorte A, el porcentaje de struts no cubiertos fue menor con los stents TiNO que con los SLE (3,2% frente a 19,6%, p <0,001). El porcentaje de struts mal apuestos fue del 0,4% en el grupo TiNO y del 2,1% en el grupo SLE (p <0,001). En la cohorte B, el porcentaje de struts no cubiertos también fue menor con los stents TiNO (0,0% frente a 8,7% (p <0,001). El porcentaje de struts mal apuestos fue del 0% en el grupo de stent TiNO y del 0,3% en el grupo de SLE (p=0,008). A ninguno de los pacientes se les tuvo que repetir la revascularización durante los 6 meses de seguimiento. Conclusiones Tras una intervención percutánea por síndrome coronario agudo, el implante de un stent TiNO se asoció a un menor porcentaje de struts no cubiertos y mal apuestos por paciente, en comparación con el SLE, en un seguimiento temprano y a medio plazo (AU)

Introduction and objectives To evaluate by optical coherence tomography neointimal healing response after implantation of cobalt-chromium-based titanium-nitride-oxide-coated (TiNO) stents and platinum-chromium-based biodegradable-polymer-coated everolimus-eluting stents (EES) in patients with acute coronary syndrome. Methods Patients were randomized (1:1) to receive either a TiNO-stent or EES. Optical coherence tomography images were obtained at 30-day (cohort A, n = 52) and 6-month (cohort B, n = 30) follow-up. The primary endpoint was the percentage of uncovered struts per patient. Results In cohort A, the percentage of uncovered struts was lower with TiNO-stents vs EES (3.2% vs 19.6%, P <.001). The percentage of malapposed struts was 0.4% in the TiNO-group and 2.1% in the EES group (P <.001). In cohort B, the percentage of uncovered struts was also lower with TiNO-stents (0.0% vs 8.7% (P <.001). The percentage of malapposed struts was 0% in the TiNO-stent group and 0.3% in the EES group (P=.008). None of the patients had repeat revascularization during the 6 months of follow-up. Conclusions Following percutaneous intervention for acute coronary syndrome, TiNO stent implantation was associated with a lower percentage of uncovered and malapposed struts per patient, compared with EES, at early and mid-term follow-up (AU)

Association Among Local Hemodynamic Parameters Derived From CT Angiography and Their Comparable Implications in Development of Acute Coronary Syndrome.

Background: Association among local hemodynamic parameters and their implications in development of acute coronary syndrome (ACS) have not been fully investigated. Methods: A total of 216 lesions in ACS patients undergoing coronary CT angiography (CCTA) before 1-24 months from ACS event were analyzed. High-risk plaque on CCTA was defined as a plaque with ≥2 of low-attenuation plaque, positive remodeling, spotty calcification, and napkin-ring sign. With the use of computational fluid dynamics analysis, fractional flow reserve (FFR) derived from CCTA (FFRCT) and local hemodynamic parameters including wall shear stress (WSS), axial plaque stress (APS), pressure gradient (PG) across the lesion, and delta FFRCT across the lesion (ΔFFRCT) were obtained. The association among local hemodynamics and their discrimination ability for culprit lesions from non-culprit lesions were compared. Results: A total of 66 culprit lesions for later ACS and 150 non-culprit lesions were identified. WSS, APS, PG, and ΔFFRCT were strongly correlated with each other (all p < 0.001). This association was persistent in all lesion subtypes according to a vessel, lesion location, anatomical severity, high-risk plaque, or FFRCT ≤ 0.80. In discrimination of culprit lesions causing ACS from non-culprit lesions, WSS, PG, APS, and ΔFFRCT were independent predictors after adjustment for lesion characteristics, high-risk plaque, and FFRCT ≤ 0.80; and all local hemodynamic parameters significantly improved the predictive value for culprit lesions of high-risk plaque and FFRCT ≤ 0.80 (all p < 0.05). The risk prediction model for culprit lesions with FFRCT ≤ 0.80, high-risk plaque, and ΔFFRCT had a similar or superior discrimination ability to that with FFRCT ≤ 0.80, high-risk plaque, and WSS, APS, or PG; and the addition of WSS, APS, or PG into ΔFFRCT did not improve the model performance. Conclusions: Local hemodynamic indices were significantly intercorrelated, and all indices similarly provided additive and independent predictive values for ACS risk over high-risk plaque and impaired FFRCT.

DynamX Bioadaptor, a novel "uncaging" platform for coronary artery revascularization: final 36-month clinical results

BACKGROUND Compared with bare-metal stents, drug-eluting stents (DES) reduce major adverse cardiac events (MACE) in the first year after percutaneous coronary intervention (PCI) but still have an ongoing 2% to 3% annual event rate reaching 20% at 5 years and 40% to 50% at 10 years. The DynamX Novolimus-Eluting Coronary Bio adaptor System is a 71-mm, cobalt-chromium platform with a novel "uncaging" mechanism of circumferential rings that maintains the axial links between the rings following uncaging. Conventional metallic DES "cage" the coronary artery, inhibiting positive adaptive remodeling and vasomotion and causing geometric distortion. These factors likely contribute to the persistent annual MACE rate after PCI. The DynamX Bioadaptor combines the acute performance of contemporary DES and unique benefits of arterial "uncaging" beyond 6 months, allowing positive adaptive remodeling, restoring compli ance, and allowing treated vessels to return toward native vessel geometry. METHODS In this study the DynamX Bioadaptor was available in di ameters of 2.5 to 3.5 mm and lengths of 14 to 28 mm. This mechanistic clinical study enrolled 50 patients (mean age 66.3 8.8 years) at 5 centers in Belgium and Italy. Multiple endpoints including target lesion failure were assessed, with clinical follow-up through 3 years. Multimodality imaging endpoint analyses using quantitative coronary angiography, intravascular ultrasound, and optical coherence to mography were performed at baseline and at 9 or 12 months in separate subgroups. RESULTS Mean area changes for Bioadaptor, reference vessel and lumen as well as percentage neointimal volume and neointimal thickness observed at 9 and 12 months demonstrate Bioadaptor per formance and ability to preserve positive adaptive remodeling. Through 24 months, target lesion failure events were observed in 4.3% of patients, which is in line with contemporary DES clinical outcomes. Detailed imaging and final clinical data through 36 months will be presented. CONCLUSION The DynamX Bioadaptor demonstrated performance attributes of contemporary metallic DES with the unique capacity to restore positive adaptive remodeling through vessel "uncaging." Final clinical data through 36 months demonstrate longer term safety and efficacy.

Platelet reactivity and coronary microvascular impairment after percutaneous revascularization in stable patients receiving clopidogrel or prasugrel.

BACKGROUND AND AIMS: Increased platelet reactivity (PR) associated with variable degree of coronary microvascular impairment has been reported in patients on clopidogrel after elective percutaneous coronary intervention (PCI). Prasugrel provides more potent platelet inhibition than clopidogrel, though it is unknown whether it might also prevent PCI-related platelet activation. In stable patients undergoing elective PCI, we compared: (1) the effects of prasugrel vs. clopidogrel on peri-procedural variations of PR and (2) the correlation of platelet inhibition potency with PCI-induced coronary microvascular impairment. METHODS: Forty thienopyridine-naive patients were randomly assigned to a loading dose of either prasugrel 60 mg (n = 20) or clopidogrel 600 mg (n = 20) at least 12 h before PCI. At the time of PCI, we assessed adenosine diphosphate (ADP)-induced PR with the Multiplate Analyzer, and the pressure-derived index of microvascular resistance (IMR) in the treated coronary, both at baseline and post-procedure. RESULTS: ADP-induced PR was significantly lower in the prasugrel compared with clopidogrel group both at baseline (16.0 ±â€¯8.7 vs. 33.9 ±â€¯18.0 aggregation units [AU], p < 0.001) and post-procedure (16.2 ±â€¯9.0 vs. 39.0 ±â€¯18.6 AU, p < 0.001). A significant peri-procedural increase in PR was observed in the clopidogrel group (p = 0.008), but not in the prasugrel group (p = 0.822). A significant correlation was found between IMR and PR both at baseline (r = 0.458, p = 0.003) and post-PCI (r = 0.487, p = 0.001). CONCLUSIONS: A loading dose of prasugrel compared with clopidogrel is able to attenuate PCI-related increase in PR in patients with stable CAD undergoing PCI, which might contribute to the beneficial effect of this drug on peri-procedural coronary microvascular function.

Economic evaluation of fractional flow reserve-guided percutaneous coronary intervention in patients with multivessel disease.

BACKGROUND: The Fractional Flow Reserve Versus Angiography for Multivessel Evaluation (FAME) study demonstrated significantly improved health outcomes at 1 year in patients randomized to multivessel percutaneous coronary intervention guided by fractional flow reserve (FFR) compared with percutaneous coronary intervention guided by angiography alone. The economic impact of routine measurement of FFR in this setting is not known. METHODS AND RESULTS: In this study, 1005 patients were randomly assigned to FFR-guided or angiography-guided percutaneous coronary intervention and followed up for 1 year. A prospective cost-utility analysis comparing costs and quality-adjusted life-years was performed with a time horizon of 1 year. Quality-adjusted life-years were calculated with the use of utilities determined by the EuroQuol 5 dimension health survey with US weights. Direct medical costs included those of the index procedure and hospitalization and costs for major adverse cardiac events during follow-up. Confidence intervals for both quality-adjusted life-years and costs were estimated by the bootstrap percentile method. Major adverse cardiac events at 1 year occurred in 13.2% of those in the FFR-guided arm and 18.3% of those in the angiography-guided arm (P=0.02). Quality-adjusted life-years were slightly greater in the FFR-guided arm (0.853 versus 0.838; P=0.2). Mean overall costs at 1 year were significantly less in the FFR-guided arm ($14 315 versus $16 700; P<0.001). Bootstrap simulation indicated that the FFR-guided strategy was cost-saving in 90.74% and cost-effective at a threshold of US $50 000 per quality-adjusted life-years in 99.96%. Sensitivity analyses demonstrated robust results. CONCLUSION: Economic evaluation of the FAME study reveals that FFR-guided percutaneous coronary intervention in patients with multivessel coronary disease is one of those rare situations in which a new technology not only improves outcomes but also saves resources. Clinical Trial Registration- URL: http://ClinicalTrials.gov. Unique identifier: NCT00267774.

Randomized comparison of primary stenting and provisional balloon angioplasty guided by flow velocity measurement

Background—Coronary stenting improves outcomes compared with balloon angioplasty, but it is costly and may haveother disadvantages. Limiting stent use to patients with a suboptimal result after angioplasty (provisional angioplasty) may be as effective and less expensive.Methods and Results—To analyze the cost-effectiveness of provisional angioplasty, patients scheduled for single-vessel angioplasty were first randomized to receive primary stenting (97 patients) or balloon angioplasty guided by Doppler flow velocity and angiography (523 patients). Patients in the latter group were further randomized after optimization to either additional stenting or termination of the procedure to further investigate what is “optimal.” An optimal result wasdefined as a flow reserve 2.5 and a diameter tenosis 36%. Bailout stenting was needed in 129 patients (25%) who were randomized to balloon angioplasty, and an optimal result was obtained in 184 of the 523 patients (35%). There was no significant difference in event-free survival at 1 year between primary stenting (86.6%) and provisional angioplasty (85.6%). Costs after 1 year were significantly higher for provisional angioplasty (EUR 6573 versus EUR 5885; (P50.014). Results after the second randomization showed that stenting was also more effective after optimal balloon angioplasty (1-year event free survival, 93.5% versus 84.1%; P50.066). Conclusions—After 1 year of follow-up, provisional angioplasty was more expensive and without clinical benefit. The beneficial value of stenting is not limited to patients with a suboptimal result after balloon angioplasty.