Determinants of operator and patient radiation exposure during cardiac catheterization: Insights from the RadiCure (RADIation reduction during cardiac catheterization using real-timE monitoring) trial.

BACKGROUND: In the RadiCure study 505 catheterization procedures were 1:1 randomized to use or no use of real-time radiation monitoring. Use of the Bleeper Sv monitor resulted in a significant reduction in operator radiation exposure. METHODS: We examined the association between several baseline and procedural parameters with operator and patient radiation exposure using univariable and multivariable analysis in the 505 patients that were enrolled in RadiCure. All baseline demographic and procedure characteristics recorded were included in the univariable analysis. RESULTS: Median fluoroscopy time was 6.2 (2.5-12.5) minutes, median patient air kerma dose was 0.908 (0.602-1.636) Gray and median first operator exposure was 10 (5-22) µSv. For analysis purposes, the 505 procedures were dichotomized based on the median operator exposure (10 µSv) and median patient radiation dose (0.908 Gray). On multivariable analysis, factors associated with high (above median or >10 µSv) first operator radiation exposure included radial access (odds ratio [OR] 5.44, 95% Confidence Interval [CI] 2.88-10.76), chronic total occlusion (CTO) intervention (OR 12.78, 95% CI 4.42-43.60), real-time radiation monitoring (OR 0.42, 95% CI 0.26-0.66), and use of a radioabsorbent drape (OR 0.53, 95% CI 0.28-0.96). High patient radiation dose (above median or >0.908 Gray) was associated with body mass index>30 kg/m2 (OR 3.22, 95% CI 1.99-5.29), prior MI (OR 2.26, 95% CI 1.29-4.04), prior cerebrovascular disease (OR 0.34, 95% CI 0.15-0.75), hypertension (OR 2.40, 95% CI 1.05-5.82), prior coronary artery bypass graft surgery (OR 2.46, 95% CI 1.40-4.39) and CTO intervention (OR 12.93, 95% CI 3.28-87.31), but was not associated with real-time radiation monitoring and use of a radioabsorbent drape. CONCLUSIONS: Several clinical and procedural factors are associated with higher patient and operator radiation exposure. Real-time radiation monitoring and use of disposable radiation shields were associated with lower operator, but not patient, radiation dose. © 2015 Wiley Periodicals, Inc.

Effect of a real-time radiation monitoring device on operator radiation exposure during cardiac catheterization: the radiation reduction during cardiac catheterization using real-time monitoring study.

BACKGROUND: The Radiation Reduction During Cardiac Catheterization Using Real-Time Monitoring study sought to examine the effect of a radiation detection device that provides real-time operator dose reporting through auditory feedback (Bleeper Sv; Vertec Scientific Ltd; Berkshire, UK) on patient dose and operator exposure during cardiac catheterization. METHODS AND RESULTS: Between January 2012 and May 2014, 505 patients undergoing coronary angiography, percutaneous coronary intervention, or both were randomized to use (n=253) or no use (n=252) of the Bleeper Sv radiation monitor. Operator radiation exposure was measured in both groups using a second, silent radiation exposure monitoring device. Mean patient age was 65±8 years, most patients (99%) were men, and 30% had prior coronary artery bypass graft surgery. Baseline clinical characteristics were similar in the 2 study groups. Radial access was used in 18% and chronic total occlusion percutaneous coronary intervention constituted 7% of the total procedures. Median procedure time was 17 (12-27) minutes for diagnostic angiography, 42 (28-70) minutes for percutaneous coronary intervention, and 27 (14-51) minutes in the overall study population, with similar distribution between the study groups. First (9 [4-17] versus 14 [7-25] µSv; P<0.001) and second (5 [2-10] versus 7 [4-14] µSv; P<0.001) operator radiation exposure was significantly lower in the Bleeper Sv group. Use of the device did not result in a significant reduction in patient radiation dose. The effect of the Bleeper Sv device on operator radiation exposure was consistent among various study subgroups. CONCLUSIONS: Use of a real-time radiation monitoring device that provides auditory feedback can significantly reduce operator radiation exposure during cardiac catheterization. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01510353.

Association of coronary lipid core plaque with intrastent thrombus formation: a near-infrared spectroscopy and optical coherence tomography study.

BACKGROUND: Optical coherence tomography (OCT) and near-infrared spectroscopy (NIRS) allow assessment of the anatomy (OCT) and composition (NIRS) of coronary lesions. We sought to examine the association between pre-stenting lipid core plaque (LCP), as assessed by NIRS and post-stenting thrombus formation, as assessed by OCT. METHODS: We reviewed the angiograms of nine patients who underwent coronary stenting in association with NIRS and OCT imaging. A large LCP by NIRS was defined as at least three 2-mm yellow blocks on the NIRS block chemogram with >200° angular extent. Intracoronary thrombus was defined as a mass of medium reflectivity protruding into the vessel lumen, discontinuous from the surface of the vessel wall. RESULTS: Mean age was 67 ± 7 years, and all patients were men, presenting with stable angina (56%), unstable angina (11%), or acute myocardial infarction (33%). The mean vessel lipid core burden index (LCBI) was 120 ± 45, and the mean highest 6-mm LCBI was 386 ± 190. Three patients had a large LCP and two of them (66%) developed intrastent thrombus after stent implantation compared to none of six patients without large LCPs (0%, P = 0.02). The thrombus resolved after intracoronary glycoprotein IIb/IIIa administration and balloon postdilation. Postprocedural myocardial infarction occurred in 33% versus 17% of patients with and without large LCP, respectively (P = 0.57). CONCLUSION: Stenting of large LCPs may be associated with intrastent thrombus formation, suggesting that more intensive anticoagulant and/or antiplatelet therapy may be beneficial in such lesions. © 2012 Wiley Periodicals, Inc.

Optical coherence tomography evaluation of drug-eluting stents: a systematic review.

AIMS: We performed a systematic review of studies reporting stent strut coverage and malapposition post implantation of different drug-eluting stent (DES), as assessed by optical coherence tomography (OCT). METHODS: A review of publications and online databases in May 2011 retrieved 33 published studies reporting stent strut coverage and malapposition post-DES implantation using OCT: 24 for sirolimus-eluting stents (SES), 13 for paclitaxel-eluting stents (PES), 10 for zotarolimus-eluting stents (ZES), and two for everolimus-eluting stents (EES). The follow-up duration ranged from 3 months to 4 years. Stent strut coverage and malapposition were compared between DES at various time intervals post implantation. RESULTS: Significant differences in stent strut coverage and malapposition exist between various DES. The SES had the highest frequency of uncovered struts at 3, 6, 9, and 12 months (13.1%, 10.9%, 8.1%, and 7.5%, respectively), followed by PES (5.5%, 4.4%, and 5.7% at 6, 9, and 12 months, respectively) and ZES (0.7%, 0%, and 0.5% at 3, 6, and 9 months, respectively) (P < 0.001 for all comparisons between stents). Only two studies reported 3.1% uncovered struts at 9 months with the EES. Stent strut malapposition at 6, 9, and 12 months was highest with SES (3.2%, 2.2%, and 1.2%, respectively) followed by PES (1.6%, 1.3%, and 0.9%, respectively), EES (0.46% at 9 months), and ZES (0.7% and 0.1% at 6 and 9 months, respectively). CONCLUSIONS: SES had the highest rates of uncovered struts and malapposition, followed by PES and ZES. Such differences may explain the different clinical outcomes between various DES. © 2012 Wiley Periodicals, Inc.

Retrograde coronary chronic total occlusion revascularization: procedural and in-hospital outcomes from a multicenter registry in the United States.

OBJECTIVES: This study sought to examine the contemporary outcomes of retrograde chronic total occlusion (CTO) interventions among 3 experienced U.S. centers. BACKGROUND: The retrograde approach, pioneered and developed in Japan, has revolutionized the treatment of coronary CTO, yet limited information exists on procedural efficacy, safety, and reproducibility of outcomes in other settings. METHODS: Between 2006 and 2011, 462 consecutive retrograde CTO interventions were performed at 3 U.S. institutions. Patient characteristics, procedural outcomes, and in-hospital clinical events were ascertained. RESULTS: Mean patient age was 65 ± 9.7 years, 84% were men, and 50% had prior coronary artery bypass surgery. The CTO target vessel was the right coronary artery (66%), circumflex (18%), left anterior descending artery (15.5%), and left main artery or bypass graft (0.5%). The retrograde approach was used as the primary method in 46% of cases and after failed antegrade recanalization in 54%. Retrograde collateral vessels were septal (68%), epicardial (24%), and bypass grafts (8%). Technical and procedural success was 81.4% (n = 376) and 79.4% (n = 367), respectively. The mean contrast volume and fluoroscopy time were 345 ± 177 ml and 61 ± 40 min, respectively. A major complication occurred in 12 patients (2.6%). In multivariable analysis, years since initiation of retrograde CTO percutaneous coronary intervention (PCI) at each center, female sex, and ejection fraction ≥40% were associated with higher technical success. CONCLUSIONS: Among selected U.S. programs, retrograde CTO PCI is often performed in patients with prior coronary bypass graft surgery and is associated with favorably high success and low complication rates.

Subintimal dissection/reentry strategies in coronary chronic total occlusion interventions.

Subintimal dissection/reentry techniques are increasingly being used for crossing coronary chronic total occlusions both antegradely (using a knucle wire or the Bridgepoint system) or retrogradely (using the controlled antegrade and retrograde tracking and dissection, and reverse controlled antegrade and retrograde tracking and dissection technique). Subintimal dissection/reentry techniques can increase procedural success rates, but their subsequent clinical outcomes are poorly studied, and they appear to be associated with high rates of in-stent restenosis and repeat target lesion revascularization. In the present review, we describe in detail the chronic total occlusions subintimal dissection/reentry techniques, clarify the related terminology and summarize the published studies in this area and the current gaps of knowledge.

Optical coherence tomography analysis of the stenting of saphenous vein graft (SOS) Xience V Study: use of the everolimus-eluting stent in saphenous vein graft lesions.

OBJECTIVES: The Stenting of Saphenous Grafts-Xience V (SOS-Xience V) trial prospectively examined the frequency of angiographic in-stent restenosis in saphenous vein graft (SVG) lesions 12 months after implantation of a Xience V everolimus-eluting stent (EES; Abbott Vascular). Optical coherence tomography (OCT) during follow-up angiography was added to the protocol after OCT was approved for clinical use in the United States. METHODS: Forty patients with 40 SVG lesions were enrolled in the study, of whom 27 underwent 12-month coronary angiography and 12 (only 1 of whom had in-stent restenosis) also had follow-up OCT evaluation. OCT strut-level analysis was performed to determine the percentage of strut coverage, malapposition, strut protrusion, neointimal thickness, and the existence of thrombus. RESULTS: Mean patient age was 67 ± 7 years, and 95% were men. A total of 2584 struts were evaluated by OCT. The percentages for uncovered, malapposed, and protruding struts were 4%, 9%, and 15%, respectively. The mean strut neointimal thickness was 0.094 ± 0.094 mm. Of the 12 stents analyzed, 4 (33%) showed full neointimal coverage, 2 (17%) had all the struts embedded, 7 (58%) had at least 1 malapposed strut, and 10 (83%) had at least 1 protruding strut. The mean difference between the stent area and the lumen area was 0.36 ± 1.6 mm². No thrombus was detected in the stented areas. CONCLUSIONS: Use of EES in SVGs is associated with high rates of stent strut coverage and high malapposition rates at 12 months post implantation.

Retrograde wiring: a novel technique for identifying the origin of unusual saphenous vein grafts.

BACKGROUND: In the absence of radiopaque graft markers, engaging unusual saphenous vein grafts can be challenging. METHODS: We describe a case in which a saphenous vein graft to the first obtuse marginal branch could not be located, in spite of performing aortic root angiography. The saphenous vein graft was wired retrogradely through the native left main and the wire was advanced into the aorta, serving as a marker of the abnormally low origin of the graft that was successfully engaged with a multipurpose catheter. RESULTS: The guidewire was successfully advanced retrogradely through the SVG into the aorta, allowing localization of the SVG ostium that was sewn in an unusually low location. CONCLUSIONS: Retrograde SVG wiring is an advanced, "last resort" technique for identifying the ostium and cannulating unusual aortocoronary bypass grafts.

Challenges associated with use of the GuideLiner catheter in percutaneous coronary interventions.

The GuideLiner catheter is an easy-to-use guide catheter extension that can facilitate vessel engagement and equipment delivery. We present two cases that illustrate two potential challenges associated with use of the GuideLiner catheter: (1) stent loss and deformation during attempts to advance it through the GuideLiner catheter collar; and (2) displacement of the GuideLiner catheter distal marker into a coronary artery. Awareness of these potential complications may render safer the use of this valuable interventional tool.

Embolic protection device utilization during stenting of native coronary artery lesions with large lipid core plaques as detected by near-infrared spectroscopy.

BACKGROUND: Stenting of large lipid core plaques (LCPs), as assessed by near-infrared spectroscopy (NIRS), has been associated with periprocedural myocardial infarction (MI), possibly due to distal embolization. METHODS: An embolic protection device (EPD) was inserted before stenting in nine native coronary arteries with large LCP, as assessed by NIRS. Embolized material was assessed by histopathology. RESULTS: Mean age was 64 ± 7 years and all patients were men. The target lesion was located in the right (67%) or left anterior descending (33%) coronary artery. A filter was utilized in eight patients (89%) and proximal embolic protection in one (11%). In one patient two filters were required because the originally placed filter became obstructed with debris after initial stent placement. The mean percent angiographic stenosis prestenting and poststenting was 87% ± 9% and 2% ± 4%, respectively and final TIMI 3 flow was achieved in all patients. Embolized material was retrieved in eight of nine patients (89%) and consisted mainly of platelet and fibrin thrombi. The mean target segment lipid core burden index decreased from 395 ± 114 before stenting to 152 ± 106 after stenting (P < 0.001) and the lesion angular extent decreased from 312° ± 70° to 240° ± 90° (P = 0.07). Postprocedural MI occurred in two of nine patients (22%), in one of whom two filters were required. CONCLUSION: Use of EPDs frequently resulted in embolized material retrieval after stenting of native coronary artery lesions with large LCPs. These findings support further study of EPDs as a means to prevent poststenting MI.

Role of embolic protection devices in ostial saphenous vein graft lesions.

BACKGROUND: Although embolic protection devices (EPDs) have been shown to be beneficial in saphenous vein graft (SVG) lesions, their role in the subgroup of ostial SVG lesions has received limited study. METHODS: The coronary angiograms and procedural outcomes of 109 patients undergoing stenting of 113 ostial SVG lesions were retrospectively reviewed to determine the frequency of EPD use and the periprocedural outcomes. RESULTS: Ninety-eight (87%) of the 113 lesions were suitable for EPD use, that was used in 70 lesions (71%). A Filterwire (Boston Scientific) or a SPIDER (ev3) filter were used in 54 (77%) and 16 (23%) of lesions, respectively. Difficulty retrieving the filter post stenting was encountered in eight lesions (11%) and led to stent thrombosis causing cardiac arrest in one patient (1%). Angiographic success was achieved in 111 (98%) of 113 lesions. CONCLUSIONS: EPDs can be utilized in the majority of ostial SVG lesions, but in 11% of cases filter retrieval can be challenging and may rarely (in approximately 1%) lead to a significant complication.

Relation between the presence and extent of coronary lipid core plaques detected by near-infrared spectroscopy with postpercutaneous coronary intervention myocardial infarction.

We aimed to examine whether an association exists between the presence and extent of coronary lipid core plaques (LCPs) detected by near-infrared spectroscopy (NIRS) performed before percutaneous coronary intervention (PCI) with postprocedural myocardial infarction (MI). NIRS was performed in the native coronary arteries of 30 patients before PCI. Angular extent of LCP, lesion segment lipid core burden index, and block chemogram were evaluated. Cardiac biomarkers were measured before and 16 to 24 hours after PCI to determine occurrence of postprocedural MI. Mean number of 2-mm yellow blocks within the stented lesion was 1.4 ± 2.1 and mean lesion lipid core burden index was 110.3 ± 99. Using a definition of creatine kinase-MB >1 time upper limit of normal (ULN), >2 times ULN, and >3 times ULN, MI after PCI occurred in 23%, 13%, and 10% of patients, respectively. Compared to patients who did not have MI after PCI, those who did had similar clinical characteristics but received more stents and had more blocks within the stented lesion. Creatine kinase-MB increase >3 times ULN was observed in 27% of patients with ≥1 yellow block versus in none of the patients without a yellow block within the stented lesion (p = 0.02). In conclusion, PCI of LCP-positive lesions as assessed by NIRS is associated with increased risk for MI after PCI. NIRS may allow lesion-specific risk stratification before PCI and optimization of PCI strategies for myocardial injury risk minimization.