Reducing Fluoroscopic and Cineangiographic Contribution to Radiation Exposure for Chronic Total Coronary Occlusion Interventions.

BACKGROUND: The treatment of chronic total coronary occlusions (CTO) carries the highest radiation exposure among percutaneous coronary interventions (PCI). In order to minimize radiation damage, we need to understand and optimize the contribution of all components of radiation exposure. METHODS: A total of 1000 CTO procedures performed between 2011 and 2020 were compared according to implemented radiation modifications. Group 1 used the original set-up of the X-ray equipment (Artis Zee, Siemens). In group 2 a modified protocol aimed at reducing the fluoroscopy exposure, in group 3 further modifications aimed at reducing cineangiographic exposure. RESULTS: Despite an increased lesion complexity, Air Kerma (AK) was reduced from 2619 mGy (1653-4574) in group 1 to 2178 mGy (1332-3500; p < 0.001) in group 2 by mainly reducing fluoroscopic contribution by 54.1%, the cineangiographic contribution was lowered by only 6.6%. In group 3 AK dropped drastically to 746 mGy (480-1225; p < 0.001) mainly by reducing the cineangiographic contribution by 53.4%, still there was a further reduction of fluoroscopy contribution of 8.2%. This also led to a reduction of the skin entry dose from 1038 mGy (690-1589) in group 2 to 359 mGy (204-591; p < 0.001) in group 3. This was achieved both in normal weight and obese patients, and both in antegrade and retrograde procedures. CONCLUSIONS: The present study demonstrates that by modifying both the fluoroscopic and cineangiographic contribution to radiation exposure a drastic reduction of radiation risk can be achieved, even in obese patients. Currently accepted radiation thresholds may no longer be a limit for CTO PCI.

A prospective study on the incidence of contrast-associated acute kidney injury after recanalization of chronic total coronary occlusions with contemporary interventional techniques.

BACKGROUND: Contrast-associated acute kidney injury (CA-AKI) is a potential risk associated with the percutaneous coronary interventions (PCI) for chronic total coronary occlusions (CTO). This study should evaluate the incidence of CA-AKI in an era of advanced strategies of recanalization techniques and identify modifiable determinants. METHODS: We analysed 1924 consecutive CTO procedures in 1815 patients between 2012 and 2019. All patients were carefully monitored at least up to 48 h after a CTO procedure for changes in renal function. RESULTS: The incidence of CA-AKI was 5.6%, but there was no relation to the technical approach such as frequency of the retrograde technique, intravascular ultrasound or radial access. Procedures with CA-AKI had longer fluoroscopy times (37.6 vs 46.1 min; p = 0.005). The major determinants of CA-AKI were age, presence of diabetes and reduced ejection fraction, as well as chronic kidney disease stage ≥2, serum haemoglobin, and fluoroscopy time. Contrast volume or contrast volume/GFR ratio were not independent determinants of CA-AKI. Periprocedural perforations were more frequent in CA-AKI patients (11.3 vs 2.3%; p < 0.001), and in-hospital mortality was higher (2.8 vs 0.4%; p < 0.001). CONCLUSIONS: CA-AKI was associated with the risk of in-hospital adverse events. Established patient-related risk factors for CA-AKI (age, diabetes, preexisting chronic kidney disease, low ejection fraction) were confirmed in this study. In addition, the length of the procedure, coronary perforations and low preprocedural serum haemoglobin were risk factors that might be preventable in patients at high risk for CA-AKI.

Modulated radiation protocol achieves marked reduction of radiation exposure for chronic total coronary occlusion intervention.

OBJECTIVE: To evaluate the feasibility of a new acquisition protocol to reduce radiation exposure. BACKGROUND: Percutaneous coronary interventions (PCI) for chronic total coronary occlusions (CTO) are characterized by the highest radiation exposure among PCI procedures. METHODS: We analyzed 552 consecutive CTO procedures between January 2018 and October 2019. After 366 procedures (Group 1) a modified radiation acquisition protocol was implemented for the subsequent 186 procedures (Group 2). Besides a low fluoroscopy frame rate of 6/s and cine frame rate of 7.5/s for both groups, additional modifications consisted of increased copper filtering with lower entry dose in combination with a modified image postprocessing. Radiation exposure was assessed as air kerma (AK; mGy), and dose-area product (DAP; cGy*cm2 ). RESULTS: There was no significant difference in lesion or procedural complexity between the study groups with 46 and 43% of the procedures done via the retrograde approach. While fluoroscopy time remained similar (median: 32.7 vs. 34.3 min), the protocol modifications resulted in a drastic reduction of AK by 68% from 2,040 (1,321-3,339) mGy to 655 (415-1,113) mGy (p < .001) without affecting the procedural success rate. DAP was equally decreased by 71%. These considerable reductions were observed even in obese patients of BMI > 30. In Group 2, not a single procedure exceeded the 5 Gy threshold as compared to 10.4% in Group 1. CONCLUSIONS: Radiation exposure decreased considerably with a new acquisition protocol without affecting procedure duration and success. These modifications were applicable also to patients with a high BMI.

Sports-Related Sudden Cardiac Arrest in Germany.

BACKGROUND: Knowledge about causes of sports-related sudden cardiac arrest (SrSCA) may influence national strategies to prevent such events. Therefore, we established a prospective registry on SrSCA to estimate the incidence and in particular describe the etiologies of SrSCA in the general population in Germany. METHODS: The registration of SrSCA based upon 4 pillars: a web-based platform to record SrSCA cases in competitive and recreational athletes, media-monitoring, cooperation with the German Resuscitation Registry, and 15 institutes of forensic medicine. RESULTS: After an observation period of 6 years, a total of 349 cases was recorded (mean age 48.0 ± 12.7 years); 109 subjects survived. Most of the cases occurred during nonelite competitive or recreational sports. Bystander cardiopulmonary resuscitation (CPR) was initiated in 262 cases (75%); however, rhythm analysis and defibrillation (if indicated) was mainly performed by medical services. In patients ≤ 35 years of age, premature coronary artery disease (CAD) and sudden arrhythmic death syndrome (SADS) prevailed, followed by myocarditis. In athletes ≥ 35 years of age, CAD predominated. CONCLUSIONS: Country-specific registries are necessary to define the national screening and prevention strategy optimally. In Germany, premature CAD, SADS, and myocarditis are the leading causes of SrSCA in young athletes, reinforcing the great disparity of the prevalence of cardiac diseases among different countries. Extension of on-site SCD-prevention campaigns, with training of CPR and explanation of the efficient use of automated external defibrillators (AEDs), may decrease the burden of SrSCD.

Bioresorbable vascular scaffolds for complex chronic total occlusions.

PURPOSE: This analysis of a consecutive series of bioresorbable vascular scaffolds (BVS) implanted for complex chronic total occlusions (CTOs) was done to evaluate the potential of this device to avoid a permanent full metal jacket with drug-eluting stents. PATIENTS: We analyzed 52 young patients (50.8 ±â€¯8.3 years) for the BVS group, and additionally we followed a subgroup of 17 patients where DES were combined with BVS mainly because severe calcification at the lesion site (hybrid group). RESULTS: BVS were successfully implanted in 69 of 70 patients. An average of 3.17 BVS were used per lesion in the BVS group, with a CTO length of 28 ±â€¯20 mm, and a reference diameter of 2.92 ±â€¯0.34 mm, 69% were J-CTO ≥ 2. The retrograde approach was used in 38%. The device length was 79 ±â€¯25 mm with 3.65 ±â€¯0.34 mm final balloon diameter. In the hybrid group BVS was used to cover the distal segment beyond the actual occlusion predominantly in LAD lesions. Patients were discharged with dual antiplatelet therapy prescribed for 12 months. At 12 months, no patient had died or experienced an acute myocardial infarction. Angiography or MSCT follow-up available in 67% showed no reocclusion within 12 months. The target revascularization was 7% at 12 months. Two patients experienced a late non-acute reocclusion at 17 and 19 months. CONCLUSIONS: The implantation of BVS for long complex CTOs was feasible with no stent thrombosis despite the high complexity of lesions and multiple BVS implanted. The lack of mechanical strength may lead to the need for focal reintervention, but still the long-term burden of full metal jacketed vessels could be avoided.

Reduction of radiation exposure during complex interventions for chronic total coronary occlusions: Implementing low dose radiation protocols without affecting procedural success rates.

BACKGROUND: The increasing complexity of percutaneous coronary intervention (PCI) for chronic total coronary occlusions (CTO) leads to a significant increase of radiation exposure for both patient and operator. OBJECTIVE: To study the potential of modified settings of the X-ray equipment combined with operator protocols to reduce radiation dose despite increasing procedural complexity. PATIENTS AND METHODS: We analyzed a consecutive cohort of 984 PCIs for CTOs in 863 patients between January 2010 and July 2015. During that period, the X-ray equipment was changed from an analog to a digital detector system, and a subsequent filter and imaging modification was implemented. The fluoroscopy settings were reduced from 15 pulses/s to 7.5, and then to 6. The cine framerate was reduced from 15 to 7.5/s. For the last time period, with optimized settings, procedural, and lesion related factors influencing the radiation exposure were analyzed. RESULTS: The lesion complexity increased from a J-CTO score of 1.64 to 2.33 with an increase of retrograde procedures from 21.6 to 50.4%. With a similar fluoroscopy time, the dose area product was reduced from period 1 to 2 by 20%, and further by 7% to period 3. There was a significant reduction of Air Kerma from period 2 to 3 from 3.5 to 2.7 Gy. The operator exposure was reduced by more than half. The patient's weight and the complexity of the procedure were the main determinants of radiation exposure. CONCLUSIONS: The radiation exposure for patient and operator was decreased considerably during the three observation periods despite an increase in lesion and procedural complexity. Rigorous implementation of radiation device settings did reduce radiation exposure without impeding procedural success. © 2017 Wiley Periodicals, Inc.

Periprocedural ischaemia during recanalisation of chronic total coronary occlusions: the influence of the transcollateral retrograde approach.

AIMS: Percutaneous coronary intervention for chronic total coronary occlusions (CTO) becomes increasingly more complex with the transcollateral retrograde approach. This study assesses the effect of the retrograde approach on markers of ischaemia and clinical events. METHODS AND RESULTS: Four hundred and ninety-two consecutive procedures in 392 patients were prospectively evaluated. Before and within 18-24 hours after the PCI creatine kinase (CK) and cardiac troponin I (cTnI) were obtained. A CK increase of greater than three times the upper limit of normal (ULN) was considered a periprocedural MI. Patients with initially elevated cTnI were excluded. In 106 patients with a retrograde wire passage of the septal collaterals, the incidence of a CK or TnI increase was higher as compared to the antegrade group. Patients with septal dilatation or passage of a dilatation catheter (Corsair) showed the highest cTnI. There was no difference in cardiac death or cerebral complications between the groups with antegrade and retrograde approach within the first 30 days. CONCLUSIONS: Complex retrograde recanalisation procedures for CTOs lead to an increased periprocedural ischaemic burden, most likely due to obstruction of the collateral pathway, and to the increased plaque burden of complex lesions treated with the retrograde approach.

Management of total restenotic occlusions.

Among lesions with in-stent restenosis (ISR), the in-stent chronic re-occlusions (ISR-CTO) is a subset with particularly unfavourable features regarding both the repeat procedure success and the prevention of lesion recurrence. A review of the literature and personal databases reveals that the prevalence of complete occlusive ISR represents about 5-10% of all CTO lesions, with little evidence regarding the successful long-term treatment. In fact, these lesions had been excluded from large contemporary trials dealing with the best modality for ISR management, and which showed eventually the superiority of drug-eluting stents (DES) as compared to brachytherapy. Only a limited experience exists with brachytherapy for ISR-CTOs, showing an inferior outcome as compared to non-occlusive ISRs. The lack of large study experience is true also for DES, so that only anecdotal experience in small series of patients is available. In some of the recent studies of DES in CTOs, again, ISR-CTOs were not included. Our own experience shows a slightly lower primary success rate of about 70% in ISR-CTOs as compared to 85% in primary CTOs, with a slightly higher recurrence rate with DES of 25%. ISR-CTOs are a clinical problem that had not been systematically addressed. However, we hope that this lesion subset may be of less relevance in the future when the use of DES in lesions which are prone for lesion recurrence will lead to less diffuse and occlusive ISR, and leaves rather focal and better manageable recurrent lesions.