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.

Long-term effects of a standardized feedback-driven quality improvement program for timely reperfusion therapy in regional STEMI care networks.

AIMS: Current European Society of Cardiology guidelines state that repetitive monitoring and feedback should be implemented for ST-elevation myocardial infarction (STEMI) treatment, but no evidence is available supporting this recommendation. We aimed to analyze the long-term effects of a formalized data assessment and systematic feedback on performance and mortality within the prospective, multicenter Feedback Intervention and Treatment Times in STEMI (FITT-STEMI) study. METHODS: Regular interactive feedback sessions with local STEMI management teams were performed at six participating German percutaneous coronary intervention (PCI) centers over a 10-year period starting from October 2007. RESULTS: From the first to the 10th year of study participation, all predefined key-quality indicators for performance measurement used for feedback improved significantly in all 4926 consecutive PCI-treated patients - namely, the percentages of patients with pre-hospital electrocardiogram (ECG) recordings (83.3% vs 97.1%, p < 0.0001) and ECG recordings within 10 minutes after first medical contact (41.7% vs 63.8%, p < 0.0001), pre-announcement by telephone (77.0% vs 85.4%, p = 0.0007), direct transfer to the catheterization laboratory bypassing the emergency department (29.4% vs 64.2%, p < 0.0001), and contact-to-balloon times of less than 90 minutes (37.2% vs 53.7%, p < 0.0001). Moreover, this feedback-related continuous improvement of key-quality indicators was linked to a significant reduction in in-hospital mortality from 10.8% to 6.8% (p = 0.0244). Logistic regression models confirmed an independent beneficial effect of duration of study participation on hospital mortality (odds ratio = 0.986, 95% confidence interval = 0.976-0.996, p = 0.0087). In contrast, data from a nationwide PCI registry showed a continuous increase in in-hospital mortality in all PCI-treated STEMI patients in Germany from 2008 to 2015 (n = 398,027; 6.7% to 9.2%, p < 0.0001). CONCLUSIONS: Our results indicate that systematic data assessment and regular feedback is a feasible long-term strategy and may be linked to improved performance and a reduction in mortality in STEMI management.

Long-term effects of a standardized feedback-driven quality improvement program for timely reperfusion therapy in regional STEMI care networks.

AIMS: Current European Society of Cardiology guidelines state that repetitive monitoring and feedback should be implemented for ST-elevation myocardial infarction (STEMI) treatment, but no evidence is available supporting this recommendation. We aimed to analyze the long-term effects of a formalized data assessment and systematic feedback on performance and mortality within the prospective, multicenter Feedback Intervention and Treatment Times in STEMI (FITT-STEMI) study. METHODS: Regular interactive feedback sessions with local STEMI management teams were performed at six participating German percutaneous coronary intervention (PCI) centers over a 10-year period starting from October 2007. RESULTS: From the first to the 10th year of study participation, all predefined key-quality indicators for performance measurement used for feedback improved significantly in all 4926 consecutive PCI-treated patients - namely, the percentages of patients with pre-hospital electrocardiogram (ECG) recordings (83.3% vs 97.1%, p < 0.0001) and ECG recordings within 10 minutes after first medical contact (41.7% vs 63.8%, p < 0.0001), pre-announcement by telephone (77.0% vs 85.4%, p = 0.0007), direct transfer to the catheterization laboratory bypassing the emergency department (29.4% vs 64.2%, p < 0.0001), and contact-to-balloon times of less than 90 minutes (37.2% vs 53.7%, p < 0.0001). Moreover, this feedback-related continuous improvement of key-quality indicators was linked to a significant reduction in in-hospital mortality from 10.8% to 6.8% (p = 0.0244). Logistic regression models confirmed an independent beneficial effect of duration of study participation on hospital mortality (odds ratio = 0.986, 95% confidence interval = 0.976-0.996, p = 0.0087). In contrast, data from a nationwide PCI registry showed a continuous increase in in-hospital mortality in all PCI-treated STEMI patients in Germany from 2008 to 2015 (n = 398,027; 6.7% to 9.2%, p < 0.0001). CONCLUSIONS: Our results indicate that systematic data assessment and regular feedback is a feasible long-term strategy and may be linked to improved performance and a reduction in mortality in STEMI management.

Prognostic significance of emergency department bypass in stable and unstable patients with ST-segment elevation myocardial infarction.

BACKGROUND: In ST-segment elevation myocardial infarction (STEMI) patients treated with percutaneous coronary intervention, direct transport from the scene to the catheterisation laboratory bypassing the emergency department has been shown to shorten times to reperfusion. The aim of this study was to investigate the effects of emergency department bypass on mortality in both haemodynamically stable and unstable STEMI patients. METHODS: The analysis is based on a large cohort of STEMI patients prospectively included in the German multicentre Feedback Intervention and Treatment Times in ST-Elevation Myocardial Infarction (FITT-STEMI) trial. RESULTS: Out of 13,219 STEMI patients who were brought directly from the scene by emergency medical service transportation and were treated with percutaneous coronary intervention, the majority were transported directly to the catheterisation laboratory bypassing the emergency department (n=6740, 51% with emergency department bypass). These patients had a significantly lower in-hospital mortality than their counterparts with no emergency department bypass (6.2% vs. 10.0%, P<0.0001). The reduced mortality related to emergency department bypass was observed in both stable (n=11,594, 2.8% vs. 3.8%, P=0.0024) and unstable patients presenting with cardiogenic shock (n=1625, 36.3% vs. 46.2%, P<0.0001). Regression models adjusted for the Thrombolysis In Myocardial Infarction (TIMI) risk score consistently confirmed a significant and independent predictive effect of emergency department bypass on survival in the total study population (odds ratio 0.64, 95% confidence interval 0.56-0.74, P<0.0001) and in the subgroup of shock patients (OR 0.69, 95% CI 0.54-0.88, P=0.0028). CONCLUSION: In STEMI patients, emergency department bypass is associated with a significant reduction in mortality, which is most pronounced in patients presenting with cardiogenic shock. Our data encourage treatment protocols for emergency department bypass to improve the survival of both haemodynamically stable patients and, in particular, unstable patients. Clinical Trial Registration: NCT00794001 ClinicalTrials.gov: NCT00794001.

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.

Reduction in treatment times through formalized data feedback: results from a prospective multicenter study of ST-segment elevation myocardial infarction.

OBJECTIVES: This study sought to evaluate the effect of systematic data analysis and standardized feedback on treatment times and outcome in a prospective multicenter trial. BACKGROUND: Formalized data feedback may reduce treatment times in ST-segment elevation myocardial infarction (STEMI). METHODS: Over a 15-month period, 1,183 patients presenting with STEMI were enrolled. Six primary percutaneous coronary intervention hospitals in Germany and 29 associated nonpercutaneous coronary intervention hospitals participated. Data from patient contact to balloon inflation were collected and analyzed. Pre-defined quality indicators, including the percentage of patients with pre-announced STEMI, direct handoff in the catheterization laboratory, contact-to-balloon time <90 min, door-to-balloon time <60 min, and door-to-balloon time <30 min were discussed with staff on a quarterly basis. RESULTS: Median door-to-balloon time decreased from 71 to 58 min and contact-to-balloon time from 129 to 103 min between the first and the fifth quarter (p < 0.05 for both). Contributing were shorter stays in the emergency department, more direct handoffs from ambulances to the catheterization laboratory (from 22% to 38%, p < 0.05), and a slight increase in the number of patients transported directly to the percutaneous coronary intervention facility (primary transport). One-year mortality was reduced in the total group of patients and in the subgroup of patients with primary transport (p < 0.05). The sharpest fall in mortality was observed in patients with primary transport and TIMI (Thrombolysis In Myocardial Infarction) risk score ≥ 3 (n = 521) with a decrease in 30-day mortality from 23.1% to 13.3% (p < 0.05) and in 1-year mortality from 25.6% to 16.7% (p < 0.05). CONCLUSIONS: Formalized data feedback is associated with a reduction in treatment times for STEMI and with an improved prognosis, which is most pronounced in high-risk patients. (Feedback Intervention and Treatment Times in ST-Elevation Myocardial Infarction [FITT-STEMI]; NCT00794001).

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.