The Belgian Registry on Coronary Function Testing (BELmicro Registry): Study Population, Prevalence of Coronary Vascular Dysfunction, and Procedural Safety.

Coronary function testing (CFT) plays a pivotal role in the diagnosis of coronary vascular dysfunction and providing patients with tailored therapy. The Belgian registry on CFT (BELmicro registry) is a prospective, observational, multicenter registry including 14 centers in Belgium. All patients who underwent clinically indicated CFT were included in the registry. Baseline characteristics, CFT data, and clinical outcomes were collected. This analysis aimed to describe the baseline characteristics of a real-world population of patients who underwent CFT, evaluate the prevalence of coronary vascular dysfunction, and assess the safety of CFT in daily clinical practice. Between October 2021 and September 2023, 449 patients were enrolled. The mean age was 65 ± 10 years, and 47.4% of patients were men. A total of 59% of patients had hypertension, 18.7% had diabetes, 69.5% had hypercholesterolemia, and 40.1% had a smoking habit. Angina and nonobstructive coronary arteries (ANOCAs) were identified in 85.1% of the patients. Microvascular physiology assessment was performed in 95.5% of patients, vasoreactivity test in 28.5%, and both in 24.0%. coronary microvascular dysfunction was diagnosed in 23.4% of patients with ANOCA, epicardial vasospasm in 26.3%, and microvascular spasm in 14.9%. Rates of major complications were 0.7% for microvascular physiology assessment and 0% for vasoreactivity test. In conclusion, participants in the BELmicro registry represented a real-world population of patients, characterized by a high burden of cardiovascular risk factors. Coronary microvascular dysfunction and coronary vasospasm were frequent in patients with ANOCA. Performing CFT in daily clinical practice was feasible, with a low rate of complications.

Impact of Postprocedural Graft Flow on Outcomes Following Chronic Total Occlusion Intervention in Postcoronary Artery Bypass Graft Patients: A Detailed Angiographic Analysis.

Chronic total occlusions (CTOs) are frequent in patients with previous coronary artery bypass graft (CABG) surgery. Percutaneous coronary intervention (PCI) is the usual revascularization strategy. Whether or not the presence of a graft on a CTO vessel and post-PCI graft patency impacts outcomes after CTO-PCI is unknown. We sought to evaluate the impact of post-PCI graft patency on the durability of CTO-PCI. In total, 259 patients with previous CABG who underwent CTO-PCI in 12 international centers in 2019 to 2023 were categorized into "grafted" and "ungrafted" groups based on the presence of graft on a CTO vessel. The grafted group was subdivided into "graft-occluded" and "graft-patent" groups, depending on graft patency. The primary end points were (1) technical success rate, (2) target vessel failure, and (3) CTO failure rates at 1 year. CTO failure was defined as target vessel revascularization and/or significant in-stent restenosis. A total of 199 patients (77%) were in the grafted group. Grafted CTOs showed higher complexity and lower technical success rates (70% vs 80%, p = 0.004) than nongrafted CTOs. Of the grafted CTOs, 140 (70%) were in the grafted-occluded group and 59 (30%) were in the grafted-patent group. The technical success was lower in the former group (65% vs 81%, p = 0.022). An occluded graft was an independent predictor of technical failure (odds ratio 2.04, 95% confidence interval 1.03 to 4.76, p = 0.049) and persistent post-PCI graft patency was a strong independent predictor of CTO failure at 1 year (hazard ratio 5.6, 95% confidence interval 1.2 to 27.5, log-rank p = 0.033). In conclusion, in patients with previous CABG who underwent CTO-PCI, post-PCI graft patency was a significant predictor of CTO failure.

The safety and feasibility of live-stream proctoring for CTO procedures.

OBJECTIVE: To assess the technical feasibility of a new method of educational training, based on audio-video (AV) communication between an interventional cardiologist and the cath lab staff members in one location and a remote expert proctor. METHODS: Overall, 9 patients underwent a percutaneous coronary intervention (PCI) targeting a chronic total occlusion (CTO) between June 2021 and January 2022 at a single Belgian center using the virtual proctoring approach. For this assessment, the strategic planning of the CTO PCI and all the decisions throughout the intervention were the responsibility of the proctor. The operator was guided via an AV link, by the proctor throughout the procedure. RESULTS: The operator performed each procedural step, guided by the remote proctor, who had continuous access to all relevant interventional details. No major adverse cardiac events (MACE) occurred during the index hospitalization or within 6 months follow-up. CONCLUSIONS: A new method of virtual proctoring based on live AV communication is feasible, even in the case of highly complex CTO PCI procedures. This strategy also appears safe and may provide the patient the benefit of incremental expertise. This approach is facilitated by advances in AV communication and allows physicians to share expertise irrespective of location. It could increase global interaction between colleagues and facilitate sharing of knowledge, which are both key aspects in the development of CTO PCI. This preliminary experience could serve as a basis for future large studies to study the potential role and benefits of virtual proctoring for complex CTO PCI procedures.

iFR/FFR/IVUS Discordance and Clinical Implications: Results From the Prospective Left Main Physiology Registry.

OBJECTIVES: This study aimed to assess discordance between results of instantaneous wave-free ratio (iFR), fractional flow reserve (FFR), and intravascular ultrasound (IVUS) in intermediate left main coronary (LM) lesions, and its impact on clinical decision making and outcome. METHODS: We enrolled 250 patients with a 40%-80% LM stenosis in a prospective, multicenter registry. These patients underwent both iFR and FFR measurements. Of these, 86 underwent IVUS and assessment of the minimal lumen area (MLA), with a 6 mm2 cutoff for significance. RESULTS: Isolated LM disease was recognized in 95 patients (38.0%), while 155 patients (62.0%) had both LM disease and downstream disease. In 53.2% of iFR+ and 56.7% of FFR+ LM lesions, the measurement was positive in only one daughter vessel. iFR/FFR discordance occurred in 25.0% of patients with isolated LM disease and 36.2% of patients with concomitant downstream disease (P=.049). In patients with isolated LM disease, discordance was significantly more common in the left anterior descending artery and younger age was an independent predictor of iFR-/FFR+ discordance. iFR/MLA and FFR/MLA discordance occurred in 37.0% and 29.4%, respectively. Within 1 year of follow-up, major cardiac adverse events (MACE) occurred in 8.5% and 9.7% (P=.763) of patients whose LM lesion was deferred or revascularized, respectively. Discordance was not an independent predictor of MACE. CONCLUSIONS: Current methods of estimating LM lesion significance often yield discrepant findings, complicating therapeutic decision-making.

Mortality in STEMI Patients With Cardiogenic Shock: Results From a Nationwide PCI Registry and Focus on Left Main PCI.

BACKGROUND: The study aims to assess real-life short- and long-term outcomes of patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) complicated with cardiogenic shock (CS). Outcome after left main (LM) PCI is of particular interest. METHODS: Procedural, 30-day, and >30-day mortality rates were assessed in 2744 CS-STEMI patients enrolled between 2012 and 2019 in a nationwide registry involving 49 centers. RESULTS: Procedural, 30-day, and >30-day mortality rates were 6.9%, 39.8%, and 12.6%, respectively. The mortality rates were significantly higher in the 348 patients (12.7%) who underwent LM-PCI (13.5%, 59.5%, and 18.4%, respectively). LM-PCI, a suboptimal PCI result, and transfemoral access were independent predictors of procedural and 30-day mortality. Operator experience was an independent predictor of procedural mortality, but not 30-day mortality. CONCLUSIONS: Mortality remains high in CS-STEMI patients, especially within the first month. Patients undergoing LM-PCI are particularly at risk. Operator experience is predictive of procedural mortality.

Clinical validation of a 13-lead electrocardiogram derived from a self-applicable 3-lead recording for diagnosis of myocardial supply ischaemia and common non-ischaemic electrocardiogram abnormalities at rest.

Aims: In this study, we compare the diagnostic accuracy of a standard 12-lead electrocardiogram (ECG) with a novel 13-lead ECG derived from a self-applicable 3-lead ECG recorded with the right exploratory left foot (RELF) device. The 13th lead is a novel age and sex orthonormalized computed ST (ASO-ST) lead to increase the sensitivity for detecting ischaemia during acute coronary artery occlusion. Methods and results: A database of simultaneously recorded 12-lead ECGs and RELF recordings from 110 patients undergoing coronary angioplasty and 30 healthy subjects was used. Five cardiologists scored the learning data set and five other cardiologists scored the validation data set. In addition, the presence of non-ischaemic ECG abnormalities was compared. The accuracy for detection of myocardial supply ischaemia with the derived 12 leads was comparable with that of the standard 12-lead ECG (P = 0.126). By adding the ASO-ST lead, the accuracy increased to 77.4% [95% confidence interval (CI): 72.4-82.3; P < 0.001], which was attributed to a higher sensitivity of 81.9% (95% CI: 74.8-89.1) for the RELF 13-lead ECG compared with a sensitivity of 76.8% (95% CI: 71.9-81.7; P < 0.001) for the 12-lead ECG. There was no significant difference in the diagnosis of non-ischaemic ECG abnormalities, except for Q-waves that were more frequently detected on the standard ECG compared with the derived ECG (25.9 vs. 13.8%; P < 0.001). Conclusion: A self-applicable and easy-to-use 3-lead RELF device can compute a 12-lead ECG plus an ischaemia-specific 13th lead that is, compared with the standard 12-lead ECG, more accurate for the visual diagnosis of myocardial supply ischaemia by cardiologists.

Practice and long-term outcome of unprotected left main PCI: real-world data from a nationwide registry.

BACKGROUND: Percutaneous coronary intervention (PCI) is increasingly performed in significant left main (LM) lesions. Left untreated, the prognosis is poor, but PCI and coronary bypass surgery (CABG) behold risks as well. Additional long-term outcome data might guide future treatment decisions. METHODS: Between 2012 and 2019, all 6783 patients who underwent LM PCI were prospectively enrolled in a national registry. Patients with prior CABG or prior LM PCI, and patients presenting in cardiogenic shock or after out-of-hospital cardiac arrest were excluded. From the remaining 5284 patients, baseline and procedural data as well as long-term survival were assessed. RESULTS: The annual rate of LM PCI increased from 422 (2.2% of PCIs) in 2012 to 868 in 2018 (3.0%). By 2018, 71% of the interventional cardiologists performed at least 1 LM PCI a year, though only 5 on average. Use of transradial access (TRA) in LM PCI increased from 20.4% in 2012 to 59.5% in 2019. All-cause mortality was 6.0% at 30 days and 18.5% at a mean follow-up of 33.5 months. Independent predictors of higher long-term mortality were older age, diabetes, multivessel disease, an urgent indication, a suboptimal angiographical result, and non-exclusive use of drug-eluting stents. TRAand higher operator and centre LM PCI experience were independent predictors of a lower long-term mortality. CONCLUSION: LM PCI is associated with high short- and long-term mortality. Use of TRA and higher expertise in LM PCI were associated with better survival.

Right Coronary Artery Chronic Total Occlusion After Bypass Grafting Successfully Treated Using Reverse Controlled Antegrade and Retrograde Subintimal Tracking (CART) Technique via the Gastroepiploic Artery: A Case Report.

BACKGROUND Percutaneous coronary intervention (PCI) of chronic total occlusions (CTO) is a well-established treatment option, improving health status and angina in selected patients with angina and/or a large area of documented ischemia and suitable anatomy. It has been used in patients with a history of coronary artery bypass grafting (CABG) but remains controversial in unusual bypass constructions. This report is of a 63-year-old man with angina due to right coronary CTO, 6 years following CABG, successfully treated using the reverse controlled antegrade and retrograde subintimal tracking technique (reverse CART technique) via the gastroepiploic (GE) artery. CASE REPORT A 63-year-old man with a history of extensive coronary artery disease, including a CTO of the right coronary artery (RCA), previously treated with a right GE artery bypass graft, presented with unacceptable angina despite optimal medical treatment. A vascular CT scan suggested severe stenosis at the level of the anastomosis between the GE artery graft and the posterior descending (PD) artery. A PCI of the native RCA CTO was successfully performed using the GE artery bypass graft as a retrograde conduit, with good angiographical and clinical outcomes. CONCLUSIONS PCI of a CTO via the GE artery has been described only occasionally before, and remains a rare treatment. This report shows that retrograde coronary artery recanalization of CTO using the reverse CART technique, via the GE artery bypass graft, was safe and effective in this case, and that it can and should be considered in selected patients.

Physiology-Based Revascularization of Left Main Coronary Artery Disease.

It is of critical importance to correctly assess the significance of a left main lesion. Underestimation of significance beholds the risk of inappropriate deferral of revascularization, whereas overestimation may trigger major but unnecessary interventions. This article addresses the invasive physiological assessment of left main disease and its role in deciding upon revascularization. It mainly focuses on the available evidence for fractional flow reserve and instantaneous wave-free ratio, their interpretation, and limitations. We also discuss alternative invasive physiological indices and imaging, as well as the link between physiology, ischemia, and prognosis.

Revascularisation of chronic total occlusions and recurrence rate of ventricular arrhythmias.

BACKGROUND: The impact of revascularisation of chronic total occlusions (CTO) on the incidence of ventricular arrhythmias (VA) remains to be elucidated. METHODS: Based on prospectively gathered data, the recurrence rate of VAs following CTO treatment was retrospectively investigated. Patients presenting with VAs as clinical indication for CTO revascularisation were retrospectively selected out of three Belgian CTO registries (i.e. Ziekenhuis Oost-Limburg, UZ Leuven and CHR de la Citadelle). Freedom of VAs was defined as absence of non-sustained or sustained tachycardias (VT), ventricular fibrillations (Vfib) and ventricular extrasystoles (VES; <2500 VES/24 h). Long-term outcome in terms of reoccurrence of VAs was evaluated by reviewing patient records. RESULTS: Between 2011 and 2019, 912 patients underwent a CTO-PCI across three Belgian centres. In total 43 patients (5%) presented with VAs as clinical indication for CTO revascularisation. Overall follow-up was 723 (391 - 1144) days. Fourteen (33%), 18 (42%), 5 (11%) and 6 (14%) presented with >2500 VES/24 hrs, non-sustained VT, sustained VT and Vfib, respectively. In those patients with a one-year follow-up available (n = 34), overall recurrence rate of VAs was 38% (within VA group: VES: 25%, non-sustained VT: 46%; sustained VT: 25% and Vfib: 60%). CONCLUSION: Based on this retrospective data analysis, CTO revascularisation, in patients presenting with VAs as the main clinical indication, seems to beneficially impact the incidence of VAs, which ultimately might result in improved patients' outcome.

iFR uncovers profound but mostly reversible ischemia in CTOs and helps to optimize PCI results.

OBJECTIVES: The study aimed to demonstrate through instant wave-free ratio (iFR) measurements that myocardium distal to a chronic total occlusion (CTO) is ischemic, that ischemia is reversible by PCI, and that iFR assessment after PCI can be used to optimize PCI results. BACKGROUND: The greatest benefit of revascularization is found in patients with low fractional flow reserve. In patients with CTOs, iFR measurement may be more appropriate to evaluate ischemia as it does not require maximal microvascular vasodilation, which may be hampered by microvascular dysfunction. METHODS: The iFR was measured in 81 CTO patients, both pre- and post-PCI in 63 patients, and only post-PCI in the following 18 patients. A pressure wire pullback was performed post-PCI if iFR ≤0.89. RESULTS: The first 63 patients all had significant ischemia distal to the CTO with a median iFR of 0.33 [0.22; 0.44], improving significantly post-PCI to a median iFR of 0.93 [0.89;0.96] (p < .001). In the complete cohort, the median iFR post-PCI was 0.93 [0.86;0.96] but still ≤0.89 in 23 patients (30%). 12 of these patients had further PCI optimization because of a residual focal pressure gradient on pullback, after which only two had a final iFR ≤0.89. CONCLUSIONS: In CTO patients with an indication for PCI, iFR consistently demonstrated profound myocardial ischemia. Successful PCI immediately relieved ischemia in 70% of patients. In the remaining 30% of cases, a manual iFR pullback proved helpful in guiding further optimization of the PCI result.

The evolution of the CTO-PCI landscape in Belgium and Luxembourg: a four-year appraisal.

BACKGROUND: To chart the evolution of the CTO-PCI landscape in Belgium and Luxembourg, the Belgian Working Group on Chronic Total Occlusions (BWGCTO) was established in 2016. METHODS: Between May 2016 and December 2019, patients undergoing a CTO-PCI treatment were prospectively and consecutively enrolled. Twenty-one centres in Belgium and one in Luxembourg participated. Individual operators had mixed levels of expertise in treating CTO lesions. Demographic, angiographic, procedural parameters and incidence of major adverse cardiac and cerebrovascular events (MACCE) were systematically registered. RESULTS: Over a four-year enrolment period, 1832 procedures were performed in 1733 patients achieving technical success in 1474 cases (80%), with an in-hospital MACCE rate of 2.3%. Fifty-nine (3%) cases were re-attempt procedures of which 41 (69%) were successful. High-volume centres treated more complex lesions (mean J-CTO score: 2.15 ± 1.21) as compared to intermediate (mean J-CTO score: 1.72 ± 1.23; p < 0.001) and low-volume centres (mean J-CTO score: 0.99 ± 1.21; p = 0.002). Despite this, success rates did not differ between centres (p = 0.461). Overall success rates did not differ over time (p = 0.810). High-volume centres progressively tackled more complex CTOs while keeping success rates stable. In all centres, the most applied strategy was antegrade wire escalation (83%). High-volume centres more often successfully applied antegrade dissection and re-entry and retrograde techniques in lesions with higher complexity. CONCLUSION: With variable experience levels, operators treated CTOs with high success and relatively few complications. Although AWE remains the most used technique, it is paramount for operators to be skilled in all contemporary techniques in order to be successful in more complex CTOs.

Feasibility and Safety of Performing Complex Coronary Interventions by Distal Radial Artery Using the Railway Sheathless Vascular System.

AIMS: The aim of this clinical study is to assess the feasibility and safety of the 7 Fr Railway sheathless access system (Cordis Corporation) for complex percutaneous coronary interventions (PCI) using distal radial artery access. METHODS AND RESULTS: Over a 2-month period, we enrolled 20 patients (all those undergoing complex PCI) where a 7 Fr guide catheter was deemed necessary. Multiple bifurcation techniques and calcified plaque modifying tools were used. The primary endpoint was procedural success (95%) without need for access-site crossover (0%) or major adverse cardiovascular event within the first month (0%), while our secondary endpoint was the access-site complication rate (arterial spasm in 1 case [5%]). CONCLUSION: Distal radial access with the 7 Fr Railway sheathless access system was a feasible and safe access option for complex PCI in our very high-risk study population. This approach could be a valuable option for decreasing the risk of a major bleeding event or vascular complication in cases that require a large guide catheter.

Different dynamics of new-onset electrocardiographic changes after balloon- and self-expandable transcatheter aortic valve replacement: Implications for prolonged heart rhythm monitoring.

BACKGROUND: New onset electrocardiographic (ECG) changes after transcatheter aortic valve replacement (TAVR) are used to assess the risk for late atrioventricular block. However, the time of ECG evaluation remains controversial. We aimed to compare the time course and dynamics of new onset ECG changes according to valve design in balloon- (BEV) and self-expandable (SEV) TAVR. METHODS AND RESULTS: This single center study enrolled 133 consecutive TAVR patients (28.6% SEV, 71.4% BEV). Patients with pre-existent permanent pacemaker implant (PPMI), procedural death or incomplete ECG registration were excluded. Standard 12­lead ECG was performed before the procedure, at 1, 24, 48 and 120 h and 1 month. In BEV patients, no significant PR prolongation occurred, whereas in SEV patients the PR interval prolonged significantly with 33.7 ± 22.0 ms (p < 0.001, compared to pre-TAVR) but only after 48 h after TAVR. Widening of QRS duration was comparable among both BEV and SEV patients (6.7 ± 21.5 versus 17.0 ± 26.9 ms, p = 0.061) and occurred immediately after TAVR. New-onset left bundle branch block was seen in 18.5% of BEV and 30.8% of SEV patients (p = 0.120) and occurred within 24 h after TAVR in both groups. Late PPMI (>24 h after TAVR) was higher in SEV compared to BEV patients (15.3% versus 1.5%, p = 0.008). CONCLUSION: Self-expandable valves cause more impairment in atrioventricular conduction with a delayed time course compared to balloon expandable valves. This might explain the higher pacemaker need beyond 24 h after TAVR. Our findings suggest that patients with self-expandable valves require at least 48 h ECG monitoring post TAVR.

Feasibility of His-bundle pacing in patients with conduction disorders following transcatheter aortic valve replacement.

BACKGROUND: Conduction disorders requiring permanent pacemaker implantation occur frequently after transcatheter aortic valve replacement (TAVR). This multicenter study explored the feasibility and safety of His bundle pacing (HBP) in TAVR patients with a pacemaker indication to correct a TAVR-induced left bundle branch block (LBBB). METHODS: Patients qualifying for a permanent pacemaker implant after TAVR were planned for HBP implant. HBP was performed using the Select Secure (3830; Medtronic) pacing lead, delivered through a fixed curve or deflectable sheath (C315HIS or C304; Medtronic). Successful HBP was defined as selective or nonselective HBP, irrespective of LBB recruitment. Successful LBBB correction was defined as selective or nonselective HBP resulting in paced QRS morphology similar to pre-TAVR QRS and paced QRS duration (QRSd) less than 120 milliseconds with thresholds less than 3.0 V at 1.0-millisecond pulse width. RESULTS: The study enrolled 16 patients requiring a permanent pacemaker after TAVR (age 85 ± 4 years, 31% female, all LBBB; QRSd: 161 ± 14 milliseconds). Capture of the His bundle was achieved in 13 of 16 (81%) patients. HBP with LBBB correction was achieved in 11 of 16 (69%) and QRSd narrowed from 162 ± 14 to 99 ± 13 milliseconds and 134 ± 7 milliseconds during S-HBP and NS-HBP, respectively (P = .005). At implantation, mean threshold for LBBB correction was 1.9 ± 1.1 V at 1.0 millisecond. Thresholds remained stable at 11 ± 4 months follow-up (1.8 ± 0.9 V at 1.0 millisecond, P = .231 for comparison with implant thresholds). During HBP implant, one temporary complete atrioventricular block occurred. CONCLUSION: Permanent HBP is feasible in the majority of patients with TAVR requiring a permanent pacemaker with the potential to correct a TAVR-induced LBBB with acceptable pacing thresholds.

Feasibility and performance of a device for automatic self-detection of symptomatic acute coronary artery occlusion in outpatients with coronary artery disease: a multicentre observational study.

BACKGROUND: Time delay between onset of symptoms and seeking medical attention is a major determinant of mortality and morbidity in patients with acute coronary artery occlusion. Response time might be reduced by reliable self-detection. We aimed to formally assess the proof-of-concept and accuracy of self-detection of acute coronary artery occlusion by patients during daily life situations and during the very early stages of acute coronary artery occlusion. METHODS: In this multicentre, observational study, we tested the operational feasibility, specificity, and sensitivity of our RELF method, a three-lead detection system with an automatic algorithm built into a mobile handheld device, for detection of acute coronary artery occlusion. Patients were recruited continuously by physician referrals from three Belgian hospitals until the desired sample size was achieved, had been discharged with planned elective percutaneous coronary intervention, and were able to use a smartphone; they were asked to perform random ambulatory self-recordings for at least 1 week. A similar self-recording was made before percutaneous coronary intervention and at 60 s of balloon occlusion. Patients were clinically followed up until 1 month after discharge. We quantitatively assessed the operational feasibility with an automated dichotomous quality check of self-recordings. Performance was assessed by analysing the receiver operator characteristics of the ST difference vector magnitude. This trial is registered with ClinicalTrials.gov, number NCT02983396. FINDINGS: From Nov 18, 2016, to April 25, 2018, we enrolled 64 patients into the study, of whom 59 (92%) were eligible for self-applications. 58 (91%) of 64 (95% CI 81·0-95·6) patients were able to perform ambulatory self-recordings. Of all 5011 self-recordings, 4567 (91%) were automatically classified as successful within 1 min. In 65 balloon occlusions, 63 index tests at 60 s of occlusion in 55 patients were available. The mean specificity of daily life recordings was 0·96 (0·95-0·97). The mean false positive rate during daily life conditions was 4·19% (95% CI 3·29-5·10). The sensitivity for the target conditions was 0·87 (55 of 63; 95% CI 0·77-0·93) for acute coronary artery occlusion, 0·95 (54 of 57; 0·86-0·98) for acute coronary artery occlusion with electrocardiogram (ECG) changes, and 1·00 (35 of 35) for acute coronary artery occlusion with ECG changes and ST-segment elevation myocardial infarction criteria (STEMI). The index test was more sensitive to detect a 60 s balloon occlusion than the STEMI criteria on 12-lead ECG (87% vs 56%; p<0·0001). The proportion of total variation in study estimates due to heterogeneity between patients (I2) was low (12·6%). The area under the receiver operator characteristics curve was 0·973 (95% CI 0·956-0·990) for acute coronary artery occlusion at different cutoff values of the magnitude of the ST difference vector. No patients died during the study. INTERPRETATION: Self-recording with our RELF device is feasible for most patients with coronary artery disease. The sensitivity and specificity for automatic detection of the earliest phase of acute coronary artery occlusion support the concept of our RELF device for patient empowerment to reduce delay and increase Survival without overloading emergency services. FUNDING: Ghent University, Industrial Research Fund.

Validation of a Novel System for Co-Registration of Coronary Angiographic and Intravascular Ultrasound Imaging.

INTRODUCTION: Intravascular ultrasound (IVUS) is a useful adjunct to guide percutaneous coronary intervention (PCI). Correlating IVUS images with angiographic findings can be challenging. We evaluated the utility of a novel co-registration system for IVUS and coronary angiography. METHODS AND RESULTS: A 3-D virtual catheter trajectory was constructed from separate angiographic imaging runs using bespoke software. Intravascular ultrasound images were obtained using a commercially available mechanical rotational transducer with motorized pullback. Co-registration of ultrasound and angiographic images was then performed retrospectively based on the length of pullback, the 3-D trajectory and the start position of the catheter. Validation was performed in a spherical phantom model and in vivo in the coronary circulation of patients undergoing coronary angiography and intravascular imaging for clinical purposes. 111 paired angiographic and IVUS runs were performed in 3 phantom models. The differences between the reference length and the length measured on the 3D reconstructed path was -0.01 ±â€¯0.40 mm. Intra-observer variability was 0.4%. We enrolled 25 patients in 3 European hospitals and performed 35 co-registration attempts with an 86% success rate. 71 landmarks were selected by the first operator, 68 by the second. Differences between angiographic and IVUS landmarks were -0.22 ±â€¯0.72 mm and 0.05 ±â€¯1.01 mm, respectively. Inter-observer variability was 0.23 ±â€¯0.63 mm. CONCLUSION: We present a novel method for the co-registration of IVUS and coronary angiographic images. This system performed well in a phantom model and using images obtained from the human coronary circulation. CLASSIFICATIONS: Innovation, intravascular ultrasound, other technique.

DOSIMETRY DURING PERCUTANEOUS CORONARY INTERVENTIONS OF CHRONIC TOTAL OCCLUSIONS.

Percutaneous coronary interventions (PCI) of coronary chronic total occlusions (CTO) increase the risk of high radiation exposure for both the patient and the cardiologist. This study evaluated the maximum dose to the patients' skin (MSD) and the exposure of the cardiologists during CTO-PCI. Moreover, the efficiency of radioprotective drapes to reduce cardiologist exposure was assessed. Patient dose was measured during 31 procedures; dose to the cardiologist's extremities were measured during 65 procedures, among which 31 were performed with radioprotective drapes. The MSD was high (median: 1254 mGy; max: 6528 mGy), and higher than 2 Gy for 33% of the patients. The dose to the cardiologists' extremities per procedure was also of concern (median: 25-465 µSv), particularly to the left eye (median: 68 µSv; max: 187 µSv). Radioprotective drapes reduced the exposure to physician's upper limbs and eyes; especially to the left side (from -28 to -49%).

One-Year Clinical Outcomes of the Hybrid CTO Revascularization Strategy After Hospital Discharge: A Subanalysis of the Multicenter RECHARGE Registry.

OBJECTIVES: Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) has historically been associated with higher event rates during follow-up. The hybrid algorithm and contemporary wiring and dissection re-entry (DR) techniques can potentially improve long-term outcomes after CTO-PCI. This study assessed the long-term clinical outcomes of the hybrid CTO practice, when applied by operators with varying experience levels. METHODS: We examined the 1-year clinical events after hospital discharge of the RECHARGE population, according to technical outcome and final technique. The primary endpoint was major adverse cardiac event (MACE) rate. Centers that provided ≥90% complete 12-month follow-up were included. RESULTS: Follow-up data of 1067 out of 1165 patients (92%) were provided by 13 centers. Mean follow-up duration was 362.8 ± 0.9 days. One-year MACE-free survival rate was 91.3% (974/1067). MACE included death (1.9%; n = 20), myocardial infarction (1.4%; n = 15), target-vessel failure (5.9%; n = 63), and target-vessel revascularization (TVR) (5.5%; n = 59). Non-TVR was performed in 6.7% (n = 71). MACE was significantly in favor of successful CTO-PCI (8.0% vs 13%; P=.04), even after adjusting for baseline differences (adjusted hazard ratio, 0.59; 95% confidence interval, 0.36-0.98; P=.04). Other events, including individual MACE components, were comparable with respect to technical outcome and final technique (DR vs non-DR techniques). CONCLUSIONS: The use of the hybrid algorithm with contemporary techniques by moderate to highly experienced operators for CTO-PCI is safe and associated with a low 1-year event rate. Successful procedures are associated with a better MACE rate. DR techniques can be used as first-line strategies alongside intimal wiring techniques without compromising clinical outcomes.