Shortened radiofrequency delivery time to optimize efficiency and safety of pulmonary vein isolation with the radiofrequency balloon: insights from the COLLABORATE registry.

AIMS: Previous clinical studies on pulmonary vein isolation (PVI) with a radiofrequency balloon (RFB) reported safe and effective procedures using conventional ablation settings with 20/60 s RF delivery via posterior/anterior (PST/ANT) electrodes. The latest evidence suggests that reducing the application time to 15 s (s) on the posterior wall when facing the oesophageal region is as effective as applying 20 s. To prospectively assess whether reducing RF time on PST/ANT segments to 15/45 s can ensure sufficient quality of lesion metrics and compare the new shortened ablation settings with the conventional one in terms of safety, and effectiveness at 1-year. METHODS AND RESULTS: A total of 641 patients from seven European centres were enrolled in a collaborative registry, with 374 in the conventional RF delivery group and 267 in the shortened RF delivery group. Procedural outcomes, lesion metrics, and safety profiles were assessed and compared between the groups. Freedom of any atrial tachycarrythmias at one year was 85.4% and 88.2% in the SHRT and CONV groups, respectively. The shortened RF delivery strategy was associated with significantly shorter procedure times (median 63.5 vs. 96.5 min, P < 0.001) and shortened fluoroscopy exposure (median 10.0 vs. 14.0 min, P < 0.001) compared to conventional delivery. Efficacy metrics, including first-pass isolation rates and time to isolation, were comparable between groups. Shortened RF delivery was associated with a lower incidence of procedural complications (1.4% vs. 5.3%, P = 0.04) and optimized thermal characteristics. CONCLUSION: Analyses from the COLLABORATE registry demonstrate that shortening RF energy delivery times to 15/45 s (PST/ANT) during PVI with the RFB resulted in comparable freedom from recurrent atrial tachyarrhythmia compared to conventional delivery times with comparable efficiency and safety.

Emerging Hybrid Intracoronary Imaging Technologies and Their Applications in Clinical Practice and Research.

Intravascular ultrasound and optical coherence tomography are used with increasing frequency for the care of coronary patients and in research studies. These imaging tools can identify culprit lesions in acute coronary syndromes, assess coronary stenosis severity, guide percutaneous coronary intervention (PCI), and detect vulnerable plaques and patients. However, they have significant limitations that have stimulated the development of multimodality intracoronary imaging catheters, which provide improvements in assessing vessel wall pathology and guiding PCI. Prototypes combining 2 or even 3 imaging probes with complementary attributes have been developed, and several multimodality systems have already been used in patients, with near-infrared spectroscopy intravascular ultrasound-based studies showing promising results for the identification of high-risk plaques. Moreover, postmortem histology studies have documented that hybrid imaging catheters can enable more accurate characterization of plaque morphology than standalone imaging. This review describes the evolution in the field of hybrid intracoronary imaging; presents the available multimodality catheters; and discusses their potential role in PCI guidance, vulnerable plaque detection, and the assessment of endovascular devices and emerging pharmacotherapies targeting atherosclerosis.

Electroporation saves the day again: Pulsed-field ablation for phrenic nerve-sparing in right atrial tachycardia.

INTRODUCTION: Pulsed-field ablation (PFA) is a novel nonthermal energy that shows unique features that can be of use beyond pulmonary vein ablation, like tissue selectivity or proximity rather than contact dependency. METHODS AND RESULTS: We report three cases of right focal atrial tachycardias arising from the superior cavoatrial junction and the crista terminalis, in close relationship with the phrenic nerve, effectively ablated using a commercially available PFA catheter designed for pulmonary vein isolation without collateral damage. CONCLUSION: PFA can be useful for treating right atrial tachycardias involving sites near the phrenic nerve, avoiding the need for complex nerve-sparing strategies.

Use of dual-lumen microcatheter pullback injection in complex percutaneous coronary intervention.

Dual-lumen microcatheters (DLMC) are utilized in challenging wiring scenarios as well as for contrast and medication injections. Nonetheless, lesion characterization remains extremely challenging in many cases. We describe a DLMC-facilitated technique which can assist in locating the distal anastomosis while navigating an occluded bypass graft during retrograde chronic total occlusion recanalization, as well as in the differential diagnosis of abrupt vessel closure. This "DLMC Pullback Injection" technique is performed by injecting contrast through the over-the-wire port of the DLMC, while the latter is quickly pulled back across the region of interest in a dynamic fashion. We believe this technique has the potential to solve challenging scenarios and to enrich the complex percutaneous coronary intervention operator's armamentarium.

Prevention and treatment of coronary catheter kinking.

Coronary catheter kinking is an uncommon but potentially catastrophic complication of cardiac catheterization. Although simple maneuvers can often result in resolution of a kink, tighter knots may not respond to such measures. We provide a systematic, stepwise approach to the prevention and treatment of catheter kinking.

Application repetition and electrode-tissue contact result in deeper lesions using a pulsed-field ablation circular variable loop catheter.

AIMS: Pulsed-field ablation (PFA) is a novel, myocardial-selective, non-thermal ablation modality used to target cardiac arrhythmias. Although prompt electrogram (EGM) signal disappearance is observed immediately after PFA application in the pulmonary veins, whether this finding results in adequate transmural lesions is unknown. The aim of this study is to check whether application repetition and catheter-tissue contact impact lesion formation during PFA. METHODS AND RESULTS: A circular loop PFA catheter was used to deliver repeated energy applications with various levels of contact force. A benchtop vegetal potato model and a beating heart ventricular myocardial model were utilized to evaluate the impact of application repetition, contact force, and catheter repositioning on contiguity and lesion depth. Lesion development occurred over 18 h in the vegetal model and over 6 h in the porcine model. Lesion formation was found to be dependent on application repetition and contact. In porcine ventricles, single and multiple stacked applications led to a lesion depth of 3.5 ± 0.7 and 4.4 ± 1.3 mm, respectively (P = 0.002). Furthermore, the greater the catheter-tissue contact, the more contiguous and deeper the lesions in the vegetal model (1.0 ± 0.9 mm with no contact vs. 5.4 ± 1.4 mm with 30 g of force; P = 0.0001). CONCLUSION: Pulsed-field ablation delivered via a circular catheter showed that both repetition and catheter contact led independently to deeper lesion formation. These findings indicate that endpoints for effective PFA are related more to PFA biophysics than to mere EGM attenuation.

Shepherd's Crook Curve: A Novel Technique for Angulated Side Branch Access in Bifurcation Angioplasty.

Coronary intervention involving the region of bifurcation remains a challenging issue for the cardiologist as well as a complication. A number of factors including the angulation of side branch with the main branch determines the success. Though provisional strategy remains the best option in bifurcation intervention, at times a two-stent strategy cannot be avoided. We report a case in which percutaneous coronary intervention was performed on the left anterior descending artery (LAD) at its bifurcation with a major diagonal branch (> 2.5 mm). The ostium of the diagonal was diseased, and the branch took off from the LAD at an unfavorable angle (> 120°). We describe the use of the "shepherd's crook wire curve" approach, a modification of the reverse wire technique, which allowed us to successfully wire, dilate, and protect the diagonal and so named to reflect its resemblance to the shape of a shepherd's crook.

Outcomes With Limus- vs Paclitaxel-Coated Balloons for Percutaneous Coronary Intervention: Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Randomized controlled trials (RCTs) examining the outcomes with limus drug-coated balloons (DCBs) vs paclitaxel DCBs were small and underpowered for clinical endpoints. OBJECTIVES: This study sought to compare the angiographic and clinical outcomes with limus DCBs vs paclitaxel DCBs for percutaneous coronary intervention (PCI). METHODS: An electronic search of Medline, EMBASE, and Cochrane databases was performed through January 2024 for RCTs comparing limus DCBs vs paclitaxel DCBs for PCI. The primary endpoint was clinically driven target lesion revascularization (TLR). The secondary endpoints were late angiographic findings. Summary estimates were constructed using a random effects model. RESULTS: Six RCTs with 821 patients were included; 446 patients received a limus DCB, and 375 patients received a paclitaxel DCB. There was no difference between limus DCBs and paclitaxel DCBs in the incidence of TLR at a mean of 13.4 months (10.3% vs 7.8%; risk ratio [RR]: 1.32; 95% CI: 0.84-2.08). Subgroup analysis suggested no significant interaction among studies for de novo coronary lesions vs in-stent restenosis (Pinteraction = 0.58). There were no differences in the risk of major adverse cardiovascular events, cardiac mortality, or target vessel myocardial infarction between groups. However, limus DCBs were associated with a higher risk of binary restenosis (RR: 1.89; 95% CI: 1.14-3.12), late lumen loss (mean difference = 0.16; 95% CI: 0.03-0.28), and a smaller minimum lumen diameter (mean difference = -0.12; 95% CI: -0.22 to -0.02) at late follow-up. In addition, late lumen enlargement occurred more frequently (50% vs 27.5%; RR: 0.59; 95% CI: 0.45-0.77) with paclitaxel DCBs. CONCLUSIONS: Among patients undergoing DCB-only PCI, there were no differences in the risk of clinically driven TLR and other clinical outcomes between limus DCBs and paclitaxel DCBs. However, paclitaxel DCBs were associated with better late angiographic outcomes. These findings support the need for future trials to establish the role of new-generation limus DCBs for PCI.

Intracardiac vascular access in haemodialysis: A last resort for exhausted traditional access.

Depletion of veins for dialysis access is a challenging life threatening situation for patients in need of haemodialysis. The utilisation of intracardiac catheter is a rare procedure with scarce reported experience. We describe the case of a 68-year-old male that contributes to the limited knowledge of performing a life-saving intracardiac catheter placement for emergency haemodialysis in a patient without immediate alternative renal replacement therapy available. We also retrospectively analyse the experience reported so far and summarise complications and outcomes. In our case, the patient was able to pursue haemodialysis after intracardiac catheter placement without any complications. Two weeks later, the patient successfully received a kidney transplant from a deceased donor and has a serum creatinine of 1.7 mg/dL after 2 years of follow-up. There are only four reported cases of kidney transplantation after the procedure, including our own. Intracardiac catheter is an emerging option that could be considered in certain patients as the last resort. Further investigation with regards to patient candidacy and procedure security are necessary.

Long-Term Outcomes Following Sirolimus-Coated Balloon or Drug-Eluting Stents for Treatment of In-Stent Restenosis.

BACKGROUND: Evidence suggests that drug-coated balloons may benefit in-stent restenosis (ISR) treatment. However, the efficacy of new-generation sirolimus-coated balloon (SCB) compared with the latest generation drug-eluting stents (DESs) has not been studied in this setting. METHODS: All patients in the EASTBORNE (The All-Comers Sirolimus-Coated Balloon European Registry) and DEB-DRAGON (DEB vs Thin-DES in DES-ISR: Long Term Outcomes) registries undergoing percutaneous coronary intervention for DES-ISR were included in the study. The primary study end point was target lesion revascularization at 24 months. Secondary end points were major adverse cardiovascular events, all-cause death, myocardial infarction, and target vessel revascularization at 24 months. Our goal was to evaluate the efficacy and safety of SCB versus thin-struts DES in ISR at long-term follow-up. RESULTS: A total of 1545 patients with 1679 ISR lesions were included in the pooled analysis, of whom 621 (40.2%) patients with 621 lesions were treated with thin-strut DES and 924 (59.8%) patients with 1045 lesions were treated with SCB. The unmatched cohort showed no differences in the incidence of target lesion revascularization (10.8% versus 11.8%; P=0.568); however, there was a trend toward lower rates of myocardial infarction (7.4% versus 5.0%; P=0.062) and major adverse cardiovascular events (20.8% versus 17.1%; P=0.072) in the SCB group. After propensity score matching (n=335 patients per group), there were no significant differences in the rates of target lesion revascularization (11.6% versus 11.8%; P=0.329), target vessel revascularization (14.0% versus 13.1%; P=0.822), myocardial infarction (7.2% versus 4.5%; P=0.186), all-cause death (5.7% versus 4.2%; P=0.476), and major adverse cardiovascular event (21.5% versus 17.6%; P=0.242) between DES and SCB treatment. CONCLUSIONS: In patients with ISR, angioplasty with SCB compared with thin-struts DES is associated with comparable rates of target lesion revascularization, target vessel revascularization, myocardial infarction, all-cause death, and major adverse cardiovascular events at 2 years.

The impact of novel scoring balloon and cutting balloon after orbital atherectomy on severely calcified coronary lesion as assessed by optical coherence tomography.

BACKGROUND: Debulking devices are often followed by a scoring or cutting balloon in percutaneous coronary intervention (PCI) for severely calcified lesions. However, there are limited data on balloon preparation after orbital atherectomy (OA) assessed using optical coherence tomography (OCT). AIM: We aimed to compare the effects of a novel scoring and cutting balloon on calcified coronary lesions with OCT. METHODS: We retrospectively examined 38 patients (38 lesions) who underwent PCI with a scoring or a cutting balloon after OA. All patients underwent pre-PCI, preballooning, postballooning, and post-PCI OCT imaging. We divided the patients into novel scoring-balloon (group A: n = 22) and cutting-balloon (group B: n = 16) groups and compared the OCT findings, including minimum lumen area (MLA) and expansion ratio (MLA divided by mean reference lumen area). RESULTS: The mean patient age was 76.1 ± 8.7 years; 71.5% were male. There were no significant differences in patient background between both groups. Regarding procedural characteristics, the maximum balloon pressure was significantly higher in group A (median 23 atm, interquartile range [IQR] 18-24 vs. 12 atm [IQR: 10-12], p < 0.01). Although a calcium score of 4 was more frequently observed in group A (86.4% vs. 62.5%, p = 0.12), post-PCI MLA was comparable between both groups (3.95 mm2 [IQR: 3.27-4.41] vs. 3.43 mm2 [IQR: 2.90-4.82], p = 0.63). Furthermore, the expansion ratio was significantly greater in group A (0.83 ± 0.20 vs. 0.68 ± 0.14, p < 0.01). CONCLUSION: Despite a higher calcium score, a larger expansion ratio was achieved in patients with a novel scoring balloon than in those with a cutting balloon after OA.

Evaluation of Ablation Parameters to Predict Irreversible Lesion Size During Pulsed Field Ablation.

BACKGROUND: During pulsed field ablation (PFA), relationships between ablation parameters (contact force [CF], number of burst pulses, impedance decrease, and electrode temperature) and lesion size in beating hearts have not been well validated. METHODS: A 7.5F-catheter with a 3.5-mm ablation electrode and CF sensor (ThermoCool SmartTouch SF-Dual-Energy, Biosense Webster, Inc, Irwindale, CA) was connected to a PFA system (TRUPULSE2, Biosense Webster, Inc). In 11 closed-chest swine, biphasic PFA current was delivered between the ablation electrode and the skin patch at 219 sites in left ventricle and right ventricle using 12, 18, and 24 burst pulses with 4 different levels of CF: (1) low (n=57; CF, 4-15g; median, 10g); (2) moderate (n=60; CF, 16-30g; median, 22.5g); (3) high (n=68; CF, 32-65g; median, 40g); and (4) no electrode contact (n=34), 2 mm away from the endocardium. Swine were euthanized 2 hours after ablation, and lesion size was measured using triphenyl tetrazolium chloride staining. RESULTS: All PFA lesions with electrode-myocardium contact were well demarcated with triphenyl tetrazolium chloride staining, demonstrating (1) pale central zone (contraction band necrosis with minimal coagulation necrosis), (2) dark brown zone (contraction band necrosis with hemorrhage), and (3) hyperstained red zone by triphenyl tetrazolium chloride (unaffected normal myocardium with preserved mitochondrial activity, consistent with reversible zone). Lesion depth increased significantly with increasing CF and the number of PFA burst pulses. An exponential/logarithmic formula combined with CF and the number of PFA burst pulses correlated lesion depth with high accuracy: R=0.809, P<0.0001, ±1.0-mm accuracy in 128 of 163 (79%) lesions, and ±1.5-mm accuracy in 153 of 163 (94%) lesions. Impedance decrease and electrode temperature were poor predictors of lesion size. There were no detectable lesions resulting from ablation without electrode contact. CONCLUSIONS: Acute PFA ventricular lesions demonstrate irreversible and reversible lesion boundaries. Electrode-tissue contact is required for effective lesion formation. Lesion depth increases significantly with increasing CF and PFA burst pulses. A new exponential/logarithmic formula combined with CF and the number of PFA burst pulses correlates lesion depth with high accuracy.