Concomitant Mitral Regurgitation in Severe Aortic Stenosis　- Insights From the CURRENT AS Registry-2.

BACKGROUND: Data on concomitant mitral regurgitation (MR) in patients with severe aortic stenosis (AS) are scarce.Methods and Results: We investigated the risk of concomitant MR in patients with severe AS in the CURRENT AS Registry-2 according to initial treatment strategy (transcatheter aortic valve implantation [TAVI], surgical aortic valve replacement [SAVR], or conservative). Among 3,365 patients with severe AS, 384 (11.4%) had moderate/severe MR (TAVI: n=126/1,148; SAVR: n=68/591; conservative: n=190/1,626). The cumulative 3-year incidence for death or heart failure (HF) hospitalization was significantly higher in the moderate/severe than no/mild MR group in the entire population (54.6% vs. 34.3%, respectively; P<0.001) and for each treatment strategy (TAVI: 45.0% vs. 31.8% [P=0.006]; SAVR: 31.9% vs. 18.7% [P<0.001]; conservative: 67.8% vs. 41.6% [P<0.001]). The higher adjusted risk of moderate/severe MR relative to no/mild MR for death or HF hospitalization was not significant in the entire population (hazard ratio [HR] 1.15; 95% confidence interval [CI] 0.95-1.39; P=0.15); however, the risk was significant in the SAVR (HR 1.92; 95% CI 1.04-3.56; P=0.04) and conservative (HR 1.30; 95% CI 1.02-1.67; P=0.04) groups, but not in the TAVI group (HR 1.03; 95% CI 0.70-1.52; P=0.86), despite no significant interaction (Pinteraction=0.37). CONCLUSIONS: Moderate/severe MR was associated with a higher risk for death or HF hospitalization in the initial SAVR and conservative strategies, while the association was less pronounced in the initial TAVI strategy.

Successful Balloon-Expandable Transcatheter Aortic Valve Replacement for Extremely Large Annulus (>1,000 mm2).

Transcatheter aortic valve replacement in extra-large annulus is challenging because of the limited sizes and data of the current commercial prosthesis sizes available. We present a case of successful transcatheter aortic valve replacement with a new balloon-expandable SAPIEN 3 Ultra RESILIA valve for an aortic annulus area >1,000 mm2 on computed tomography.

Optimal Intravascular Ultrasound-Guided Percutaneous Coronary Intervention in Patients With Multivessel Disease and Diabetes.

There is a scarcity of data on clinical outcomes after intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) in patients with multivessel disease and diabetes. OPTIVUS-Complex PCI study multivessel cohort was a prospective multicenter single-arm trial enrolling 1021 patients who underwent multivessel PCI including left anterior descending coronary artery using IVUS aiming to meet the prespecified OPTIVUS criteria for optimal stent expansion. We compared the clinical outcomes between those patients with and without diabetes. The primary endpoint was a composite of death, myocardial infarction, stroke, or any coronary revascularization. There were 560 patients (54.8%) with diabetes, and 461 patients (45.2%) without diabetes. Mean age was not different between the 2 groups (70.9±9.7 years versus 71.7±10.4 years, P=0.17). Patients with diabetes more often had chronic kidney disease and complex coronary artery disease as indicated by the greater total number of stents and longer total stent length. The rate of meeting OPTIVUS criteria was not different between the 2 groups (61.2% vs. 60.7%, P=0.83). The cumulative 1-year incidence of the primary endpoint was not different between the 2 groups (10.8% versus 9.8%, log-rank P=0.65). After adjusting confounders, the risk of diabetes relative to non-diabetes remained insignificant for the primary endpoint (HR, 0.97; 95%CI, 0.65-1.44; P=0.88). In conclusion, in patients who underwent multivessel IVUS-guided PCI, and were managed with contemporary clinical practice, patients with diabetes had similar 1-year outcomes compared with patients without diabetes.

Carcinoid Heart Disease With Hypoxemia.

Patent foramen ovale (PFO) complicated with carcinoid heart disease (CHD) can cause severe hypoxia and worsening clinical conditions. We report the case of a patient with CHD in poor general condition with multiple severe valve regurgitations and PFO, who underwent successful percutaneous closure of the PFO.

Long-term prognostic value of the H2FPEF score in patients undergoing transcatheter aortic valve implantation.

AIMS: A considerable proportion of candidates for transcatheter aortic valve implantation (TAVI) have underlying heart failure (HF) with preserved ejection fraction (HFpEF), which can be challenging for diagnosis because significant valvular heart disease should be excluded before diagnosing HFpEF. This study investigated the long-term prognostic value of the pre-procedural H2FPEF score in patients with preserved ejection fraction (EF) undergoing TAVI. METHODS AND RESULTS: Patients who underwent TAVI between October 2013 and May 2017 were enrolled from the Optimized CathEter vAlvular iNtervention-Transcatheter Aortic Valve Implantation Japanese multicentre registry. After excluding 914 patients, 1674 patients with preserved EF ≥ 50% (median age: 85 years, 72% female) were selected for calculation of the H2FPEF score and were dichotomized into two groups: the low H2FPEF score [0-5 points; n = 1399 (83.6%)] group and the high H2FPEF score [6-9 points; n = 275 (16.4%)] group. Patients with high H2FPEF scores were associated with a higher prevalence of New York Heart Association Functional Class III/IV (59.3% vs. 43.7%, P < 0.001), diabetes (24.4% vs. 18.5%, P = 0.03), and paradoxical low-flow, low-gradient aortic stenosis (15.9% vs. 6.2%, P < 0.001). These patients showed worse prognoses than those with low H2FPEF scores regarding the cumulative 2 year all-cause mortality (26.3% vs. 15.5%, log-rank P < 0.001), cardiovascular mortality (10.5% vs. 5.4%, log-rank P < 0.001), HF hospitalization (16.2% vs. 6.7%, log-rank P < 0.001), and the composite endpoint of cardiovascular mortality and HF hospitalization (23.8% vs. 10.8%, log-rank P < 0.001). After adjustment for several confounders, the high H2FPEF scores were independently associated with increased risk for all-cause mortality [adjusted hazard ratio (HR), 1.48; 95% confidence interval (CI), 1.09-2.00; P = 0.011] and for the composite endpoint of cardiovascular mortality and HF hospitalization (adjusted HR, 1.95; 95% CI, 1.38-2.74; P < 0.001). Subgroup analysis confirmed the excess risk of high H2FPEF scores relative to low H2FPEF scores for the composite endpoint of cardiovascular mortality and HF hospitalization increased with a lower Society of Thoracic Surgeons (STS) score (STS score <8%: adjusted HR, 2.40; 95% CI, 1.50-3.85; P < 0.001; STS score ≥8%: adjusted HR, 1.34; 95% CI, 0.79-2.28; P = 0.28; Pinteraction = 0.030). CONCLUSIONS: The H2FPEF score is useful for predicting long-term adverse outcomes after TAVI, including all-cause mortality, cardiovascular mortality, and HF hospitalization for patients with preserved EF. More aggressive interventions targeting HFpEF in addition to the TAVI procedure might be relevant in patients with high H2FPEF scores, particularly in those with a lower surgical risk.

Outcomes of left bundle branch area pacing compared to His bundle pacing and right ventricular apical pacing in Japanese patients with bradycardia.

Background: His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) emerge as better alternatives to right ventricular apical pacing (RVAP) in patients with bradycardia requiring permanent cardiac pacing. We aimed to compare the clinical outcomes of LBBAP, HBP, and RVAP in Japanese patients with bradycardia. Methods: A total of 424 patients who underwent successful pacemaker implantation (HBP, n = 53; LBBAP, n = 75; and RVAP, n = 296) were retrospectively enrolled in this study. The primary study endpoint was the cumulative incidence of heart failure hospitalization (HFH) during the follow-up. Results: The success rate for implantation was higher in the LBBAP group than in the HBP group (94.9% and 81.5%, respectively). Capture threshold increase >1V during the follow-up occurred in the HBP and RVAP groups (9.4% and 5.1%, respectively), while it did not in the LBBAP group. The cumulative incidence of HFH was significantly lower in the LBBAP group than the RVAP (adjusted hazard ratio, 0.12 [95% confidence interval: 0.02-0.86]; p = .034); it did not differ between the HBP and RVAP groups (adjusted hazard ratio, 0.48 [95% confidence interval: 0.17-1.34]; p = .16). Advanced age, mean percent right ventricular pacing (per 10% increase), left ventricular ejection fraction <50%, and RVAP were associated with HFH. Conclusions: Compared to RVAP and HBP, LBBAP appeared more feasible and effective in patients with bradycardia requiring permanent cardiac pacing.

Ticagrelor or Clopidogrel Monotherapy vs Dual Antiplatelet Therapy After Percutaneous Coronary Intervention: A Systematic Review and Patient-Level Meta-Analysis.

Importance: Among patients undergoing percutaneous coronary intervention (PCI), it remains unclear whether the treatment efficacy of P2Y12 inhibitor monotherapy after a short course of dual antiplatelet therapy (DAPT) depends on the type of P2Y12 inhibitor. Objective: To assess the risks and benefits of ticagrelor monotherapy or clopidogrel monotherapy compared with standard DAPT after PCI. Data Sources: MEDLINE, Embase, TCTMD, and the European Society of Cardiology website were searched from inception to September 10, 2023, without language restriction. Study Selection: Included studies were randomized clinical trials comparing P2Y12 inhibitor monotherapy with DAPT on adjudicated end points in patients without indication to oral anticoagulation undergoing PCI. Data Extraction and Synthesis: Patient-level data provided by each trial were synthesized into a pooled dataset and analyzed using a 1-step mixed-effects model. The study is reported following the Preferred Reporting Items for Systematic Review and Meta-Analyses of Individual Participant Data. Main Outcomes and Measures: The primary objective was to determine noninferiority of ticagrelor or clopidogrel monotherapy vs DAPT on the composite of death, myocardial infarction (MI), or stroke in the per-protocol analysis with a 1.15 margin for the hazard ratio (HR). Key secondary end points were major bleeding and net adverse clinical events (NACE), including the primary end point and major bleeding. Results: Analyses included 6 randomized trials including 25 960 patients undergoing PCI, of whom 24 394 patients (12 403 patients receiving DAPT; 8292 patients receiving ticagrelor monotherapy; 3654 patients receiving clopidogrel monotherapy; 45 patients receiving prasugrel monotherapy) were retained in the per-protocol analysis. Trials of ticagrelor monotherapy were conducted in Asia, Europe, and North America; trials of clopidogrel monotherapy were all conducted in Asia. Ticagrelor was noninferior to DAPT for the primary end point (HR, 0.89; 95% CI, 0.74-1.06; P for noninferiority = .004), but clopidogrel was not noninferior (HR, 1.37; 95% CI, 1.01-1.87; P for noninferiority > .99), with this finding driven by noncardiovascular death. The risk of major bleeding was lower with both ticagrelor (HR, 0.47; 95% CI, 0.36-0.62; P < .001) and clopidogrel monotherapy (HR, 0.49; 95% CI, 0.30-0.81; P = .006; P for interaction = 0.88). NACE were lower with ticagrelor (HR, 0.74; 95% CI, 0.64-0.86, P < .001) but not with clopidogrel monotherapy (HR, 1.00; 95% CI, 0.78-1.28; P = .99; P for interaction = .04). Conclusions and Relevance: This systematic review and meta-analysis found that ticagrelor monotherapy was noninferior to DAPT for all-cause death, MI, or stroke and superior for major bleeding and NACE. Clopidogrel monotherapy was similarly associated with reduced bleeding but was not noninferior to DAPT for all-cause death, MI, or stroke, largely because of risk observed in 1 trial that exclusively included East Asian patients and a hazard that was driven by an excess of noncardiovascular death.

Difference in one-year late lumen loss between high- and low-dose paclitaxel-coated balloons for femoropopliteal disease.

The objective of the study is to investigate the difference in 1-year late lumen loss (LLL) between the high- (IN.PACT Admiral) and low-dose (Lutonix) paclitaxel-coated balloon (PCB). Although a recent randomized clinical trial demonstrated no difference in efficacy endpoint between high- and low-dose PCB, it remains unclear whether high-dose PCB was superior to low-dose PCB in actual clinical practice. We enrolled 64 patients with 67 de novo femoropopliteal lesions who underwent PCB angioplasty at Kokura Memorial Hospital from May 2014 to March 2020 and subsequent follow-up angiography after 1 year. The primary endpoint was 1-year LLL, whereas the secondary endpoints were binary restenosis and clinically driven target lesion revascularization (CD-TLR) after 1 year. The high- and low-dose PCB groups had 45 and 22 lesions, respectively. Although the low-dose PCB group had higher rates of coronary artery disease, hemodialysis, and chronic limb-threatening ischemia than the high-dose PCB group, the latter had a longer lesion length and more lesions with a TASC classification C or D than the former. The high-dose PCB group had a significantly lower LLL than the low-dose PCB group (0.40 ± 1.05 vs. 1.19 ± 1.03 mm; P = 0.003, respectively). Moreover, the high-dose PCB group had significantly lower rates of binary restenosis at 1 year than the low-dose PCB group (22.2% vs. 50.0%; P = 0.02, respectively). Moreover, negative LLL was only observed in the high-dose PCB group (33.3% vs. 0%, P = 0.005). The high-dose PCB group had a significantly lower LLL than the low-dose PCB group.

Auxiliary roles of nardilysin in the early diagnosis of acute coronary syndrome: a prospective cohort study, the Nardi-ACS study.

Acute coronary syndrome (ACS) includes myocardial infarction (MI) and unstable angina (UA). MI is defined by elevated necrosis markers, preferably high-sensitivity cardiac troponins (hs-cTn). However, it takes hours for cTn to become elevated after coronary occlusion; therefore, difficulties are associated with diagnosing early post-onset MI or UA. The aim of this prospective cohort study was to examine the diagnostic ability of serum nardilysin (NRDC) for the early detection of ACS. This study consisted of two sequential cohorts, the Phase I cohort, 435 patients presenting to the emergency room (ER) with chest pain, and the Phase II cohort, 486 patients with chest pain who underwent coronary angiography. The final diagnosis was ACS in 155 out of 435 patients (35.6%) in the phase I and 418 out of 486 (86.0%) in the phase II cohort. Among 680 patients who presented within 24 h of onset, 466 patients (68.5%) were diagnosed with ACS. Serum NRDC levels were significantly higher in patients with ACS than in those without ACS. The sensitivity of NRDC in patients who presented within 6 h after the onset was higher than that of hsTnI, and the AUC of NRDC within 1 h of the onset was higher than that of hsTnI (0.718 versus 0.633). Among hsTnI-negative patients (300 of 680 patients: 44.1%), 136 of whom (45.3%) were diagnosed with ACS, the sensitivity and the NPV of NRDC were 73.5 and 65.7%, respectively. When measured in combination with hsTnI, NRDC plays auxiliary roles in the early diagnosis of ACS.

Impact of a Less Than 50% Residual Stenosis Following Vessel Preparation in Femoropopliteal Drug-Coated Balloon Angioplasty.

PURPOSE: Drug-coated balloon (DCB) has been established as first-line therapy in femoropopliteal (FP) intervention, and successful vessel preparation (VP) is considered a key element. However, the clinical impact of successful VP remains unknown. This retrospective study examined the clinical impact of successful VP in DCB FP intervention. METHODS: In total, 268 patients (308 limbs) who underwent successful FP intervention using DCB without atherectomy devices for symptomatic lower extremity artery disease between March 2018 and December 2019 were included in this study (high-dose DCB: 69.8%; low-dose DCB: 30.2%). Successful VP was defined as <50% residual stenosis and

Assessing Potential Risks of Future Redo Transcatheter Aortic Valve Replacement in Asian Patients.

Background: In the Asian cohort, data are limited on the risk for coronary obstruction due to sinus of Valsalva (SOV) sequestration in redo transcatheter aortic valve replacement (TAVR) procedures. Objectives: The aim of this study was to assess the potential risk for coronary obstruction in simulated redo TAVR in Asian patients. Methods: Post-TAVR computed tomographic data from 788 patients who received balloon-expandable (BE) SAPIEN 3 transcatheter aortic valves (TAVs) and 334 patients who received self-expanding (SE) Evolut R or Evolut PRO TAVs were analyzed. The risk for coronary obstruction due to SOV sequestration in redo TAVR, defined as the TAV commissure level above the sinotubular junction (STJ) and a TAV-to-STJ distance <2.0 mm in each coronary sinus, was retrospectively evaluated. Results: The potential risks for coronary obstruction due to SOV sequestration at 1 or both coronary arteries were identified in 52.1% of the BE TAV group and 71.3% of the SE TAV group (P < 0.001). After adjusting for multiple covariates, STJ diameter, STJ height, TAV oversizing degree by area, and implantation depth were independently associated with SOV sequestration risk in the BE TAV group, whereas STJ diameter and implantation depth were independently associated with SOV sequestration risk in the SE TAV group. Conclusions: Coronary obstruction due to SOV sequestration in redo TAVR may occur in a substantial number of Asian patients. This finding suggests the importance of considering the structural feasibility of future redo TAVR when implanting the first TAV, especially in Asian patients with long life expectancy.

von Willebrand factor Ristocetin co-factor activity to von Willebrand factor antigen level ratio for diagnosis of acquired von Willebrand syndrome caused by aortic stenosis.

Background: Severe aortic stenosis (AS) causes acquired von Willebrand syndrome by the excessive shear stress-dependent cleavage of high molecular weight multimers of von Willebrand factor (VWF). While the current standard diagnostic method is so-called VWF multimer analysis that is western blotting under nonreducing conditions, it remains unclear whether a ratio of VWF Ristocetin co-factor activity (VWF:RCo) to VWF antigen levels (VWF:Ag) of <0.7, which can be measured with an automated coagulation analyzer in clinical laboratories and is used for the diagnosis of hereditary von Willebrand disease. Objectives: To evaluated whether the VWF:RCo/VWF:Ag is useful for the diagnosis of AS-induced acquired von Willebrand syndrome. Methods: VWF:RCo and VWF:Ag were evaluated with the VWF large multimer index as a reference, which represents the percentage of a patient's VWF high molecular weight multimer ratio to that of standard plasma in the VWF multimer analysis. Results: We analyzed 382 patients with AS having transaortic valve maximal pressure gradients of >30 mmHg, 27 patients with peripheral artery disease, and 46 control patients free of cardiovascular disease with osteoarthritis, diabetes, and so on. We assumed a large multimer index of <80% as loss of VWF large multimers since 59.0% of patients with severe AS had the indices of <80%, while no control patients or patients with peripheral artery disease, except for 2 patients, exhibited the indices of <80%. The VWF:RCo/VWF:Ag ratios, measured using an automated blood coagulation analyzer, were correlated with the indices (rs = 0.470, P < .001). When the ratio of <0.7 was used as a cut-off point, the sensitivity and specificity to VWF large multimer indices of <80% were 0.437 and 0.826, respectively. Conclusion: VWF:RCo/VWF:Ag ratios of <0.7 may indicate loss of VWF large multimers with high specificity, but low sensitivity. VWF:RCo/VWF:Ag ratios in patients with AS having a ratio of <0.7 may be useful for monitoring the loss of VWF large multimers during their clinical courses.

Aspirin-free strategy for percutaneous coronary intervention in acute coronary syndrome based on the subtypes of acute coronary syndrome and high bleeding risk: the STOPDAPT-3 trial.

BACKGROUND AND AIMS: High bleeding risk (HBR) and acute coronary syndrome (ACS) subtypes are critical in determining bleeding and cardiovascular event risk after percutaneous coronary intervention (PCI). METHODS: In 4476 ACS patients enrolled in the STOPDAPT-3, where the no-aspirin and dual antiplatelet therapy (DAPT) strategies after PCI were randomly compared, the pre-specified subgroup analyses were conducted based on HBR/non-HBR and ST-segment elevation myocardial infarction (STEMI)/non-ST-segment elevation ACS (NSTE-ACS). The co-primary bleeding endpoint was BARC type 3 or 5, and the co-primary cardiovascular endpoint was a composite of cardiovascular death, myocardial infarction, definite stent thrombosis, or ischemic stroke at 1 month. RESULTS: Irrespective of the subgroups, the effect of no-aspirin compared with DAPT was not significant for the bleeding endpoint (HBR [N = 1803]: 7.27% and 7.91%, HR 0.91, 95%CI 0.65-1.28; non-HBR [N = 2673]: 3.40% and 3.65%, HR 0.93, 95%CI 0.62-1.39; Pinteraction = 0.94; STEMI [N = 2553]: 6.58% and 6.56%, HR 1.00, 95% CI 0.74-1.35; NSTE-ACS [N = 1923]: 2.94% and 3.64%, HR 0.80, 95%CI 0.49-1.32; Pinteraction = 0.45), and for the cardiovascular endpoint (HBR: 7.87% and 5.75%, HR 1.39, 95%CI 0.97-1.99; non-HBR: 2.56% and 2.67%, HR 0.96, 95%CI 0.60-1.53; Pinteraction = 0.22; STEMI: 6.07% and 5.46%, HR 1.11, 95%CI 0.81-1.54; NSTE-ACS: 3.03% and 1.71%, HR 1.78, 95%CI 0.97-3.27; Pinteraction = 0.18). CONCLUSIONS: In patients with ACS undergoing PCI, the no-aspirin strategy compared to the DAPT strategy failed to reduce major bleeding events irrespective of HBR and ACS subtypes. The numerical excess risk of the no-aspirin strategy relative to the DAPT strategy for cardiovascular events was observed in patients with HBR and in patients with NSTE-ACS.

In-hospital outcomes after SAVR or TAVI in patients with severe aortic stenosis.

There were no data comparing the in-hospital outcomes after transcatheter aortic valve implantation (TAVI) with those after surgical aortic valve replacement (SAVR) in Japan. Among consecutive patients with severe AS between April 2018 and December 2020 in the CURRENT AS Registry-2, we identified 1714 patients who underwent aortic valve replacement (TAVI group: 1134 patients, and SAVR group: 580 patients). Patients in the TAVI group were much older (84.4 versus 73.6 years, P < 0.001) and more often had comorbidities than those in the SAVR group. In-hospital death rate was numerically lower in the TAVI group than in the SAVR group (0.6% versus 2.2%). After excluding patients with dialysis, in-hospital death rate was very low and comparable in the TAVI and SAVR groups (0.6% versus 0.8%). The rates of major bleeding and new-onset atrial fibrillation during index hospitalization were higher after SAVR than after TAVI (72% versus 20%, and 26% versus 4.6%, respectively), while the rate of pacemaker implantation was higher after TAVI than after SAVR (8.1% versus 2.4%). Regarding the echocardiographic data at discharge, the prevalence of patient-prosthesis mismatch was lower in the TAVI group than in the SAVR group (moderate: 9.0% versus 26%, and severe: 2.6% versus 4.8%). In this real-world data in Japan, TAVI compared with SAVR was chosen in much older patients with more comorbidities with severe AS. In-hospital death rate was numerically lower in the TAVI group than in the SAVR group.

One-year safety and effectiveness of the Agent paclitaxel-coated balloon for the treatment of small vessel disease and in-stent restenosis.

The Agent device consists of a semi-compliant balloon catheter, which is coated with a therapeutic low-dose formulation of paclitaxel (2 µg/mm2) blended with an inactive excipient acetyl-tri-n-butyl citrate (ATBC). AGENT Japan SV is a randomized controlled study that enrolled 150 patients from 14 Japanese sites treated with Agent or SeQuent Please paclitaxel-coated balloon. This study also includes a single-arm substudy evaluating the safety and effectiveness of Agent in patients with in-stent restenosis (ISR). Patients with a single de novo native lesion (lesion length ≤ 28 mm and reference diameter ≥ 2.00 to < 3.00 mm) were randomized 2:1 to receive either Agent (n = 101) or SeQuent Please (n = 49). The ISR substudy enrolled 30 patients with lesion length ≤ 28 mm and reference diameter ≥ 2.00 to ≤ 4.00 mm. In the SV RCT, target lesion failure (TLF) at 1 year occurred in four patients treated with Agent (4.0%) versus one patient with SeQuent Please (2.0%; P = 1.00). None of the patients in either treatment arm died. There were no significant differences in the rates of myocardial infarction, target lesion revascularization and target lesion thrombosis through 1 year. In the ISR substudy, the 1-year rates of TLF and target lesion thrombosis were 6.7% and 0.0%, respectively. These data support the safety and effectiveness of the Agent paclitaxel-coated balloon in patients with small vessels and ISR.

Influence of the irrigation flow pattern and catheter tip design on the lesion formation: an ex vivo experimental model.

BACKGROUND: Lesion formation during catheter ablation is influenced by the power, contact force (CF), time, and catheter stability. However, the influence of the irrigation effects on lesion formation remains unknown. METHODS: An ex vivo experiment using conductive gel was performed. Using three different catheter designs (TactiFlex ™ SE [TF], IntellaNav MiFi ™ OI [MiFi], QDOT MICRO™ [QDOT]), a cross-sectional analysis of the lesion size and surface lesion type of 10g/40W lesions with a combination of various ablation times was performed in protocol 1. A longitudinal analysis (combination of various powers [30, 40, and 50W] and various ablation times with a 10g setting) was performed to investigate the influence of the auto-regulated irrigation system (QDOT) on lesion formation in protocol 2. RESULTS: The lesion formation with the QDOT catheter tended to create larger ablation lesions, while that with the TF catheter created smaller lesions than the other catheters. The lesion surface characteristics were divided into two patterns: ring (MiFi catheter and QDOT) and crescent (TF) patterns. The auto-regulated irrigation system did not influence the lesion formation, and the relationship between the lesion formation and RF energy exhibited similar changes regardless of the ablation power setting. CONCLUSION: The lesion formation and lesion surface characteristics differed among the different irrigation tip designs. An auto-regulated irrigation system did not affect the lesion creation or surface lesion characteristics. Care should be given to the inter-product differences in the lesion characteristics during RF catheter ablation, partly due to the irrigation flow control and tip design.