Results of open thoracoabdominal aortic replacement in patients unsuitable for or after endovascular repair with remaining disease components.

OBJECTIVES: Our goal was to evaluate outcomes in all-comer patients undergoing open thoracoabdominal aortic replacement either unsuitable for or after failed endovascular aortic repair. METHODS: Within a 4-year period, we analysed a consecutive series of 80 patients undergoing elective, urgent and emergency thoracoabdominal aortic replacement. Preoperative data, intraoperative data and outcomes were evaluated. Specific attention was given to technical refinements needed in patients after previous endovascular aortic repair. RESULTS: Eighty patients underwent thoracoabdominal aortic replacement: 11.3% (n = 9) had connective tissue disorders. Twenty-six patients (32.5%) had previous endovascular aortic repair and 54 (67.5%) did not have previous endovascular repair. The mean age was 64.2 ± 12 years, and 70% (n = 56) were male. The mean EuroSCORE was 7.9 ± 2.6. Urgent or emergency operations were done in 22.5% (n = 18). Overall mortality was 20% (n = 16); symptomatic spinal cord injury occurred in 5% (n = 4). We did not observe differences in survival according to the presence or absence of previous endovascular aortic repair (P = 0.524). Multivariate regression analysis revealed the amount of packed red blood cell units (P = 0.009, confidence interval 1.028-1.215, odds ratio = 1.117) as a predictor of in-hospital death. Follow-up was 100% (37.9 ± 15.8 months); freedom from aortic-related reintervention was 96.3%. CONCLUSIONS: Despite an early attrition rate, survival after open thoracoabdominal aortic replacement is excellent, and freedom from aortic-related reintervention is high. Open surgery continues to remain an essential component in the treatment armamentarium of acute and chronic thoracoabdominal aortic pathology.

Electrocardiographic diagnosis of atrial cardiomyopathy to predict atrial contractile dysfunction, thrombogenesis and adverse cardiovascular outcomes.

Thromboembolism and stroke are dreaded complications in atrial fibrillation (AF). Established risk stratification models identify susceptible patients, but their discriminative properties are poor. Atrial cardiomyopathy (ACM) is associated to thromboembolism and stroke in smaller studies, but the modalities used for ACM-diagnosis (MRI and endocardial mapping) are unsuitable for widespread population screening. We aimed to investigate an ECG-based diagnosis of ACM using amplified p-wave analysis (APWA) for stratification of thromboembolic risk and cardiovascular outcome. In this case-control study, ACM-staging was performed using APWA on digital 12-lead sinus rhythm-ECGs in patients with LAA-thrombus and a propensity-score-matched control-cohort. Left atrial contractile function and thrombi were evaluated by transesophageal echocardiography (TEE). Outcome for MACCE including death was assessed using official registries and structured phone interviews. Left-atrial appendage [LAA]-thrombi and appropriate sinus rhythm-ECGs for ACM-staging were found in 109 of 4086 patients that were matched 1:1 to control patients without thrombus (218 patients in total). Both cohorts were comparable regarding cardiovascular risk factors, anticoagulants and CHA2DS2-VASC-score. ACM-stages 1 to 3 (equivalent to no, moderate and extensive ACM) were found in 63 (57.8%), 36 (33.0%) and 10 (9.2%) of patients without and 3 (2.8%), 23 (21.1%) and 83 (76.1%) of patients with LAA-thrombi. Atrial contractile function decreased from ACM-stages 1 to 3 (LAA-flow velocities 38 ± 16 cm/s, 31 ± 15 cm/s and 21 ± 12 cm/s; p < 0.0001), while the likelihood for LAA-thrombus increased (2.8%, 21.1% and 76.1%, p < 0.001). Multivariable analysis confirmed an independent odds ratio for LAA-thrombus of 24.6 (p < 0.001) per ACM-stage. Two-year survival free of stroke/TIA, hospitalization for heart failure, myocardial infarction or all-cause death was strongly reduced in ACM-stage 3 (53.8%) compared to no or moderate ACM (82.8% and 84.7%, respectively; p < 0.0001). Electrocardiographic diagnosis of ACM identifies patients with atrial contractile dysfunction and atrial thrombi at risk for adverse cardiovascular outcomes and death.

Rotational thromboelastometry and conventional coagulation tests in patients undergoing major cardiac or aortic surgery: a retrospective single-center cohort study.

Algorithms for treatment of diffuse bleeding in cardiac surgery are based on intervention thresholds of coagulation tests, such as rotational thromboelastometry (ROTEM) or conventional laboratory tests. The relationship between these two approaches is unclear in patients with increased risk of coagulation abnormalities. We retrospectively analyzed the data of 248 patients undergoing major cardiac and/or aortic surgery. ROTEM and conventional laboratory tests were performed simultaneously after termination of cardiopulmonary bypass and protamine administration to investigate the extrinsic and intrinsic system, and to determine deficiencies in platelets and fibrinogen. We evaluated the association between ROTEM and conventional tests by linear regression analysis and compared the frequency of exceeding established thresholds for clinical intervention. Significant linear associations between ROTEM 10 min after the start of coagulation, and plasma fibrinogen concentration or platelet count (FIBTEM A10, R2 = 0.67, p < 0.001; EXTEM A10, R2 = 0.47, p < 0.001) were obtained. However, the 95% prediction intervals exceeded clinically useful ranges (92-233 mg/dL fibrinogen at the intervention threshold of FIBTEM A10 = 10 mm; 14 × 103-122 × 103/µL platelets at the intervention threshold of EXTEM A10 = 40 mm). The association between EXTEM and INR (R2 = 0.23), and INTEM and aPTT (R2 = 0.095) was poor. The frequency of exceeding intervention thresholds and, consequently, of triggering treatment, varied markedly between ROTEM and conventional tests (p < 0.001 for all comparisons). The predictability of conventional coagulation test results by ROTEM is limited, thus hampering the interchangeability of methods in clinical practice.

Direct Versus Side Graft Cannulation From the Right Axillary Artery in Thoracic Aortic Surgery.

BACKGROUND: The axillary artery can be cannulated for antegrade cerebral perfusion directly or by employing a prosthetic vascular graft anastomosed to the artery. METHODS: From 2008 until 2019, 688 patients underwent axillary artery cannulation. Of those, 287 underwent direct cannulation and 401 cannulation through a side graft. We identified risk factors for cannulation-related complications, and after propensity score matching, we compared the 2 matched cohorts' cannulation-related and postoperative outcomes. RESULTS: A smaller axillary-artery diameter (odds ratio = 0.70; 95% confidence interval, 0.56-0.87) and emergency surgery (odds ratio = 2.23; 95% confidence interval, 1.27-3.92) were identified as risk factors for cannulation-associated complications. In the propensity score-matched cohorts (n = 266 in each), the number of patients experiencing cannulation-related complications was significantly higher in the direct cannulation group than in the side-graft group (n = 33 [12.4%] versus n = 15 [5.6%]; P = .01). The direct group's incidence of iatrogenic axillary artery dissection was significantly higher (n = 17 [6.4%] versus n = 4 [1.5%] P = .008); their incidence of postoperative stroke was also significantly higher (n = 39 [14.7%] versus n = 21 [7.9%]; P = .025). Patients cannulated with a side graft needed more transfusions of blood products (median [IQR]: 3.0 [1.0-6.0] versus 4.0 [2.0-7.0;] P = .009). CONCLUSIONS: Cannulating the right axillary through a vascular prosthetic graft reduces cannulation-related complications such as iatrogenic axillary artery dissection and lowers stroke rates. To help prevent cannulation-related complications and stroke, we recommend the routine use of a side graft when cannulating the axillary artery.

Perioperative Changes of Right Ventricular Function in Cardiac Surgical Patients Assessed by Myocardial Deformation Analysis and 3-Dimensional Echocardiography.

OBJECTIVES: To test the hypothesis that longitudinal strain of the right ventricle (RV) is significantly reduced in patients undergoing cardiac surgery with extracorporeal circulation and cardioplegic cardiac arrest at the end of surgery, whereas RV ejection fraction remains unchanged. DESIGN: Prospective observational cohort study. SETTING: Single university hospital. PARTICIPANTS: Thirty patients with normal myocardial function undergoing coronary artery bypass grafting with cardioplegic cardiac arrest. INTERVENTIONS: Right ventricular 3-dimensional echocardiography and strain analysis were performed preoperatively, intraoperatively, and postoperatively. MEASUREMENTS AND MAIN RESULTS: Peak longitudinal systolic strain of the RV lateral and inferior wall, RV outflow tract, and interventricular septum was reduced significantly at the end of surgery after sternal closure compared to preoperatively (lateral: -16 ± 5 v -22 ± 4, p < 0.001; inferior: -12 ± 4 v -19 ± 5, p < 0.001; outflow tract, -11 ± 5 v . -20 ± 6, p < 0.001; septum: -9 ± 3 v -14 ± 4, p < 0.001), whereas peak circumferential systolic strain of the RV lateral wall had increased significantly (-16 ± 4 v -12 ± 5, p = 0.008). Right ventricular ejection fraction remained stable (51 ± 6% v. 50 ± 7%, p = 0.34). CONCLUSION: In patients undergoing coronary artery bypass grafting with cardioplegic cardiac arrest, the longitudinal contraction of the RV lateral and inferior wall, the RV outflow tract, and the interventricular septum is impaired at the end of surgery. This impairment is compensated by an increase in circumferential contraction without changes in RV ejection fraction.

The Duration of the Amplified Sinus-P-Wave Identifies Presence of Left Atrial Low Voltage Substrate and Predicts Outcome After Pulmonary Vein Isolation in Patients With Persistent Atrial Fibrillation.

OBJECTIVES: Left atrial (LA) low-voltage substrate (LVS) potentially slows intra-atrial conduction, which might identify patients at risk for arrhythmia recurrence following pulmonary vein isolation (PVI). BACKGROUND: Up to 50% of patients with persistent atrial fibrillation (AF) have arrhythmia recurrence following PVI, mostly due to arrhythmogenic LA LVS. METHODS: Seventy-two patients with persistent AF underwent electrocardioversion to sinus rhythm and high-density voltage mapping of the left atrium. Invasively measured LA activation time and P-wave duration (PWD; total PWD and LA PWD [measured from -dV/dt in leads V1 and V2 until the end of the P-wave]) on amplified (40 to 50 mm/mV, 100 to 200 mm/s) digitized 12-lead electrocardiography (ECG) were compared with the extent of LA LVS (<0.5 and <1. 0mV). Freedom from arrhythmia following PVI was evaluated in 143 patients with persistent AF stratified according to amplified PWD before ablation. RESULTS: LA LVS resulted in regional conduction delay, which increased LA activation time (r = 0.79). LA PWD strongly correlated with LA activation time (r = 0.96) and LA LVS (r = 0.80). As the first (right atrial) portion of the P-wave (from P-wave beginning until -dV/dt in leads V1 and V2) was not affected by LA LVS, total PWD correlated with LA LVS (r = 0.84). PWD ≥150 ms identified advanced LA LVS with 94.3% sensitivity and 91.7% specificity. One-year arrhythmia freedom following PVI-only was significantly higher in patients with PWD <150 ms (n = 73) compared with those with prolonged PWD ≥150 ms (n = 70) (72.0% vs. 40.8%; p = 0.003). CONCLUSIONS: Advanced arrhythmogenic LVS is associated with significant intra-atrial conduction delay, which is accurately measurable by prolongation of PWD on amplified 12-lead ECG. PWD ≥150 ms during sinus rhythm measured prior to ablation identifies patients with persistent AF who are at increased risk for arrhythmia recurrence following PVI.

Alteration of von Willebrand Factor after Transcatheter Aortic Valve Replacement in the Absence of Paravalvular Regurgitation.

Moderate or severe paravalvular regurgitation after transcatheter aortic valve implantation (TAVI) is frequently associated with a loss of high-molecular-weight multimers of von Willebrand factor (VWF) and a reduced VWF collagen-binding capacity. It is unclear whether this phenomenon can also be observed in patients with mild paravalvular regurgitation, and whether there are differences between patients undergoing conventional aortic valve replacement (AVR) or TAVI. We analysed the multimeric structure of VWF and the ratio of VWF collagen-binding capacity to VWF antigen pre- and postoperatively in 12 patients scheduled for AVR and in 31 patients scheduled for TAVI. Echocardiographic examinations were performed pre-, intra- and postoperatively. Nine patients (75%) undergoing AVR and 18 patients (58%) undergoing TAVI showed pathological VWF functionality preoperatively (p = 0.48). Five to 7 days postoperatively, VWF functionality normalised in all patients with AVR, four of them with mild paravalvular regurgitation. VWF functionality was still altered in nine patients after TAVI (p = 0.044 between groups), five of them with and four without mild paravalvular regurgitation (p = 0.1).Altered VWF functionality was observed in nearly one-third of patients after TAVI, but not after AVR. This phenomenon was not related to paravalvular regurgitation, but may indicate differences in the response of the haemostatic system to the prosthetic heart valve design or the valve replacement procedure.

Aortic Replacement After TEVAR-Diameter Correction With Modified Use of the Siena Prosthesis.

BACKGROUND: To report a new technique for diameter correction in patients after thoracic endovascular aortic repair (TEVAR) with large stent-grafts using the Vascutek Siena 4-branch collared prosthesis (Vascutek Terumo, Inchinnan, Scotland, UK) in patients undergoing thoracoabdominal (TA) aortic replacement. METHODS: Within a 24-month period, 39 patients underwent TA replacement at our center. Of these, 6 patients had undergone previous TEVAR with large stent-grafts (42 to 48 mm diameter). Indications for TEVAR were aneurysm formation in 3 patients and residual type B aortic dissection (status post repair of type A dissection) in 3 patients. In these patients, the Vascutek Siena 4-branch prosthesis was used in a reversed fashion, removing the elephant trunk portion and using the sewing collar for diameter correction at the anastomotic site. RESULTS: No 30-day mortality and no stroke or symptomatic spinal cord ischemia was observed. Median diameter of the TEVAR graft at the anastomotic site was 44 mm. Median size of the Siena graft used was 26 mm. Diameter correction was successfully achieved in all patients by tailoring the sewing collar of the Siena 4-branch prosthesis to the individual need according to the diameter of the distal end of the stent-graft. CONCLUSIONS: Using the sewing collar of the Vascutek Siena 4-branch prosthesis for diameter correction in patients undergoing TA replacement after previous TEVAR with large stent-grafts adds a useful adjunct to the armamentarium of options in a growing patient population.

Important reduction of the radiation dose for pulmonary vein isolation using a multimodal approach.

Aims: The number of pulmonary vein isolation (PVI) ablation procedures is steadily increasing worldwide resulting in a substantial radiation exposure to patients and operators. The aim of our study was to reduce radiation exposure during these procedures to a critical amount without compromising patient safety. Methods and results: First, we assessed radiation exposure for primary PVI procedures over time (2005-2015) at the University Heart Center Freiburg-Bad Krozingen. Second, we prospectively evaluated in 52 patients, the efficacy and safety of a novel radiation reduction program (particularly applying an enhanced fluoroscopy pulse dose-reduction and optimized 3D-mapping system use). In 2035 primary PVI procedures, radiation exposure, assessed as estimated effective dose (eED in mSv, dose area product * 0.002 * conversion factor for females), fluoroscopy-time, and procedure-time decreased significantly from 2005 to 2015 (e.g. eED decreased from 9.3 (interquartile range (IQR) 6.4-13.4) mSv to 0.9 (IQR 0.5-1.6) mSv, p for trend <0.001). Importantly, application of the enhanced radiation reduction program further reduced eED to 0.4 mSv (IQR 0.3-0.6, P < 0.001 vs. control), a value not significantly different from slow-pathway ablation procedures (P = 0.41). Multiple linear regression analysis identified the radiation reduction program as the only independent variable associated with a decrease in radiation exposure. Conclusion: Radiation exposure during PVI decreased over the last decade and can further be reduced significantly by the implementation of an enhanced radiation reduction program.

Ablation of Persistent Atrial Fibrillation Targeting Low-Voltage Areas With Selective Activation Characteristics.

BACKGROUND: Complex-fractionated atrial electrograms and atrial fibrosis are associated with maintenance of persistent atrial fibrillation (AF). We hypothesized that pulmonary vein isolation (PVI) plus ablation of selective atrial low-voltage sites may be more successful than PVI only. METHODS AND RESULTS: A total of 85 consecutive patients with persistent AF underwent high-density atrial voltage mapping, PVI, and ablation at low-voltage areas (LVA < 0.5 mV in AF) associated with electric activity lasting > 70% of AF cycle length on a single electrode (fractionated activity) or multiple electrodes around the circumferential mapping catheter (rotational activity) or discrete rapid local activity (group I). The procedural end point was AF termination. Arrhythmia freedom was compared with a control group (66 patients) undergoing PVI only (group II). PVI alone was performed in 23 of 85 (27%) patients of group I with low amount (< 10% of left atrial surface area) of atrial low voltage. Selective atrial ablation in addition to PVI was performed in 62 patients with termination of AF in 45 (73%) after 11 ± 9 minutes radiofrequency delivery. AF-termination sites colocalized within LVA in 80% and at border zones in 20%. Single-procedural arrhythmia freedom at 13 months median follow-up was achieved in 59 of 85 (69%) patients in group I, which was significantly higher than the matched control group (31/66 [47%], P < 0.001). There was no significant difference in the success rate of patients in group I with a low amount of low voltage undergoing PVI only and patients requiring PVI+selective low-voltage ablation (P = 0.42). CONCLUSIONS: Ablation of sites with distinct activation characteristics within/at borderzones of LVA in addition to PVI is more effective than conventional PVI-only strategy for persistent AF. PVI only seems to be sufficient to treat patients with left atrial low voltage < 10%.

Argatroban pharmacokinetics and pharmacodynamics in critically ill cardiac surgical patients with suspected heparin-induced thrombocytopenia.

Only limited data are available on the pharmacokinetic and pharmacodynamic properties of argatroban in critically ill patients under clinical conditions. We determined plasma concentrations of argatroban, and its main metabolite M1, within a time period of 48 hours in 25 critically ill cardiac surgical patients, who were suspected of heparin-induced thrombocytopenia and had the clinical need for anticoagulation. Argatroban infusion was started at 0.5 µg/kg/minute, and adjusted in 0.1-0.25 µg/kg/minute increments when the activated partial thromboplastin time (aPTT) was not within the target range. Median argatroban plasma half-life was 2.7 hours (interquartile range 1.8 to 7.3). Linear regression analysis revealed that argatroban half-life was significantly related to the total bilirubin concentration (R² = 0.66, p< 0.001), as well as to the metabolism of argatroban, which was assessed by the ratio of the areas under the concentration time curves (AUC) of argatroban and M1 (R² = 0.60, p< 0.001). Continuous veno-venous haemodialysis did not significantly affect argatroban plasma half-life. The predictive property of argatroban plasma levels for aPTT was low (R² = 0.28, p< 0.001). Multiple linear regression analysis revealed significant contributions of age and serum albumin levels to the effect of argatroban on aPTT, expressed as the AUC ratio argatroban/aPTT (R² = 0.67, adjusted R² = 0.65, p< 0.001). In conclusion, argatroban plasma half-life is markedly increased in critically ill cardiac surgical patients, and further prolonged by hepatic dysfunction due to impaired metabolism. Patient age and serum albumin concentration significantly contribute to the variability in the anticoagulant activity of argatroban.

Right ventricular function after aortic valve replacement: a pilot study comparing surgical and transcatheter procedures using 3D echocardiography.

OBJECTIVES: Previous studies have found that standard echocardiographic measures of right ventricular (RV) function were impaired after surgical replacement of the aortic valve (SAVR), but not after transcatheter aortic valve implantation (TAVI). We used 3D echocardiography to gain further insight into the changes of RV performance in patient undergoing SAVR or TAVI. METHODS: We conducted a prospective non-randomized study with two parallel groups and performed echocardiographic evaluation in 20 patients with aortic stenosis undergoing SAVR (age 77 ± 4 years), and in 20 patients undergoing TAVI via the transfemoral approach (age 83 ± 6 years) 1 week before and between the fifth and seventh day after the procedure. RESULTS: Tricuspid annular plane systolic excursion was postoperatively markedly reduced in patients undergoing SAVR (13 ± 2 vs 26 ± 4 mm, post- vs preoperative, P < 0.001), but not in patients undergoing TAVI (24 ± 7 vs 24 ± 5 mm, P = 0.90). Fractional shortening of the RV midcavity transverse diameter, however, increased after SAVR (50 ± 8 vs 31 ± 11%, P < 0.001) in contrast to TAVI (33 ± 10 vs 34 ± 9%, P = 0.85). The RV ejection fraction, assessed by 3D echocardiography, remained unchanged in both patient groups (SAVR, 55 ± 6 vs 55 ± 7%, P = 0.52; TAVI, 56 ± 8 vs 54 ± 7%, P = 0.28). CONCLUSIONS: RV longitudinal contraction decreased after SAVR, whereas RV transverse contraction increased. Both parameters did not change after TAVI. RV ejection fraction and RV stroke volume remained constant irrespective of the technique of aortic valve replacement, thus indicating that global systolic RV function is not compromised after SAVR.

Unilateral pulmonary oedema after minimally invasive cardiac surgery via right anterolateral minithoracotomy.

OBJECTIVES: To investigate the incidence of unilateral pulmonary oedema after minimally invasive cardiac surgery (MICS) requiring unilateral lung collapse has been unknown until now. METHODS: We analysed the data of 484 consecutive patients undergoing minimally invasive cardiac surgery with unilateral lung collapse between January 2008 and December 2013. The clinical regimen was changed in 2010 to a single dose of dexamethasone (approximately 1 mg/kg body weight) administered after anaesthesia induction. RESULTS: Thirty-eight patients developed a radiographically evident unilateral pulmonary oedema within 24 h after surgery. Dexamethasone significantly reduced the incidence of this event [4.0 vs 12.9%; unadjusted odds ratio (OR) 0.28, 95% confidence interval (CI) 0.14-0.58, P < 0.001]. One patient with and six patients without dexamethasone were clinically symptomatic (P = 0.001). Logistic regression analysis identified four variables significantly associated with the development of a unilateral lung oedema: dexamethasone (OR 0.28, 95% CI 0.13-0.58, P = 0.001), diabetes mellitus (OR 3.17, 95% CI 1.04-9.63, P = 0.04), the level of mean pulmonary arterial pressure (OR 1.05 per mmHg, 95% CI 1.004-1.09, P = 0.03) and transfusion of fresh frozen plasma (OR 2.31, 95% CI 1.02-5.25, P = 0.045). CONCLUSIONS: Our data revealed a 7.9% incidence of radiographically evident unilateral pulmonary oedema after MICS with intraoperative collapse of a lung. Of the total number of patients, 1.5% simultaneously developed clinical symptoms. The influence of corticosteroids, as well as the contribution of possible risk factors, needs further evaluation.

Mechanisms of pulmonary vein reconnection after radiofrequency ablation of atrial fibrillation: the deterministic role of contact force and interlesion distance.

INTRODUCTION: Pulmonary vein reconnection (PVR) is an important cause of AF recurrence after ablation. With the advent of force sensing catheters, catheter-tissue contact can be determined quantitatively. Since contact force (CF) plays a major role in determining the characteristics of RF lesion, we prospectively assessed the mechanisms of PVR with regard to catheter-contact and lesion distances in patients undergoing AF ablation. METHODS AND RESULTS: Forty symptomatic AF patients underwent wide circumferential PV isolation (PVI) with SmartTouch™ CF catheter. The exact locations of acute PVI and spontaneous or adenosine-provoked PVR were annotated on CARTO. One thousand nine hundred and twenty-six RF lesions isolated 153 PVs. PVR occurred in 35 (23%) PVs: 22 (63%) adenosine-provoked and 13 (37%) spontaneous. CF was significantly lower at PVR versus PVI sites for RF lesions within 6 mm from these sites: mean CF 5 versus 11 g (P < 0.0001) and force-time integral (FTI) 225 versus 415 gs (P < 0.0001); 86% of PVR occurred with a mean CF < 10 g (FTI < 400 gs); and the remaining 14% occurred at ablation sites with a long interlesion distance (≥5 mm) despite mean CF ≥ 10 g. Eighty percent of PVR sites were located anteriorly. There were no significant differences in regard to arrhythmia freedom between the patients without (69%) versus with PVR (67%; P = 1.0). CONCLUSIONS: Acutely durable PVI can be achieved when RF lesions are delivered with a mean CF ≥ 10 g and an interlesion distance <5 mm. The majority of PVR occur anteriorly due to inadequate CF or long interlesion distances.

Enhanced efficiency of a novel porous tip irrigated RF ablation catheter for pulmonary vein isolation.

INTRODUCTION: Irrigated tip radiofrequency (RF) catheter ablation is the most frequently used technology for pulmonary vein isolation (PVI). The purpose of this study was to compare the efficiency and the safety of 2 different open irrigated tip RF ablation catheters. METHODS AND RESULTS: A total of 160 patients with symptomatic AF (29% persistent, 68% male, 61 ± 10 years) were randomized to circumferential PVI using 2 different irrigated tip catheters: (1) the novel Thermocool SF(®) with a porous tip (56 holes) or (2) the Thermocool(®) catheter with 6 irrigation holes at the distal tip in both power- and temperature-controlled modes. PVI procedural time and RF duration were significantly shorter with SF(®) versus Thermocool(®) catheter: 104.5 versus 114 minutes (P = 0.023) and 35.4 minutes versus 39.9 minutes (P < 0.001), respectively. Similarly, the total fluoroscopy time and dose were shorter with SF(®) versus. Thermocool(®) catheter: 21 minutes versus 24 minutes (P = 0.02) and 1014.5 µGy*m(2) versus 1377 µGy*m(2) (P < 0.0001), respectively. Irrigation volume was lower with SF(®): 600 mL versus 1100 mL, (P < 0.0001) and the rates of complications were not significantly different (0.6% vs 0.49%, P = 0.66). At 20.5 ± 7.5 months follow-up, there were no significant differences with regard to arrhythmia freedom between SF(®) (59.2%) and TC® groups (59.3%), (P = 0.61). CONCLUSIONS: Using the novel irrigated tip SF catheter, PVI is achieved within a shorter ablation and procedural durations. The underlying mechanisms and potential differences in RF lesion size remain to be elucidated.