Feasibility of the Figure-of-8-Suture as Venous Closure in Interventional Electrophysiology: One Strategy for All?

Background: Venous vascular access with higher sheath size is common in interventional electrophysiology. In contrast to arterial vascular access, no dedicated closure devices exist for closure after venous access with higher sheath sizes. The Figure-of-8-Suture, an easy to apply suture, may be as a feasible approach for closure venous puncture. Our aim was to evaluate the feasibility of closure of femoral venous access. Methods: From November 2016 to February 2018, patients undergoing electrophysiological procedures, closure of left atrial appendage or patent foramen ovale were included. Until May 2017, manual compression was performed to achieve haemostasis at venous access site (control group). From May 2017, patients were treated with a Figure-of-8-Suture (treatment group, Figure 1). Turnaround time and incidence of vascular complications were compared between the two groups. Results: In total, 290 patients were included, 132 in the control group and 158 in the Figure-of-8-Suture group. Hemostasis after sheath removal was achieved in 100% of the cases in the control group by manual compression and in 98.7% of the cases with the Figure-of-8-Suture (p=0.2). Vascular complications were more common in the control group (6.8 vs. 1.3 %, p=0.01). Turnaround time was significantly lower in the Figure-of-8-Suture group (58.6 ± 14 vs. 77 ± 33.9 min, p=0.004). In a sub-analysis in obese patients with body mass index (BMI) ≥30 kg/m2 (Figure-of-8 n=45, controls n=35), vascular complications were significantly more common in the control group (9.4 vs 0%, p=0.045). Conclusion: The Figure-of-8-Suture is an easy-to-apply, effective approach for venous closure after electrophysiological procedures.

First data on cardiac mapping and outcome of pulmonary vein isolation using a novel ablation catheter with tip mini electrodes.

AIMS: Pulmonary vein isolation (PVI) is a standard treatment of atrial fibrillation (AF). AF recurrence after PVI occurs in a substantial number of cases. A novel ablation catheter equipped with mini-electrodes (ME) may facilitate PVI. Our study evaluated outcome after PVI with the ME catheter compared to a standard catheter. METHODS: Patients undergoing PVI with the ME catheter were compared to a control group ablated with a standard contact force sensing catheter. Freedom of AF after 12 months was the study endpoint. Additionally, low voltage areas (LVA) <0.5 mV were identified with a circular mapping catheter (CMC) and the ablation catheter in each group. LVA were compared between the maps obtained with the CMC and the ME or standard catheter, respectively. RESULTS: A total of 110 patients underwent PVI with ME catheter (n = 59) or the standard catheter (n = 51). Procedure duration (117.4 ±â€¯43 vs. 103.1 ±â€¯32.8 min, p = 0.15), radiation dose (1135.6 ±â€¯1125.7 vs. 1078.8 ±â€¯951.4 µGy/m2, p = 0.91), incidence of complications and 12-month success rate (64.4 vs 72.5%, p = 0.36) were not significantly different between the groups. LVA were significantly smaller when obtained with the standard catheter compared to the CMC (14 ±â€¯13 vs. 58.5 ±â€¯22.1 cm2, p < 0.001), while no such difference was seen for mapping with the ME compared to the CMC (37 ±â€¯30.3 vs. 33.4 ±â€¯39 cm2, p = 0.4). CONCLUSION: Clinical outcomes are comparable between ME catheter and a standard contact force sensing catheter. Furthermore, better LVA detection points to improved mapping capabilities of the ME catheter.

[Radiation reduction in interventional electrophysiology : Results from operators with different levels of experience]. / Strahlenreduktion in der interventionellen Elektrophysiologie : Verlaufsdaten bei Untersuchern mit unterschiedlicher Erfahrung.

BACKGROUND: Radiation exposure in the catherization laboratory is associated with significant health risks. It is unclear whether a reduction of radiation exposure with the use of "near-zero fluoroscopy" protocols is possible when applied by less experienced operators. METHODS: Consecutive ablation procedures with the use of a 3D mapping system were analyzed. Three time periods were analyzed. During the first period (standard), no specific radiation-reduction protocol was used. During the second period (initial phase of radiation reduction) a near "near-zero fluoroscopy" protocol was implemented; however, the majority of procedures were performed by an expert. During the third period (routine use of radiation reduction), less experienced operators (fellow and beginner) performed a growing number of procedures with the "near-zero fluoroscopy" protocol. RESULTS: In all, 290 procedures were analyzed. After implementation of a radiation-reduced protocol, a significant reduction of radiation exposure was observed (standard 850 ± 831.7 vs. initial phase 197.2 ± 481.8 µGy/m2, p < 0.001, and vs. routine use 283 ± 493.8 µGy/m2, p < 0.001). No significant difference was observed between the initial phase and routine phase (p = 1). Over the three periods, the proportion of procedures performed by less experienced operators grew significantly for complex (fellow: 0% vs. 10% vs. 30%; p < 0.001) and noncomplex procedures (fellow: 30% vs. 39% vs. 49%; beginner: 15% vs. 38% vs. 34%; p = 0.002). Complication rates were not significantly different. CONCLUSIONS: Implementation of a radiation-reduced protocol leads to a significant reduction of radiation exposure even in less experienced operators during training.

Implementation of a near-zero fluoroscopy approach in interventional electrophysiology: impact of operator experience.

PURPOSE: Catheter ablation is performed under fluoroscopic guidance. Reduction of radiation dose for patients and staff is emphasized by current recommendations. Previous studies have shown that lower operator experience leads to increased radiation dose. On the other hand, less experienced operators may depend even more on fluoroscopic guidance. Our study aimed to evaluate feasibility and efficacy of a non-fluoroscopic approach in different training levels. METHODS: From January 2017, a near-zero fluoroscopy approach was established in two centers. Four operators (beginner, 1st year fellow, 2nd year fellow, expert) were instructed to perform the complete procedure with the use of a 3-D mapping system without fluoroscopy. A historical cohort that underwent procedures with fluoroscopy use served as control group. Dose area product (DPA), procedure duration, acute procedural success, and complications were compared between the groups and for each operator. RESULTS: Procedures were performed in 157 patients. The first 100 patients underwent procedures with fluoroscopic guidance, the following 57 procedures were performed with the near-zero fluoroscopy approach. The results show a significant reduction in DPA for all operators immediately after implementation of the near-zero fluoroscopy protocol (control 637 ± 611 µGy/m2; beginner 44.1 ± 79.5 µGy/m2, p = 0.002; 1st year fellow 24.3 ± 46.4.5 µGy/m2, p = 0.001; 2nd year fellow 130.3 ± 233.3 µGy/m2, p = 0.003; expert 9.3 ± 37.4 µGy/m2, P < 0.001). Procedure duration, acute success, and complications were not significantly different between the groups. CONCLUSION: Our results show a 90% reduction of DPA shortly after implementation of a near-zero fluoroscopy approach in interventional electrophysiology even in operators in training.

Cardiac mapping and pulmonary vein isolation using a novel ablation catheter with tip minielectrodes.

BACKGROUND: Pulmonary vein isolation (PVI) is a standard treatment for atrial fibrillation (AF). Identification of gaps in the ablation line is difficult. Tip-ring electrograms from ablation catheters represent relative large areas of myocardial tissue. Recently, an ablation catheter with three minielectrodes (ME) on the catheter tip with closer interelectrode spacing was introduced. The aim of our study was to evaluate the novel electrodes during PVI. METHODS: PVI was performed with an irrigated ablation catheter equipped with conventional electrodes and three additional radial tip electrodes. Detection of pulmonary vein potentials (PVPs), local signal amplitude, amplitude reduction during ablation, and loss of capture after ablation were compared between the ME and the conventional tip-ring electrodes. RESULTS: Thirty-one patients (mean age 67.8 ± 10.3 years, 45.2 % men) were included. A total of 306 mapping/lesion points were analyzed. A PVP was significantly more often obtained with the ME compared to the conventional tip-ring electrodes (99.2% vs 83.5%, P < 0.001). Local amplitude was significantly higher on the ME (0.8 ± 0.6 mV vs 0.67 ± 0.46 mV, P  =  0.003). Amplitude reduction during 1 RF pulse was significantly greater on the ME (82.9 ± 19.5% vs. 61.8 ± 26.9%, P < 0.001). During pace mapping, loss of capture after 1 RF pulse was observed significantly more often on ME (98.3% vs 63.3%, P < 0.001). CONCLUSION: Signal amplitude is higher and sensitivity during PVP mapping and ablation is increased when ME are used. ME may facilitate catheter ablation of AF in the future.

Hypothermia induced alteration of repolarization - impact on acute and long-term outcome: a prospective cohort study.

BACKGROUND: The effects of target temperature management (TTM) on the heart aren't thoroughly studied yet. Several studies showed the prolongation of various ECG parameters including Tpeak-Tend-time under TTM. Our study's goal is to evaluate the acute and long-term outcome of these prolongations. METHODS: In this study we included patients with successful resuscitation after cardiac arrest who were admitted to the Charité Virchow Klinikum Berlin or the Heart and Vascular Centre of the Ruhr University Bochum between February 2006 and July 2013 (Berlin) or May 2014 to November 2015 (Bochum). For analysis, one ECG during TTM was recorded after reaching the target temperature (33-34 °C) or in the first 6 h of TTM. If possible, another ECG was taken after TTM. The patients were being followed until February 2016. Primary endpoint was ventricular arrhythmia during TTM, secondary endpoints were death and hospitalization due to cardiovascular diseases during follow-up. RESULTS: One hundred fifty-eight patients were successfully resuscitated in the study period of which 95 patients had usable data (e.g. ECGs without artifacts). During TTM significant changes for different parameters of ventricular de- and repolarization were noted: QRS (103.2 ± 23.7 vs. 95.3 ± 18.1; p = 0.003),QT (405.8 ± 76.4 vs. 373.8 ± 75.0; p = 0.01), QTc (474.9 ± 59.7 vs. 431.0 ± 56.8; p < 0.001), JT (302.8 ± 69.4 vs. 278.5 ± 75.2; p = 0.043), JTc (354.3 ± 60.2 vs. 318.7 ± 59.1; p = 0.001). 13.7% of the patients had ventricular arrhythmias during TTM, however these patients showed no difference regarding their ECG parameters in comparison to those were no ventricular arrhythmias occurred. We were able to follow 69 Patients over an average period of 35 ± 31 months. The 14 (21.5%) patients who died during the follow-up had significant prolongations of the TpTe-time in the ECGs without TTM (103.9 ± 47.2 vs. 75.8 ± 28.6; p = 0.023). CONCLUSION: Our results show a significant prolongation of ventricular repolarization during TH. However, there was no significant difference between the ECG parameters of those who developed a ventricular arrhythmia and those who did not. The temporary prolongation of the repolarization during TTM seems to be less important for the prognosis of the patient. Whereas the prolongation of the repolarization in the basal ECG is associated with a higher mortality in our study.

Tailored antiplatelet therapy can overcome clopidogrel and aspirin resistance--the BOchum CLopidogrel and Aspirin Plan (BOCLA-Plan) to improve antiplatelet therapy.

BACKGROUND: Dual antiplatelet therapy using acetylsalicylic acid (ASA, aspirin) and clopidogrel is of great importance following coronary stenting. However, the variable platelet inhibitory effectiveness compromises the antithrombotic advantages provided by dual antiplatelet therapy. The aim of this single-center prospective study was to reduce the low response incidence of dual antiplatelet therapy with ASA and clopidogrel according to a prespecified therapy algorithm. METHODS: Platelet function testing using whole blood aggregometry (Chronolog 590) was performed 48 hours following coronary stenting (for either acute coronary syndromes or stable coronary artery disease) on 504 patients. The antiplatelet therapy included a loading dose of 600 mg clopidogrel and 500 mg ASA, followed by 75 mg clopidogrel and 100 mg ASA once daily. Clopidogrel low responders (CLR: >5 ohm; adenosine diphosphate (ADP) 5 µM) and/or ASA low responders (ALR: >0 ohm; arachidonic acid 10 µM) were treated according to a structured therapy plan: in the case of CLR, the maintenance + dose was doubled (repeated loading dose followed by 150 mg daily), and when still ineffective ticlopidine or prasugrel, if available and not contraindicated, were used. ALR was treated by increasing the dose to 300 mg in a first step or to 500 mg ASA when the first modification did not take effect sufficiently. In addition, ADP receptor antagonist 2-methylthioadenosine 5'-monophosphate triethylammonium salt (MeSAMP) testing and ASA incubation were performed to rule out either a platelet ADP-receptor defect or an ASA pharmacokinetic resistance. RESULTS: Of the total cohort of 504 patients, we detected 30.8% clopidogrel low-responders and 19.4% aspirin low-responders. For ALR, with a dose adjustment of 300 mg ASA daily, 94.6% of ALR were effectively treated and the residual 5.4% by administration of daily dosages of 500 mg ASA. This means that after modification of the ASA maintenance dose, all initial ALRs had an adequate antiplatelet response. The results for clopidogrel revealed that 69% of the CLR were treated effectively by increasing the clopidogrel dose to 150 mg daily. When prasugrel was not available or contraindicated, 12.7% of the remaining low responders showed an adequate result after being switched to ticlopidine. Consequently, by applying the therapy algorithm, we were able to reduce the CLR prevalence by 86.6%. On including prasugrel in the therapy plan, we were finally able to eliminate thienopyridine low response. In addition, no ADP receptor defect was found in this study as a potential reason for CLR. We identified the following factors associated with both CLR and ALR status: acute coronary syndromes, positive troponin values as well as diabetes mellitus and elevated HbA1C values and a higher platelet count. Furthermore, our data revealed for CLR elevated C-reactive protein values and a high PREDICT-score (including an age >65 years, acute coronary syndrome, diabetes mellitus, renal failure, and reduced left ventricular function) as risk factors. The following factors correlated with the risk of ASA low response: patients with elevated hemoglobin, serum creatinine and C-reactive protein values. In addition, medication with nitrates reduced the risk of being CLR. As also holds true for CLR, we found the PREDICT-score to be correlated to the risk of being ALR. However, by far the strongest risk factor for CLR or ALR was the fact of dual resistance. CONCLUSION: Following a structured therapy plan based on a "test and treat" strategy, the prevalence of clopidogrel or aspirin low response can be significantly reduced and the risk of inadequate dual antiplatelet therapy minimized.

Pantoprazole does not influence the antiplatelet effect of clopidogrel-a whole blood aggregometry study after coronary stenting.

Recent attention has been drawn to a potential drug-drug interaction observed between clopidogrel and proton pump inhibitors (PPIs). However, this potential interaction may not be a class effect of PPIs. We investigated if pantoprazole, which has a different metabolism than omeprazole, diminishes the effectiveness of clopidogrel. Our study included 336 patients (mean age 64.6 years; 106 women) 48 hours after percutaneous coronary stent implantation with a loading dose of 600 mg clopidogrel hydrogensulfate and 500 mg aspirin, followed by 75 mg clopidogrel and 100 mg aspirin daily. Whereas 188 patients (59 women) were not given any PPI comedication, 122 patients received pantoprazole and 26 either omeprazole or esomeprazole. The platelet aggregation followed by impedance aggregometry (in Ohm) was induced by 5 mmol/L adenosine diphosphate. The percentage of clopidogrel low-response (CLR) was similar between the non-PPI group [2.75 Ohm (confidence interval, CI: 2.25-3.26); 21.9% CLR] and the pantoprazole group [2.33 Ohm (CI: 1.79-2.87); 16.4% CLR] but higher in patients treated with omeprazole/esomeprazole (3.00 Ohm (CI: 1.49-4.51); 30.8% CLR). Multivariate regression analysis reveals that the risk of CLR in the pantoprazole comedication group was not increased compared with the group without any PPI [odds ratio 0.59 (CI: 0.31-1.13) 0.11]. Our data suggest that pantoprazole does not diminish the antiplatelet effectiveness of clopidogrel early after coronary stenting. Therefore, the use of pantoprazole seems preferable in patients treated with clopidogrel when a concomitant medication with a PPI is indicated.

Comparing the antiplatelet effect of clopidogrel hydrogensulfate and clopidogrel besylate: a crossover study.

BACKGROUND: Clopidogrel hydrogensulfate is a thienopyridine acting as an important antiplatelet agent alone or in combination with acetyl salicylic acid to prevent cardiovascular complications. A different clopidogrel salt, clopidogrel besylate, was approved in Germany as a "new drug" in May 2008. Only one study with 46 healthy men compared the plasma concentrations of both clopidogrel formulas. In our crossover study we measured the antiplatelet effect of clopidogrel hydrogensulfate (CHS, clopidogrel bisulfate) and clopidogrel besylate (CB) using two techniques, whole blood impedance aggregometry and flow cytometry in healthy subjects. METHODS: Twenty-one healthy volunteers (14 male, 7 female, mean age 36.3 years) were treated either with CHS or CB (300 mg loading, followed by 75 mg/day) and after a wash-out period of at least 21 days, the participants were switched to the other clopidogrel salt in a crossover design. Blood samples were drawn before and 2, 4 and 48 h after the initial dose was taken. Flow cytometry measurements of CD62P (P-selectin) expression were done at baseline and 48 h thereafter with three different ADP concentrations (5, 15, 50 micromol/L ADP). Whole blood impedance aggregometry testing (Chrono-log Model 590) was performed at baseline and after 2, 4 and 48 h with two ADP concentrations (5 and 20 micromol/L ADP). RESULTS: Using flow cytometry, the mean inhibitory effect of clopidogrel on the CD62P expression was similar and no significant differences were noted in subjects treated with either of the clopidogrel formulas for hydrogensulfate or besylate salt (5 micromol/L ADP: 8.12 +/- 5.53 CHS vs. 6.48 +/- 5.01 CB; 15 micromol/L ADP: 9.33 +/- 6.44 CHS vs. 8.99 +/- 8.27 CB; 50 micromol/L ADP: 11.17 +/- 6.81 CHS vs. 9.52 +/- 6.17 CB). It is important to note that clopidogrel CB shows similar and conspicuously high interindividual variability as was reported earlier on CHS. We observed both possibilities, subjects responding less to the hydrogensulfate salt, but better to the besylate salt, and vice versa. Using aggregometry, both salt formulas achieved similar inhibitory effects regarding initial platelet function (2 h/5 micromol/L ADP: CHS 4.5 +/- 3.66 Omega; CB 3.89 +/- 3.81 Omega and 4 h/5 micromol/L ADP: CHS 5.78 +/- 3.51 Omega; CB 4.89 +/- 4.03 Omega) as well as during the maintenance phase (48 h/5 micromol/L ADP: CHS 2.86 +/- 2.92 Omega; CB 3.43 +/- 3.06 Omega). Once again the aggregometry results for CB showed a similarly high interindividual variability as also holds true for CHS. Some subjects had a better antiplatelet effect with clopidogrel besylate and vice versa with clopidogrel hydrogensulfate. CONCLUSION: The crossover study using whole blood aggregometry and flow cytometry shows no overall significant difference in the antiplatelet effect of clopidogrel hydrogensulfate as compared to clopidogrel besylate. However, it is important to note that besides high interindividual there is also high intraindividual variability between the two different clopidogrel formulas. We observed both: subjects responding less to besylate salt, but better to hydrogensulfate salt, and vice versa.

How to optimise clopidogrel therapy? Reducing the low-response incidence by aggregometry-guided therapy modification.

The inhibitory platelet effect of clopidogrel is insufficient in approximately 5 to 30% of patients. These low responders (LR) face a significantly higher risk of cardiovascular complications. The therapeutic management of LR is still undefined. In the present study, we evaluate a novel therapeutic algorithm to reduce the incidence of clopidogrel resistance. One hundred sixty-one patients on 100 mg of aspirin co-medication underwent elective coronary stenting and were given an initial dosage of 600 mg clopidogrel, followed by 75 mg clopidogrel daily. 48 h later, the platelet responsiveness was tested with ADP (5-20 microM) stimulation by impedance aggregometry (Chronolog 590). A significant rise in impedance (>5 Omega after 6 minutes, aggregation index >65%) was defined as LR. In this subgroup, platelets were stimulated with the selective P2Y(12)-ADP receptor antagonist 2-MeS-AMP. One hundred twenty-three patients were clopidogrel-responders (76.4%) and 38 patients were LR (23.6%). A defect of the ADP-receptor P2Y(12) was found in three out of 38 LR (7.9%). Inhibition of platelet aggregation indicating clopidogrel-responsiveness was achieved with either a clopidogrel high-dose regimen (22/38, 57.9%); a repeat loading dose, doubling the maintenance dose) or with an alternative therapy with ticlopidine (8/38 (21.1%); 250 mg twice daily). Thus the incidence of LR was reduced from 23.6% to 5.0%. Our aggregometer-guided therapeutic algorithm reduced the relative percentage of clopidogrel LR by 78.9%. This approach could prove to be helpful in achieving a further decrease in the incidence of clopidogrel resistance.