Background—: Cryoablation has emerged as an alternative to radiofrequency catheter ablation (RFCA) for the treatment of atrioventricular (AV) nodal reentrant tachycardia (AVNRT). The purpose of this prospective randomized study was to test whether cryoablation is as effective as RFCA during both short-term and long-term follow-up with a lower risk of permanent AV block. Methods and Results—: A total of 509 patients underwent slow pathway cryoablation (n=251) or RFCA (n=258). The primary end point was immediate ablation failure, permanent AV block, and AVNRT recurrence during a 6-month follow-up. Secondary end points included procedural parameters, device functionality, and pain perception. Significantly more patients in the cryoablation group than the RFCA group reached the primary end point (12.6% versus 6.3%; P =0.018). Whereas immediate ablation success (96.8% versus 98.4%) and occurrence of permanent AV block (0% versus 0.4%) did not differ, AVNRT recurrence was significantly more frequent in the cryoablation group (9.4% versus 4.4%; P =0.029). In the cryoablation group, procedure duration was longer (138±54 versus 123±48 minutes; P =0.0012) and more device problems occurred (13 versus 2 patients; P =0.033). Pain perception was lower in the cryoablation group ( P <0.001). Conclusions—: Cryoablation for AVNRT is as effective as RFCA over the short term but is associated with a higher recurrence rate at the 6-month follow-up. The risk of permanent AV block does not differ significantly between cryoablation and RFCA. The potential benefits of cryoenergy relative to ablation safety and pain perception are counterbalanced by longer procedure times, more device problems, and a high recurrence rate. Clinical Trial Registration—: URL: http://www.clinicaltrials.gov . Unique identifier: NCT00196222.

BACKGROUND: Pulsed field ablation (PFA) is increasingly used in clinical practice for the treatment of atrial fibrillation. While the susceptibility of erythrocytes to electroporation is well established, the effect of cardiac PFA technologies on hemolysis has remained underreported. The aim of this study was to investigate the incidence, severity, and clinical impact of PFA-induced hemolysis. METHODS: We included n=145 patients undergoing atrial fibrillation catheter ablation with a pentaspline PFA catheter (biphasic, bipolar pulses of 2 kV) and n=70 patients receiving radiofrequency ablation (40–90 W) at 4 high-volume European centers. The lesion set comprised pulmonary vein isolation for paroxysmal atrial fibrillation and pulmonary vein isolation±additional lesions for persistent atrial fibrillation. Hemolysis and renal function biomarkers were analyzed in blood samples at baseline, at the end of ablation, and 24 hours after the procedure. RESULTS: Baseline characteristics were well balanced between groups (overall mean 65.7±9.4 years; 69.3% men). The ablation procedures comprised a mean of 61.6±27.4 PFA deliveries and 26.3±15.0 minutes RF duration. Hemolysis was detected in 94.3% versus 6.8% of patients after PFA versus radiofrequency ablation ( P <0.001): PFA was associated with significantly lower haptoglobin levels (0.5±0.4 versus 1.0±0.4 g/L), while free plasma hemoglobin (592.8±330.6 versus 147.8±183.0 mg/L), bilirubin (21.3±11.3 versus 14.8±8.8 µmol/L), and LDH (lactate dehydrogenase, 352.7±115.7 versus 253.2±56.5 U/L) were significantly higher after PFA compared with radiofrequency ablation (all P <0.001). Hemolysis correlated with the number of PFA deliveries (r=0.62 [95% CI, 0.33–0.80]; P <0.001), with the highest severity occurring ≥54 PFA deliveries. After PFA, hemoglobinuria occurred in 36.4%, while creatinine increase was higher in patients with baseline glomerular filtration rate 50 mL/min (Δcrea, 27.0±103.1 versus −0.2±12.1 µmol/L; P =0.010). CONCLUSIONS: Intravascular hemolysis is a frequent finding after PFA and increases with the number of PFA deliveries. Until the clinical impact of PFA-associated hemolysis is fully elucidated, a careful titration of PFA deliveries during the ablation procedure is warranted.

In many clinical research applications the time to occurrence of one event of interest, that may be obscured by another—so called competing—event, is investigated. Specific interventions can only have an effect on the endpoint they address or research questions might focus on risk factors for a certain outcome. Different approaches for the analysis of time-to-event data in the presence of competing risks were introduced in the last decades including some new methodologies, which are not yet frequently used in the analysis of competing risks data. Cause-specific hazard regression, subdistribution hazard regression, mixture models, vertical modelling and the analysis of time-to-event data based on pseudo-observations are described in this article and are applied to a dataset of a cohort study intended to establish risk stratification for cardiac death after myocardial infarction. Data analysts are encouraged to use the appropriate methods for their specific research questions by comparing different regression approaches in the competing risks setting regarding assumptions, methodology and interpretation of the results. Notes on application of the mentioned methods using the statistical software R are presented and extensions to the presented standard methods proposed in statistical literature are mentioned.

Introduction: Liver failure patients might be at risk for citrate accumulation during continuous venovenous hemodialysis (CVVHD) with regional citrate anticoagulation. The aim of this study was to investigate the predictive capability of baseline liver function parameters regarding citrate accumulation, expressed as an increase in the calcium total/calcium ionized (Ca_tot/Ca_ion) ratio ≥2.5, and to describe the feasibility of citrate CVVHD in liver failure patients. Methods: We conducted a prospective observational study in medical ICU patients treated in a German university hospital. We performed 43 CVVHD runs using citrate for regional anticoagulation in 28 critically ill patients with decompensated liver cirrhosis or acute liver failure (maximum of two CVVHD runs per patient). Liver function was characterized before CVVHD using laboratory parameters, calculation of Child-Pugh and Model of End-stage Liver Disease scores, and determination of the plasma disappearance rate of indocyanine green. In addition to blood gas analysis, we measured total calcium and citrate in serum at baseline and after definitive time points for each CVVHD run. Results: Accumulation of citrate in serum correlated with an increase in the Ca_tot/Ca_ion ratio. Although the critical upper threshold of Ca_tot/Ca_ion ratio ≥2.5 was exceeded 10 times in seven different CVVHD runs, equalization of initial metabolic acidosis was possible without major disturbances of acid-base and electrolyte status. Standard laboratory liver function parameters showed poor predictive capabilities regarding citrate accumulation in terms of an elevated Ca_tot/Ca_ion ratio ≥2.5. In contrast, serum lactate ≥3.4 mmol/l and prothrombin time ≤26% predicted an increase in the Ca_tot/Ca_ion ratio ≥2.5 with high sensitivity (86% for both lactate and prothrombin time) and specificity (86% for lactate, 92% for prothrombin time). Conclusions: Despite substantial accumulation of citrate in serum, CVVHD with regional citrate anticoagulation seems feasible in patients with severely impaired liver function. Citrate accumulation in serum is reflected by an increase in the Ca_tot/Ca_ion ratio. To identify patients at risk for citrate accumulation in terms of a Ca_tot/Ca_ion ratio ≥2.5, baseline serum lactate (threshold ≥3.4 mmol/l) and prothrombin time (threshold ≤26%) may be useful for risk prediction in daily clinical practice. Careful monitoring of electrolytes and acid-base status is mandatory to ensure patient safety.

The aim of this study was to evaluate the impact of pathologic complete response (pCR) on outcome in patients with gastric or esophagogastric junction (EGJ) adenocarcinoma after neoadjuvant docetaxel/platin/fluoropyrimidine-based chemotherapy. Patients received at least one cycle of chemotherapy for potentially operable disease. Pretreatment clinicopathologic factors and pCR were investigated. Disease-free survival (DFS), overall survival (OS) and tumor-related death were correlated with pCR. One hundred twenty patients were included in this analysis. Eighteen patients (15%) achieved a pCR. Tumor localization in the EGJ was identified as the only significant predictor of pCR (P = 0.019). Median follow-up was 41.1 months. Median DFS and OS for all patients were 24.1 and 48.6 months, respectively. Median DFS for patients with a pCR was not reached versus 22.1 months non-pCR patients (hazard ratio, HR 0.38; 3-year DFS: 71.8% and 37.7%, respectively, P = 0.018). While OS was not significantly different, the risk for tumor-related death was significantly lower for pCR patients compared with non-pCR patients (3-year cumulative incidences of 6.4% and 45.4%, respectively, P = 0.009). A pCR following preoperative docetaxel/platin/fluoropyrimidine indicates favorable outcome in patients with gastric or EGJ adenocarcinoma. Tumor location in the EGJ is associated with a higher pCR rate.