Atrial fibrillation cryoablation is an effective day case treatment: the UK PolarX vs. Arctic Front Advance experience.

AIMS: Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation for atrial fibrillation (AF). There are limited data on the PolarX Cryoballoon. The study aimed to establish the safety, efficacy, and feasibility of same day discharge for Cryoballoon PVI. METHODS AND RESULTS: Multi-centre study across 12 centres. Procedural metrics, safety profile, and procedural efficacy of the PolarX Cryoballoon with the Arctic Front Advance (AFA) Cryoballoon were compared in a cohort large enough to provide definitive comparative data. A total of 1688 patients underwent PVI with cryoablation (50% PolarX and 50% AFA). Successful PVI was achieved with 1677 (99.3%) patients with 97.2% (n = 1641) performed as day case procedures with a complication rate of <1%. Safety, procedural metrics, and efficacy of the PolarX Cryoballoon were comparable with the AFA cohort. The PolarX Cryoballoon demonstrated a nadir temperature of -54.6 ± 7.6°C, temperature at 30 s of -38.6 ± 7.2°C, time to -40°C of 34.1 ± 13.7 s, and time to isolation of 49.8 ± 33.2 s. Independent predictors for achieving PVI included time to reach -40°C [odds ratio (OR) 1.34; P < 0.001] and nadir temperature (OR 1.24; P < 0.001) with an optimal cut-off of ≤34 s [area under the curve (AUC) 0.73; P < 0.001] and nadir temperature of ≤-54.0°C (AUC 0.71; P < 0.001), respectively. CONCLUSIONS: This large-scale UK multi-centre study has shown that Cryoballoon PVI is a safe, effective day case procedure. PVI using the PolarX Cryoballoon was similarly safe and effective as the AFA Cryoballoon. The cryoablation metrics achieved with the PolarX Cryoballoon were different to that reported with the AFA Cryoballoon. Modified cryoablation targets are required when utilizing the PolarX Cryoballoon.

Recurrent vascular events and mortality outcomes in patients with known atrial fibrillation, compared to atrial fibrillation detected early after stroke.

INTRODUCTION: Atrial fibrillation (AF) detected after stroke (AFDAS) may represent a distinct clinical entity to that of known AF (KAF). However, there is limited long-term outcome data available for patients with AFDAS. More information regarding prognosis in AFDAS is required to inform future trial design in these patients. PATIENTS AND METHODS: We used data (2015-2019) from a national prospective stroke registry of consecutive patients with acute ischaemic stroke and AF. AFDAS was defined as a new diagnosis of AF after stroke detected on electrocardiograph or cardiac monitoring. The co-primary endpoints were: (1) all-cause mortality; (2) recurrent major adverse cardiovascular events (MACE) at 3 years. Secondary endpoints were: (1) recurrent stroke; (2) functional outcome at discharge; (3) presence of co-existing stroke mechanisms. RESULTS: 583 patients were included. After a median follow-up of 2.65 years (cumulative 1064 person-years) 309 patients died and 23 had recurrent MACE. Compared with AFDAS, KAF was associated with a higher risk of all-cause mortality (adjusted Hazard Ratio (aHR) 1.56, 95% CI 1.12-2.18), a higher prevalence of co-existing stroke mechanisms (adjusted odds ratio (aOR) 2.28, 95% CI 1.14-4.59), but not poor functional outcome (aOR 1.61, 95% CI 0.98-2.64). A trend towards a higher risk of MACE was observed in patients with KAF, but this was limited by statistical power (aHR 2.90, 95% CI 0.67-12.51). All 14 recurrent strokes occurred in the KAF group (Log-rank p = 0.03). DISCUSSION AND CONCLUSION: These data provide further evidence that AFDAS differs to KAF with respect to risk of recurrent stroke, MACE, and all-cause mortality.

The contribution of competing mechanisms in stroke despite anticoagulation in patients with atrial fibrillation.

BACKGROUND: For reasons poorly understood, strokes frequently occur in patients with atrial fibrillation (AF) despite oral anticoagulation. Better data are needed to inform randomised trials (RCTs) of new strategies to prevent recurrence in these patients. We investigate the relative contribution of competing stroke mechanisms in patients with AF who have stroke despite anticoagulation (OAC+) compared with those who are anticoagulant naïve (OAC-) at the time of their event. PATIENTS AND METHODS: We performed a cross-sectional study leveraging data from a prospective stroke registry (2015-2022). Eligible patients had ischemic stroke and AF. Stroke classification was performed by a single stroke-specialist blinded to OAC status using TOAST criteria. The presence of atherosclerotic plaque was determined using duplex ultrasonography, computerised tomography (CT) or magnetic resonance (MR) angiography. Imaging was reviewed by a single reader. Logistic regression was used to identify independent predictors of stroke despite anticoagulation. RESULTS: Of 596 patients included, 198 (33.2%) were in the OAC+ group. A competing cause for stroke was more frequent in patients with OAC+ versus OAC- (69/198 (34.8%)) versus 77/398 (19.3%), p < 0.001). After adjustment, both small vessel occlusion (odds ratio (OR): 2.46, 95% CI: 1.20-5.06) and arterial atheroma (⩾50% stenosis) (OR: 1.78, 95% CI: 1.07-2.94) were independently associated with stroke despite anticoagulation. DISCUSSION AND CONCLUSION: Patients with AF-associated stroke despite OAC are much more likely than patients who are OAC-naïve to have competing stroke mechanisms. Rigorous investigation for alternative stroke causes in stroke despite OAC has a high diagnostic yield. These data should be used to guide patient selection for future RCTs in this population.

Blood Biomarkers and Structural Imaging Correlations Post-Traumatic Brain Injury: A Systematic Review.

BACKGROUND: Blood biomarkers are of increasing importance in the diagnosis and assessment of traumatic brain injury (TBI). However, the relationship between them and lesions seen on imaging remains unclear. OBJECTIVE: To perform a systematic review of the relationship between blood biomarkers and intracranial lesion types, intracranial lesion injury patterns, volume/number of intracranial lesions, and imaging classification systems. METHODS: We searched Medical Literature Analysis and Retrieval System Online, Excerpta Medica dataBASE, and Cumulative Index to Nursing and Allied Health Literature from inception to May 2021, and the references of included studies were also screened. Heterogeneity in study design, biomarker types, imaging modalities, and analyses inhibited quantitative analysis, with a qualitative synthesis presented. RESULTS: Fifty-nine papers were included assessing one or more biomarker to imaging comparisons per paper: 30 assessed imaging classifications or injury patterns, 28 assessed lesion type, and 11 assessed lesion volume or number. Biomarker concentrations were associated with the burden of brain injury, as assessed by increasing intracranial lesion volume, increasing numbers of traumatic intracranial lesions, and positive correlations with imaging classification scores. There were inconsistent findings associating different biomarkers with specific imaging phenotypes including diffuse axonal injury, cerebral edema, and intracranial hemorrhage. CONCLUSION: Blood-based biomarker concentrations after TBI are consistently demonstrated to correlate burden of intracranial disease. The relation with specific injury types is unclear suggesting a lack of diagnostic specificity and/or is the result of the complex and heterogeneous nature of TBI.