Imaging in percutaneous ablation for atrial fibrillation

Percutaneous ablation for electrical disconnection of the arrhythmogenic foci using various forms of energy has become a well-established technique for treating atrial fibrillation (AF). Success rate in preventing recurrence of AF episodes is high although associated with a significant incidence of pulmonary vein (PV) stenosis and other rare complications. Clinical workup of AF patients includes imaging before and after ablative treatment using different noninvasive and invasive techniques such as conventional angiography, transoesophageal and intracardiac echocardiography, computed tomography (CT) and magnetic resonance imaging (MRI), which offer different information with variable diagnostic accuracy. Evaluation before percutaneous ablation involves assessment of PVs (PV pattern, branching pattern, orientation and ostial size) to facilitate position and size of catheters and reduce procedure time as well as examining the left atrium (presence of thrombi, dimensions and volumes). Imaging after the percutaneous ablation is important for assessment of overall success of the procedure and revealing potential complications. Therefore, imaging methods enable depiction of PVs and the anatomy of surrounding structures essential for preprocedural management and early detection of PV stenosis and other ablation-related procedures, as well as long-term follow-up of these patients

The golden hour of prehospital reperfusion with triple antiplatelet therapy: A sub-analysis from the Ongoing Tirofiban in Myocardial Evaluation 2 (On-TIME 2) trial early initiation of triple antiplatelet therapy

Background It is known that the efficacy of thrombolytic therapy in ST-segment elevation myocardial infarction (STEMI) is highly time dependent with the best efficacy when given within the so-called golden hour. This analysis from the On-TIME 2 trial evaluated the efficacy of triple antiplatelet therapy on initial patency and ST-segment resolution (STR) in relation to time from symptom onset to first medical contact. Methods The On-TIME 2 trial included 1,398 consecutive STEMI patients referred for primary percutaneous coronary intervention (PCI). Patients were randomized to dual (500 mg aspirin and 600 mg clopidogrel) or triple antiplatelet (500 mg aspirin, 600 mg clopidogrel, and tirofiban 25 mu g/kg bolus and 0.15 mu g/kg per minute maintenance infusion for 18 hours) pretreatment in the ambulance. Primary outcome of this sub-analysis was initial patency of the infarct-related vessel and STR before PCI according to time from symptom onset to first medical contact in quartiles. In addition, the incidence of aborted myocardial infarction, defined as the absence of a rise in creatinine kinase, was assessed. Results Initial patency, STR before PCI, and the incidence of aborted myocardial infarction gradually increased with shorter time from symptom onset to first medical contact. Initial Thrombolysis in Myocardial Infarction flow was present in 21.2% in the total population and 26.2%, 21.5%, 18.1%, and 18.8% in the time quartiles, respectively (P for trend = .01). The incidence of complete STR pre-angiography was 16.6% in the total population and 23.4%, 18.2%, 14.7%, and 9.9% in the 4 quartiles, respectively (P for trend <.001). This was largely driven by the effect of triple antiplatelet therapy, which further improved initial patency and STR and led to a significantly higher incidence of aborted myocardial infarction (13.2% vs 8.7%, P = .011), especially in the patients with short duration of symptoms. Conclusion Antiplatelet pretreatment before primary PCI, including a glycoprotein IIb/IIIa blocker, seems to be most effective when given shortly after symptom onset. Further studies should be performed to test this hypothesis. (Am Heart J 2010;160:1079-84.

Comprehensive Molecular Characterization of the Hippo Signaling Pathway in Cancer

Hippo signaling has been recognized as a key tumor suppressor pathway. Here, we perform a comprehensive molecular characterization of 19 Hippo core genes in 9,125 tumor samples across 33 cancer types using multidimensional “omic” data from The Cancer Genome Atlas. We identify somatic drivers among Hippo genes and the related microRNA (miRNA) regulators, and using functional genomic approaches, we experimentally characterize YAP and TAZ mutation effects and miR-590 and miR-200a regulation for TAZ. Hippo pathway activity is best characterized by a YAP/TAZ transcriptional target signature of 22 genes, which shows robust prognostic power across cancer types. Our elastic-net integrated modeling further reveals cancer-type-specific pathway regulators and associated cancer drivers. Our results highlight the importance of Hippo signaling in squamous cell cancers, characterized by frequent amplification of YAP/TAZ, high expression heterogeneity, and significant prognostic patterns. This study represents a systems-biology approach to characterizing key cancer signaling pathways in the post-genomic era. Wang et al. perform a comprehensive analysis of 19 Hippo core genes across 33 cancer types using multidimensional “omic” data from The Cancer Genome Atlas. They characterize Hippo pathway activity by a YAP/TAZ transcriptional target signature of 22 genes and highlight the importance of Hippo signaling in squamous cell cancers