Clinical Implications of CT-detected Hypoattenuation Thickening on Left Atrial Appendage Occlusion Devices.

Background At follow-up CT after left atrial appendage occlusion (LAAO), hypoattenuation thickening (HAT) on the atrial aspect of the device is a common finding but the clinical implications require further study. Purpose To assess the association of HAT grade at follow-up CT with clinical characteristics and outcomes in patients who underwent LAAO. Materials and Methods This prospective study included consecutive participants with atrial fibrillation and who were at high risk for stroke (CHA2DS2-VASc score ≥4) who underwent LAAO and were administered pacifier or nonpacifier devices at two French medical centers between January 2012 and November 2020. Postprocedure CT images were evaluated by two radiologists in consensus and device-specific interpretation algorithms were applied to classify HAT as low grade (low suspicion of thrombosis) or high grade (high suspicion of thrombosis). The association between HAT grade and clinical characteristics was assessed using multinomial logistic regression, and variables associated with risk of stroke were assessed using a Cox proportional hazard model. Results This study included 412 participants (mean age, 76 years ± 8 [SD]; 284 male participants) who underwent follow-up CT at a mean of 4.2 months ± 1.7 after LAAO. Low-grade and high-grade HAT were depicted in 98 of 412 (23.8%) and 21 of 412 (5.1%) participants, respectively. High-grade HAT was associated with higher odds of antithrombotic drug discontinuation during follow-up (odds ratio, 9.5; 95% CI: 3.1, 29.1; P < .001), whereas low-grade HAT was associated with lower odds of persisting left atrial appendage patency (odds ratio, 0.46; 95% CI: 0.27, 0.79; P = .005). During a median follow-up of 17 months (IQR, 11-41 months), stroke occurred in 24 of 412 (5.8%) participants. High-grade HAT was associated with stroke (hazard ratio, 4.6; 95% CI: 1.5, 14.0; P = .008) and low-grade HAT (P = .62) was not. Conclusion Low-grade HAT was a more common finding at CT performed after LAAO CT (24%) than was high-grade HAT (5%), but it was associated with more favorable outcomes than high-grade HAT, which was associated with higher stroke risk. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Choe in this issue.

Effectiveness and Safety of a Prolonged Hemodynamic Support by the IVAC2L System in Healthy and Cardiogenic Shock Pigs.

BACKGROUND: Mechanical circulatory supports are used in case of cardiogenic shock (CS) refractory to conventional therapy. Several devices can be employed, but are limited by their availability, benefit risk-ratio, and/or cost. AIMS: To investigate the feasibility, safety, and effectiveness of a long-term support by a new available device (IVAC2L) in pigs. METHODS: Experiments were carried out in male pigs, divided into healthy (n = 6) or ischemic CS (n = 4) groups for a median support time of 34 and 12 h, respectively. IVAC2L was implanted under fluoroscopic and TTE guidance under general anesthesia. CS was induced by surgical ligation of the left anterior descending artery. An ipsilateral lower limb reperfusion was created with the Solopath® system. Reperfusion was started after 1 h of support in healthy pigs and upon IVAC2L insertion in CS pigs. Hemodynamic and biological parameters were monitored before and during the whole period of support in each group. RESULTS: Occurrence of an ipsilateral lower limb ischemia was systematic in healthy and CS pigs in a few minutes after IVAC2L implantation, and could be reversed by the arterial reperfusion, as demonstrated by distal transcutaneous pressure in oxygen (TcPO2) and lactate normalization. IVAC2L support decreased pulmonary capillary wedge pressure (PCWP) (15.3 ± 0.3 vs. 7.5 ± 0.9 mmHg, p < 0.001), increased systolic blood pressure (SBP) (70 ± 4.5 vs. 101.3 ± 3.1 mmHg, p < 0.01), and cardiac output (CO) (4.0 ± 0.3 vs. 5.2 ± 0.6 l/min, p < 0.05) in CS pigs; at CS onset and after 12 h of support, without effects on heart rate or pulmonary artery pressure (PAP). Non-sustained ventricular arrhythmias were frequent at implantation (50%). A non-significant hemolysis was observed under support in CS pigs. Bleedings were frequent at the insertion and/or operating sites (30%). CONCLUSION: Long-term support by IVAC2L is feasible and associated with a significant hemodynamic improvement in a porcine model. These preclinical data open the door for a study of IVAC2L in human ischemic CS, keeping in mind the need for systematic reperfusion of the lower limb and the associated risk of bleeding.