Temporal Analysis of Tachycardia During Catheter Directed Thrombolysis for Acute Pulmonary Embolism.

PURPOSE: To evaluate the effect of catheter directed thrombolysis (CDT) on heart rate (HR) in patients with sinus tachycardia and acute pulmonary embolism (PE). METHODS: A retrospective chart review was performed for patients who underwent CDT with tPA for acute massive or submassive PE between 12/2009 and 2/2020. Included were patients who presented with tachycardia at the time of initiation of CDT. Patients with chronic PE, atrial fibrillation, beta blocker therapy, adjunctive endovascular therapy, systemic thrombolysis, or who expired before conclusion of CDT were excluded. HR was measured approximately every hour during CDT. Graphs were plotted of HR as a function of CDT duration. Two interventional radiologists identified the point of plateau (POP) on the graph where CDT had maximized its benefit in decreasing the patient's HR. Discrepancies were adjudicated by a third interventional radiologist and the median of the 3 measurements was selected. The primary endpoint was the duration of CDT from initiation until the POP. RESULTS: 48 patients were included (52.5 ± 14.7 years, 56.3% female). The POP occurred after 13.1 ± 6.1 hours, by which point HR had been reduced from 110 ± 9.2 bpm to 88 ± 10.6 bpm. Sinus tachycardia was not resolved in 10 patients even though they achieved maximal improvement in HR after 11.3 ± 6.7 hours. CONCLUSION: Patients presenting with sinus tachycardia related to acute PE achieved maximal, sustained reduction in heart rate from CDT, after approximately 13 hours of infusion. Patients who did not resolve their tachycardia by that point in time were unlikely to resolve it by the conclusion of CDT.

Evaluation of the Benefit of Extended Catheter-Directed Thrombolysis with Serial Angiography for Acute Pulmonary Embolism.

PURPOSE: To evaluate whether extended catheter-directed thrombolysis (CDT) with repeat visits to the angiography suite provide added benefit in treatment of acute pulmonary embolism (PE). MATERIALS AND METHODS: This was a retrospective review of CDT procedures performed for acute PE in 156 patients (age 56.1 y ± 15.3, 46.2% women) between 2009 and 2019. All patients underwent at least 1 follow-up visit to the angiography suite for evaluation of pulmonary artery pressure (PAP) and thrombus burden (Miller score) before termination (111/156, 71.2%) or continuation of CDT (45/156, 28.8%). RESULTS: Patients who had CDT extended beyond the first follow-up visit required a higher total dose of tissue plasminogen activator (40.7 mg ± 14.3 vs 22.6 mg ± 9.9, P < .001) to achieve a similar final Miller score (6.4 ± 3.8 vs 7.6 ± 3.9, P = .1) and a similar reduction in systolic PAP (-14.4 mm Hg ± 10.2 vs -12.6 mm Hg ± 11.9, P = .6). The initial Miller scores were similar in both groups (19.7 ± 5.8 vs 19 ± 4, P = .4) but were significantly higher during the first follow-up visit (after 18 hours ± 5.5 vs 20 hours ± 4.8, P = .06) in patients requiring multiple follow-up visits (12.2 ± 5 vs 7.6 ± 3.9, P < .001). Multiple regression analyses identified heart rate > 100 beats/min and systolic PAP > 55 mm Hg as associated with the need for extended CDT. Extended CDT did not result in a higher hemorrhagic complication rate (1/45 vs 6/111, P = .7). CONCLUSIONS: Patients presenting with higher heart rates and systolic PAP may benefit from extended CDT to achieve similar reductions in PAP and thrombus burden, without clear added risk of hemorrhage.

Large-Bore Aspiration Thrombectomy versus Catheter-Directed Thrombolysis for Acute Pulmonary Embolism: A Propensity Score-Matched Comparison.

PURPOSE: To compare effectiveness and safety of large-bore aspiration thrombectomy (LBAT) with catheter-directed thrombolysis (CDT) for treatment of acute massive and submassive pulmonary embolism (PE). MATERIALS AND METHODS: This retrospective review included patients with acute PE treated with LBAT or CDT using tissue plasminogen activator (tPA) between December 2009 and May 2020. A propensity score based on Pulmonary Embolism Severity Index class and PE severity (massive vs submassive) was calculated, and 26 LBAT cases (age 60.2 y ± 17.1, 14/26 women) were matched with 26 CDT cases (age 59.7 y ± 14.2, 14/26 women). RESULTS: The CDT group had 22.1 mg ± 8.1 tPA infused over 21.2 h ± 6.6. Both groups demonstrated similar initial and final systolic pulmonary artery pressure (PAP) (LBAT: 54.5 mm Hg ± 12.9 vs CDT: 54.5 mm Hg ± 16.3, P = .8, and LBAT: 42.5 mm Hg ± 14.1 vs CDT: 42.6 mm Hg ± 12.1, P = .8, respectively) and similar reductions in heart rate (LBAT: -5.4 beats/min ± 19.2 vs CDT: -9.6 beats/min ± 15.8, P = .4). CDT demonstrated a higher reduction in Miller score (-10.1 ± 3.9 vs -7.5 ± 3.8, P = .02). LBAT resulted in 1 minor hemorrhagic complication and 2 procedure-related mortalities, and CDT resulted in 1 minor and 1 major hemorrhagic complication. CONCLUSIONS: LBAT and CDT resulted in similar reductions of PAP and heart rate when used to treat acute PE. CDT reduced thrombus burden to a greater degree. Although hemorrhagic complications rates were not significantly different, the LBAT group demonstrated a higher rate of procedure-related mortality. Larger studies are needed to compare the safety of these techniques.

Evaluation of the Effect of Routine Antibiotic Administration after Uterine Artery Embolization on Infection Rates.

PURPOSE: To evaluate the effect of routine administration of post-procedural antibiotics following elective uterine artery embolization (UAE) on infectious complication rates. MATERIALS AND METHODS: The charts of patients who underwent UAE between January 2013 and September 2019 were retrospectively reviewed. Prior to January 15, 2016, all patients received post-procedural antibiotics with 500 mg of ciprofloxacin twice a day orally for 5 days. After January 15, 2016, none of the patients received post-procedural antibiotics. All patients in both groups received pre-procedural intravenous antibiotics. The post-procedural antibiotics group included 217 patients (age, 44.7 ± 6 years); the no-antibiotics group included 158 patients (age, 45.4 ± 5.6 years). Patients in the no-antibiotics group had a significantly higher rate of diabetes mellitus (P = .03) but fewer cases of adenomyosis (P = .048). Otherwise, demographic and fibroid characteristics were similar between the groups. RESULTS: Six infectious complications (6/375, 1.6%) were recorded. No statistically significant difference (P = .66) was observed in the number of infections between the post-procedural antibiotics group (4/217, 1.8%) and the no-antibiotics group (2/158, 1.3%). Three of the 6 infectious complications presented with malodorous vaginal discharge (3/375, 0.8%) and received nominal therapy. The 3 remaining complications (0.8%) were considered major and included 2 patients (0.5%) who underwent hysterectomy and 1 patient (0.3%) who underwent myomectomy. The major infection rate was 0.9% (2/217) in the post-procedural antibiotics group and 0.7% (1/158) in the no-antibiotics group (P = 1). There were no 90-day post-procedural mortalities. CONCLUSIONS: Discontinuation of routine post-procedural antibiotics with ciprofloxacin after elective UAE did not result in increased rates of infectious complications within the first 90 days post procedure.

Direct visualization of the arterial wall water permeability barrier using CARS microscopy.

The artery wall is equipped with a water permeation barrier that allows blood to flow at high pressure without significant water leak. The precise location of this barrier is unknown despite its importance in vascular function and its contribution to many vascular complications when it is compromised. Herein we map the water permeability in intact arteries, using coherent anti-Stokes Raman scattering (CARS) microscopy and isotopic perfusion experiments. Generation of the CARS signal is optimized for water imaging with broadband excitation. We identify the water permeation barrier as the endothelial basolateral membrane and show that the apical membrane is highly permeable. This is confirmed by the distribution of the AQP1 water channel within endothelial membranes. These results indicate that arterial pressure equilibrates within the endothelium and is transmitted to the supporting basement membrane and internal elastic lamina macromolecules with minimal deformation of the sensitive endothelial cell. Disruption of this pressure transmission could contribute to endothelial cell dysfunction in various pathologies.

The electrochemical transmission in I-Band segments of the mitochondrial reticulum.

Within the mitochondrial reticulum of skeletal muscle, the I-Band segments (IBS) traverse the cell and form a contiguous matrix with the mitochondrial segments at the periphery (PS) of the cell. A tight electrical coupling via the matrix between the PS and IBS has been demonstrated. In addition, oxidative phosphorylation complexes that generate the proton motive force (PMF) are preferentially located in the PS, while Complex V, which utilizes the PMF, is primarily located along the IBS. This has led to the hypothesis that PS can support the production of ATP in the IBS by maintaining the potential energy available to produce ATP deep in the muscle cell via conduction of the PMF down the IBS. However, the mechanism of transmitting the PMF down the IBS is poorly understood. This theoretical study was undertaken to establish the physical limits governing IBS conduction as well as potential mechanisms for balancing the protons entering the matrix along the IBS with the ejection of protons in the PS. The IBS was modeled as a 300 nm diameter, water-filled tube, with an insulated circumferential wall. Two mechanisms were considered to drive ion transport along the IBS: the electrical potential and/or concentration gradients between the PS to the end of the IBS. The magnitude of the flux was estimated from the maximum ATP production rate for skeletal muscle. The major transport ions in consideration were H(+), Na(+), and K(+) using diffusion coefficients from the literature. The simulations were run using COMSOL Multiphysics simulator. These simulations suggest conduction along the IBS via H(+) alone is unlikely requiring un-physiological gradients, while Na(+) or K(+) could carry the current with minor gradients in concentration or electrical potential along the IBS. The majority of conduction down the IBS is likely dependent on these abundant ions; however, this presents a question as to how H(+) is recycled from the matrix of the IBS to the PS for active extrusion. We propose that the abundant cation-proton antiporter in skeletal muscle mitochondria operates in opposite directions in the IBS and PS to permit local recycling of H(+) at each site driven by cooperative gradients in H(+) and Na(+)/K(+) which favor H(+) entry in the PS and H(+) efflux in the IBS. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016,' edited by Prof. Paolo Bernardi.