The clinical and economic impact of extended battery longevity of a substernal extravascular implantable cardioverter defibrillator.

INTRODUCTION: The extravascular implantable cardioverter defibrillator (EV ICD) has extended projected battery longevity compared to the subcutaneous implantable cardioverter defibrillator (S-ICD). This study used modeling to characterize the need for generator changes, long-term complications, and overall costs for both the EV ICD and S-ICD in healthcare systems of various countries. METHODS: Battery longevity data were modeled using a Markov model from averages reported in device labeling for the S-ICD and with engineering estimates based on real life usage from EV ICD Pivotal Study patient data to introduce variability. Clinical demographic data were derived from published literature. The primary outcomes were defined as the number of generator replacement surgeries, complications, and total healthcare system costs due to battery depletion over the expected lifetime of patients receiving EV ICD or S-ICD therapy. RESULTS: Average modeled battery longevity was determined to be 7.3 years for the S-ICD versus 11.8 years for the EV ICD. The probability of a complication after a replacement procedure was 1.4%, with an operative mortality rate of 0.02%. The use of EV ICD was associated with 1.4-1.6 fewer replacements on average over an expected patient lifetime as compared to S-ICD and a 24.3%-26.0% reduction in cost. A one-way sensitivity analysis of the model for the US healthcare system found that use of an EV ICD resulted in a reduction in replacement surgeries of greater than 1 (1.1-1.6) along with five-figure cost savings in all scenarios ($18 602-$40 948). CONCLUSION: The longer projected battery life of the EV ICD has the potential to meaningfully reduce long-term morbidity and healthcare resources related to generator changes from the perspective of multiple diverse healthcare systems.

Management of Lisfranc Injuries: A Critical Analysis Review.

¼: There is a spectrum of midtarsal injuries, ranging from mild midfoot sprains to complex Lisfranc fracture-dislocations. ¼: Use of appropriate imaging can reduce patient morbidity, by reducing the number of missed diagnoses and, conversely, avoiding overtreatment. Weight-bearing radiographs are of great value when investigating the so-called subtle Lisfranc injury. ¼: Regardless of the operative strategy, anatomical reduction and stable fixation is a prerequisite for a satisfactory outcome in the management of displaced injuries. ¼: Fixation device removal is less frequently reported after primary arthrodesis compared with open reduction and internal fixation based on 6 published meta-analyses. However, the indications for further surgery are often unclear, and the evidence of the included studies is of typically low quality. Further high-quality prospective randomized trials with robust cost-effectiveness analyses are required in this area. ¼: We have proposed an investigation and treatment algorithm based on the current literature and clinical experience of our trauma center.

Efficacy and Safety of an Extravascular Implantable Cardioverter-Defibrillator.

BACKGROUND: The extravascular implantable cardioverter-defibrillator (ICD) has a single lead implanted substernally to enable pause-prevention pacing, antitachycardia pacing, and defibrillation energy similar to that of transvenous ICDs. The safety and efficacy of extravascular ICDs are not yet known. METHODS: We conducted a prospective, single-group, nonrandomized, premarket global clinical study involving patients with a class I or IIa indication for an ICD, all of whom received an extravascular ICD system. The primary efficacy end point was successful defibrillation at implantation. The efficacy objective would be met if the lower boundary of the one-sided 97.5% confidence interval for the percentage of patients with successful defibrillation was greater than 88%. The primary safety end point was freedom from major system- or procedure-related complications at 6 months. The safety objective would be met if the lower boundary of the one-sided 97.5% confidence interval for the percentage of patients free from such complications was greater than 79%. RESULTS: A total of 356 patients were enrolled, 316 of whom had an implantation attempt. Among the 302 patients in whom ventricular arrhythmia could be induced and who completed the defibrillation testing protocol, the percentage of patients with successful defibrillation was 98.7% (lower boundary of the one-sided 97.5% confidence interval [CI], 96.6%; P<0.001 for the comparison with the performance goal of 88%); 299 of 316 patients (94.6%) were discharged with a working ICD system. The Kaplan-Meier estimate of the percentage of patients free from major system- or procedure-related complications at 6 months was 92.6% (lower boundary of the one-sided 97.5% CI, 89.0%; P<0.001 for the comparison with the performance goal of 79%). No major intraprocedural complications were reported. At 6 months, 25 major complications were observed, in 23 of 316 patients (7.3%). The success rate of antitachycardia pacing, as assessed with generalized estimating equations, was 50.8% (95% CI, 23.3 to 77.8). A total of 29 patients received 118 inappropriate shocks for 81 arrhythmic episodes. Eight systems were explanted without extravascular ICD replacement over the 10.6-month mean follow-up period. CONCLUSIONS: In this prospective global study, we found that extravascular ICDs were implanted safely and were able to detect and terminate induced ventricular arrhythmias at the time of implantation. (Funded by Medtronic; ClinicalTrials.gov number, NCT04060680.).

Evaluation of a program for outpatient sotalol loading with physician and pharmacist monitoring.

BACKGROUND: Dose-dependent QT prolongation with class III antiarrhythmics mandates close monitoring often in an inpatient setting. Outpatient sotalol loading monitor provides an alternative to patients that is cost effective and allows preservation of hospital resources. OBJECTIVES: The objectives for this study include assessing adverse events, assessing patient adherence to monitoring and follow-up, comparing hospital cost and resource utilization, and evaluating patient satisfaction with outpatient sotalol loading program. PRACTICE DESCRIPTION: One pharmacist in the antiarrhythmic clinic at OhioHealth Riverside Methodist Hospital completed 3-day outpatient sotalol loads under a collaborative practice agreement. Clinic services included pharmacotherapy management, medication counseling, and device education. PRACTICE INNOVATION: This service allows pharmacists to provide direct patient monitoring to provide increased patient access. EVALUATION METHODS: All data were collected via the electronic medical record, patient journal documentation, and a patient satisfaction survey. RESULTS: A total of 12 patients completed outpatient sotalol loading; 10 patients started in normal sinus rhythm, and 1 patient was cardioverted during the load. No patients experienced any adverse events during the loading phase. One patient completed a successful dose increase during the loading phase. All 12 patients attended the first visit, completed baseline laboratory tests, and uploaded electrocardiograms for all 3 days. A total of 11 patients were evaluated as a cost comparison for inpatient sotalol loading. On average, outpatient loading cost was $886.30, in comparison with $7571.76 for inpatient loading (P < 0.001). A total of 10 patients completed the satisfaction survey, and all of the patients preferred to complete this in the outpatient setting. CONCLUSION: In this study, 12 patients safely completed outpatient sotalol loading, with an overall decrease in the cost of their care in comparison with inpatient loading. This study showed that pharmacists can serve as physician extenders to continue to provide high-quality and safe care to patients in the antiarrhythmic space.

Longitudinal QTc stability and impact of baseline cardiac rhythm on discharge dose in dofetilide-treated patients.

INTRODUCTION: Dofetilide suppresses atrial fibrillation (AF) in a dose-dependent fashion. The protective effect of AF against QTc prolongation induced torsades de pointe and transient post-cardioversion QTc prolongation may result in dofetilide under-dosing during initiation. Thus, the optimal timing of cardioversion for AF patients undergoing dofetilide initiation to optimize discharge dose remains unknown as does the longitudinal stability of QTc . The purpose of this study was to evaluate the impact of baseline rhythm on dofetilide dosing during initiation and assess the longitudinal stability of QTc-all (Bazzett, Fridericia, Framingham, and Hodges) over time. METHODS: Medical records of patients who underwent preplanned dofetilide loading at a tertiary care center between January 2016 and 2019 were reviewed. RESULTS: A total of 198 patients (66 ± 10 years, 32% female, CHADS2 -Vasc 3 [2-4]) presented for dofetilide loading in either AF (59%) or sinus rhythm (SR) (41%). Neither presenting rhythm, nor spontaneous conversion to SR impacted discharge dose. The cumulative dofetilide dose before cardioversion moderately correlated (r = .36; p = .0001) with discharge dose. Postcardioversion QTc-all prolongation (p < .0001) prompted discharge dose reduction (890 ± 224 mcg vs. 552 ± 199 mcg; p < .0001) in 30% patients. QTc-all in SR prolonged significantly during loading (p < .0001). All patients displayed QTc-all reduction (p < .0001) from discharge to short-term (46 [34-65] days) that continued at long-term (360 [296-414] days) follow-ups. The extent of QTc-all reduction over time moderately correlated with discharge QTc-all (r = .54-0.65; p < .0001). CONCLUSION: Dofetilide initiation before cardioversion is equivalent to initiation during SR. Significant QTc reduction proportional to discharge QTc is seen over time in all dofetilide-treated patients. QTc returns to preloading baseline during follow-up in patients initiated in SR.

Relationship between Surpoint Tag Index, a Radiofrequency Ablation lesion quality indicator, and Atrial wall thickness in Cavotricuspid isthmus Ablations exhibiting bidirectional block.

BACKGROUND: An RFA lesion quality indicator, Surpoint Tag Index® (TI) incorporates key factors: power, time, and contact force, impacting lesion quality. TI accurately estimates lesion depth in animal studies. However, the relationship between TI and in-vivo atrial wall thickness in patients exhibiting bidirectional block remains unknown. OBJECTIVE: To describe the relationship between atrial wall thickness and TI in CTI exhibiting bidirectional block. METHODS: Data from 492 RFA lesions from 25 patients undergoing PVI and CTI ablations in SR with point-by-point RF lesions (<45 W) utilizing a Thermocool Smarttouch® SF ablation catheter and CARTO-3 mapping were retrospectively analyzed. Operators were blinded to TI data and CTI thickness. CTI thickness was obtained using ICE images on Cartosound pre-ablation. Durable lesions were defined as part of a lesion set exhibiting bidirectional block of >30 min. RESULTS: In lesions exhibiting bidirectional block, the thinnest (1-2 mm; 5% lesions) and thickest (8-10 mm; 6% lesions) portions of the CTI correlated with the lowest (429 ± 75) and highest (516 ± 64) TI. The bulk of thickness (2-6 mm; 80%) correlated with a TI of 455 ± 72 (p = 0.001). There was a weak but positive correlation between TI and CTI thickness (r = 0.2; p ≤ 0.01). Examined in sectors, the anterior 1/3rd CTI was the thickest (4.8 ± 1.9 mm) but correlated with a similar TI value (479 ± 75 vs. 471 ± 70; p = 0.34) as the thinner middle 1/3rd (3.8 ± 1.7 mm; p ≤ 0.0001). CONCLUSION: A mean TI value of 455 correlates with bidirectional block across the bulk of CTI with lower and higher values needed for the thinner and thicker portions, respectively. Tissue composition, aside from wall thickness, influences TI values for the creation of the bidirectional block.

Impact of a dedicated atrial fibrillation clinic on diagnosis-to-ablation time.

Background: Outcomes following catheter ablation (CA) for atrial fibrillation (AF) improve as the diagnosis-to-ablation time (DAT) shortens. Use of a protocol-based integrated care model through a dedicated atrial fibrillation clinic (AFC) may serve to standardize treatment pathways and decrease DAT. Objective: To evaluate the DAT and clinical characteristics of patients with AF referred from an AFC vs a conventional electrophysiology clinic (EC). Methods: Retrospective analysis was completed in consecutive patients undergoing index AF ablation at Riverside Methodist Hospital in 2019 with minimum 1 year follow-up. Patients were categorized based off their CA referral source (AFC vs EC) and where the initial visit following index diagnosis of AF occurred (AFC vs EC). Results: A total of 182 patients (mean age 65 years, 64% male) were reviewed. Patients referred from an AFC (21%) had a median DAT of 342 days (interquartile range [IQR], 125-855 days) compared to patients referred from EC (79%) with a median DAT of 813 days (IQR, 241-1444 days; P = .01). Patients with their index visit following AF diagnosis occurring in the AFC (9%) had significantly shorter median DAT (127 days [IQR, 95-188 days]) compared to EC (91%) (789 days [IQR, 253-1503 days]; P = .002). Patients with DAT <1 year had lower AF recurrence than patients with DAT >1 year (P = .04, hazard ratio = 0.58, 95% confidence interval 0.3418-1.000). Conclusion: DAT is a modifiable factor that may affect CA outcomes. Significant reductions in DAT were observed in patients evaluated through a dedicated AF clinic.

Lead Macrodislodgement of a Subcutaneous Implantable Cardioverter-Defibrillator Results in a Reel Problem.

Lead macrodislodgement is a rare complication of cardiac implantable electronic devices associated with patient-related risk factors. This paper outlines a case of reel syndrome secondary to device manipulation 3 months after subcutaneous implantable cardioverter-defibrillator implantation and describes the challenges with lead macrodislodgement diagnosis, mechanisms, and management. (Level of Difficulty: Beginner.).

Cell-associated type I collagen in nondegenerate and degenerate human articular cartilage.

Chondrocytes with abnormal morphology are present in nondegenerate human cartilage suggesting dedifferentiation to a fibroblastic phenotype and production of a mechanically-weakened matrix of unknown composition. We determined the relationship between in situ chondrocyte morphology, chondrocyte clusters, and levels of cell-associated collagen type I. Chondrocyte morphology in fresh femoral head cartilage from 19 patients with femoral neck fracture and collagen type I labelling was identified with Cell TrackerTM fluorescence and immunofluorescence, respectively, in axial/coronal orientations using confocal microscopy with images analysed by ImarisTM . In axial images of grade 0 cartilage, 87 ± 8% were normal chondrocytes with a small (10 ± 6%) abnormal population possessing ≥1 cytoplasmic process. More normal chondrocytes (78 ± 11%) were collagen type I negative than those labelling positively (p < 0.001). For abnormal chondrocytes, 81 ± 14% labelled negatively for collagen type I compared to those labelling positively (19 ± 3%; p = 0.007; N(n)=11(3)). Overall, approximately 9% of the cells in normal cartilage labelled for collagen type I. With degeneration, the percentage of normal chondrocytes decreased (p < 0.001) but increased for abnormal cells (p = 0.036) and clusters (p = 0.003). A larger percentage of normal, abnormal and clustered chondrocytes now demonstrated collagen type I labelling (p = 0.004; p = 0.009; p = 0.001 respectively). Coronal images exhibited increased (p = 0.001) collagen type I labelling in the superficial zone of mildly degenerate cartilage with none in the mid or deep zones. These results show that collagen type I was identified around normal and abnormal chondrocytes in nondegenerate cartilage, which increased with degeneration. This suggested the presence of mechanically weak fibro-cartilaginous repair tissue in otherwise macroscopically nondegenerate human cartilage which progressed with degeneration as occurs in osteoarthritis.

Evaluating the role of transesophageal echocardiography (TEE) or intracardiac echocardiography (ICE) in left atrial appendage occlusion: a meta-analysis.

PURPOSE: Intracardiac echocardiography (ICE) is increasingly common among periprocedural imaging modalities used during complex cardiac procedures. We sought to perform a meta-analysis comparing transesophageal echocardiography (TEE) and ICE in endocardial left atrial appendage occlusion (LAAO). METHODS: We searched PubMed and Google Scholar regarding abstracts and manuscripts using keywords: atrial fibrillation, left atrial appendage occlusion, Watchman, Amplatzer Cardiac Plug, Amulet, intracardiac echocardiography, and transesophageal echocardiography from their inception to July 12, 2019. Data extraction was performed using standard form for the following: title, year of publication, sample size, comorbid conditions, LAAO device, type of pre-procedural imaging, intraprocedural imaging, and clinical outcomes including the following: acute procedural success, fluoroscopy, and total procedure time and complications. RESULTS: A total of 42 relevant studies were screened resulting in inclusion of 8 observational studies comparing TEE and ICE in endocardial LAAO. Outcomes assessed including procedural success (RR 1.00, 95% CI (0.97-1.03, p = 0.98)), complications (RR 0.77, 95% CI (0.52 to 1.15, p = 0.20)), fluoroscopy time (mean difference - 0.40, 95% CI (-3.12-2.32, p = 0.77)), and procedural time (mean difference - 8.02, 95% CI (-22.81 to 6.76, p = 0.29)) were found to be similar between both groups. CONCLUSIONS: While TEE is the gold standard for perioperative imaging with LAAO, ICE is a feasible and safe alternative that reduces exposure to general anesthesia and associated potential risks.

Hinge location and apical drill holes in opening wedge high tibial osteotomy: A finite element analysis.

At the time of medial opening wedge high tibial osteotomy (HTO) to realign the lower limb and offload medial compartment knee osteoarthritis, unwanted fractures can propagate from the osteotomy apex. The aim of this study was to use finite element (FE) analysis to determine the effect of hinge location and apical drill holes on cortical stresses and strains in HTO. A monoplanar medial opening wedge HTO was created above the tibial tuberosity in a composite tibia. Using the FE method, intact lateral hinges of different widths were considered (5, 7.5, and 10 mm). Additional apical drill holes (2, 4, and 6 mm diameters) were then incorporated into the 10 mm hinge model. The primary outcome measure was the maximum principal strain in the cortical bone surrounding the hinge axis. Secondary outcomes included the force required for osteotomy opening, minimum principal strain, and mean cortical bone stresses (maximum principal/minimum principal/von Mises). Larger intact hinges (10 mm) were associated with higher cortical bone maximum principal strain and stress, lower minimum principal strain/stress, and required greater force to open. Lateral cortex strain concentrations were present in all scenarios, but extended to the joint surface with the 10 mm hinge. Apical drill holes reduced the mean cortical bone maximum principal strain adjacent to the hinge axis: 2 mm hole 6% reduction; 4 mm 35% reduction; and 6 mm 55% reduction. Incorporating a 4-mm apical drill hole centered 10 mm from the intact lateral cortex maintains a cortical bone hinge, minimizes cortical bone strains and reduces the force required to open the HTO; thus improving control.

Optimization and Validation of a Human Ex Vivo Femoral Head Model for Preclinical Cartilage Research and Regenerative Therapies.

OBJECTIVE: Articular cartilage is incapable of effective repair following injury or during osteoarthritis. While there have been developments in cartilage repair technologies, there is a need to advance biologically relevant models for preclinical testing of biomaterial and regenerative therapies. This study describes conditions for the effective ex vivo culture of the whole human femoral head. DESIGN: Fresh, viable femoral heads were obtained from femoral neck fractures and cultured for up to 10 weeks in (a) Dulbecco's modified Eagle's medium (DMEM); (b) DMEM + mixing; (c) DMEM + 10% human serum (HS); (d) DMEM + 10% HS + mixing. The viability, morphology, volume, and density of fluorescently labelled in situ chondrocytes and cartilage surface roughness were assessed by confocal microscopy. Cartilage histology was studied for glycosaminoglycan content using Alcian blue and collagen content using picrosirius red. RESULTS: Chondrocyte viability remained at >95% in DMEM + 10% HS. In DMEM alone, viability remained high for ~4 weeks and then declined. For the other conditions, superficial zone chondrocyte viability fell to <35% at 10 weeks with deeper zones being relatively unaffected. In DMEM + 10% HS at 10 weeks, the number of chondrocytes possessing cytoplasmic processes increased compared with DMEM (P = 0.017). Alcian blue labeling decreased (P = 0.02) and cartilage thinned (P ≤ 0.05); however, there was no change to surface roughness, chondrocyte density, chondrocyte volume, or picrosirius red labeling (P > 0.05). CONCLUSIONS: In this ex vivo model, chondrocyte viability was maintained in human femoral heads for up to 10 weeks in culture, a novel finding not previously reported. This human model could prove invaluable for the exploration, development, and assessment of preclinical cartilage repair and regenerative therapies.

Percutaneous reduction and fixation of low energy Lisfranc injuries results in better outcome compared to open reduction and internal fixation: Results from a matched case-control study with minimum 12 months follow up.

BACKGROUND: Percutaneous fixation of Lisfranc injuries is potentially less invasive to traditional open techniques but evidence of any clinical benefit is lacking. The aim of this study is to compare the clinical outcomes of percutaneous reduction and internal fixation (PRIF) of low energy Lisfranc injuries with a matched, control group of patients treated with ORIF. METHODS: Over a seven-year period (2012-2019), 16 consecutive patients with a low energy Lisfranc injury (Myerson B2-type) were treated with PRIF. Patient demographics, injury mechanism and radiological outcomes were recorded within a prospectively maintained database at the institution. This study sample was matched for age, sex and mechanism of injury to a control group of 16 patients with similar low energy Lisfranc injuries (Myerson B2-type) treated with ORIF. Clinical outcome was compared using the American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score and Manchester Oxford Foot Questionnaire (MOXFQ). RESULTS: At a mean follow up of 43 months (95% CI 35.6 - 50.4), both the AOFAS and MOXFQ scores were significantly higher in the PRIF group compared to the control ORIF group (AOFAS 89.1vs 76.4, p=0.03; MOXFQ 10.0 vs 27.6, p=0.03). There were no immediate postoperative complications in either group. There was no radiological evidence of midfoot osteoarthritis in the PRIF group, three patients in the ORIF group developed midfoot osteoarthritis (p=0.2). CONCLUSIONS: PRIF of low energy Lisfranc injures is a safe, minimally invasive technique and is associated with better mid-term clinical outcomes compared to ORIF.

Editorial Commentary: Raising the Osmolarity of Arthroscopic Irrigating Solutions May Be Chondroprotective: We Must Be Kind to Joints During Arthroscopy!

The irrigation of joints during arthroscopic procedures typically uses a non-physiological solution. This replaces the natural synovial fluid and rapidly subjects the connective tissues to an alien hypo-osmotic environment in which cartilage cells are far more sensitive to iatrogenic injury. Raising the osmolarity of the irrigating solution may be a simple, safe, and effective chondroprotective strategy.

Population mobility and adult orthopaedic trauma services during the COVID-19 pandemic: fragility fracture provision remains a priority.

AIMS: This study aims to define the epidemiology of trauma presenting to a single centre providing all orthopaedic trauma care for a population of ∼ 900,000 over the first 40 days of the COVID-19 pandemic compared to that presenting over the same period one year earlier. The secondary aim was to compare this with population mobility data obtained from Google. METHODS: A cross-sectional study of consecutive adult (> 13 years) patients with musculoskeletal trauma referred as either in-patients or out-patients over a 40-day period beginning on 5 March 2020, the date of the first reported UK COVID-19 death, was performed. This time period encompassed social distancing measures. This group was compared to a group of patients referred over the same calendar period in 2019 and to publicly available mobility data from Google. RESULTS: Orthopaedic trauma referrals reduced by 42% (1,056 compared to 1,820) during the study period, and by 58% (405 compared to 967) following national lockdown. Outpatient referrals reduced by 44%, and inpatient referrals by 36%, and the number of surgeries performed by 36%. The regional incidence of traumatic injury fell from 5.07 (95% confidence interval (CI) 4.79 to 5.35) to 2.94 (95% CI 2.52 to 3.32) per 100,000 population per day. Significant reductions were seen in injuries related to sports and alcohol consumption. No admissions occurred relating to major trauma (Injury Severity Score > 16) or violence against the person. Changes in population mobility and trauma volume from baseline correlated significantly (Pearson's correlation 0.749, 95% CI 0.58 to 0.85, p < 0.001). However, admissions related to fragility fractures remained unchanged compared to the 2019 baseline. CONCLUSION: The profound changes in social behaviour and mobility during the early stages of the COVID-19 pandemic have directly correlated with a significant decrease in orthopaedic trauma referrals, but fragility fractures remained unaffected and provision for these patients should be maintained.Cite this article: Bone Joint Open 2020;1-6:182-189.