Abstract WMP58: Blacks Have Higher Risk of 1-Year Recurrent Ischemic Stroke: An Analysis of White and Black Medicare Beneficiaries 1999-2013

Introduction: Blacks have a higher incidence of stroke compared with whites. Most stroke survivors in the United States are 65 years and older but few data are available on racial differences in recurrent stroke risk in this age group.

Methods: We conducted a retrospective cohort of Medicare beneficiaries in the 5% sample from 1999-2013 to compare 1-year recurrent stroke risk in older black and white Americans following hospitalization for ischemic stroke. We studied beneficiaries with Medicare fee-for-service coverage for 182 days before the index stroke hospitalization with no claims for stroke-related events. Patients were divided into two age groups (66-74, 75 years and above) and stratified into 3 calendar periods (1999-2001, 2002-2006, 2007-2013) allowing for implementation of secondary stroke prevention trial findings (PROGRESS, 2001; SPARCL, 2006). Hazard ratios for recurrent ischemic stroke comparing blacks to whites were calculated with adjustment for demographics, risk factors, and the competing risk of death.

Results: Of 128,789 ischemic stroke patients (mean age 80 years [SD 8], 11.1% black, 60.4% male), 7.8% of whites and 11.0% of blacks had a recurrent ischemic stroke overall (Table 1). For each time period, blacks had a higher risk of recurrent stroke compared with whites (Figure 1). This disparity increased over time among patients age 66-74 years (p=0.038) but no trend was present for those 75 years and above (p=0.301).

Conclusion: The risk of stroke recurrence among older Americans hospitalized for ischemic stroke is higher for blacks than whites, regardless of age group.

Referencing the sulcus line of the trochlear groove and removing intraoperative parallax errors improve femoral component rotation in total knee arthroplasty

PURPOSE

Firstly, to assess and compare the accuracy and reproducibility of the sulcus line compared to Whiteside's line. Secondly, to assess the accuracy of intraoperative techniques for using the rotational alignment of the trochlear groove to set femoral rotation. Thirdly, to assess the reproducibility of a trochlear alignment guide which removes parallax errors that occur when projecting the sulcus line onto the surface of the femur. Finally, to measure the result of combining the geometrically accurate sulcus line and the posterior condylar axis.

METHODS

Three surgeons measured eight rotational angles on ten cadaveric femora. This included Whiteside's line, the sulcus line and the techniques in which they can be referenced during surgery.

RESULTS

Relative to the anatomical epicondylar axis, the sulcus line (mean -2.8°, SD 2.0°, range -5.4° to 0.8°) had significantly lower variance (F = 5.16, p = 0.036) than Whiteside's line (mean -2.0°, SD 3.7°, range -6.0° to 3.4°). The trochlear alignment guide produced the best results of the intraoperative techniques by maintaining the accuracy of the sulcus line and projecting it onto the distal cut surface of the femur without change in rotational angle.

CONCLUSION

The sulcus line is more accurate and reproducible than Whiteside's line. Removing parallax errors during surgery improves femoral component rotation. The trochlear alignment guide produced accurate results suggesting that it may be beneficial in a clinical setting. Averaging the sulcus line and posterior condylar axis on the cut surface of the femur improved accuracy over the individual landmarks. Femoral component malrotation is a common cause of patient dissatisfaction and revision surgery. By isolating the rotational alignment of the trochlear groove using the sulcus line, and maintaining its accuracy with an intraoperative guide, we can decrease the risk of femoral component malrotation and improve patient outcomes.

High Rates of Anal High-Grade Squamous Intraepithelial Lesions in HIV-Infected Women Who Do Not Meet Screening Guidelines

BACKGROUND

Human immunodeficiency virus (HIV)-infected women have a higher burden of anal high-grade squamous intraepithelial lesions (HSIL) and anal cancer (AC) compared with HIV-uninfected women. Guidelines for AC screening in this population are heterogeneous. Here we report outcomes and risk factors for anal HSIL following implementation of universal AC screening offered to all HIV-infected women.

METHODS

Data from women who underwent AC screening with anal cytology from April 2009 to July 2014 were analyzed. Routine clinical data included anal and cervical cytology, demographic/behavioral data, and high-resolution anoscopy (HRA) results. We evaluated the association of cytology with HRA results, and predictors of HSIL pathology, and compared rates of HSIL pathology among women meeting screening guidelines to those who did not.

RESULTS

Seven hundred forty-five HIV-infected women were screened with anal cytology. Thirty-nine percent had abnormal anal cytology on initial screen and 15% on secondary screen; 208 women underwent HRA following abnormal anal cytology. HSIL was found in 26% and 18% of anal biopsies following initial and secondary screening, respectively. One woman had AC. Cigarette smoking more than doubled HSIL risk. Among women who underwent AC screening despite not meeting existing guideline criteria, 21% and 10%, respectively, were found to have HSIL on biopsy. Neither meeting criteria for screening nor history of receptive anal sex was significantly associated with HSIL.

CONCLUSIONS

Anal HSIL is common in HIV-infected women. Substantial numbers of HSIL would have been missed by strictly adhering to existing AC screening guidelines. These results support routine screening of all HIV-infected women regardless of human papillomavirus history or sexual practices.

Percutaneous Device Closure of Paravalvular Leak: Combined Experience From the United Kingdom and Ireland

BACKGROUND

Paravalvular leak (PVL) occurs in 5% to 17% of patients following surgical valve replacement. Percutaneous device closure represents an alternative to repeat surgery.

METHODS

All UK and Ireland centers undertaking percutaneous PVL closure submitted data to the UK PVL Registry. Data were analyzed for association with death and major adverse cardiovascular events (MACE) at follow-up.

RESULTS

Three hundred eight PVL closure procedures were attempted in 259 patients in 20 centers (2004-2015). Patient age was 67±13 years; 28% were female. The main indications for closure were heart failure (80%) and hemolysis (16%). Devices were successfully implanted in 91% of patients, via radial (7%), femoral arterial (52%), femoral venous (33%), and apical (7%) approaches. Nineteen percent of patients required repeat procedures. The target valve was mitral (44%), aortic (48%), both (2%), pulmonic (0.4%), or transcatheter aortic valve replacement (5%). Preprocedural leak was severe (61%), moderate (34%), or mild (5.7%) and was multiple in 37%. PVL improved postprocedure (P<0.001) and was none (33.3%), mild (41.4%), moderate (18.6%), or severe (6.7%) at last follow-up. Mean New York Heart Association class improved from 2.7±0.8 preprocedure to 1.6±0.8 (P<0.001) after a median follow-up of 110 (7-452) days. Hospital mortality was 2.9% (elective), 6.8% (in-hospital urgent), and 50% (emergency) (P<0.001). MACE during follow-up included death (16%), valve surgery (6%), late device embolization (0.4%), and new hemolysis requiring transfusion (1.6%). Mitral PVL was associated with higher MACE (hazard ratio [HR], 1.83; P=0.011). Factors independently associated with death were the degree of persisting leak (HR, 2.87; P=0.037), New York Heart Association class (HR, 2.00; P=0.015) at follow-up and baseline creatinine (HR, 8.19; P=0.001). The only factor independently associated with MACE was the degree of persisting leak at follow-up (HR, 3.01; P=0.002).

CONCLUSION

Percutaneous closure of PVL is an effective procedure that improves PVL severity and symptoms. Severity of persisting leak at follow-up is independently associated with both MACE and death. Percutaneous closure should be considered as an alternative to repeat surgery.

Speckle-Tracking Echocardiographic Measures of Right Ventricular Function Correlate With Improvement in Exercise Function After Percutaneous Pulmonary Valve Implantation

BACKGROUND

Speckle-tracking echocardiographic (STE) measures of right ventricular (RV) function appear to improve after transcatheter pulmonary valve implantation (TPVI). Measures of exercise function, such as ventilatory efficiency (the minute ventilation [VE]/carbon dioxide production [VCO2] slope), have been shown to be prognostic of mortality in patients who may require TPVI. The aim of this study was to evaluate the correlation between STE measures of RV function and changes in VE/VCO2 after TPVI.

METHODS

Speckle-tracking echocardiography and cardiopulmonary exercise testing were performed at baseline and 6 months after TPVI in 24 patients from four centers. Conventional echocardiographic measures of RV function were also assessed. Echocardiographic and exercise stress test results were interpreted by single blinded observers at separate core laboratories.

RESULTS

All patients demonstrated relief of pulmonary regurgitation and stenosis after TPVI. Improvements in RV longitudinal strain (-16.9 ± 3.5% vs -19.7 ± 4.3%, P < .01) and strain rate (-0.9 ± 0.4 vs. -1.2 ± 0.4 s(-1), P < .01) were noted. The VE/VCO2 slope improved (32.4 ± 5.7 vs 31.5 ± 8.8, P = .03). No other significant echocardiographic or exercise changes were found. On multivariate regression, the change in VE/VCO2 was independently associated with change in RV longitudinal early diastolic strain rate (P < .001) and tricuspid A velocity (P < .001). Preintervention RV longitudinal strain was found to be a predictor of change in VE/VCO2 after TPVI (r = -0.60, P < .001).

CONCLUSIONS

STE measures of RV function appear to hold the potential for use as predictors of improved outcomes in patients requiring TPVI. Future studies should directly assess the prognostic significance of STE measures of RV function in this population.

Abstract T P202: Implementation of a 24/7 Enrollment Process Improves Recruitment Rate in a Multi-Center, Randomized Clinical Trial

Background: Enrollment into acute ischemic stroke (AIS) trials is usually limited to weekday working hours. At our center, the majority of patients (64%) that receive tPA arrive after-hours. As a result, a large portion of eligible patients do not receive the opportunity to participate in these trials, hence enrollment rate suffers.

Objectives: Demonstrate ongoing experience regarding feasibility and implementation of a 24/7 enrollment plan for an international AIS trial. Compare differences in patients’ characteristics enrolled during working hours ( WH - Mon-Fri 07:00-17:00) vs. after hours+weekend ( AH ).

Methods: Data obtained from an on-going, multi-center, randomized, time-sensitive, tPA-adjunctive clinical trial (ARTSS-2; NCT01464788) Centers capable of doing so, implemented an on-call system for coordinators to respond AH. AH enrollment includes a coordinated effort to reduce time and meet the time challenges of screening, consent, randomization and starting study drug before the end of tPA infusion. The coordinator arrives at the ED to assist in-house physician with study procedures. We conducted descriptive analyses that explore differences between WH vs. AH .

Results: As of 08/14, a total of 240 patients were eligible of which 75 were enrolled. Of these, 32 (43%) were enrolled AH at a total of 6 sites. 15 of 32 AH patients were enrolled at non-coordinating centers. AH patients were younger and more likely to be male (Table 1). Compared to WH, AH enrollment did not delay tPA initiation, time to website randomization, or initiation of study drug. No signal of increased harm or trial protocol deviations was evident between the two groups.

Conclusion: 24/7 clinical trial enrollment is safe and feasible in a multicenter, international thrombolysis trial. We increased recruitment by 75% with no delays in randomization or initiation of study treatment. Efforts to provide 24/7 coverage should be implemented to improve trial recruitment rates.

The Flatstent versus the conventional umbrella devices in the percutaneous closure of patent foramen ovale

BACKGROUND

Patent foramen ovale (PFO) has been associated with paradoxical embolism leading to stroke/transient ischemic attack, migraine, and neurological decompression sickness. In search for the optimal device that would achieve effective clinical closure with minimal complications, a better device selection based on PFO anatomy and improvements in device design is needed. The Flatstent is a new device designed to treat the highly prevalent long-tunnel PFOs from within, minimizing the amount of material left behind in an attempt to reduce device-related complications. The objective is to compare the safety and efficacy of the novel Flatstent versus the conventional umbrella devices in the transcatheter closure of PFO in a nonrandomized, retrospective, single-center study.

METHODS

Between March 2010 and March 2013, 88 patients underwent PFO closure at The Heart Hospital, London with either the novel Flatstent or one of the four conventionally used umbrella devices (GORE Helex Septal Occluder, Occlutech Figulla Flex, Biostar Septal Occluder, and Amplatzer PFO Occluder) depending on their PFO anatomy. Patients were then evaluated with contrast transthoracic echocardiography (TTE) and/or transoesophageal echocardiography (TOE) at 6 weeks and 1 year after the procedure. The residual shunt and complication rates between the Flatstent and umbrella devices were compared.

RESULTS

The Flatstent was used in 27 patients (30.7%), whereas 61 patients (69.3%) received one of the four umbrella devices. Primary efficacy point of clinical closure defined as grade 0 or grade 1; residual shunt was achieved in 81.3% in the Flatstent cohort and 80.3% in the umbrella device group at 6 weeks follow-up. At 1 year, the clinical closure rates reached 92.6 and 91.8%. There were two device embolizations, one in each cohort during the immediate postoperative period (<24 hrs), with successful retrieval. One patient in the umbrella device group developed transient atrial fibrillation, which was controlled medically. Event recurrence rate was 0% at 1 year.

CONCLUSION

No difference was found in closure or complication rates between the Flatstent and the umbrella devices. With appropriate preassessment of the PFO anatomy, the Flatstent works as a safe and effective method of treating the PFO from within the tunnel, especially in those with long-tunnel PFOs. Longer follow-up is needed to establish superiority.

Maximizing the rigidity of a large planar orifice air bearing

A rotating support for a large astronomical mirror has been implemented using an opposed surface planar orifice air bearing. This bearing needs to provide rotation as free as possible of static and dynamic friction, as well as maximizing the resistance to sudden angular deviations produced by wind gusts. Information on the design of traditional bearings, namely, a cavity supplied with air under pressure through an orifice or diffuser flow restriction and closed by the moving member, has been published in detail. These traditional bearings are not suitable for the application described, due to their slow speed of response to transient changes in forces, a considerable volume of air being needed to change the pressure in the cavity. The air bearing used in this application has no cavity but consists of two flat surfaces in close proximity with air under pressure introduced at the center of one of the surfaces. The volume of air in the bearing is therefore minimized, improving the response to load change transients. The load capacity of this type bearing is reduced as the air between the bearing surfaces is not at constant pressure, but is expanding from the center point of injection to its escape at the edges. This paper indicates a quantitative method of determining the size of the air supply orifices to achieve the maximum rigidity orthogonal to the direction of motion. The approach described can also be applied to optimizing the geometry of other non-cavity air bearings.