Robert L. Hooker

Exclusion of the left atrial appendage with a novel device: Early results of a multicenter trial

OBJECTIVE Up to 90% of embolic strokes that occur in patients with atrial fibrillation originate from the left atrial appendage. Exclusion of the left atrial appendage during cardiac surgery may decrease the future risk of stroke, especially in patients with atrial fibrillation or at high risk for developing atrial fibrillation. We report the initial results of a multicenter Food and Drug Administration trial to assess the safety and efficacy of a novel left atrial appendage exclusion clip. METHODS Patients undergoing elective cardiac surgery via median sternotomy with atrial fibrillation or a Congestive Heart Failure, Hypertension, Age > 75 Years, Diabetes Mellitus, Stroke score greater than 2 were eligible for concomitant AtriClip (Atricure Inc, Westchester, Ohio) device insertion. Device insertion (35, 40, 45, and 50 mm) was performed at any point after sternotomy on or off cardiopulmonary bypass. Safety was assessed at 30 days, and efficacy of left atrial appendage exclusion was assessed at operation (by transesophageal echocardiography) and 3-month follow-up (by computed tomography angiography or transesophageal echocardiography). RESULTS A total of 71 patients (mean age, 73 years) undergoing open cardiac surgery at 7 US centers were enrolled in the study. The left atrial appendage in 1 patient was too small and did not meet eligibility criteria; the remaining 70 patients had successful placement of an AtriClip device. Intraprocedural successful left atrial appendage exclusion was confirmed in 67 of 70 patients (95.7%). Although significant adverse events occurred in 34 of 70 patients (48.6%), there were no adverse events related to the device and no perioperative mortality. At 3-month follow-up, 1 patient died and 65 of 70 patients (92.9%) were available for assessment. Of the patients who underwent imaging, 60 of 61 patients (98.4%) had successful left atrial appendage exclusion by computed tomography angiography or transesophageal echocardiography imaging. CONCLUSIONS In this small study, safe and atraumatic exclusion of the left atrial appendage can be performed during open cardiac surgery with the AtriClip device with greater than 95% success and appears to be durable in the short term by imaging. Long-term studies are needed to evaluate the efficacy in the prevention of stroke.

Recombinant factor VIIa (NovoSeven RT) use in high risk cardiac surgery

OBJECTIVE The use of recombinant factor VIIa (rFVIIa) (NovoSeven RT(®)) to establish hemostasis during massive perioperative bleeding in cardiac surgery has been explored in several retrospective studies. While early results are promising, a paucity of data leaves many questions about its safety profile. We sought to further define its use and associated outcomes in a large cohort study at a single institution. METHODS A retrospective cohort study design was used, in which 236 patients received rFVIIa for bleeding after cardiac surgery. These patients were matched with a cohort of 213 subjects, who had similar operations during the same period of time. Primary end points included thrombo-embolic events, mortality, incidence of re-operation, use of blood products, and patient disposition at 30 days. Statistical significance was assessed at p < 0.05. RESULTS There was no statistically significant difference in the incidence of stroke (3.4%, 1.9%; p = 0.32), renal failure (8.5%, 7.0%; p = 0.57), or 30-day mortality (7.7%, 4.3%; p = 0.14) between the rFVIIa and the control groups, respectively. The rFVIIa group did experience a higher rate of re-operation for bleeding (11.0%, 1.9%; p = 0.0001) and had a two-fold increase in the use of each of the following: cryoprecipitate, fresh-frozen plasma, platelets, and packed red blood cells, relative to the control group (p < 0.00001). CONCLUSIONS rFVIIa is an effective hemostatic agent for intractable bleeding in high-risk cardiac surgery with an acceptable safety profile. rFVIIa does not appear to be associated with increased postoperative complications, including thrombo-embolic events and death.

Sales and operations planning

Purpose – The purpose of this paper is to outline the usage of interactive marketing tools in the area of sales and operations planning (S&OP) to further collaboration among supply chain partners. Emergent challenges and research directions are proposed. Design/methodology/approach – Using extant literature from S&OP, supply chain management and interactive marketing, the authors integrate those to show the value of using interactive marketing tools to further integration across the supply chain of important S&OP processes. Findings – S&OP utilizes sophisticated software to integrate various business processes beyond B2C and into B2B relationships. Research limitations/implications – Uncertainty exists as to the measurement of the performance of a supply chain, or the network or system of companies, is not developed enough to deal with that issue. However, this is addressed in the research questions section. Practical implications – The practical implications for the use of integrative marketing tools to ...

The effect of pulmonary hypertension on ovine tricuspid annular dynamics

OBJECTIVES Pulmonary hypertension (PHT) is associated with tricuspid annular dilatation, but the effect of acute increase of pulmonary pressure on three-dimensional (3D) tricuspid annular dynamics and shape is unknown. Better understanding of tricuspid annular dynamics may lead to improved and more durable surgical reparative techniques. METHODS In nine open-chest anaesthetized sheep nine sonomicrometry crystals were implanted on the right ventricle while on cardiopulmonary bypass. Additional nine crystals were implanted around the tricuspid annulus (TA) with one crystal at each commissure defining three separate annular regions: anterior, posterior and septal. Two additional equidistant crystals were implanted between each commissure, creating three segments for every region. Pressure transducers were placed in the left ventricular (LV), right ventricular (RV) and right atrium. PHT was induced by acute pulmonary artery constriction with a pneumatic occluder. Sonomicrometry and echocardiographic data were collected before and after induction of PHT. TA area, regional and total perimeter, and 3D annular geometry were calculated from 3D crystal coordinates. Regional annular contraction was defined as the percentage difference between maximal and minimal region length during the cardiac cycle. RESULTS PHT increased RV pressure from 31 ± 9 mmHg to 46 ± 13 mmHg (P = 0.001) and decreased left ventricular (LV) pressure from 111 ± 24 mmHg to 78 ± 36 mmHg (P = 0.018). There was no significant tricuspid regurgitation observed with PHT. During PHT, the TA area increased by 12 ± 13% from 641 ± 139 mm(2) to 721 ± 177 mm(2) (P = 0.037). The total perimeter increased from 103 ± 11 mm to 109 ± 13 mm (P = 0.02). All annular regions dilated significantly with PHT with 8 ± 10, 5 ± 5 and 5 ± 5% increase in anterior, posterior and septal annular length, respectively (P < 0.05). PHT reduced regional annular contraction in the anterior region only (17 ± 7 vs 14 ± 8%; P = 0.02). The TA had a complex 3D saddle geometry and the shape of the annulus was altered during PHT only in the antero-posterior region. CONCLUSIONS The changes in tricuspid annular conformation, contractility and its 3D geometry observed during acute ovine PHT may help in the design of new pathology-specific tricuspid annular rings.

Aortic Valve Replacement in Octogenarians With Prior Cardiac Surgery

BACKGROUND Transcatheter aortic valve implantation (TAVI) has been advocated for very elderly patients with aortic stenosis, and prior cardiac surgery as a less invasive treatment option. Although surgical aortic valve replacement (AVR) is safe and effective in selected elderly patients, the perioperative and mid-term outcomes of AVR in very elderly with prior cardiac surgery are unknown. METHODS The Society of Thoracic Surgeons (STS) Database at our center enrolled 3,735 patients after AVR since 1997. In this time interval, we identified 61 patients 80 years and older who underwent AVR for severe AS or failed aortic bioprosthesis after having prior cardiac surgery. All clinical parameters were derived from the STS database. Follow-up mortality was assessed using the Social Security Death Index. RESULTS The average age of the patients was 83 ± 2 years, 77% were male, and 75% underwent an isolated coronary artery bypass graft (CABG) as their first cardiac procedure. The mean ejection fraction was 0.53 ± 0.13. The CABG was performed concurrently in 49% of patients at the time of redo sternotomy and AVR. Stented bioprosthesis was implanted in 61% of patients and stentless in 39%. Perioperative mortality was 1.6% (1 of 61). One, 3, 5, and 7 year survival rates were 85%, 69%, 63%, and 43%, respectively. Patients with AVR only had similar survival to patients who underwent concomitant AVR and CABG. Type of aortic prosthesis did not influence postoperative survival. CONCLUSIONS In selected patients over the age of 80 with history of prior cardiac surgery, AVR can be performed safely with very good mid-term outcomes. Age alone should not be exclusion criteria for surgical AVR in octogenarians with prior cardiac surgery.

Early Catastrophic Stentless Valve Failure Secondary to Possible Immune Reaction

Aortic valve replacement with stentless xenografts has become routine since their introduction in the early 1990s. Although concerns of structural valve deterioration and long-term durability have been voiced, the reports on the causes or pathology associated with early valve failure have been sparse. We report two unusual cases of failure leading to patient death within the first year after implantation of the aortic valve and root with the Freestyle prostheses (Medtronic Inc, Minneapolis, MN). We suggest an early immunologic reaction to the xenograft, leading to a fatal inflammatory process, as a mechanism for unusual early valve failure in these patients.

The effect of acute mechanical left ventricular unloading on ovine tricuspid annular size and geometry

OBJECTIVES Left ventricular assist device (LVAD) implantation may alter right ventricular shape and function and lead to tricuspid regurgitation. This in turn has been reported to be a determinant of right ventricular (RV) failure after LVAD implantation, but the effect of mechanical left ventricular (LV) unloading on the tricuspid annulus is unknown. The aim of the study was to provide insight into the effect of LVAD support on tricuspid annular geometry and dynamics that may help to optimize LV unloading with the least deleterious effect on the right-sided geometry. METHODS In seven open-chest anaesthetized sheep, nine sonomicrometry crystals were implanted on the right ventricle. Additional nine crystals were implanted around the tricuspid annulus, with one crystal at each commissure defining three separate annular regions: anterior, posterior and septal. Left ventricular unloading was achieved by connecting a cannula in the left atrium and the aorta to a continuous-flow pump. The pump was used for 15 min at a full flow of 3.8 ± 0.3 l/min. Epicardial echocardiography was used to assess the degree of tricuspid insufficiency. Haemodynamic, echocardiographic and sonomicrometry data were collected before and during full unloading. Tricuspid annular area, and the regional and total perimeter were calculated from crystal coordinates, while 3D annular geometry was expressed as the orthogonal distance of each annular crystal to the least squares plane of all annular crystals. RESULTS There was no significant tricuspid regurgitation observed either before or during LV unloading. Right ventricular free wall to septum diameter increased significantly at end-diastole during unloading from 23.6 ± 5.8 to 26.3 ± 6.5 mm (P = 0.009), but the right ventricular volume, tricuspid annular area and total perimeter did not change from baseline. However, the septal part of the annulus significantly decreased its maximal length (38.6 ± 8.1 to 37.9 ± 8.2 mm, P = 0.03). Annular contraction was not altered. The tricuspid annulus had a complex 3D saddle-shaped geometry that was unaffected during experimental conditions. CONCLUSIONS In healthy sheep hearts, left ventricular unloading increased septal-free wall RV diameter and reduced the length of the septal annulus, without altering the motion or geometry of the tricuspid annulus. Acute left ventricular unloading alone in healthy sheep was not sufficient to significantly perturb tricuspid annular dynamics and result in tricuspid insufficiency.

Five-year real world outcomes of GeoForm ring implantation in patients with ischemic mitral regurgitation.

BACKGROUND Reductive ring annuloplasty represents the current standard surgical therapy for ischemic mitral regurgitation (IMR); however, the clinical results have been suboptimal. Etiology-specific prostheses such as the GeoForm annuloplasty ring have been designed to better address the annular and subvalvular perturbations associated with IMR. However, clinical experience is limited, and mid-term results are lacking. METHODS We reviewed the clinical outcomes of 86 patients who had undergone implantation of a GeoForm ring at our center from 2005 to 2011. Perioperative mortality and clinical parameters were derived from The Society of Thoracic Surgeons database. Follow-up survival was assessed using the Social Security Death Index. Surviving patients were interviewed by telephone for valve-specific follow-up data and to complete the Medical Outcomes Study, short-form, 36-item, quality-of-life questionnaire. RESULTS The mean grade of IMR preoperatively was 3.1±0.8 (range, 1-4+), 0.2±0.4 in the immediate postoperative period, and 0.7±0.7 at the last mean follow-up point of 41 months; only 2 patients developed ≥2+IMR during the follow-up period, for a 5-year freedom from recurrent 2+ IMR of 86%. The mean left ventricular end-diastolic and end-systolic diameters decreased from before to after surgery from 6.0±0.0 cm to 5.3±09 cm and 5.0±0.9 cm to 4.3±1.1 cm, respectively (P<.001). Perioperative mortality was 5.8% (5 of 86), and 1-, 3-, and 5-year survival was 87%, 81%, and 75%, respectively. At the last follow-up point, 80% of patients were in New York Heart Association class I and II, and their quality of life was equal to, or better than, age-matched controls from the general population. CONCLUSIONS Implantation of the GeoForm ring offers very good control of IMR, with low rate of recurrent IMR at mid-term follow-up. The use of this prosthesis was associated with good perioperative mortality, mid-term survival, and quality of life.

Repair of paravalvular prosthetic mitral valve leaks with septal occluder devices in severely high-risk patients: a word of caution

Paravalvular leak following a mitral valve replacement is a complication seen in approximately 1 of 10 replacements. The corrective method has traditionally been reoperation. Septal occluder devices are more commonly being utilized as an alternative percutaneous correction method. We report the use of septal occluder devices in the repair of mitral paravalvular leak in two patients at severely high EuroSCORE II mortality risk. In both patients, the occluder devices became unstable, leading to a recurrence of severe paravalvular leak.

Differences in Clinical Characteristics, Management, and Outcomes of Intraoperative Versus Spontaneous Acute Type A Aortic Dissection

BACKGROUND The clinical characteristics, management, and outcomes of patients who had intraoperative aortic dissection (IAD) have not been thoroughly investigated. This study compared early and late clinical outcomes in patients with IAD vs spontaneous (non-IAD) acute type A aortic dissection. METHODS Between January 1, 2000, and July 1, 2008, 251 patients from 4 academic medical centers underwent repair of acute type A aortic dissection; of those, 11 had IAD. The mean age was 72 ± 9 years for patients experiencing IAD and 59 ± 13 years for those with non-IAD (p = 0.001). Patients with IAD were more likely to have coronary artery disease (p = 0.003) and a history of arrhythmia (p = 0.038). Rates for major morbidity, operative mortality, and 5-year actuarial survival were compared between groups. RESULTS Operative mortality was not adversely influenced by IAD (27% IAD vs 17% non-IAD, p = 0.42). There were no differences in the rates of reoperation for bleeding (10% IAD vs 20% non-IAD, p = 0.69), stroke (18% IAD vs 18% non-IAD, p ≥ 0.99), or acute renal failure (9% IAD vs 22% non-IAD, p = 0.47) between the two groups. Actuarial 5-year survival was 64% for IAD patients vs 73% for non-IAD patients (p = 0.33). CONCLUSIONS IAD does not adversely influence early outcomes and actuarial 5-year survival of patients with type A dissection.