The Dual Ownership Structure: a Model to Connect the Cooperative Model With Financial Markets

In business literature, the conflicts among workers, shareholders and the management have been studied mostly in the frame of stakeholder theory. The stakeholder theory recognizes this issue as an agency problem, and tries to solve the problem by establishing a contractual relationship between the agent and principals. However, as Marcoux pointed out, the appropriateness of the contract as a medium to reduce the agency problem should be questioned. As an alternative, the cooperative model minimizes the agency costs by integrating the concept of workers, owners and management. Mondragon Corporation is a successful example of the cooperative model which grew into the sixth largest corporation in Spain. However, the cooperative model has long been ignored in discussions of corporate governance, mainly because the success of the cooperative model is extremely difficult to duplicate in reality. This thesis hopes to revitalize the scholarly examination of cooperatives by developing a new model that overcomes the fundamental problem in the cooperative model: the limited access to capital markets. By dividing the ownership interest into financial and control interest, the dual ownership structure allows cooperatives to issue stock in the capital market by making a financial product out of financial interest.

Separation of Ownership from Control and Discretionary Managerial Behaviour in a Transition Economy

This study was the final stage of a four-year study of managerial behaviour and company performance in Bulgaria and examined the influence of changing ownership and control structures of companies on managerial behaviour and initiative. It provides a theoretical summary of the specific types of ownership, control, governance structures and managerial strategies in the Bulgarian transitional economy during 1992-1996. It combines two theoretical approaches, the property-rights approach to show concentrated property-rights structure and private and majority types of control as determinants of efficient enterprise risk bearing and constrained managerial discretion, and the agency theory approach to reveal the efficient role of direct non-market governance mechanisms over managers. Mr. Peev also used empirical information collected from the Central Statistical office in Bulgaria, three different enterprise investigations of corporatised state-owned enterprises between 1992 and 1994, and his own data base of privatised and private de novo industrial companies in 1996-1996. The project gives a detailed description of the main property-rights structures in Bulgaria at the present time and of the various control structures related to these. It found that there is a strong owner type of control in private and privatised firms, although, contrary to expectations, 100% state -owned enterprises tended to be characterised by a separation of ownership from control, leaving scope for managerial discretion. Mr. Peev predicts that after the forthcoming mass privatisation, many companies will acquire a dispersed ownership structure and there will be a greater separation of ownership from control and potential or inefficient managerial behaviour. The next aspect considered in detail was governance structures and the influence of the generally unstable macroeconomic environment in the country during the period in question. In examining managerial strategies, Mr. Peev divided the years since 1990 into 3 periods. Even in the first period (1990-1992) there were some signs of a more efficient role for managers and between 1992 and 1994 the picture of control structures and different managerial behaviour in state-owned companies became more diversified. Managerial strategies identified included managerial initiatives for privatisation, where managers took initiative in resolving problems of property rights and introducing restructuring measures and privatisation proposals, managerial initiatives for restructuring without privatisation, and passive adjustment and passive management, where managers seek outside services for marketing, finance management, etc. in order to adjust to the new environment. During 1995-1996 some similarities and differences between the managerial behaviour of privatised and state-owned firms emerged. Firstly, the former have undergone many changes in investment and technology, while managers of state-owned companies have changed little in this field, indicating that the private property-rights structure is more efficient for the long-term adaptation of enterprises. In the area of strategies relating to product quality, marketing, and pricing policy there was little difference between managers of private, privatised and state-owned firms. The most passive managerial behaviour was found in non-incorporated state-owned firms, although these have only an insignificant stake in the economy.

Iatrogenic atrial septal defect, erosion of the septum primum after device closure of a patent foramen ovale as a new medical entity

Iatrogenic atrial septal defects are described in 2 patients. They occurred after implantation of Amplatzer occluders to close a patent foramen ovale. While device erosions to the extra-atrial space have been described, erosion induced atrial septal defects are a new medical entity. They may be fairly common in the situation of an atrial septal aneurysm whipping the rim of the device incessantly. They are clinically silent and benign and require echocardiography for detection. A second device solved the problem in the cases described.

Instant percutaneous closure of patent foramen ovale in patients with acute myocardial infarction and normal coronary arteries

Two young women with angiographically normal coronary arteries suffered an acute myocardial infarction. Both were found to have a patent foramen ovale (PFO), the likely pathway of a paradoxical embolus causing the infarction. The PFOs were diagnosed and closed percutaneously with an Amplatzer PFO Occluder during the emergency coronary angiography.

Contrast-enhanced transcranial Doppler ultrasound for diagnosis of patent foramen ovale

The suspected cause of clinical manifestations of patent foramen ovale (PFO) is a transient or a permanent right-to-left shunt (RLS). Contrast-enhanced transcranial Doppler ultrasound (c-TCD) is a reliable alternative to transesophageal echocardiography (TEE) for diagnosis of PFO, and enables also the detection of extracardiac RLS. The air-containing echo contrast agents are injected intravenously and do not pass the pulmonary circulation. In the presence of RLS, the contrast agents bypass the pulmonary circulation and cause microembolic signals (MES) in the basal cerebral arteries, which are detected by TCD. The two main echo contrast agents in use are agitated saline and D-galactose microparticle solutions. At least one middle cerebral artery (MCA) is insonated, and the ultrasound probe is fixed with a headframe. The monitored Doppler spectra are stored for offline analysis (e.g., videotape) of the time of occurrence and number of MES, which are used to assess the size and functional relevance of the RLS. The examination is more sensitive, if both MCAs are investigated. In the case of negative testing, the examination is repeated using the Valsalva maneuver. Compared to TEE, c-TCD is more comfortable for the patient, enables an easier assessment of the size and functional relevance of the RLS, and allows also the detection of extracardiac RLS. However, c-TCD cannot localize the site of the RLS. Therefore, TEE and TCD are complementary methods and should be applied jointly in order to increase the diagnostic accuracy for detecting PFO and other types of RLS.

Patent foramen ovale and high-altitude pulmonary edema

CONTEXT: Individuals susceptible to high-altitude pulmonary edema (HAPE) are characterized by exaggerated pulmonary hypertension and arterial hypoxemia at high altitude, but the underlying mechanism is incompletely understood. Anecdotal evidence suggests that shunting across a patent foramen ovale (PFO) may exacerbate hypoxemia in HAPE. OBJECTIVE: We hypothesized that PFO is more frequent in HAPE-susceptible individuals and may contribute to more severe arterial hypoxemia at high altitude. DESIGN, SETTING, AND PARTICIPANTS: Case-control study of 16 HAPE-susceptible participants and 19 mountaineers resistant to this condition (repeated climbing to peaks above 4000 m and no symptoms of HAPE). MAIN OUTCOME MEASURES: Presence of PFO determined by transesophageal echocardiography, estimated pulmonary artery pressure by Doppler echocardiography, and arterial oxygen saturation measured by pulse oximetry in HAPE-susceptible and HAPE-resistant participants at low (550 m) and high altitude (4559 m). RESULTS: The frequency of PFO was more than 4 times higher in HAPE-susceptible than in HAPE-resistant participants, both at low altitude (56% vs 11%, P = .004; odds ratio [OR], 10.9 [95% confidence interval {CI}, 1.9-64.0]) and high altitude (69% vs 16%, P = .001; OR, 11.7 [95% CI, 2.3-59.5]). At high altitude, mean (SD) arterial oxygen saturation prior to the onset of pulmonary edema was significantly lower in HAPE-susceptible participants than in the control group (73% [10%] vs 83% [7%], P = .001). Moreover, in the HAPE-susceptible group, participants with a large PFO had more severe arterial hypoxemia (65% [6%] vs 77% [8%], P = .02) than those with smaller or no PFO. CONCLUSIONS: Patent foramen ovale was roughly 4 times more frequent in HAPE-susceptible mountaineers than in participants resistant to this condition. At high altitude, HAPE-susceptible participants with a large PFO had more severe hypoxemia. We speculate that at high altitude, a large PFO may contribute to exaggerated arterial hypoxemia and facilitate HAPE.

Paradoxical emboli through the patent foramen ovale as the suspected cause of myocardial and renal infarction in a 48-year-old woman

We review the case of a 48-year-old woman who underwent elective percutaneous patent foramen ovale closure following successive renal and myocardial infarction with normal renal and coronary arteries, probably as a consequence of paradoxical emboli.

Long-term results after fluoroscopy-guided closure of patent foramen ovale for secondary prevention of paradoxical embolism

OBJECTIVES: To carry out long-term follow-up after percutaneous closure of patent foramen ovale (PFO) in patients with cryptogenic stroke. DESIGN: Prospective cohort study. SETTING: Single tertiary care centre. PARTICIPANTS: 525 consecutive patients (mean (SD) age 51 (12) years; 56% male). INTERVENTIONS: Percutaneous PFO closure without intraprocedural echocardiography. MAIN OUTCOME MEASURES: Freedom from recurrent embolic events. RESULTS: A mean (SD) of 1.7 (1.0) clinically apparent embolic events occurred for each patient, and 186 patients (35%) had >1 event. An atrial septal aneurysm was associated with the PFO in 161 patients (31%). All patients were followed up prospectively for up to 11 years. The implantation procedure failed in two patients (0.4%). There were 13 procedural complications (2.5%) without any long-term sequelae. Contrast transoesophageal echocardiography at 6 months showed complete closure in 86% of patients, and a minimal, moderate or large residual shunt in 9%, 3% and 2%, respectively. Patients with small occluders (<30 mm; n = 429) had fewer residual shunts (small 11% vs large 27%; p<0.001). During a mean (SD) follow-up of 2.9 (2.2) years (median 2.3 years; total 1534 patient-years), six ischaemic strokes, nine transient ischaemic attacks (TIAs) and two peripheral emboli occurred. Freedom from recurrent stroke, TIA, or peripheral embolism was 98% at 1 year, 97% at 2 years and 96% at 5 and 10 years, respectively. A residual shunt (hazard ratio = 3.4; 95% CI 1.3 to 9.2) was a risk factor for recurrence. CONCLUSIONS: This study attests to the long-term safety and efficacy of percutaneous PFO closure guided by fluoroscopy only for secondary prevention of paradoxical embolism in a large cohort of consecutive patients.

Clinical relevance of coronary angiography at the time of percutaneous closure of a patent foramen ovale

BACKGROUND: The value of incidental coronary angiography during percutaneous shunt closure to screen for asymptomatic coronary artery disease (CAD) is unknown. METHODS: On the occasion of percutaneous closure of patent foramen ovale (PFO), incidental coronary angiography routinely offered to men >40 and women >50 years, or younger patients with particular risk patterns, was performed in 575 patients (64% men, mean age 55 +/- 10 years, mean 1.5 +/- 1.1 cardiovascular risk factors) without overt history, signs, or symptoms of CAD. RESULTS: CAD was found in 164 patients (29%); 53 (9%) had >or=50% diameter stenoses. Thirty patients (5%) had one-vessel, 13 (2%) two-vessel, and 10 (2%) three-vessel disease. Patients with CAD (n = 164) were older (60 +/- 9 vs. 53 +/- 10 years; P < 0.0001), more frequently male (76% vs. 59%; P = 0.0002), and had a higher body mass index (26.5 +/- 4.0 vs. 25.4 +/- 4.6; P = 0.006) and more cardiovascular risk factors (2.0 +/- 1.1 vs. 1.2 +/- 1.0; P < 0.0001). There were six procedural complications (1%). Two were unequivocally related to coronary angiography: one minor stroke (diplopia), and one iatrogenic dissection of the right coronary ostium requiring stenting. Furthermore, four arteriovenous fistulae at the puncture site requiring elective surgical closure were possibly related to coronary angiography. Forty-five patients (8% of total) underwent percutaneous (n = 43) or surgical (n = 2) revascularization. CONCLUSIONS: In selected asymptomatic patients referred for percutaneous PFO closure, incidental coronary angiography discloses a rather high prevalence of clinically unsuspected CAD. These findings are relevant not only for timely revascularization but also for maintenance of long-term antiplatelet therapy beyond the few months recommended after PFO closure.

Patent foramen ovale closure: a new therapy for migraine

Migraine is a recurrent disabling disorder predominantly affecting middle-aged women. Migraine occurs with or without aura symptoms. Several studies have shown an increased prevalence of right-to-left shunts (RLSs) in migraine with aura. The overwhelming majority of these shunts were due to a patent foramen ovale (PFO). Furthermore, migraine with aura is more prevalent in clinical entities associated with a RLS, e.g. cryptogenic stroke, decompression illness in divers, or in patients with hereditary hemorrhagic teleangiectasia and pulmonary arteriovenous fistulas. Retrospective studies have consistently shown that shunt closure was associated with a significant reduction in migraine frequency. Its beneficial effect seemed to exceed the efficacy of conventional migraine therapy. Several randomized clinical trials to prospectively assess the benefit of shunt closure in migraine patients have been initiated. The only one completed, the MIST trial (Migraine Intervention with STARFLEX Technology), showed a significant reduction of migraine with aura after device implantation, compared with controls. However, the benefit of PFO closure was more modest than expected. This review recapitulates the current data regarding PFO closure and migraine with aura and summarizes in brief the current knowledge regarding migraine pathophysiology and the link to a RLS.