A Rare Case of Partial Aortic Mechanical Valve Thrombosis With Intact Mitral Mechanical Valve Presenting With ST-Elevation Myocardial Infarction Patients.

The incidence of mechanical valve thrombosis (MVT) is around 0.4 per 100 patient-years. Mitral valve thrombosis has a higher incidence than aortic valve thrombosis with a nearly 5-fold increase. Various factors contribute to MVT. The most common cause of valve thrombosis is poor adherence/disruption of anticoagulation therapy. Low cardiac output is known to increase the risk of prosthetic valve thrombosis. Other factors such as diabetes, hypertension, and other patient comorbidities might also play a role. Decreased flow promotes hypercoagulability. Lower pressure in the left atrium (and higher velocities in the left ventricle) can partially contribute to the higher incidence of mitral MVT versus aortic MVT. The presenting symptoms usually depend on the severity of the valve thrombosis; nonobstructive valve thrombosis patients have progressive dyspnea, signs of heart failure, and systemic embolization with strokes being the most common complication. In this article, we present a case of a middle-aged woman with a history of mitral and aortic mechanical prosthesis who presented with an ST-segment elevation myocardial infarction and pulmonary edema due to mechanical aortic valve prosthesis thrombosis. She had an isolated mechanical aortic valve prosthesis thrombosis with intact mitral valve, which, to the best of our knowledge, has not yet been described. We performed a literature review by searching PubMed and Embase using the keywords "mechanical valve," "thrombosis," "aortic," and "mitral," our search did not show similar cases.

A Macroeconomic Model of Healthcare Saturation, Inequality & the Output-Pandemia Tradeoff (preprint)

COVID-19 became a global health emergency when it threatened the catastrophic collapse of health systems as demand for health goods and services and their relative prices surged. Governments responded with lockdowns and increases in transfers. Empirical evidence shows that lockdowns and healthcare saturation contribute to explain the cross-country variation in GDP drops even after controlling for COVID-19 cases and mortality. We explain this output-pandemia tradeoff as resulting from a shock to subsistence health demand that is larger at higher capital utilization in a model with entrepreneurs and workers. The health system moves closer to saturation as the gap between supply and subsistence narrows, which worsens consumption and income inequality. An externality distorts utilization, because firms do not internalize that lower utilization relaxes healthcare saturation. The optimal policy response includes lockdowns and transfers to workers. Quantitatively, strict lockdowns and large transfer hikes can be optimal and yield sizable welfare gains because they prevent a sharp rise in inequality. Welfare and output costs vary in response to small parameter changes or deviations from optimal policies. Weak lockdowns coupled with weak transfers programs are the worst alternative and yet are in line with what several emerging and least developed countries have implemented.