Interatrial shunting for the treatment of heart failure: an on‐demand, self‐regulating left atrial pressure lowering system

Abstract

Two-time U.S. Open Title winner Curtis Strange said, ‘Under pressure, one of the most important things I have to remember to do is breathe.’ For millions of heart failure patients around the world, the opposite is true: under pressure, one of the things they cannot forget to do is breathe. In fact, breathing is frequently all that they can think about. Of course, the pressure we are talking about is left atrial pressure. In heart failure patients, regardless of their left ventricular ejection fraction, frequent and dynamic elevations in left atrial pressure occur during exercise, stress, and changes in salt and water intake and renal function. These elevations in left atrial pressure are causal for worsening heart failure symptoms, particularly for worsening shortness of breath, and increase the risk of morbidity and mortality. Conversely, chronic lowering of elevated left atrial pressure improves heart failure symptoms, morbidity, and possibly mortality as demonstrated in studies of implantable haemodynamic monitoring systems.1,2 In these studies, left atrial pressure or pulmonary artery pressure as its surrogate were pharmacologically lowered, primarily through the use of pressure-guided changes in diuretic therapy, resulting in improved quality of life and fewer heart failure hospitalizations. Unfortunately, many patients do not tolerate or are refractory to pharmacological therapies that lower left atrial pressure, and pharmacological therapies cannot adequately address the so-called fast pathway leading to elevated left atrial pressure through rapid venous redistribution of blood volume.3 In addition, pressure-guided heart failure management has many delay and failure points, due to its reliance on patient adherence and physician compliance in taking and responding to pressure measurements, respectively.