Dr Dan Burkhoff opened the symposium with his state-of-the-field address highlighting the history of the A-CURE Symposium over the past 6 years. He presented an overview of some of the pivotal studies that emerged from collaborations at A-CURE, including: the pivotal STEMI-DTU (door-to-unload) study, which is currently recruiting patients; the PROTECT Kidney study, which evaluates the impact of unloading on acute kidney injury and other end organs; VENUS-HF, an early feasibility study that assesses early efficacy signals for diuresis in acute decompensated heart failure patients; the IMPACT trial, which tests the prophylactic use of unloading in patients with a low ejection fraction undergoing cardiac surgery; and the SmartPump study, which examines the use of mechanical support devices as diagnostic tools.
The A-CURE Working Group previously defined ventricular unloading as ‘the reduction of the total mechanical power expenditure of the ventricle which correlates with reduction in myocardial oxygen consumption and haemodynamic forces that lead to ventricular remodelling’.1 Certain mechanical circulatory support (MCS) devices, such as the Impella pump, can achieve primary unloading of the ventricle that results in decreased left ventricular end diastolic pressure, stroke work, pressure–volume area and myocardial oxygen consumption while improving blood pressure, total cardiac output and myocardial perfusion. There are also secondary benefits of cardiac unloading, particularly in cases of cardiogenic shock and MI, where the patient is being treated with vasopressors and inotropes. Unloading the heart under these stress conditions allows cardiac output and blood pressure to be maintained with little input from the native heart. By taking over the workload of the heart, unloading potentially allows for the safe withdrawal of pressors and inotropes, which significantly impact myocardial oxygen consumption. Altogether, the effects of unloading on cardiac haemodynamics and energetics help reduce myocardial injury and prevent the remodelling process that follows an acute myocardial insult.
Research by the A-CURE Working Group over the past years has further uncovered the cardioprotective effects of unloading beyond haemodynamics and energetics.2 Some of these studies will be presented at the A-CURE symposium, including mechanistic studies of the molecular players behind cardiac unloading and translational studies applying these concepts in the clinical arena to improve patient outcomes. In addition, there has been a growing appreciation of unloading beyond MCS, such as research around renal unloading, invasive monitoring to quantify the degree of unloading and catheter-based ventricular remodelling devices.3
Dr Burkhoff invited the in-person and virtual audience to actively participate in the symposium featuring four sessions of the latest research in the space of cardiac unloading and recovery.