TWO CLINICAL SITUATIONS: Mechanical circulatory assistance can be indicated in two clinical situations: i) patients on the waiting list for heart transplantation who have chronic heart failure unresponsive to drug therapy and whose clinical status worsens; ii) patients with acute heart failure.
The exact indications for mechanical circulatory assistance are difficult to establish. Hemodynamic criteria are no longer sufficient. Circulatory assistance may be proposed for chronic heart failure patients with a high risk of death or in a situation of acute deterioration. Among these patients, several risk factors can be used to establish scores that have a better predictive value than risk factors taken alone. Two predictive models have been recently established. The first one takes into account 7 independent variables: etiology, heart rate at rest, left ventricle ejection fraction, mean blood pressure, intraventricular rhythm disorder, VO2max and serum sodium). In addition to these variables, the second model also includes pulmonary wedge pressure. In selected patients with acute heart failure, circulatory assistance is needed as early as possible to avoid irreversible multiple organ failure. The crucial problem is rapid assessment of the feasibility of heart transplantation.
Several variables can be used to predict survival in candidates for mechanical circulatory assistance on the heart transplantation waiting list. They include hemodynamic criteria, renal function, liver function, preoperative infection and the emergency nature of the need for circulatory assistance.
The choice depends both on the patient (surface area is important) and the underlying disease.