Perioperative pharmacotherapy in patients with left ventricular assist devices.
Review
Overview
abstract
Heart failure remains the leading cause of death in Western countries, affecting 4.9 million individuals and causing >300 000 deaths annually in the US alone. The disease is highly prevalent in the elderly population and often follows a course of progressive disability and deterioration. An estimated 15 000 patients with end-stage heart failure could benefit from heart transplant each year. Yet, as a result of a significant shortage of donor organs, only 2500 hearts are donated annually, and approximately one-third of patients awaiting heart transplant die each year. Mechanical circulatory support, primarily in the form of left ventricular assist devices (LVADs), has come to the forefront of treatment for severe congestive heart failure by providing a feasible alternative to patients who might otherwise die awaiting heart transplant. The arrival of LVADs has resulted in a dramatic shift in the management of heart failure, one that will undoubtedly affect and include a vast proportion of elderly patients. While LVADs represent a surgical approach to a disease that has traditionally been managed medically, the pharmacological application throughout the perioperative period remains of critical importance. Five primary classes of drugs bear specific application to the LVAD population: (i) drugs that provide haemodynamic support; (ii) antimicrobials; (iii) anticoagulants and antiplatelets; (iv) agents that promote myocardial recovery; and (v) miscellaneous other medications. Drugs that provide haemodynamic support are subdivided into inotropes, vasopressors and pulmonary vasodilators. Some combination of these medications is usually administered within the perioperative period in order to maintain stable patient haemodynamics and assure proper LVAD function. Antimicrobials are of paramount importance in the pre-, intra- and postoperative periods to minimise the risk of infection, an unfortunately common complication of LVAD therapy that can have potentially morbid consequences. Anticoagulants and antiplatelet medications are necessary for certain types of LVADs and serve to curb the incidence of device thrombus formation and associated embolic phenomena. Pharmacotherapeutic agents that facilitate myocardial recovery are being investigated as adjuncts to LVAD support so that bridge to recovery can become a realistic outcome for a growing number of LVAD patients. The miscellaneous class of medications used with LVADs includes those that minimise the risk of bleeding in select patients and those that enhance proper vitamin and nutrient status in the postoperative period, the attainment of which may serve vital to a successful recovery.
