Mechanical support: assist or nemesis?

Abstract

Our 6-year experience with ventricular assist devices was reviewed to determine variables associated with improved survival. Forty-three patients (mean age 62 +/- 14 years) were supported after balloon pumping and pressors proved inadequate. Twenty-eight patients could not be weaned from cardiopulmonary bypass, 12 patients deteriorated in the intensive care unit after cardiac surgery, and three had a bridged to transplantation. Overall, 47% (20/43) of patients could not be weaned from the ventricular assist devices, and 26% (11/43) were weaned but died before discharge, resulting in a hospital mortality rate of 72% (31/43). The remaining 28% (12/43) of patients were discharged and have survived 9 to 62 months. Early institution of ventricular assist devices (p less than 0.01), use of biventricular support (p less than 0.01), use of ventricular assist devices as a bridge to transplantation (p less than 0.05), and increased operator experience (p less than 0.05) were associated with improved survival. When patient and disease-related variables were analyzed, only age less than 60 years (p less than 0.01) and unexpectedly preoperative myocardial infarction associated with shock (p less than 0.05) were related to improved survival. Death was caused by insufficient ventricular recovery, stroke, multiple organ system failure, sepsis, or a combination of these complications. During long-term follow-up, two patients have died of congestive heart failure, and one is significantly impaired from a stroke. Two other patients are functional class III and seven patients are class I. Although hospital mortality was high (72%), the use of ventricular assist device support resulted in overall "long-term" survival of a significant percentage (28%) of patients, 47% (8/17), in the past 12 months, all of whom would have died without it. Therefore we currently recommend a trial of ventricular assist devices support for most patients who fail to be weaned from cardiopulmonary bypass, deteriorate in the perioperative period, and as a bridge to transplantation. Long-term survival is determined by the complications from ventricular assist devices support and functional status of the remaining myocardium.