IMPLANTABLE DEFIBRILLATORS FOR HIGH-RISK PATIENTS WITH HEART-FAILURE WHO ARE AWAITING CARDIAC TRANSPLANTATION

The objective of this study was to assess the operative risk and effic acy of implantable defibrillators for preventing sudden death in patie nts with heart failure awaiting transplantation. The average waiting t ime for elective cardiac transplantation is 6 months to 1 year. Sudden cardiac death is the major source of mortality in outpatients in stab le condition awaiting cardiac transplantation. The efficacy of implant able defibrillator therapy in this population is not established. We a nalyzed the operative risk, time to appropriate shock, and sudden deat h in 15 patients determined to be at high risk of sudden death who wer e accepted onto the outpatient cardiac transplant waiting list. Nonfat al postoperative complications occurred in two (13%) subjects with epi cardial defibrillating lead systems and in none with transvenous lead systems. Defibrillation energies were 16 +/- 2 J versus 24 +/- 2 J wit h epicardial and transvenous lead systems, respectively. Sudden death free survival until transplantation was 93%. Most of the patients (60% ) had an appropriate shock during a mean follow-up of 11 +/- 12 months . The mean time to an appropriate shock was 3 +/- 3 months. Hospital r eadmission was required in three (20%) subjects to await transplantati on on al? urgent basis. However, two of these subjects had received ap propriate shocks before readmission. In selected patients at high risk for sudden death while on the outpatient cardiac transplant waiting l ist, the operative risk is low and adequate defibrillation energies ca n be obtained to allow implantable defibrillator placement. Most subje cts will have an appropriate shock as outpatients before transplantati on, and sudden death free survival is excellent. Even in patients even tually requiring readmission to await transplantation on an urgent bas is, there is a high likelihood of appropriate device discharge before decompensation.