LONG-TERM OUTCOMES AND MODES OF DEATH OF PATIENTS TREATED WITH NONTHORACOTOMY IMPLANTABLE DEFIBRILLATORS

Long-term outcomes of all patients who underwent nonthoracotomy implan table cardioverter-defibrillator (ICD) implantation at our institution from April 1991 to October 1994 were studied using the intention-to-t reat analysis. Of 94 consecutive patients, 81 underwent nonthoracotomy ICD implantation and 13 underwent thoracotomy (for concomitant surger y in 11 and unavailability of nonthoracotomy leads in 2). Six of 81 pa tients had a high defibrillation threshold, 4 subsequently underwent t horacotomy, and 2 were treated with amiodarone. Surgical mortality was 0%. The duration of follow-up was 20 +/- 13 months, and was >12 month s in 74% of 67 living patients. Actuarial survival rates at 1 and 2 ye ars were, respectively, 98% and 94% for sudden death and 91% and 83% f or total mortality. Deaths during long-term follow-up were mostly due to nonsudden cardiac or noncardiac deaths. Two-year mortality rates we re 12% and 25% in patients with ejection fraction greater than or equa l to 30% and <30%, respectively. Thus, instances of sudden death and s urgical mortality are very few in patients with nonthoracotomy ICDs. D eaths during long-term follow-vp are mostly due to nonsudden cardiac a nd noncardiac deaths. Therefore, ICD therapy may have greater impact o n survival in patients with lower risks of nonsudden cardiac and cardi ac death (e.g., younger patients with minimal heart disease) than in p atients with severe cardiac or noncardiac disease. Prospective studies are needed to address this question.