Value of programmed ventricular stimulation for prophylactic internal cardioverter-defibrillator implantation in postinfarction patients preselected by noninvasive risk stratifiers

OBJECTIVES The aim of this prospective study was to evaluate the role of pr ogrammed ventricular stimulation (PVS) after noninvasive risk stratificatio n to identify a subgroup of acute myocardial infarction (AMI) survivors con sidered at risk for ventricular arrhythmias and whether these patients coul d benefit from internal cardioverter-defibrillators (ICDs). BACKGROUND The predictive value of noninvasive and invasive risk stratifier s after AMI has been questioned. The question of whether the group of patie nts with inducible monomorphic ventricular tachycardia (VT) after AMI could profit from ICD implantation is unanswered. METHODS A consecutive series of 1,436 AMI survivors was screened noninvasiv ely by Holter monitoring, heart rate variability, ventricular late potentia ls, and ejection fraction. A subgroup of 248 patients (17.3%) were identifi ed as high-risk patients and scheduled for PVS. Due to the study design, 54 patients >75 years were excluded; thus, 194 patients were eligible for PVS . Triple extrastimuli at two paced cycle lengths (600 ms and 400 ms) were a pplied. RESULTS In a subgroup of 98 (51%) high-risk patients, PVS was performed; 21 patients had an abnormal response, and in 20 patients an ICD was implanted . During a mean follow-up of 607 days the arrhythmic event rate (sudden car diac death, symptomatic VT, cardiac arrest) was 33% with a positive electro physiological test versus 2.6% (p < 0.0001) with a negative electrophysiolo gical test. A subgroup of 96 high-risk patients declined electrophysiologic al study. In this nonconsent group, cardiac mortality (combined sudden and nonsudden) was significantly higher (log-rank chi-square 9.38, p = 0.0022, relative risk 4.7, 1.6 to 13.9) compared to the group guided by electrophys iological testing and consecutive ICD implantation. CONCLUSIONS After a two-step risk stratification, PVS is helpful in selecti ng a subgroup of AMI survivors without spontaneous ventricular arrhythmias who benefit from prophylactic ICD implantation. (J Am Coll Cardiol 2001;37: 1901-7) (C) 2001 by the American College of Cardiology.