Primary Prevention of Sudden Cardiac Death in a Nonischemic Dilated Cardiomyopathy Population: Reappraisal of the Role of Programmed Ventricular Stimulation
Is programmed ventricular stimulation (PVS) useful for risk stratification in patients with idiopathic dilated cardiomyopathy (IDC)?
PVS with up to three ventricular extrastimuli was performed in 158 patients with IDC (mean age 59 years, mean ejection fraction 31%). An implantable cardioverter-defibrillator (ICD) was implanted in 69 patients. The primary endpoints were total mortality and the composite of sudden cardiac death (SCD) or an appropriate ICD therapy.
Ventricular tachycardia (VT) or ventricular fibrillation (VF) was inducible in 44 patients (28%). An ICD was implanted in 41/44 of these patients and in 28/114 patients without inducible VT/VF. During a mean follow-up of 47 months, all-cause mortality did not differ significantly between the patients with and without inducible VT/VF. An appropriate ICD therapy occurred significantly more often in patients with than without inducible VT/VF (73% vs. 18%), as did the composite endpoint of SCD or an appropriate ICD therapy (68% vs. 5%). By multivariate analysis, inducible VT/VF was the only independent predictor of an appropriate ICD therapy.
Inducible VT/VF by PVS in patients with IDC is predictive of a subsequent appropriate ICD therapy or SCD, but not all-cause mortality.
The results of this relatively large study refute the findings of several prior smaller studies. However, although inducible VT/VF appears to increase the odds of an appropriate ICD therapy, it is noteworthy that 18% of patients without inducible VT/VF nevertheless received an appropriate ICD therapy. Therefore, the study clearly demonstrates that PVS cannot be used to identify IDC patients who do not require an ICD for primary prevention of SCD.
Keywords: Multivariate Analysis, Tachycardia, Ventricular, Ventricular Fibrillation, Death, Sudden, Cardiac, Defibrillators, Implantable, Cardiomyopathy, Dilated, Primary Prevention
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