Potential Progress in ICD Risk Stratification

Microvolt T-wave alternans exercise testing shows promise as a way to identify the best candidates for prophylactic ICD therapy.

Prophylactic implantable cardioverter-defibrillator (ICD) therapy prolongs survival in selected patients with impaired LV function who are at increased risk for sudden death, and Medicare now pays for ICDs in certain patient groups (Journal Watch Cardiology Mar 4 2005). However, the absolute mortality benefit of ICD therapy is <10%, and 14 to 18 ICDs must be implanted to save one life.

Given prior research showing the potential value of microvolt T-wave alternans (MTWA) testing in stratifying patients according to risk for sudden death, researchers conducted a prospective study of MTWA exercise testing in 549 patients (mean age, 56; 71% men) with LV ejection fractions ≤40% (mean, 25%) who were in sinus rhythm and had no history of sustained …

Reviewing Author

Hugh Calkins, MD