Abstract 2428: Patients Who Receive an Implantable Cardioverter Defibrillator for MADIT-II Criteria in Clinical Practice are Different From Patients Enrolled in MADIT-II
Background: The generalizability of findings from randomized controlled trials to routine clinical practice is often unclear. We compared the characteristics of patients meeting MADIT-II criteria and treated with an ICD in the ACC-NCDR ICD Registry with those of patients enrolled in MADIT-II.
Methods: Currently, 1,438 US hospitals are participating in the ICD Registry, and 85% of these hospitals submit data on all ICD implants. We identified 19,636 Registry patients with a history of an MI, an EF ≤ 30%, and no previous ICD. We excluded patients with an MI within 40 days, coronary revascularization within 3 months or NYHA class IV symptoms. We also excluded patients who received an ICD for secondary prevention or an ICD with cardiac resynchronization therapy.
Results: Patients in the ICD Registry averaged 4 years older and had worse functional status and more atrial fibrillation than patients enrolled in MADIT-II (Table⇓). Patients in the ICD Registry were significantly more likely to receive a beta-blocker (p < 0.01) and a statin (p < 0.01), but they were significantly less likely to receive an ACE-inhibitor (p < 0.01), digoxin (p < 0.01), diuretics (p < 0.01) and amiodarone (p < 0.01).
Conclusions: This study is the first to show that patients who receive an ICD in routine clinical practice differ in a number of important ways from patients enrolled in MADIT-II. Whether these differences translate into differences in ICD effectiveness needs to be examined by future studies.