The landmark MADIT II study presents strong evidence that implantable cardioverter defibrillator (ICD) therapy increases survival in post-MI patients with an ejection fraction (EF) <30%. Results demonstrate that prophylactic ICD therapy, in conjunction with conventional therapy, significantly reduces the risk of death compared with conventional therapy alone.1
MADIT II included 1232 patients with prior MI and an EF <30%. Patients were randomly assigned in a 3:2 ratio for ICD therapy + conventional therapy (n=742) or conventional therapy alone (n=490). Patients receiving Guidant ICDs also received conventional therapy as determined by each patient's attending physician.1 There were no significant differences at baseline between the ICD + conventional therapy and conventional therapy groups.
Medication use in both groups was recorded from the time of enrollment until the last follow-up visit. The mean interval for that time frame was 18 months in the ICD + conventional therapy group and 17 months in the conventional therapy group.1
There was no significant difference in medication use between the conventional therapy group and the Guidant ICD group.1
MADIT II: Medications at Last Follow-Up
Conventional Therapy(%) |
ICD + Conventional Therapy(%) |
|
ACE inhibitors |
72 |
68 |
Amiodarone |
10 |
13 |
Antiarrhythmics |
2 |
3 |
Beta-blockers |
70 |
70 |
Digitalis |
57 |
57 |
*No significant differences between ICD + conventional therapy
and conventional therapy groups
During an average follow-up of 20 months, the mortality rates in the ICD + conventional therapy and conventional therapy groups were 19.8% and 14.2%, respectively.
There was a 31% lower relative risk of death in patients treated with prophylactic ICD in addition to conventional therapy than in patients receiving only conventional therapy. The results of MADIT II demonstrate that conventional therapy alone is significantly less likely than prophylactic ICD and conventional therapy to reduce mortality in post-MI patients with an EF <30%.1