Pitfalls in health-economic evaluations: the case of cost-effectiveness of prophylactic implantable cardioverter-defibrillator therapy in Belgium

Abstract

Variations in the medical therapy directed at the underlying disease among the trials also play a role. In the MADIT I trial, 65% of patients took an ACE-inhibitor, and only 14% of patients were on b-blocking therapy by the end of the study. In MADIT II, 70% of patients took an ACE-inhibitor, and 70% took a b-blocker, whereas in SCD-HeFT, 94% took an ACE-inhibitor or an angiotensin-II-receptor blocker, and 69% took a b-blocker. Apart from medical treatment of acute myocardial infarction (AMI), there is evidence from clinical trials that early reperfusion reduces the risk of sudden cardiac death (SCD) in selected AMI patients. This may have influenced the occurrence of sudden cardiac arrest in the trials and could have inflated the perceived efficacy of the ICD in the older studies. Pooling the results from trials that also considered asymptomatic patients with nonischaemic disease is inconsistent. The clinical effectiveness of ICD therapy in primary prevention of death seems best reflected by the results of the SCD-HeFT trial. In a German series of 3000 ambulatory patients with heart failure and a low ejection fraction, 17.0 and 71.1% of patients fulfilled MADIT II and SCD-HeFT criteria, respectively. 4 SCD-HeFT is the most recent and the largest randomized trial that has been published, with the longest follow-up duration, and enrolling heart failure patients with ischaemic or non-ischaemic cardiomyopathy who were receiving up-to-date medical treatment for the underlying disease.