Results of a US study suggest that recipients of primary prevention non-evidence based (NEB) implantable cardioverter-defibrillators (ICDs) have similar therapeutic benefits and outcomes as evidence-based (EB) ICD recipients.

The findings arise from an analysis of data from the OMNI Registry, a large-scale, longitudinal registry of nearly 3,000 heart device patients, and were presented at the Heart Rhythm Society 2012 Scientific Sessions in Boston, Massachusetts, US.

Recent evidence has suggested that nearly one in four ICDs implanted for primary prevention were outside evidence-based criteria.

The research team, led by Christian Machado, Providence Hospital, Detroit, Michigan, therefore performed a retrospective study to evaluate outcomes among EB versus NEB primary prevention ICD recipients over long-term follow up.

NEB patients were defined as those receiving treatment within 30 days of myocardial infarction; within 3 months of non-ischemic dilated cardiomyopathy diagnosis; or in the setting of New York Heart Association class IV symptoms.

The authors reviewed data for 1,412 OMNI ICD patients and identified 570 who received primary prevention ICD therapy. Of these, 10.4 % were receiving NEB treatment.

NEB patients were significantly younger (mean age 61 vs 67 years) and more likely non-ischemic (56 vs 15 %).

Over an average 3.3-year follow-up, 156 primary prevention patients received appropriate ICD therapy and 119 patients died.

Compared with the EB group, the NEB group experienced statistically similar outcomes with regards to time to first appropriate ICD therapy, risk for death, and time to first inappropriate ICD therapy.

“While in real-world practice we see many patients who are either excluded or unaddressed by evidence base, we have observed that some non-evidence-based ICD patients are showing positive outcomes, which until now there was little research to support this anecdotal observation,” commented Machado.

“We feel this study is a valuable surrogate of real-world clinical practice, whether clinical needs require real medical decisions. Additionally, it continues to emphasize he importance of the physician-patient relationship,” he added.

“While guidelines are important, our ultimate mission is to save our patient’s life and we know we are giving them a fighting change. We believe this study provides that knowledge.”

By Nikki Withers