MADIT-RIT: Changes in ICD Programming Associated With Mortality Reduction and Reductions in Inappropriate Shocks

Changes in implantable cardioverter defibrillator (ICD) programming may reduce the incidence of inappropriate shocks and are associated with reductions in all-cause mortality, according to results from the MADIT-RIT trial, presented as part of AHA 2012 on Nov. 6 and published simultaneously in The New England Journal of Medicine.

MADIT-RIT randomized 1,479 patients at 98 centers to conventional ICD and CRT-D device programming (activation at ≥170 beats per minute [bpm]), high-rate therapy (activation at ≥200 bpm), and duration-delay therapy (60 second monitoring before device firing at 170-199 bpm). Results showed that during an average follow-up of 1.4 years, high-rate therapy and delayed ICD therapy, as compared to conventional device programming, were associated with reductions in a first occurrence of inappropriate therapy (hazard ratio with high-rate therapy vs. conventional therapy, 0.21; 95 percent confidence interval [CI], 0.13 to 0.34; P<0.001; hazard ratio with delayed therapy vs. conventional therapy, 0.24; 95 percent CI, 0.15 to 0.40; P<0.001) and reductions in all-cause mortality (hazard ratio with high-rate therapy vs. conventional therapy 0.45; 95 percent CI, 0.24 to 0.85; P=0.01; hazard ratio with delayed therapy vs. conventional therapy 0.56; 95 percent CI, 0.30 to 1.02; P=0.06).

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Study investigators noted that high-rate therapy, in particular, was associated with a 79 percent reduction in first occurrence of inappropriate therapy and a 55 percent reduction in all-cause mortality. Moving forward, they suggest that "programming ICD devices to respond to tachyarrhythmias of 200 or more bpm with a prolonged delay in therapy at 170 bpm or higher, could improve patient outcomes."

Meanwhile, the ACC is currently developing appropriate use criteria (AUC) on implantable defibrillators and cardiac resynchronization in order to ensure patients are receiving the most appropriate care. The new AUC is slated for publication in early 2013.

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