Age and triggers of inappropriate implantable cardioverter-defibrillator therapy in primary prevention patients
A Barsheshet, I Goldenberg, S Gelikas, S McNitt, B Polonsky, A Erez, G Goldenberg, I Kumets, S Tal, M Aktas, W Zareba, G GolovchinerAbstract
Background
Data on the association between age and triggers of inappropriate therapy among implantable cardioverter-defibrillator (ICD) recipients remain limited. We evaluated the relationship between age and the risk of inappropriate ICD therapy and examined age-related differences according to specific therapy triggers.
Methods
The study population comprised 5,170 primary prevention ICD recipients enrolled in MADIT-II, MADIT-Risk, MADIT-CRT, MADIT-RIT, and RAID. Patients were categorized by age tertiles (≤60, 61–70, and >70 years). Multivariable Cox proportional-hazards models assessed associations between age and inappropriate therapy overall (primary endpoint) and by trigger type (secondary endpoints): atrial fibrillation (AF, including atrial flutter), supraventricular tachycardia (SVT, including sinus tachycardia), and other causes (primarily oversensing or lead malfunction).
Results
At 3 years, the cumulative incidence of any inappropriate ICD therapy was highest in patients ≤60 years and progressively lower across older tertiles (16%, 13%, and 11%, respectively; p=0.001; Figure, left panel).
In multivariable analysis, patients aged ≤60 years and 61–70 years had a higher risk of inappropriate ICD therapy compared with those >70 years (HR 1.35 and 1.20, respectively; p for trend=0.008). Consistently, each 10-year decrease in age was independently associated with a 15% increase in the risk of inappropriate therapy (p<0.001).
The excess risk was predominantly driven by SVT-triggered inappropriate therapy (Figure, right panel). Patients aged ≤60 years and 61–70 years had a higher SVT-related risk compared with those >70 years (HR 2.02 and 1.33, respectively; p for trend<0.001). Each 10-year decrease in age was associated with a 31% increase in SVT-related risk (p<0.001). Age was not significantly associated with AF-triggered or other causes of inappropriate therapy.
Conclusions
Among primary prevention ICD recipients, younger age is independently associated with a graded increase in inappropriate ICD therapy, predominantly driven by SVT-triggered events. These findings support age-tailored ICD programming strategies to reduce inappropriate therapies in younger patients.Inappropriate ICD Therapy by Age: Overall/SVT