Effects of implantable cardioverter/defibrillator shock and antitachycardia pacing on anxiety and quality of life: A MADIT-RIT substudy.

Effects of implantable cardioverter/defibrillator (ICD) shocks and antitachycardia pacing (ATP) on anxiety and quality of life (QoL) in ICD patients are poorly understood.

METHODS: We evaluated changes in QoL from baseline to 9-month follow-up using the EQ-5D questionnaire in patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial-Reduce Inappropriate Therapy (MADIT-RIT) (n=1,268). We assessed anxiety levels using the Florida Shock Anxiety Scale (1-10 score) in patients with appropriate or inappropriate shocks or ATP compared to those with no ICD therapy during the first 9 months postimplant. The analysis was stratified by number of ATP or shocks (0-1 vs ≥2) and adjusted for covariates.

RESULTS: In MADIT-RIT, 15 patients (1%) had ≥2 appropriate shocks, 38 (3%) had ≥2 appropriate ATPs. Two or more inappropriate shocks were delivered in 16 patients (1%); ≥2 inappropriate ATPs, in 70. In multivariable analysis, patients with ≥2 appropriate shocks had higher levels of shock-related anxiety than those with ≤1 appropriate shock (P<.01). Furthermore, ≥2 inappropriate shocks produced more anxiety than ≤1 inappropriate shock (P=.005). Consistently, ≥2 appropriate ATPs resulted in more anxiety than ≤1 (P=.028), whereas the number of inappropriate ATPs showed no association with anxiety levels (P=.997). However, there was no association between QoL and appropriate or inappropriate ATP/shock (all P values > .05).

CONCLUSIONS: In MADIT-RIT, ≥2 appropriate or inappropriate ICD shocks and ≥2 appropriate ATPs are associated with more anxiety at 9-month follow-up despite no significant changes in the assessment of global QoL by the EQ-5D questionnaire. Innovative ICD programming reducing inappropriate therapies may help deal with patient concerns about the device.