Differences in predictors of implantable cardioverter-defibrillator therapies in patients with ischaemic and non-ischaemic cardiomyopathies.

AIMS: Implantable cardioverter-defibrillators (ICDs) have been shown to reduce mortality in patients with both ischaemic and non-ischaemic cardiomyopathy by terminating life-threatening arrhythmias. However, such arrhythmic events are unequally distributed among different patient subgroups. We aimed to evaluate predictors of appropriate ICD therapies as a step towards risk stratification in a real-world cohort.

METHODS AND

RESULTS

The prevalence and predictors of appropriate ICD therapies were analysed in 330 consecutive patients (mean age 65 ± 11, 81% male) with implanted ICDs due to ischaemic (n = 204) or dilated (n = 126) cardiomyopathy. During a mean follow-up of 19 ± 9 months, 1545 appropriate ICD therapies (antitachycardia pacing and shocks) were detected in 94 patients (29%). In multivariate analysis applied on the whole cohort, the presence of atrial fibrillation [AF: odds ratio (OR) = 1.906, confidence interval (CI) = 1.143-3.177, P = 0.013] and secondary prevention indication (OR = 1.963, CI = 1.123-3.432, P = 0.018) was associated with ICD therapy. The presence of cardiac resynchronization therapy (CRT) had a protective value (OR = 0.563, CI = 0.327-0.968, P = 0.038). Moreover, the predictors were different depending on the aetiology of the cardiomyopathy: in the ischaemic group, only secondary prevention indication (OR = 2.0, CI = 1.029-3.891, P = 0.041) and the presence of a biventricular system (OR = 0.359, CI = 0.163-0.794, P = 0.011) remained significant, while in the non-ischaemic group, an association with AF was observed (OR = 4.281, CI = 1.632-11.231, P = 0.003).

CONCLUSION

The aetiology of cardiomyopathy should be taken into consideration for the therapy of ICD patients. The protective role of CRT devices should be pointed out in ischaemic cardiomyopathy (ICM) and a more rigorous antiarrhythmic treatment should be considered for ICM patients with secondary prevention or for dilated cardiomyopathy patients with AF.