A restrictive inflow pattern does not predict implantable cardioverter-defibrillator therapy in primary prevention

Abstract

Background: Current guidelines for the use of implantable cardioverter-defibrillators (ICDs) are broad and significantly increase the cost of caring for patients with heart failure. In an effort to identify the specific subset of patients who benefit from this therapy, the predictive value of numerous echocardiographic parameters have been studied. Severe diastolic dysfunction has been shown to predict adverse events in a group of patients who received an ICD for secondary prevention, but has not been tested in those who receive ICDs for primary prevention.

Hypothesis: We tested the hypothesis that a restrictive mitral inflow pattern on echocardiography will predict the risk of appropriate therapy in this patient population.

Methods: This retrospective study identified 145 consecutive patients who met primary prevention criteria for ICD implantation and had an echo performed no more than 1 year prior to receiving the ICD. A restrictive pattern was defined as a mitral inflow E/A > 2 or a deceleration time < 150 ms.

Results: A restrictive pattern was present in 69 patients (40.7% of the group). Appropriate ICD therapy occurred in 8 (11.5%) subjects with a restrictive pattern and 14 (18.4%) with a nonrestrictive pattern over 680 days of average follow-up (P = not significant). Cox regression analysis showed the presence of a restrictive pattern was not helpful in predicting time to first ICD therapy.

Conclusions: In a population of patients who received ICDs for primary prevention, echocardiographic findings of severe diastolic dysfunction were not helpful in targeting the use of ICDs to those at highest risk.