Use of a regional wall motion score to enhance risk stratification of patients receiving an implantable cardioverter-defibrillator

Abstract

Objectives: We postulated that preoperative assessment of both regional wall motion and left ventricular ejection fraction would serve as an accurate prognostic indicator of long-term cardiac mortality and functional outcome in patients treated with an implantable cardioverter-defibrillator.

Background: Long-term cardiac mortality has remained high in patients receiving an implantable cardioverter-defibrillator. The ability to risk stratify patients before defibrillator implantation is becoming increasingly important from a medical and economic standpoint.

Methods: The hypothesis was retrospectively tested in 74 patients who had received an implantable cardioverter-defibrillator. Left ventricular ejection fraction and regional wall motion score, derived from centerline chord motion analysis, were calculated for each patient from the preoperative right anterior oblique contrast ventriculogram. Wall motion score was the only significant independent predictor of long-term cardiac mortality and functional status by multivariate analysis because of its enhanced prognostic capability in patients with an ejection fraction in the critical range of 30% to 40%.

Results: Patients with an ejection fraction > 40% had a 3-year cardiac mortality rate of 0% compared with 25% for those with an ejection fraction of 30% to 40% and 48% for those with an ejection fraction < 30% (p < 0.05). Similarly, 75% of patients with an ejection fraction > 40% were in New York Heart Association functional class I or II during long-term follow-up compared with 59% of those with an ejection fraction 30% to 40% and 29% of those with an ejection fraction < 30%. Among patients with an ejection fraction of 30% to 40%, those with a wall motion score > 16% had a 3-year cardiac mortality rate of 0% compared with 71% of those with a wall motion score < or = 16% (p = 0.002). In addition, 86% of patients with a wall motion score > 16% were in functional class I or II during long-term follow-up compared with 13% of those with a wall motion score < or = 16% (p = 0.001).

Conclusions: Long-term cardiac mortality and functional outcome in patients receiving an implantable cardioverter-defibrillator can be predicted if the left ventricular ejection fraction and regional wall motion score are measured preoperatively.