Abstract 12762: Impact of the Relation of Lead Position to Scar by Speckle Tracking Radial Strain on Clinical Outcomes in Patients Receiving Resynchronization Therapy: Results from the STARTER Randomized Trial
Background: The importance of the relationship of left ventricular (LV) lead placement to myocardial scar for cardiac resynchronization therapy (CRT) remains unclear.
Objective: To determine the impact of scar location at the lead placement site on clincial outcomes in the the Speckle Tracking Assisted Resynchronization Therapy for Electrode Region (STARTER) randomized clinical trial.
Methods: STARTER was a prospective double-blinded randomized trial of 187 CRT patients randomized to echo guided LV lead position at site of latest mechanical activation vs. a routine approach. All patients had NYHA Class II-IV heart failure, QRS> 120 ms, and ejection fraction < 35%. Speckle tracking echo determined latest time to peak radial strain in free-wall segments at basal and mid LV levels. LV lead was confirmed by biplane cine fluoroscopy. Tl201 SPECT previously validated <10% radial strain indicative of scar in freewall segments (90% specific for absent isotope uptake) in a cohort of 62 patients with ischemic disease. A 16 segment model classified the relationship of LV lead to scar as concordant (exactly within the segment), adjacent (within an immediate neighboring segment), or remote (at least 1 segment away).The pre-specified primary endpoint was first heart failure hospitalization or death over 2 years.
Results: Of 149 patients with matched speckle tracking echo, fluroscopic and outcome data, 96 (64%) had ischemic cardiomyopathy and 53 (36%) had nonischemic cardiomyopathy. Among ischemic cardiomyopathy patients, LV lead position was classified as: 38 remote from scar, 36 adjacent to scar, and 22 within scar. Two year events were 17 (45%) in patients with leads remote from scar, 22 (61%) in patients with leads adjacent to scar, and 14 (64%) in patients leads within scar, p=0.004. (Figure).
Conclusion: Speckle tracking radial strain has promise to identify scar in patients with ischemic cardiomyopathy and assist in guiding LV lead positioning to improve outcomes after CRT.
- © 2012 by American Heart Association, Inc.