CRT-D PATIENT TARGETING REFINED

Researchers led by Dr Scott D Solomon (Brigham and Women’s Hospital, Boston, MA) analysed echocardiograms from 1,077 patients enrolled in MADIT-CRT.  They found that CRT-D produced improvements in both synchrony and contractile function, compared to treatment with implantable cardioverter defibrillation (ICD) alone, and that the extent of this benefit related to subsequent outcomes.

Results showed that patients with mild to moderate dyssynchrony  at baseline (defined as a time-to peak transverse strain SD of 142-230 ms) and greater  baseline contractile function (longitudinal strain < -8.7%) improved to a greater  extent when randomised to the CRT-D group than the ICD only group.

The study showed that over a year each 10 ms decrease in LV dyssynchrony was associated with a 3% reduction in the primary outcome of death or heart failure, and each 5 point absolute increase in LV strain was associated with a 75% reduction in the primary outcome.

“It’s important to target patients in whom CRT-D works well because the technology is quite expensive,” explained Solomon.
  “These results suggest that the patients who are most likely to benefit from CRT-D are those with at least some dyssynchrony who have relatively preserved contractile function”.

Solomon observed that improvements in synchrony and contractile function were associated with reduced death and heart failure events, suggesting that the benefits delivered by CRT-D relate to improvements in these factors. “Future studies will continue to try to identify the patients who are most likely to benefit from this expensive but highly effective therapy,” he said.