Local electrogram delay recorded from left ventricular lead at implant predicts response to cardiac resynchronization therapy: Retrospective study with 1 year follow up
BMC Cardiovascular Disorders, 05/21/2012
Polasek R et al. – Left ventricular (LV) lead position assessed by duration of the QLV interval was found the strongest independent predictor of beneficial clinical response to cardiac resynchronization therapy (CRT).Methods
- Authors conducted a retrospective, single–centre analysis of 161 consecutive patients with heart failure and LBBB or nonspecific intraventricular conduction delay (IVCD) treated with CRT.
- They routinely intend to implant the LV lead in a region with long QLV.
- Clinical response to CRT, left ventricular (LV) reverse remodelling (i.e. decrease in LV end–systolic diameter – LVESD [greater than or equal to]10%) and reduction in plasma level of NT–proBNP >30% at 12–month post–implant were the study endpoints.
- They analyzed association between pre–implant variables and the study endpoints.
- Clinical CRT response rate reached 58%, 84% and 92% in the lowest ([less than or equal to]105 ms), middle (106–130 ms) and the highest (>130 ms) QLV tertile (p < 0.0001), respectively.
- Longer QRS duration (p = 0.002), smaller LVESD and a non–ischemic cardiomyopathy (both p = 0.02) were also univariately associated with positive clinical CRT response.
- In a multivariate analysis, QLV remained the strongest predictor of clinical CRT response (p < 0.00001), followed by LVESD (p = 0.01) and etiology of LV dysfunction (p = 0.04).
- Comparable predictive power of QLV for LV reverse remodelling and NT–proBNP response rates was observed.