August 30, 2018Scientific Reports220 citationsOpen Access
Cardiac resynchronization therapy: a comparison among left ventricular bipolar, quadripolar and active fixation leads
Key Result
Non-bipolar left ventricular leads (quadripolar and active fixation) were associated with a significantly improved clinical outcome compared to conventional bipolar leads (OR 1.99).
Study Design
Type
Observational (n=290)
Multicenter
No
Structured PICO
Do quadripolar or active fixation left ventricular leads improve technical outcomes and reverse remodeling compared to bipolar leads in CRTD candidates?
P
Population
290 patients with heart failure undergoing cardiac resynchronization therapy with a defibrillator, followed for a minimum of 10 months.
I
Intervention
Quadripolar (QL, n=97) or active fixation (AFL, n=57) left ventricular leads
C
Comparator
Conventional bipolar (BL, n=136) left ventricular leads
O
Outcome
Composite technical endpoint (phrenic nerve stimulation at 8 V@0.4 ms, safety margin between myocardial and phrenic threshold <2V, LV dislodgement, and failure to achieve the target pacing site)composite
Quadripolar and active fixation left ventricular leads significantly reduce technical complications and improve reverse remodeling compared to conventional bipolar leads in patients receiving cardiac resynchronization therapy.
Main Result
Odds Ratio: 1.99 (95% CI 1.24–3.2)
p-value: p=0.004
Limitations
- Single center, retrospective non-randomized study design
- Population is underpowered for mortality endpoints
- Inter-observer variability in measuring reverse remodeling with echocardiography
- Different implantation periods for the different lead types
Abstract
We evaluated the performance of 3 different left ventricular leads (LV) for resynchronization therapy: bipolar (BL), quadripolar (QL) and active fixation leads (AFL). We enrolled 290 consecutive CRTD candidates implanted with BL (n = 136) or QL (n = 97) or AFL (n = 57). Over a minimum 10 months follow-up, we assessed: (a) composite technical endpoint (TE) (phrenic nerve stimulation at 8 V@0.4 ms, safety margin between myocardial and phrenic threshold 15%). Baseline characteristics of the 3 groups were similar. At follow-up the incidence of TE was 36.3%, 14.3% and 19.9% in BL, AFL and QL, respectively (p < 0.01). Moreover, the incidence of RR was 56%, 64% and 68% in BL, AFL and QL respectively (p = 0.02). There were no significant differences in CE (p = 0.380). On a multivariable analysis, "non-BL leads" was the single predictor of an improved clinical outcome. QL and AFL are superior to conventional BL by enhancing pacing of the target site: AFL through prevention of lead dislodgement while QL through improved management of phrenic nerve stimulation.