Background: Cardiac resynchronisation therapy (CRT) confers symptomatic and survival benefits in chronic heart failure with reduced ejection fraction (HFrEF). There remains a paucity of data on long-term performance of left ventricular (LV) leads, particularly with newer quadripolar lead designs.
Methods: This single-centre study utilised an electronic, outpatient HFrEF database to identify CRT recipients (2008-2014). The primary endpoint was temporal trend in LV pacing thresholds during follow-up. Secondary outcomes were complications relating to acute or chronic lead failure and device-related infections.
Results: Two hundred eighty patients were included, with mean (±SD) age of 74.2 years (±9.0) and median follow-up of 7.6 years (interquartile range 4-9). Mean LV threshold was 1.37 V (±0.73) at implant and remained stable over the study period. No differences were observed based upon lead manufacturer. Compared to non-quadripolar leads (n = 216), those of quadripolar designs (n = 64) had a lower threshold at 6 months (1.20 vs 1.37 V; P = .04) and at the end of the study period (1.32 vs 1.46 V; P = .04). Patients with HFrEF of ischaemic aetiology had higher thresholds at implant (1.46 vs 1.34 V; P = .05), and this persisted until the end of follow-up (1.49 vs 1.34 V; P = .03). There was low incidence of acute (0.71%; 2/280) and chronic lead failure (1.79%; 5/280), with four cases (1.43%) of device infection.
Conclusions: LV leads in the context of CRT have excellent chronic stability and low rates of adverse events. Those with newer quadripolar lead designs have lower thresholds at initial follow-up and in the longer term.
Keywords: cardiac resynchronisation therapy; chronic heart failure; left ventricular pacing; long-term outcomes; quadripolar leads.
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