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Abstract

Background: Left ventricular (LV) leads are important devices for stimulating the most delayed site in cardiac resynchronization therapy (CRT). Since April 2020, the Attain Stability Quad (ASQ) lead, which has a side helix for facilitating active fixation, has become available in Japan. We evaluated the benefits of ASQ leads compared with those of conventional passive fixation LV leads. Methods:From April 2016 to July 2021, 70 CRT implant patients were enrolled in this single-center retrospective observational study. The patients were divided into two groups for comparison: the ASQ (n = 35) and non-ASQ groups (n = 35).Results: There were no differences in preoperative age, gender, organic heart disease, comorbidities, LV ejection fraction, preoperative QRS complex, and the LV lead implantation threshold between the two groups. Six months after CRT implantation, the threshold was lower in the ASQ group than in the non-ASQ group (p = 0.03; 0.87 ± 0.21 V/0.4 ms vs. 1.06 ± 0.36 V/0.4 ms, respectively). In the ASQ group, LV pacing continued in all cases. The ASQ group could be implanted in the LV lateral wall and avoid placement in the apical segment. By placing the LV lead in the optimal location, the event occurrence rate for cardiovascular endpoints was lower in the ASQ group than in the non-ASQ group (log-rank p = 0.02 hazard ratio 3.83). Conclusion:ASQ leads maintain a stable low threshold in the remote period after implantation. The ASQ lead performs LV pacing from a delayed optimal site in the LV and may contribute to preventing cardiovascular events.