Artificial chords in endoscopic mitral valve repair: a comparative analysis of surgical techniques and long-term outcomes

Background The use of artificial chords for mitral valve prolapse during minimally invasive mitral valve repair (MIMVR) has increased over the past two decades, driven by advancements in surgical techniques and the need for reproducible and durable repair strategies. This study aimed to compare the outcomes of single artificial chords versus premeasured loops and identify predictors for long-term success. Methods Between 2001–2023, perioperative data and long-term outcomes of 1186 consecutive patients who underwent MIMVR at the University Hospital Innsbruck, Austria were analysed and reported according to the Mitral Valve Research Consortium criteria, including all-cause mortality, freedom from reoperation and technical success defined as freedom from reoperation or recurrent mitral regurgitation>moderate. A competing risk analysis was performed to account for the risk of mortality long-term. Results The mean age of the cohort was 60.6±12.6 years, with 61.6% males. Among them, 581 patients received artificial chords (151 single chords and 430 premeasured loops). At a median follow-up of 5.0 (4.45–5.53) years, survival was 98.4%, 95.4% and 92.7% at 1, 5 and 10 years, respectively. At 15 years, cumulative incidence of death or reoperation was 8.5% in the loop group and 11.0% in the single expanded polytetrafluoroethylene (ePTFE) chord group (p=0.90), with a hazard ratio of 0.95 (95% CI 0.44 to 2.06). The loop technique was associated with shorter cross-clamp times (100 vs 121 min, p<0.001) and more implanted chords (5.0 vs 2.0, p<0.001) compared with the ePTFE chord technique. There was no significant difference in long-term success: event-free survival at 10 years: 92% (87–97%) in the loops group versus 93% (89–97%) in the single ePTFE chords group, p=0.5. Left atrial appendage occlusion emerged as the only independent predictor for long-term success (HR: 0.11 (0.014–0.839), p=0.033), whereas the choice of technique did not influence long-term outcomes. Conclusions Both single artificial chords and premeasured loops provided excellent perioperative and long-term outcomes in MIMVR. The loop technique facilitated shorter operative times and greater chordal implantation efficiency without compromising long-term repair durability or event-free survival.