Liwen Ablation versus Modified Morrow Myectomy for Obstructive Hypertrophic Cardiomyopathy: 1-Year Hemodynamic and Conduction Outcomes

Background: In obstructive hypertrophic cardiomyopathy, surgical myectomy is highly effective but carries a recognized risk of postoperative conduction disturbances. Percutaneous intramyocardial septal radiofrequency ablation (Liwen procedure) is a less invasive alternative, but head-to-head comparisons of longitudinal hemodynamic trajectories and conduction system safety remain scarce, limiting evidence-based treatment selection. Methods: This single-center retrospective cohort included 211 patients treated 2018?2023 (124 Liwen, 87 modified Morrow myectomy). The primary longitudinal analysis included 133 patients with 1-year follow-up and serial data (75 Liwen, 58 modified Morrow myectomy). Repeated outcomes were analyzed using linear mixed-effects models and generalized estimating equations, adjusted for baseline covariates. Results: Both procedures reduced LVOT gradient, but trajectories differed (interaction P=0.002). At 1 year, the covariate-adjusted mean LVOT gradient remained higher after Liwen than after myectomy (16.1 vs 1.3 mmHg, P<0.001). However, the adjusted 1-year predicted probability of new conduction abnormalities was markedly lower after Liwen (5% vs 62%, P<0.001), with no permanent pacemaker implantations in the Liwen group. Most patients achieved gradient <30 mmHg in both groups (82% vs 96%; nominal P=0.308). Liwen had shorter procedure duration (80 vs 185 min) and hospital stay (11 vs 16 days). Serious adverse event rates were similar (8.1% vs 9.2%) but profiles differed. Conclusions: Modified Morrow myectomy achieved more complete LVOT gradient reduction at 1 year, whereas Liwen ablation had fewer conduction abnormalities, shorter procedure duration, and shorter hospital stay. These findings highlight a clinically relevant trade-off between more complete hemodynamic relief and lower conduction-system injury and require prospective confirmation.