QRS DURATION CHANGE FOLLOWING AORTIC VALVE REPLACEMENT: ASSOCIATION WITH PERMANENT PACEMAKER RISK AND DIAGNOSTIC UTILITY IN INDIVIDUALS WITHOUT PRE-PROCEDURE CONDUCTION AND RHYTHM DISTURBANCES (CCC-153)

Background: Longer QRS duration (QRSd) represents a key prognostic marker for increased cardiovascular morbidity and mortality. Change in QRSd, over time or in response to treatment, can predict adverse long-term outcomes.

METHODS AND RESULTS: A retrospective evaluation of post-AVR QRSd change in milliseconds (ms), including associations with AVR modality, subsequent permanent pacemaker (PPM) risk, and diagnostic performance. Baseline and follow-up demographic and clinical characteristics were collected for 492 (mean age 73.8 years, 62.6% male) consecutive patients undergoing AVR between 2014-2020 at a tertiary care centre. Given high variability, QRSd change was stratified based on quartiles as: (a) reduction (≤ -4.0 ms), (b) stability or minimal change (-3.0 ≤ QRSd ≤ 2.0 ms), (c) small increase (3.0 ≤ QRSd ≤ 14 ms), and (d) increases beyond 14 ms. On average, AVR was associated with QRSd lengthening (11.0± 28.8 ms), increasing by 4.5±20.1, 13.1±35.5, 2.8±15.0, and 19.3±27.2 ms for conventional bio-prostheses, sutureless bio-prostheses, mechanical, and Transcatheter Aortic Valve Implantation (TAVI, p< 0.0001). Post-AVR QRSd change patterns included: 152 (31%) reductions (≤ -4.0 ms), 99 (20%) stable (-3.0 ≤ QRSd ≤ 2.0 ms), 120 (24%) small increases (3.0 ≤ QRSd ≤ 14 ms), and 121 (25%) increases >14 ms. PPM implantation rate (37/492) within 1 month post-AVR was significantly different among QRSd change quartiles (62% in quartile d; p< 0.0001), but did not differ among AVR modalities (p=0.42). Hierarchical logistic regression, adjusted for age, sex, pre-op QRSd indicated a post-AVR increase of > 14 ms to be associated with higher risk of post AVR PPM (OR: 6.04 [2.33, 15.67], p< 0.0001) compared to a post-AVR QRSd reduction of ≤ -4.0 ms (quartile a). However, modest QRSd increase was not significantly associated with higher risk of post-AVR PPM (OR: 1.12 [0.33, 3.83], p= 0.86). Change in QRSd > 14ms demonstrated elevated PPM risk even after adjustment for AVR modality (OR: 5.72 [2.18, 15.02], p< 0.0001). A post-AVR QRSd cutoff of >14 ms demonstrated sensitivity of 0.62 and specificity of 0.78 (AUC= 0.71 [0.61, 0.82], p< 0.0001), while a cutoff of 21.5 ms provided maximal sensitivity (0.62) and specificity (0.81).


Conclusion: QRSd increase of >14 ms post-AVR was significantly associated with higher risk of PPM implantation, demonstrating acceptable diagnostic utility.