Background: The combination of left bundle branch block (LBBB) morphology and QRS duration is currently used to select patients for cardiac resynchronization therapy (CRT). These parameters, however, have limitations. This study evaluates the value of QRS area compared with that of QRS duration and morphology in the association with clinical and echocardiographic outcomes in a large cohort of CRT patients. Methods: A retrospective multicentre study was conducted in 1492 CRT patients. LBBB morphology, QRS duration, and QRS area in the baseline 12-lead ECG were evaluated for their association with the occurrence of the combined primary end point of all-cause mortality, cardiac transplantation, and left ventricular assist device implantation. Secondary end points were heart failure hospitalization within the first year after implantation and echocardiographic reduction in left ventricular end-systolic volume. Results: During a mean follow-up period of 3.4 years, 32% of patients reached the primary end point. The association of QRS area with all outcomes was stronger than that of LBBB morphology and QRS duration separately and at least as strong as their combination. QRS area identified patients who did not experience the primary end point better than QRS morphology and QRS duration (area under the curve, 0.61 versus 0.55 and 0.51, respectively; P <0.001). Furthermore, QRS area identifies patients with echocardiographic remodeling in response to CRT better than QRS morphology and duration (area under the curve, 0.69 versus 0.58 and 0.58, respectively; P <0.001). QRS area was the only independent electrocardiographic determinant associated with the primary end point; hazard ratio, 0.50 (0.35–0.71). Furthermore, QRS area showed significant association with outcomes in both patients with and without LBBB and QRS ≥150 ms. Conclusions: QRS area has a strong association to clinical and echocardiographic response to CRT, at least as strong as current patient selection parameters. QRS area may be particularly useful to predict CRT response in patients without a wide LBBB.

The CAVIAR response score predicts the amount of reverse remodelling after CRT and may be used to improve patient selection. Clinical Trials: NCT01519908.

Abstract Aims Study sex-differences in efficacy and safety of atrial fibrillation (AF) ablation. Methods and results We assessed first AF ablation outcomes on continuous anticoagulation in 633 patients [209 (33%) women and 424 (67%) men] in a pre-specified subgroup analysis of the AXAFA-AFNET 5 trial. We compared the primary outcome (death, stroke or transient ischaemic attack, or major bleeding) and secondary outcomes [change in quality of life (QoL) and cognitive function] 3 months after ablation. Women were older (66 vs. 63 years, P &lt; 0.001), more often symptomatic, had lower QoL and a longer history of AF. No sex differences in ablation procedure were found. Women stayed in hospital longer than men (2.1 ± 2.3 vs. 1.6 ± 1.3 days, P = 0.004). The primary outcome occurred in 19 (9.1%) women and 26 (6.1%) men, P = 0.19. Women experienced more bleeding events requiring medical attention (5.7% vs. 2.1%, P = 0.03), while rates of tamponade (1.0% vs. 1.2%) or intracranial haemorrhage (0.5% vs. 0%) did not differ. Improvement in QoL after ablation was similar between the sexes [12-item Short Form Health Survey (SF-12) physical 5.1% and 5.9%, P = 0.26; and SF-12 mental 3.7% and 1.6%, P = 0.17]. At baseline, mild cognitive impairment according to the Montreal Cognitive Assessment (MoCA) was present in 65 (32%) women and 123 (30%) men and declined to 23% for both sexes at end of follow-up. Conclusion Women and men experience similar improvement in QoL and MoCA score after AF ablation on continuous anticoagulation. Longer hospital stay, a trend towards more nuisance bleeds, and a lower overall QoL in women were the main differences observed.