SPC365

QRS Reduction and Its Association with CRT Super-Response

Session: Sessão de Posters 49 - Insuficiência cardíaca para além da fração de ejeção do VE melhorada e recuperada: padrões de recuperação, preditores e marcadores de risco
Speaker: Sofia Andraz

Congress: CPC 2026
Topic: D. Heart Failure
Theme: 10. Chronic Heart Failure
Subtheme: 10.4 Chronic Heart Failure – Treatment
Session Type: Posters Eletrónicos
FP Number: ---
Authors: Sofia Andraz; Joana Massa Pereira; Lucas Hamann; Joana Guerreiro Pereira; Pedro de Azevedo; Hugo Costa; Jorge Mimoso

<p style="text-align:justify"><span style="font-size:14px"><span style="font-family:Aptos,sans-serif"><strong><span style="font-family:&quot;Times New Roman&quot;,serif">Introduction: </span></strong><span style="font-family:&quot;Times New Roman&quot;,serif">Changes in QRS duration/variation (</span></span>?<span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Times New Roman&quot;,serif">QRS) are often used in the clinical setting to evaluate the effect of cardiac resynchronization therapy (CRT), although an association between </span></span>?<span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Times New Roman&quot;,serif">QRS and response/super-response is not fully established. </span></span></span></p>

<p style="text-align:justify"><span style="font-size:14px"><span style="font-family:Aptos,sans-serif"><strong><span style="font-family:&quot;Times New Roman&quot;,serif">Objective: </span></strong><span style="font-family:&quot;Times New Roman&quot;,serif">We aimed to assess the link between QRS shortening and super-response in CRT patients. </span></span></span></p>

<p style="text-align:justify"><span style="font-size:14px"><span style="font-family:Aptos,sans-serif"><strong><span style="font-family:&quot;Times New Roman&quot;,serif">Methods: </span></strong><span style="font-family:&quot;Times New Roman&quot;,serif">A retrospective analysis between 2020 and 2023 included 95 patients who underwent CRT implantation. Data collected included demographics, cardiovascular risk factors and echo and electrocardiographic parameters. Super-response to CRT was defined as an absolute increase in left ventricular ejection fraction (LVEF) &ge; 10% and/or &ge; 30% reduction in left ventricular end-systolic volume and/or &ge; 20% reduction in left ventricular end-diastolic volume. ROC curve and AUC were obtained to determine the discriminative power of </span></span>?<span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Times New Roman&quot;,serif">QRS as predictor of CRT super-response. Optimal cut-point value was obtained, and patients were compared according to this value. Predictors of super-response were identified using multivariate logistic regression.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:14px"><span style="font-family:Aptos,sans-serif"><strong><span style="font-family:&quot;Times New Roman&quot;,serif">Results: </span></strong><span style="font-family:&quot;Times New Roman&quot;,serif">The final cohort consisted of 61 patients, of whom 24 (39.3%) were classified as super-responders. The mean age was 69.5&plusmn;10.4 years, with 75.8% being male. Mean baseline QRS duration was 166&plusmn;23.5 ms. Post-CRT QRS was recorded a median of 20&nbsp;hours after implantation, and the mean </span></span>?<span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Times New Roman&quot;,serif">QRS was &minus;20.2&nbsp;ms. Mean biventricular pacing was 95.9% and without differences between groups. Non-ischemic etiology (75%, p=0.014), true left bundle brunch block (tLBBB) (65.2%, p=0.003) and the degree of LVEF improvement (29.2% -&gt;50.7%, p=0.001) were more frequent among super-responders. </span></span>?<span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Times New Roman&quot;,serif">QRS with QRS shortening (26.7&plusmn;20.6 ms, p=0.048) were also more frequent in this group. Optimal cut-point value for predicting CRT super-response was </span></span>?<span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Times New Roman&quot;,serif">QRS &ge;26ms (AUC 0.653, p-value 0.049, 95% CI 0.502-0.803) with a specificity of 89%. </span></span>?<span style="font-family:Aptos,sans-serif"><span style="font-family:&quot;Times New Roman&quot;,serif">QRS &ge;26ms was one of the predictors of super-response, increasing the probability by 9 times (OR=9.612, p=0.043). Other predictors were tLBBB (OR=21.54, p=0.015), non-ischemic etiology (OR=20.14, p=0.009) and the use of ACEi (OR=15.16, p=0.022).</span></span></span></p>

<p style="text-align:justify"><span style="font-size:14px"><span style="font-family:Aptos,sans-serif"><strong><span style="font-family:&quot;Times New Roman&quot;,serif">Conclusions: </span></strong><span style="font-family:&quot;Times New Roman&quot;,serif">In this cohort of patients, acute reduction of QRS duration after CRT implantation was associated with more pronounced reverse remodeling measured by super-response in a medium/long term follow-up, with an optimal QRS shortening of at least 26ms. More studies are needed to confirm these findings and try to verify their impact on hard outcomes.</span></span></span></p>