{Reference Type}: Journal Article
{Title}: Clinical utility of QRS duration normalized to left ventricular volume for predicting cardiac resynchronization therapy efficacy in patients with "mid-range" QRS duration.
{Author}: Yamamoto N;Noda T;Nakano M;Ito T;Sato H;Hayashi H;Chiba T;Hasebe Y;Ueda N;Kamakura T;Ishibashi K;Miyata S;Kusano K;Yasuda S;
{Journal}: Heart Rhythm
{Volume}: 21
{Issue}: 6
{Year}: 2024 Jun 15
{Factor}: 6.779
{DOI}: 10.1016/j.hrthm.2024.02.019
{Abstract}: <B>BACKGROUND: </B>Cardiac resynchronization therapy (CRT) is effective for patients with heart failure with QRS duration (QRSd) ≥150 ms. However, its beneficial effect seems to be limited for those with "mid-range" QRSd (120-149 ms). Recent studies have demonstrated that modifying QRSd to left ventricular end-diastolic volume (LVEDV)-modified QRSd-improves the prediction of clinical outcomes of CRT.<BR><B>OBJECTIVE: </B>The purpose of this study was to investigate the clinical impact of the modified QRSd on the efficacy of CRT in patients with "mid-range" QRSd.<BR><B>METHODS: </B>We conducted a retrospective, multicenter, observational study, with heart failure hospitalization (HFH) after CRT as the primary endpoint. Modified QRSd is defined as QRSd divided by LVEDV, determined through the Teichholtz method of echocardiography.<BR><B>RESULTS: </B>Among the 506 consecutive patients considered, 119 (mean age 61 ± 15 years; 80% male, QRSd 135 ± 9 ms) with a "mid-range" QRSd who underwent de novo CRT device implantation were included for analysis. During median follow-up of 878 days [interquartile range 381-1663 days], HFH occurred in 45 patients (37%). Fine-Gray analysis revealed modified QRSd was an independent predictor of HFH (hazard ratio [HR] 0.97; 95% confidence interval [CI] 0.96-0.99; P <.01). Receiver operating characteristic curve analysis revealed a cutoff value of 0.65 ms/mL for the modified QRSd in predicting HFH. Patients above the threshold exhibited a significantly lower incidence of HFH than patients below the threshold (HR 0.46; 95% CI 0.25-0.86; P = .01).<BR><B>CONCLUSIONS: </B>Modified QRSd can effectively predict the efficacy of CRT in patients with a "mid-range" QRSd.