Myocardial viability as shown by left ventricular lead pacing threshold and improved dyssynchrony by QRS narrowing predicts the response to cardiac resynchronization therapy

• Published in: Journal of cardiovascular electrophysiology 2019-03, Vol.30 (3), p.311-319
• Main Authors: Takenaka, Masaki, Inden, Yasuya, Yanagisawa, Satoshi, Fujii, Aya, Ando, Monami, Funabiki, Junya, Murase, Yosuke, Otake, Noriaki, Sakamoto, Yusuke, Shibata, Rei, Murohara, Toyoaki
• Format: Article
• Language: English
• Subjects: Action Potentials; Aged; cardiac resynchronization therapy; Cardiac Resynchronization Therapy - adverse effects; Congestive heart failure; Echocardiography; Female; heart failure; Heart Failure - pathology; Heart Failure - physiopathology; Heart Failure - therapy; Heart Rate; Humans; Implantation; left ventricular pacing threshold; Male; Middle Aged; Multivariate analysis; Myocardium - pathology; QRS narrowing; Recovery of Function; responder; Retrospective Studies; Risk Factors; Time Factors; Tissue Survival; Treatment Outcome; Ventricle; Ventricular Function, Left; Viability
• ISSN: 1045-3873; 1540-8167
• DOI: 10.1111/jce.13806

Introduction Patients with advanced heart failure and dyssynchrony can benefit from cardiac resynchronization therapy (CRT). To predict the response to CRT, myocardial viability and improved dyssynchrony are suggested to be important. Methods We retrospectively investigated 93 patients who underwent CRT implantation in Nagoya University Hospital. We assessed QRS narrowing the day after implantation to measure the improvement in dyssynchrony and measured the left ventricular pacing threshold (LVPT) to determine the local myocardial viability in all patients. Responders to CRT were defined as those having a greater than or equal to 15% decrease in left ventricular end‐systolic volume by echocardiography at their 6‐month follow‐up. Results Sixty‐two patients (67%) were classified as responders. The QRS width before CRT implantation, QRS narrowing after implantation, left atrial diameter, septal‐to‐posterior wall motion delay, left ventricular end‐diastolic diameter, radial strain, and LVPT were significantly different between the responder and nonresponder groups. On multivariate analysis, QRS narrowing (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.01‐1.05; P = 0.005) and LVPT (OR, 0.42; 95% CI, 0.22‐0.82; P = 0.011) were independent predictors of a response to CRT. We calculated the cutoff values from the receiver operating characteristic curves as 22.5 milliseconds of QRS narrowing and 1.55 V of LVPT. The response rates in patients with both predictive factors (QRS narrowing ≥ 22.5 milliseconds and LVPT ≤ 1.55 V), one factor, and no factors were 91%, 61%, and 25%, respectively (P