title: Meta-Analysis of the Usefulness of Change in QRS Width to Predict Response to Cardiac Resynchronization Therapy.
abstract: The existing data regarding the role of QRS duration (QRSd) change on cardiac resynchronization therapy (CRT) response show some inconsistent results. We conducted a meta-analysis of data obtained from observational studies to examine the impact of QRS change after CRT device implantation on the clinical and/or echocardiographic response. We searched the PubMed and EMBASE databases for relevant studies published before January 2016. Twenty-seven studies were retrieved for detailed evaluation of which 12 studies with a total population of 1,545 patients met our eligibility criteria. The analysis demonstrated that QRSd narrowing was a positive predictor of response to CRT (mean difference [MD] = -19.24 ms, 95% CI = -24.00 to -14.48 ms, p <0.00001). This effect was consistent in the studies using clinical criteria (MD = -19.91 ms, 95% CI = -27.20 to -12.62 ms, p <0.00001) and in those that used echocardiographic criteria (MD = -19.51 ms, 95% CI = -25.78 to -13.25 ms, p <0.00001). The heterogeneity test showed moderate differences among the individual studies (I2= 42%). Subgroup analysis showed that QRSd change was more pronounced in studies having a follow-up ≤6 months. We did not find significant differences in studies measuring postimplantation QRSd after a certain follow-up period compared with studies measuring QRSd immediately after CRT device implantation. Further studies should clarify the exact timing of QRSd assessments during follow-up. In conclusion, QRSd shortening after CRT device implantation is associated with a favorable clinical and echocardiographic response.
authors.affiliation: First Department of Cardiology, University of Ioannina Medical School, Ioannina, Greece. Electronic address: p.korantzopoulos@yahoo.gr.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Korantzopoulos
authors.affiliation: Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, People's Republic of China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, People's Republic of China.
authors.forename: Guangping
authors.initials: G
authors.lastname: Li
authors.affiliation: Third Cardiology Department, Hippokrateion Hospital, Aristotle University Medical School, Thessaloniki, Greece.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Fragakis
authors.affiliation: Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, People's Republic of China. Electronic address: liutongdoc@126.com.
authors.forename: Tong
authors.initials: T
authors.lastname: Liu
mesh_terms: D058406:Cardiac Resynchronization Therapy; D004452:Echocardiography; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D011237:Predictive Value of Tests; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology* / Q000628:therapy*