The diagnostic value of different criteria in predicting the response of LBBB patients: a systematic review and meta-analysis

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background The left bundle branch has emerged as an essential part of the cardiac conduction system. However, many patients with conventional left bundle branch block (LBBB) QRS morphology appeared to have a poor response to cardiac resynchronization therapy (CRT) therapy; these might be due to they were non-LBBB patients who met the conventional diagnostic criteria but failed to meet the strict LBBB standard. There are different criteria to select appropriate CRT patients currently. Several studies have reported that patients with complete LBBB had worse ventricular synchronization and worse prognosis. Thus, it is of great clinical significance to distinguish between complete LBBB and non-LBBB. Purpose To compare the difference in mortality and CRT response between complete LBBB and non-LBBB patients. Methods This meta-analysis has been registered on the International Prospective Register of Systematic Reviews (ID: CRD42021242318). A systematic search on PubMed, Cochrane library, Embase databases was conducted before July 2021. All the included studies were screened and identified based on the specific inclusion and exclusion criteria. Relevant data, including time to event data for different outcomes (e.g., hazard ratio, HR), responders, electrocardiogram parameters, and echocardiographic changes, were extracted for meta-analysis. Results A total of 15 studies were ultimately involved in this meta-analysis. A random-effect model was conducted due to the substantial heterogeneity. The results showed that patients who received CRT treatment in the complete LBBB group had a 35% reduction in mortality than in the non-LBBB group (HR 0.65, 95% CI 0.56 to 0.77, P =0.000). The subgroup analysis showed that when stratified by the Strauss criteria, the survival was much higher in complete LBBB patients (HR 0.58, 95% CI 0.43 to 0.77, P =0.000), compared with other criteria, including ESC, AHA, Marriot, and conventional (HR 0.72, 95% CI 0.63 to 0.82, P =0.000). The pooled results suggested that the patient survival rate was significantly better under the Strauss criteria than other standards. Conclusions Present criteria differentiating complete LBBB and non-LBBB have good predictive value for survival. Among those, Strauss criteria may provide the most valuable information on the predictive effects of mortality and survival rate. This meta-analysis indicates that the use of Strauss criteria correlated independently with the response and prognosis of CRT patients with LBBB.