Association of fragmented QRS complex with mortality and clinical outcomes in patients with pulmonary embolism: an updated meta-analysis

OBJECTIVES: To provide an updated and methodologically rigorous assessment of the association of fragmented QRS (fQRS) on ECG with mortality and other clinical outcomes in patients with pulmonary embolism (PE). DESIGN: Systematic review and meta-analysis of observational studies using a DerSimonian-Laird random-effects model for all pooled analyses. Heterogeneity was assessed using the I² statistic, with I²>50% indicating substantial heterogeneity. Study quality was evaluated using the Newcastle-Ottawa Scale (NOS), and publication bias was assessed by funnel plot inspection. PARTICIPANTS: A systematic search of PubMed, Embase, Web of Science and Cochrane Library was conducted up to 13 August 2025. Observational studies investigating the association between fQRS and outcomes (mortality, cardiogenic shock, treatment escalation) in adults with confirmed PE were included. Patients were classified based on the presence or absence of fQRS on admission ECG. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was all-cause mortality (in-hospital and long-term). Secondary outcomes included cardiogenic shock and treatment escalation (thrombolysis, surgical embolectomy or mechanical ventilation). RESULTS: Five studies involving 1383 patients were included. All included studies scored ≥7 on the NOS, indicating moderate-to-high methodological quality. The presence of fQRS was significantly associated with an increased risk of in-hospital mortality (OR 3.40; 95% CI 1.72 to 6.71; p=0.0004; I²=51%), long-term mortality (OR 3.90; 95% CI 1.80 to 8.47; p=0.0006; I²=47%) and cardiogenic shock (OR 4.88; 95% CI 1.70 to 14.01; p=0.003; I²=65%). No significant association was found with the use of thrombolysis, surgical embolectomy or mechanical ventilation. Funnel plot inspection revealed asymmetry, suggesting potential publication bias; however, formal testing was limited by the small number of included studies. Sensitivity analysis confirmed the robustness of the primary findings. All pooled estimates were derived from unadjusted effect sizes extracted from the primary studies. CONCLUSIONS: In this updated meta-analysis, fQRS was a robust and readily available risk marker for early and late mortality and cardiogenic shock in patients with PE. Standardised ECG interpretation may enhance risk stratification and guide early, intensive management. Further large-scale, prospective studies are warranted to validate these findings across diverse populations and to establish standardised criteria for fQRS assessment in this setting.CRD420251127962.