Use of fragmented QRS in prognosticating clinical deterioration and mortality in pulmonary embolism: A meta-analysis

Background: Fragmented QRS (fQRS) on electrocardiography is potentially valuable in prognosticating acute pulmonary embolism (PE). ECG is one of the first tests performed in the emergency department, quickly interpretable, noninvasive, inexpensive, and available in remote areas. We aimed to review fQRS's role in PE prognostication. Methods: We searched MEDLINE, EMBASE, Google Scholar, Web of Science, abstracts, conference proceedings, and reference lists until October 2017. Eligible studies used fQRS to prognosticate patients for the main outcomes of death and clinical deterioration or escalation of therapy. Two authors independently selected studies, with disagreement resolved by consensus. Ad hoc piloted forms were used to extract data and assess risk of bias. We used a random-effects model to pool relevant data in meta-analysis with odds ratios (OR) and 95% confidence intervals (CI), while all other data were synthesized qualitatively. Statistical heterogeneity was assessed using the I ² index. Results: We included five studies (1,165 patients). There was complete agreement in study selection. fQRS significantly predicted in-hospital mortality (OR [95% CI], 2.92 [1.73–4.91]; p <.001), cardiogenic shock (OR [95% CI], 4.71 [1.61–13.70]; p =.005), and total mortality at 2-year follow-up (OR [95% CI], 4.42 [2.57–7.60]; p <.001). Adjusted analyses were generally consistent with these results. Conclusion: Although few studies have explored the current study's question, they showed that fQRS is potentially valuable in PE prognostication. fQRS should be considered as an entry, along with other clinical and ECG findings, in a PE risk score.