Fragmented QRS Complex Could Predict All-Cause Mortality in Patients with Connective Tissue Disease-Associated Pulmonary Arterial Hypertension.

Objectives To investigate the prognostic impact and pathophysiological characteristics of fragmented QRS complex (fQRS) on patients with CTD-associated pulmonary arterial hypertension (CTD-PAH).Methods This was a multicentre retrospective study recruiting 141 patients with CTD-PAH diagnosed by right heart catheterization (114 cases in the discovery cohort and 27 cases in the validation cohort). fQRS and ST-T change were detected on conventional 12-lead ECG. Patients were followed up every 3 months to update their status and the primary endpoint was all-cause death. Clinical information and ECG characteristics were compared between survival and death groups and Kaplan-Meier curve was used for survival analysis.Results There were significant differences in age, gender, 6-min walk distance, N-terminal pro-brain natriuretic peptide, World Health Organization class, presence of fQRS, and presence of ST-T change in inferior leads between survival group and death group. Inferior fQRS and ST-T change were significantly associated with right ventricular dilatation and reduced right ventricular ejection fraction. Kaplan-Meier curve showed that all-cause mortality was higher in CTD-PAH with fQRS (P = 0.003) and inferior ST-T change (P = 0.012). Low- and intermediate-risk CTD-PAH with inferior ST-T change had higher all-cause mortality (P = 0.005). The prognostic value of fQRS and inferior ST-T change was validated in external validation cohort.Conclusion The presence of inferior fQRS and ST-T change could predict poor prognosis in CTD-PAH.Clinical trial registration NCT05980728, https://clinicaltrials.gov.