Dyspnoea after pulmonary embolism: is it dangerous?
L Nilsson, L A Johansson, B Carlberg, S SoderbergAbstract
Background
Persistent dyspnoea is common after pulmonary embolism (PE), yet its long-term prognostic significance remains uncertain. Clinicians often struggle to determine whether dyspnoea reflects post-PE cardiopulmonary sequelae or underlying comorbidity.
Purpose
We examined whether self-reported dyspnoea following PE is associated with long-term all-cause mortality.
Methods
We analysed two population-based cohorts: all Swedish patients surviving a PE in 2005 (n=2,104) and participants in a population health survey (n=1,903). Dyspnoea was assessed using identically worded questionnaire items. Comorbidities from national inpatient and outpatient registers were incorporated as time-dependent covariates. Cox proportional hazards models were used to estimate hazard ratios for all-cause mortality, adjusting for age, sex, smoking, and comorbidity burden.
Results
Dyspnoea was assessed a median of 3.4 years (IQR 3.0–3.7) after the index PE. During a median follow-up of 10.4 years (IQR 5.9–11.3), 906 patients in the PE cohort and 262 reference participants died. Dyspnoea was associated with higher crude mortality in both cohorts (log-rank p<0.001). After adjustment, dyspnoea was not independently associated with mortality in the PE cohort (hazard ratio 1.10, 95% confidence interval 0.94–1.28) or in the reference cohort (hazard ratio 0.86, 95% confidence interval 0.64–1.16). In the PE cohort, a significant interaction with sex was observed: dyspnoea predicted higher mortality in men (hazard ratio 1.35, 95% confidence interval 1.10–1.66) but not in women (hazard ratio 0.85, 95% confidence interval 0.68–1.06; p for interaction=0.009). The association was strongest among individuals aged 50–64 years. No comparable sex- or age-specific patterns were observed in the reference cohort.
Conclusions
Persistent dyspnoea after PE is associated with reduced survival in crude analyses but is not an independent predictor of mortality overall. Its prognostic relevance appears to vary by sex and age, suggesting that dyspnoea in middle-aged men may indicate clinically relevant post-PE cardiopulmonary impairment.FigureFor image description, please refer to the figure legend and surrounding text.