Pleural effusion: a potential surrogate marker for higher-risk patients with acute type B aortic dissections

Pleural effusions (PEffs) are known to occur in type B acute aortic dissection (TBAAD). We investigated the relationship between pleural effusion and the development of early or late complications following TBAAD.

The incidence of PEff (defined as at least an obliteration of the costophrenic angle in a frontal projection) diagnosed on their initial chest X-ray in patients with TBAAD enrolled in the International Registry of Acute Aortic Dissection was examined. We analysed in-hospital outcomes and long-term survival separately for patients with and without PEffs (PEff+ versus PEff-, respectively).

Included were 1252 patients with TBAAD, of whom 224 (17.9%) had PEff. Compared with patients without PEff in the initial chest X-ray, these were significantly older [mean age 67 (SD: 14.7) vs 63.4 (SD: 14.2) years, P = 0.001] and more often female (42.4% vs 34.2%, P = 0.021) and had more comorbidities (known aortic aneurysm, chronic obstructive pulmonary disease, chronic renal failure, diabetes, congestive heart failure or mitral valve disease). PEff was associated with higher in-hospital mortality (16.1% vs 9.1%, P = 0.002) and increased rates of neurological complications (16.6% vs 11.1%, P = 0.029), acute renal failure (27.2% vs 19.7%, P = 0.017) and hypotension (17.4% vs 9.6%, P = 0.001). In addition, patients with PEff underwent aortic repair more frequently (44.6% vs 32.5%, P < 0.001). In the long-term patients with PEff showed lower 5-year post-discharge survival (67.6% vs 77.6%, P = 0.004). Multivariable analysis with propensity-matched data showed that PEff was not an independent risk factor for in-hospital mortality (odds ratio 1.9, 95% CI 0.8-4.4, P = 0.141).

Patients with TBAAD and evidence of PEff showed a higher in-hospital mortality, are more likely to develop additional in-hospital complications and have a decreased likelihood of survival during follow-up. However, according to propensity-matched analysis, PEff remained not as an independent predictor of worse outcome but might serve as an early surrogate marker to identify higher-risk patients.