Association between lung comets and subendocardial viability ratio in peritoneal dialysis patients

Pulmonary congestion is a direct result of either general overhydration or cardiac dysfunction. Lung ultrasonography (LUS) with lung B-lines (LUS comets) can be used to assess extravascular lung water in patients with end-stage renal disease on hemodialysis or peritoneal dialysis (PD). Subendocardial viability ratio (SEVR) is a pulse wave analysis parameter that is a non-invasive measure of coronary perfusion and is related to cardiac work and oxygen consumption. Our aim was to investigate the association between LUS comets and SEVR in PD patients.

We performed an observational study in 25 PD patients in a single dialysis center. Extravascular lung water was quantified by the number of LUS comets, using a portable ultrasound (US) device. LUS comets were recorded in each intercostal space and defined as hyperechoic US bundles at a narrow base extending from the transducer to the edge of the screen. The sum of LUS comets yields a score reflecting the extent of water accumulation in the lungs. SEVR was determined non-invasively by radial applanation tonometry.

Mean age of patients was 54.7 ± 10.7 years, mean PD vintage 27 ± 33 (1 - 167) months, 60% were men. The mean number of LUS comets was 13 ± 19 (0 - 71), and the mean SEVR was 153 ± 40%. We found a statistically significant negative correlation between the number of LUS comets and SEVR (r = -0.467; p = 0.019). Multiple regression analysis with LUS comets as dependent variable, and SEVR and age as independent variables showed a statistically significant relationship between SEVR and the number of LUS comets (β = -0.467, p = 0.021).

Higher number of LUS comets is associated with lower SEVR in PD patients.