Lung density associates with survival in Alpha 1 antitrypsin deficient patients

Introduction CT density correlates with quality of life (QOL) scores and impaired upper zone lung density associates with higher mortality in alpha one antitrypsin deficiency (A1ATD). We hypothesised that decline in CT densitometry would relate to survival or deterioration in QOL in A1ATD. Methods All augmentation naïve PiZZ patients in the UK A1ATD registry with ≥two successive quantitative CT scans were selected. Patients were divided into groups based on CT density decline and the relationship to survival and change in QOL compared by univariate analyses and multivariate Cox regression. Analyses were performed for whole lung, upper zone and lower zone density separately. Exploratory analyses of FEV1 subgroups were conducted. Results 110 patients were identified; 77 had whole lung and lung zone density recorded on two CT scans, 33 patients had upper zone data only on four scans. Decline in lower zone density associated with survival, even after adjustment for baseline lung density (p=0·048), however upper zone density and whole lung density decline did not. This difference appeared to be driven by those with FEV1 >30% predicted. Conclusion Rate of change in lung densitometry could predict survival in A1ATD