Poor recovery from a pulmonary exacerbation does not lead to accelerated FEV₁ decline

Patients with CF treated for pulmonary exacerbations (PEx) may experience faster subsequent declines in FEV₁. Additionally, incomplete recovery to baseline FEV₁ occurs frequently following PEx treatment. Whether accelerated declines in FEV₁ are preceded by poor PEx recovery has not been studied.

Using 2004 to 2011 CF Foundation Patient Registry data, we randomly selected one PEx among patients ≥6years of age with no organ transplantations, ≥12months of data before and after the PEx, and ≥1 FEV₁ recorded within the 6months before and 3months after the PEx. We defined poor PEx recovery as the best FEV₁ in the 3months after the PEx <90% of the best FEV₁ in the 6months before the PEx. We calculated mean (95% CI) hazard ratios (HR) of having >5% predicted/year FEV₁ decline and poor PEx recovery using multi-state Markov models.

From 13,954 PEx, FEV₁ declines of >5% predicted/year were more likely to precede poor spirometric recovery, HR 1.17 (1.08, 1.26), in Markov models adjusted for age and sex. Non-Responders were less likely to have a subsequent fast FEV₁ decline, HR 0.41 (0.37, 0.46), than patients who recovered to >90% of baseline FEV₁ following PEx treatment.

Accelerated declines in FEV₁ are more likely to precede a PEx with poor recovery than to occur in the following year. Preventing or halting declines in FEV₁ may also have the benefit of preventing PEx episodes.