Antipseudomonal treatment decisions during CF exacerbation management.

BACKGROUND: Cystic fibrosis (CF) pulmonary exacerbation (PEx) treatment guidelines suggest that Pseudomonas aeruginosa (Pa) airway infection be treated with two antipseudomonal agents. METHODS: We retrospectively studied treatment responses for STOP2 PEx treatment trial (NCT02781610) participants with a history of Pa infection. Mean lung function and symptom changes from intravenous (IV) antimicrobial treatment start to Visit 2 (7 to 10 days later) were compared between those receiving one, two, and three+ antipseudomonal classes before Visit 2 by ANCOVA. Odds of PEx retreatment with IV antimicrobials within 30 days and future IV-treated PEx hazard were modeled by logistic and Cox proportional hazards regression, respectively. Sensitivity analyses limited to the most common one-, two-, and three-class regimens, to only IV/oral antipseudomonal treatments, and with more stringent Pa infection definitions were conducted. RESULTS: Among 751 participants, 50 (6.7%) were treated with one antipseudomonal class before Visit 2, while 552 (73.5%) and 149 (19.8%) were treated with two and with three+ classes, respectively. Females and participants with a negative Pa culture in the prior month were more likely to be treated with a single class. The most common single, double, and triple class regimens were beta-lactam (BL; n = 42), BL/aminoglycoside (AG; n = 459), and BL/AG/fluoroquinolone (FQ; n = 73). No lung function or symptom response, odds of retreatment, or future PEx hazard differences were observed by number of antipseudomonal classes administered in primary or sensitivity analyses. CONCLUSIONS: We were unable to identify additional benefit when multiple antipseudomonal classes are used to treat PEx in people with CF and Pa.

Association of site of treatment with clinical outcomes following intravenous antimicrobial treatment of a pulmonary exacerbation.

BACKGROUND: In the STOP2 (Standardized Treatment of Pulmonary Exacerbations-2) study, intravenous (IV) antimicrobial treatment duration for adults with cystic fibrosis (CF) experiencing pulmonary exacerbations (PEx) was determined based on initial treatment response. The impact of home vs hospital care remains an important clinical question in CF. Our hypothesis was that STOP2 participants treated at home would have less improvement in lung function compared to those treated in the hospital. METHODS: Treating clinicians determined PEx treatment location, which was a stratification factor for STOP2 randomization. Lung function, weight, and symptom recovery were evaluated by treatment location. Propensity scores and inverse probability treatment weighting were used to test for differences in clinical response by treatment location. RESULTS: In all, 33% of STOP2 participants received IV antimicrobials in the hospital only, 46% both in the hospital and at home, and 21% at home only. Mean (95% CI) ppFEV1 improvement was significantly (p < 0.05) lower for those treated at home only, 5.0 (3.5, 6.5), compared with at home and in the hospital, 7.0 (5.9, 8.1), and in the hospital only, 8.0 (6.7, 9.4). Mean weight (p < 0.001) and symptom (p < 0.05) changes were significantly smaller for those treated at home only compared to those treated in the hospital only. CONCLUSIONS: Compared to PEx treatment at home only, treatment in the hospital was associated with greater mean lung function, respiratory symptom, and weight improvements. The limitations of home IV therapy should be addressed in order to optimize outcomes for adults with CF treated at home.

C-reactive protein (CRP) as a biomarker of pulmonary exacerbation presentation and treatment response.

BACKGROUND: C-reactive protein (CRP) has been proposed as a biomarker for pulmonary exacerbation (PEx) diagnosis and treatment response. CRP >75mg/L has been associated with increased risk of PEx treatment failure. We have analyzed CRP measures as biomarkers for clinical response during the STOP2 PEx study (NCT02781610). METHODS: CRP measures were collected at antimicrobial treatment start (V1), seven to 10 days later (V2), and two weeks after treatment end (V3). V1 log10CRP concentrations and log10CRP change from V1 to V3 correlations with clinical responses (changes in lung function and symptom score) were assessed by least squares regression. Odds of intravenous (IV) antimicrobial retreatment within 30 days and future PEx hazard associated with V1 and V3 CRP concentrations and V1 CRP >75 mg/L were studied by adjusted logistic regression and proportional hazards modeling, respectively. RESULTS: In all, 951 of 982 STOP2 subjects (92.7%) had CRP measures at V1. V1 log10CRP varied significantly by V1 lung function subgroup, symptom score quartile, and sex, but not by age subgroup. V1 log10CRP correlated moderately with log10CRP change at V3 (r2=0.255) but less so with lung function (r2=0.016) or symptom (r2=0.031) changes at V3. Higher V1 CRP was associated with greater response. CRP changes from V1 to V3 only weakly correlated with lung function (r2=0.061) and symptom (r2=0.066) changes. However, V3 log10CRP was associated with increased odds of retreatment (P = .0081) and future PEx hazard (P = .0114). DISCUSSION: Despite consistent trends, log10CRP change was highly variable with only limited utility as a biomarker of PEx treatment response.

Changes in symptom scores as a potential clinical endpoint for studies of cystic fibrosis pulmonary exacerbation treatment.

INTRODUCTION: Symptom improvement was assessed as changes in the Chronic Respiratory Infection Symptom Score (CRISS) during intravenous antimicrobial exacerbation treatments among subjects from study NCT02109822. METHODS: Median daily CRISS reduction (i.e., improvement) and covariates associated with CRISS reduction by Day 14 were assessed by logistic regression. RESULTS: Among 173 subjects, median baseline CRISS was 49 [IQR 41, 56]; 93.6% had a CRISS reduction of ≥11 (minimal clinically important difference); median time to -11 reduction was 2 days [95% CI 2, 3]. The greatest median CRISS difference from baseline, on Day 17, was -26 [-29, -23]. Odds of -26 CRISS change by Day 14 were greater in subjects with higher baseline CRISS (P=.006) and younger ages (P=.041). CONCLUSIONS: CRISS response has good dynamic range and may be a useful efficacy endpoint for PEx interventional trials. The optimal use of CRISS change as an endpoint remains uncharacterized.

Absence of rebound from diltiazem therapy in Prinzmetal's variant angina.

To determine the frequency of rebound anginal symptoms on abrupt withdrawal of calcium channel blocking agents, anginal symptoms were retrospectively examined in patients with Prinzmetal's variant angina abruptly withdrawn from diltiazem therapy as part of the design of a placebo-controlled multiple crossover trial. Rebound was defined as a return of anginal symptoms to levels exceeding those of the pretreatment baseline state. Values for daily frequency of angina were compared (after subtracting corresponding baseline values) between placebo periods following diltiazem periods and placebo periods following placebo periods. No intergroup differences existed between mean changes in daily frequency of angina from baseline value (-0.61 for placebo following diltiazem versus -1.10 for placebo following placebo) (p greater than 0.4). Furthermore, in 13 (28%) of 46 occurrences when placebo followed placebo, daily frequency of angina exceeded baseline value in the immediate 3 day period following placebo compared with 17 (21%) of 80 occurrences when placebo followed diltiazem. There was no increased rebound occurrence comparing high dose (240 mg/day) with low dose (120 mg/day) diltiazem therapy. No significant symptoms such as myocardial infarction or unstable angina occurred after withdrawal of diltiazem or placebo. The lack of difference in rebound after diltiazem or placebo withdrawal was consistent using paired and unpaired analyses. In conclusion, there appears to be no evidence that abrupt withdrawal of therapy with diltiazem results in rebound anginal symptoms.