Effect of fluticasone propionate/salmeterol on arterial stiffness in patients with COPD.

BACKGROUND: COPD is associated with increased arterial stiffness which may in part explain the cardiovascular morbidity observed in the disease. A causal relationship between arterial stiffness and cardiovascular events has not been established, though their strong association raises the possibility that therapies that reduce arterial stiffness may improve cardiovascular outcomes. Prior studies suggest that fluticasone propionate/salmeterol (FSC) may improve cardiovascular outcomes in COPD and we hypothesized that FSC would reduce arterial stiffness in these patients. METHODS: This multicenter, randomized, double-blind, placebo-controlled study compared the effects of FSC 250/50 µg twice-daily and placebo on aortic pulse wave velocity (aPWV) as determined by ECG-gated carotid and femoral artery waveforms. The primary endpoint was aPWV change from baseline at 12-weeks (last measure for each patient). RESULTS: 249 patients were randomized; the mean FEV(1) in each group was similar (55% predicted) and 60% of patients reported a cardiovascular disorder. At 12-weeks, aPWV between FSC and placebo was -0.42 m/s (95%CI -0.88, 0.03; p = 0.065). A statistically significant reduction in aPWV between FSC and placebo was observed in those who remained on study drug throughout the treatment period [-0.49 m/s (95%CI -0.98, -0.01; p = 0.045)]. A post hoc analysis suggested the effect of FSC was greater in patients with higher baseline aPWV. CONCLUSION: FSC does not reduce aPWV in all patients with moderate to severe COPD, but may have effects in those with elevated arterial stiffness. Additional studies are required to determine if aPWV could serve as a surrogate for cardiovascular events in COPD.

Prevalence of airway obstruction assessed by lung function questionnaire.

OBJECTIVE: To estimate the prevalence of unidentified chronic obstructive pulmonary disease (COPD) and determine the screening accuracy of the Lung Function Questionnaire (LFQ). PATIENTS AND METHODS: Cigarette smokers who had a smoking history of 10 or more pack-years and were aged 30 years or older were recruited from 36 centers from February 18, 2009, to May 29, 2009. A total of 1575 patients completed a Web-based survey including the 5-item LFQ. Spirometry was performed on patients with an LFQ total score of 18 or less and on a subset scoring more than 18. The primary outcome was the proportion of patients at risk of airflow obstruction as measured by the LFQ (score, ≤ 18) in whom an airflow obstruction was confirmed by spirometry. RESULTS: Of the patients who completed the LFQ, 849 (54%) had standardized spirometry data available. On the basis of LFQ and spirometry results, the estimated prevalence of possible COPD was 17.9% (95% confidence interval, 15.3%-20.6%). At a cut point of 18 or less, sensitivity, specificity, positive predictive value, and negative predictive value of the LFQ were 88%, 25%, 21%, and 90%, respectively. Approximately 1 in 5 patients (21%) aged 30 years or older and 1 in 4 (26%) aged 50 years or older scored 18 or less on the LFQ and had a ratio of forced expiratory volume in the first second of expiration to forced vital capacity less than 0.70. CONCLUSION: On the basis of postbronchodilator spirometry results using weighted estimates, approximately 1 in 5 patients (21%) aged 30 years or older with a smoking history of 10 or more pack-years seen in a primary care setting is likely to have COPD. The LFQ could be a helpful COPD case-finding tool for clinicians to identify patients who need further evaluation. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01013948.

Mechanical ventilation results in progressive contractile dysfunction in the diaphragm.

These experiments tested the hypothesis that a relatively short duration of controlled mechanical ventilation (MV) will impair diaphragmatic maximal specific force generation (specific P(o)) and that this force deficit will be exacerbated with increased time on the ventilator. To test this postulate, adult Sprague-Dawley rats were randomly divided into one of six experimental groups: 1) control (n = 12); 2) 12 h of MV (n = 4); 3) 18 h of MV (n = 4); 4) 18 h of anesthesia and spontaneous breathing (n = 4); 5) 24 h of MV (n = 7); and 6) 24 h of anesthesia and spontaneous breathing (n = 4). MV animals were anesthetized, tracheostomized, and ventilated with room air. Animals in the control group were acutely anesthetized but were not exposed to MV. Animals in two spontaneous breathing groups were anesthetized and breathed spontaneously for either 18 or 24 h. No differences (P > 0.05) existed in diaphragmatic specific P(o) between control and the two spontaneous breathing groups. In contrast, compared with control, all durations of MV resulted in a reduction (P < 0.05) in diaphragmatic specific tension at stimulation frequencies ranging from 15 to 160 Hz. Furthermore, the MV-induced decrease in diaphragmatic specific P(o) was time dependent, with specific P(o) being approximately 18 and approximately 46% lower (P < 0.05) in animals mechanically ventilated for 12 and 24 h, respectively. These data support the hypothesis that relatively short-term MV impairs diaphragmatic contractile function and that the magnitude of MV-induced force deficit increases with time on the ventilator.