The effect of intermittent pneumatic compression on deep-vein thrombosis and ventilation-free days in critically ill patients with heart failure

There are contradictory data regarding the effect of intermittent pneumatic compression (IPC) on the incidence of deep-vein thrombosis (DVT) and heart failure (HF) decompensation in critically ill patients. This study evaluated the effect of adjunctive use of IPC on the rate of incident DVT and ventilation-free days among critically ill patients with HF. In this pre-specified secondary analysis of the PREVENT trial (N = 2003), we compared the effect of adjunctive IPC added to pharmacologic thromboprophylaxis (IPC group), with pharmacologic thromboprophylaxis alone (control group) in critically ill patients with HF. The presence of HF was determined by the treating teams according to local practices. Patients were stratified according to preserved (≥ 40%) versus reduced (< 40%) left ventricular ejection fraction, and by the New York Heart Association (NYHA) classification. The primary outcome was incident proximal lower-limb DVT, determined with twice weekly venous Doppler ultrasonography. As a co-primary outcome, we evaluated ventilation-free days as a surrogate for clinically important HF decompensation. Among 275 patients with HF, 18 (6.5%) patients had prevalent proximal lower-limb DVT (detected on trial day 1 to 3). Of 257 patients with no prevalent DVT, 11/125 (8.8%) patients in the IPC group developed incident proximal lower-limb DVT compared to 6/132 (4.5%) patients in the control group (relative risk, 1.94; 95% confidence interval, 0.74–5.08, p = 0.17). There was no significant difference in ventilator-free days between the IPC and control groups (median 21 days versus 25 days respectively, p = 0.17). The incidence of DVT with IPC versus control was not different across NYHA classes (p value for interaction = 0.18), nor across patients with reduced and preserved ejection fraction (p value for interaction = 0.15). Ventilator-free days with IPC versus control were also not different across NYHA classes nor across patients with reduced or preserved ejection fraction. In conclsuion, the use of adjunctive IPC compared with control was associated with similar rate of incident proximal lower-limb DVT and ventilator-free days in critically ill patients with HF

Statistical analysis plan for the Pneumatic CompREssion for PreVENting Venous Thromboembolism (PREVENT) trial: A study protocol for a randomized controlled trial

Background: The Pneumatic CompREssion for Preventing VENous Thromboembolism (PREVENT) trial evaluates the effect of adjunctive intermittent pneumatic compression (IPC) with pharmacologic thromboprophylaxis compared to pharmacologic thromboprophylaxis alone on venous thromboembolism (VTE) in critically ill adults. Methods/design: In this multicenter randomized trial, critically ill patients receiving pharmacologic thromboprophylaxis will be randomized to an IPC or a no IPC (control) group. The primary outcome is "incident" proximal lower-extremity deep vein thrombosis (DVT) within 28 days after randomization. Radiologists interpreting the lower-extremity ultrasonography will be blinded to intervention allocation, whereas the patients and treating team will be unblinded. The trial has 80% power to detect a 3% absolute risk reduction in the rate of proximal DVT from 7% to 4%. Discussion: Consistent with international guidelines, we have developed a detailed plan to guide the analysis of the PREVENT trial. This plan specifies the statistical methods for the evaluation of primary and secondary outcomes, and defines covariates for adjusted analyses a priori. Application of this statistical analysis plan to the PREVENT trial will facilitate unbiased analyses of clinical data