Efficacy and safety of prophylactic anticoagulation in patients with primary nephrotic syndrome: a systematic review and meta-analysis

Background and Aims: Nephrotic syndrome (NS) is associated with an increased incidence of venous thromboembolism (VTE), approximately 10%. We performed a systematic review to evaluate the efficacy and safety of prophylactic anticoagulation in patients with NS. Methods: Studies evaluating prophylactic anticoagulation in NS were identified by an electronic search of MEDLINE and EMBASE databases until December 2021. Weighted mean proportion and 95% confidence intervals (CIs) of thromboembolic and haemorrhagic events were calculated using a fixed-effects and a random-effects model. The differences in the outcomes among groups were estimated as pooled odds ratio (OR) and corresponding 95% CI. Statistical heterogeneity was evaluated using the I2 statistic. Results: Five cohort studies, for a total of 414 adult patients, were included. Only two studies had a control group. The weighted mean incidence of pulmonary embolism (PE) and deep vein thrombosis in patients who received VTE prophylaxis was 1.8% (95% CI: 0.6–3.5%; I2: 4.4%) and 0.9% (95% CI: 0.2–2.2%; I2: 43.4%) respectively. The weighted mean incidence of major bleeding in patients who received VTE prophylaxis was 2.3% (95% CI: 1–4.2%; I2: 25.4%). Patients with NS that received VTE prophylaxis had a non-significant reduced risk of PE (OR: 0.63 (95% CI: 0.03–14.8; I2: 64.4%)) and an increased risk of major bleeding (OR: 2.08 (95% CI: 0.41–10.45; I2: 0%)) compared to patients with NS that did not receive VTE prophylaxis. Conclusions: Our findings suggest that prophylactic anticoagulation in adult patients with primary NS may reduce the risk of VTE, even if it may be associated with a not negligible bleeding risk.