Background: We evaluated prognostic value at 6 months of residual pulmonary vascular obstruction (RPVO) measured before discharge in patients with intermediate- or high-risk pulmonary embolism (PE).
Methods and results: Prospective registry including 416 consecutive patients with intermediate- or high-risk PE who survived the acute phase. Patients with previous cardiopulmonary disease were excluded. Perfusion lung scans were performed within 6-8 days after the onset of treatment. Residual pulmonary vascular obstruction was graded as the proportion of the lung not perfused. Primary objective was a combined endpoint at 6 months, including death, recurrent PE, and appearance of signs of heart failure. At 6 months, 32 patients (7.7%) had at least one adverse event: 12 deaths (2.9%), 12 recurrent PE (2.9%), and 14 (3.4%) heart failure. Independent predictors of combined endpoint were: cancer [odds ratio (OR) 3.07 (1.22-7.85)]; renal insufficiency at admission [OR: 2.53 (1.17-5.8)]; persistent signs of right ventricular dysfunction at 48 h echography [OR: 3.99 (1.36-11.3)]. The severity of RPVO at discharge was significantly associated with an unfavourable outcome [OR: 2.66 (1.58-3.93)]. The incremental prognostic value of RPVO information was confirmed by significantly improved goodness-of-fit. Threshold RPVO for predicting adverse events was estimated at 35% [area under the curve = 0.76 (0.73-0.82)]. Patients with RPVO greater than threshold at discharge had a significantly higher risk of death at 6 months (P = 0.01).
Conclusions: Residual pulmonary vascular obstruction evaluated before hospital discharge in patients with intermediate- to high-risk PE is a powerful prognostic factor for a 6-month outcome. RPVO ≥35% is associated with an increased risk of adverse events at 6 months.