The Predictive Value of Qanadli and Miller Index Scores in Patients with Intermediate-High-Risk and High-Risk Pulmonary Emboli Undergoing Aspiration Thrombectomy.

PURPOSE

To evaluate the correlation between clot burden and pulmonary artery pressures in patients undergoing suction thromboembolectomy for high-risk and intermediate-high-risk pulmonary embolism with secondary outcomes of 30-day mortality and intensive care unit (ICU) length of stay.

MATERIALS AND METHODS

Institutional review board (IRB) exemption was granted for this retrospective study. The charts of 120 consecutive patients who underwent mechanical thromboembolectomy using the Flowtriever system (Inari Medical, Irvine, California) between February 2020 and August 2022 were retrospectively reviewed, and the following data were collected: (a) preprocedural B-type natriuretic peptide and creatinine levels, (b) echocardiographic findings, (c) preprocedural and postprocedural pulmonary artery pressures, (d) ICU length of stay, and (e) 30-day mortality. Clot burden was scored using Qanadli and Miller indices and correlated with the clinical outcomes.

RESULTS

Of the 120 patients who underwent thromboembolectomy, pulmonary artery pressures and diagnostic-quality angiograms were available in 109 patients. In the 109 patients with adequate data, Qanadli, preprocedural Miller, and postprocedural Miller scores correlated with pulmonary artery pressures. Neither was independently associated with ICU length of stay. Freedom from 30-day mortality was 91%, and embolism-specific mortality was 92%. All-risk and high-risk patients who survived demonstrated a significantly lower preprocedural and postprocedural Miller score, respectively.

CONCLUSIONS

Thrombus burden as measured by the Qanadli and Miller scores appeared to be correlated with pulmonary artery pressures. Furthermore, catheter-directed thromboembolectomy led to a reduction in Miller scores, which appeared to be correlated with a reduction in pulmonary pressures. In high-risk patients, a reduced postprocedural Miller score and pulmonary pressure demonstrated improved 30-day survival. Further investigation into the association between Miller scores and patient mortality is warranted to stratify patients who would benefit from emergency intervention.