Plasma midregional pro-adrenomedullin improves prediction of functional outcome in ischemic stroke

Abstract

Background: To evaluate if plasma levels of midregional pro-adrenomedullin (MR-proADM) improve prediction of functional outcome in ischemic stroke.

Methods: In 168 consecutive ischemic stroke patients, plasma levels of MR-proADM were measured within 24 hours from symptom onset. Functional outcome was assessed by the modified Rankin Scale (mRS) at 90 days following stroke. Logistic regression, receiver operating characteristics (ROC) curve analysis, net reclassification improvement (NRI), and Kaplan-Meier survival analysis were applied.

Results: Plasma MR-proADM levels were found significantly higher in patients with unfavourable (mRS 3-6) compared to favourable (mRS 0-2) outcomes. MR-proADM levels were entered into a predictive model including the patients' age, National Institutes of Health Stroke Scale (NIHSS), and the use of recanalization therapy. The area under the ROC curve did not increase significantly. However, category-free NRI of 0.577 (p<0.001) indicated a significant improvement in reclassification of patients. Furthermore, MR-proADM levels significantly improved reclassification of patients in the prediction of outcome by the Stroke Prognostication using Age and NIHSS-100 (SPAN-100; NRI = 0.175; p = 0.04). Kaplan-Meier survival analysis showed a rising risk of death with increasing MR-proADM quintiles.

Conclusions: Plasma MR-proADM levels improve prediction of functional outcome in ischemic stroke when added to the patients' age, NIHSS on admission, and the use of recanalization therapy. Levels of MR-proADM in peripheral blood improve reclassification of patients when the SPAN-100 is used to predict the patients' functional outcome.

Figure 1. Plasma midregional pro-adrenomedullin (MR-proADM) levels in patients on admission.

Patients were dichotomized into favourable (mRS 0–2) and unfavourable (mRS 3–6) outcomes at day 90 after stroke. Plots display the median, interquartile range (box), 10^th and 90^th percentiles (whiskers). Abbreviation: mRS  =  modified Rankin Scale; MR-proADM  =  midregional pro-adrenomedullin.

Figure 2. Kaplan-Meier survival curves.

Time to death related to plasma MR-proADM quintiles (1^st: 0.04–0.45 nmol/l; 2^nd: 0.46–0.86 nmol/l; 3^rd: 0.87–1.27 nmol/l; 4^th: 1.28–1.68 nmol/l; 5^th: 1.69–2.10 nmol/l).