Long-term prognostic value of midregional pro-adrenomedullin and C-terminal pro-endothelin-1 in patients with acute myocardial infarction

Background: Midregional pro-adrenomedullin (MR-proADM) and endothelin-1 have been shown to predict mortality of patients with acute myocardial infarction. However, the prognostic value of both biomarkers in predicting long-term clinical events after acute myocardial infarction remains unclear. Methods: In a prospective study, 30 patients suffering from acute ST elevation myocardial infarction or non-ST elevation myocardial infarction were enrolled. Measurements of MR-proADM and CT-pro-endothelin-1 (CT-proET-1) were performed at initial presentation, 2 or 3 days and 4 months after acute myocardial infarction. Long-term clinical events (e.g., recurrent myocardial infarction, percutaneous transluminal coronary angioplasty, aorto-coronary venous bypass or cardiogenic shock) were documented over a period from the 4th until the 10th month. Results: Both MR-proADM and CT-proET-1 were able to differentiate patients with subsequent long-term clinical events (n=11) from those without (n=19). At the time of acute myocardial infarction, median MR-proADM level of the event group was 0.69 nmol/ L as compared to 0.59 nmol/L of the no-event group (p=0.036). A difference was still observed after 3 days (event group median 0.66 nmol/L; no-event group median 0.57 nmol/L; p=0.022). Accordingly, median CT-proET-1 level was 72.9 pmol/L in the event group as compared to a median of 54.4 pmol/L in patients in the no-event group (p=0.009) 3 days after acute myocardial infarction. Within the acute phase, patients with MR-proADM levels 0.67 nmol/L were 3 times more likely (relative risk 2.8; 95% confidence interval 1.2-6.9; p=0.042) to suffer from a future clinical event. The area under the curve (AUC) was 0.71 (95% confidence interval 0.51-0.86; p=0.046). After 3 days, patients with CT-proET-1 levels >= 57 pmol/L were 6 times more likely (relative risk 5.9; 95% confidence interval 0.9-40.4; p=0.036) to suffer from a future clinical event. The AUC was 0.76 (95% confidence interval 0.55-0.90; p=0.015). Conclusions: Elevated levels of MR-proADM and CT-proET-1 during the acute phase of myocardial infarction may predict an adverse long-term clinical outcome.