Background: We assessed the relation between admission levels of activated factor XII type A (XIIaA), and long-term all-cause and cardiac mortality and recurrent troponin T (TnT) positive cardiovascular events in a consecutive cohort of 870 patients admitted with a clinically strongly suspected acute coronary syndrome (ACS).
Methods and results: After a 24-month follow-up period, 138 patients (15.8%) had died and 155 (17.8%) had suffered from a recurrent TnT positive (TnT > 0.05 ng mL(-1)) event. XIIaA levels were significantly lower in long-term survivors than in patients who died (22.9 (17.7-32.1) vs. 27.2 (20.0-39.7) pmol L(-1) [median, 25 and 75% percentiles], P < 0.001). The unadjusted hazard ratio for death within 2 years in patients with XIIaA in the highest quartile was 2.49 (95% confidence interval (CI), 1.52-4.06) as compared with patients with XIIaA in the lowest quartile. In a stepwise Cox regression model for death within 2 years, XIIaA added prognostic information for all-cause mortality (HR 2.05; 95% CI, 1.21-3.47) above and beyond age, a history of heart failure, ST-segment elevation, TnT and B-type natriuretic peptide (BNP). In the subgroup of patients with an admission TnT < or = 0.05 ng mL(-1), XIIaA provided independent prognostic information for all-cause mortality (HR 3.88; 95% CI, 1.66-9.08) and for the combined endpoint of death or recurrent TnT positive event (HR 2.46; 95% CI, 1.34-4.50).
Conclusion: XIIaA, a recently identified in vivo form of activated factor XII is an independent indicator of long-term all-cause mortality in patients admitted with chest pain, providing prognostic information above and beyond conventional risk factors.
Trial registration: ClinicalTrials.gov NCT00521976.