Summary
Risk stratification at presentation with acute coronary syndromes (ACS) on the basis
of theTIMI risk score for unstable angina and non-ST-elevation myocardial infarction
(UAP/NSTEMI) identifies patients at high risk of recurrent cardiac events and those
who benefit from more aggressive treatment strategy. We hypothesised the following:
(a) that a high TIMI risk score brings a greater degree of acute changes in endothelial
damage/dysfunction (circulating endothelial cells [CECs], von Willebrand factor [vWf]),
inflammation (interleukin-6, IL-6) and blood thrombogenicity (plasma tissue factor,
TF); and (b) that these indices are higher in those with high TIMI risk score who
experienced recurrent cardiac event at day 14 and day 30. TIMI risk scores were determined
at admission and 48 hours later in 88 ACS patients (60 male, age 67±12 yrs) with UAP
or NSTEMI. CECs, IL-6 andTF levels were measured at both time points and the acute
change (Δ) calculated. Patients were split into high (score ≥4) or low (<4) TIMI score
groups. The composite end point of death, myocardial infarction, and refractory angina
requiring revascularisation following 14 and 30 days’ follow-up was ascertained. Fifty-eight
patients with high TIMI risk score (mean 4.7) had significantly higher baseline and
48 h CEC, vWf, IL-6, TF and ΔTF levels, compared to low TIMI risk score (mean 2.4)
patients (all p<0.05). Multivariate Cox regression analysis adjusted for clinical
variables and TIMI risk score expressed as either continuous or categorical variable
identified baseline CECs and ΔvWf levels (both p≤0.01) as independent predictors of
subsequent cardiac events at both 14 days and 30 days. TIMI risk score for UA/NSTEMI
identifies those patients with more profound vascular insult, inflammation and thrombogenicity
that, in the ‘high risk’ patient group, predicts short-term outcomes although vascular
damage was the more sensitive predictor. These indices may further refine global risk
stratification for short-term adverse cardiac events in these patients.
Keywords
Endothelial damage - inflammation - thrombogenesis - von Willebrand factor - tissue
factor - interleukin-6 - TIMI risk score
