Abstract 2066: Baseline Cystatin C Measurement is a Potent Predictor of Adverse Cardiovascular Outcomes Following ACS: A PROVE IT - TIMI 22 Analysis
Background: Patients with renal dysfunction are at high risk for adverse cardiovascular outcomes. Limitations of traditional measures of renal function such as serum creatinine (cr) have encouraged development of novel markers of renal function including cystatin C. Few data exist regarding cystatin C as a marker of outcome following ACS.
Methods: PROVE IT - TIMI 22 was a trial of moderate vs intensive statin therapy in patients stabilized post ACS. Patients with crcl <40 mL/min were excluded from enrollment. We measured cystatin C (Dade Behring) in samples drawn at enrollment (N =3754). Cardiovascular outcomes were determined for each quintile of cystatin C and reported as 2y Kaplan Meier estimates.
Results: Subjects with elevated cystatin C were older, more often hypertensive, more likely to have a prior MI, diabetes (DM), and less likely smokers (p<0.01 for each). There was a stepwise relationship between baseline cystatin C quintile and death (Q1-Q5 range 0.7 to 4.8%, p<0.0001), congestive heart failure (CHF, Q1-Q5 range 1.0 – 8.3%, p<0.0001) and the composite of death/CHF (Figure⇓). Adjusted for age, gender, index event, DM, prior MI, cystatin C was a potent independent predictor of recurrent events (Q5 vs Q1 HR 2.5, p<0.05 for death; 5.16, p<0.001 for CHF, and HR 3.11, p<0.001 for D/CHF). When including cystatin C, CRP, BNP, and eGFR in the model, cystatin C remained a significant predictor (p<0.001) of D/CHF while eGFR did not (p=0.70).
Conclusions: In subjects following ACS, cystatin C is a powerful independent predictor of adverse cardiovascular outcomes including death and CHF and is independent of traditional measures of renal function, inflammation and hemodynamic stress.