Kidney Dysfunction and Long-Term Outcome in Post-PCI Acute Coronary Syndrome Patients Treated by High-Dose Tirofiban: The Role of Creatinine Clearance

Aims: Few data exist on kidney dysfunction (KD) and glycoprotein IIb/IIIa inhibitors (GPI) in acute coronary syndrome (ACS) patients treated by percutaneous coronary intervention (PCI) and whether they impact on long-term outcome since most frequently patients with various degrees of KD are excluded.
Study Design: Comparison of independent but concomitant arms of a randomized investigation on GPI.
Place and Duration of Study: The Sant’ANna TIrofiban Safety study (SANTISS www.clinicaltrials.gov Identifier: NCT00566891) was an open-label investigator-initiated single centre registry at Sant’Anna Hospital, Catanzaro, during a 5-year enrollment period.
Methodology: We considered 726 ACS patients with PCI under either triple (aspirin, clopidogrel including high-dose tirofiban) or double (aspirin and clopidogrel) anti-aggregating drugs (AAD). Serum creatinine levels, creatinine clearance (CrCl, using the Cockcroft-Gault formula) and estimated glomerular filtration rate (eGFR, using both MDRD and CKD_EPI formulas) were used as continuous co-variables. Cox’s proportional hazards model tested the multivariable contribution of covariates all fitted simultaneously (forced method) in order to predict the incidence of 1-year cumulative ischemic events (CIE).
Results: There were 69 (9.5%) 1-year CIE. Incidences were 5.4, 9.8 and 13.4% (P=0.012) in CrCl tertiles 1 (96-216 ml/min), 2 (73-95 ml/min) and 3 (15-72 ml/min), respectively. Compared to CrCl, the percentile distributions of eGFR, by MDRD or CKD_EPI formulas were similar: all were comparable and significant predictors multivariately (p<0.001) of long-term CIE. The presence of diabetes (hazard ratios, HRs 1.84-1.91), intra aortic balloon pump (HRs 3.59-4.03), and thrombolysis (a protective factor) by tenecteplase (HRs 0.30-0.30) were further significant risk factors. With high-dose tirofiban there was a 20% lower but not statistically different incidence of 1-year CIE.
Conclusion: KD assessed by CrCl or eGFR in ACS patients treated by PCI equally predicted and similarly impacted on 1-year CIE, independent of the formula adopted for eGFR calculation and the presence of GPI with high-dose tirofiban