Chronic kidney disease (CKD) increases the risk of adverse outcomes in acute coronary
syndrome (ACS). The optimal regimen of dual antiplatelet therapy (DAPT) post percutaneous
coronary intervention (PCI) is challenging due to both increased bleeding and thrombotic
risks in patients with CKD, particularly since these patients were under-represented
in randomized controlled trials. We examined the patterns of DAPT use in ACS patients
post PCI stratified by presence of CKD.
METHODS AND RESULTS
The multi-centre prospective Canadian Observational Antiplatelet Study (COAPT) enrolled
patients with an ACS diagnosis from 43 hospitals between December 2011-May 2013. The
present study is a subgroup analysis comparing type and duration of DAPT, and associated
outcomes among patients with and without CKD defined as eGFR < 60 ml/min/1.73m2 (calculated
by CKD-EPI). COAPT enrolled 1921 patients (mean age: 61; 21.4% female) with a median
eGFR of 85 ml/min/1.73 m2 (25th and 75th percentiles [69, 97]). Of those, 275 (14.3%)
had CKD. CKD patients were older, more likely to be female and have comorbidities
including previous ACS, heart failure, hypertension, cerebrovascular disease, atrial
fibrillation and gastrointestinal bleeding. Patients with CKD were less frequently
prescribed the more potent P2Y12 inhibitors prasugrel/ticagrelor (18.5% vs 25.8%,
p=0.01) and had a shorter duration of DAPT therapy than patients without CKD (median
382 vs 402 days, p=0.003). CKD was associated with major adverse cardiovascular events
(MACE) at 12 months (p < 0.001) but not bleeding when compared to patients without
CKD (figure 1). CKD was associated with MACE in both patients on prasugrel/ticagrelor
(p=0.017) and those on clopidogrel (p < 0.001) (p for heterogeneity=0.70). CKD was
associated with increased bleeding only among patients receiving prasugrel/ticagrelor
(p=0.007), but not among those receiving clopidogrel (p=0.64) (p for heterogeneity=0.036).
Patients with CKD were more frequently considered to have an ongoing indication for
DAPT therapy during follow-up. Discontinuation of DAPT was more likely in patients
with CKD due to the need for an oral anticoagulant.
Patients with CKD had a shorter DAPT duration and were less frequently prescribed
potent P2Y12 inhibitors than patients without CKD. Overall, compared with patients
without CKD, patients with CKD had higher rates of MACE and similar bleeding rates.
However, among those prescribed more potent P2Y12 inhibitors, CKD was associated with
more bleeding than those without CKD. Further studies are needed to better define
the benefit/risk ratio, and establish a more tailored and evidence-based DAPT regimen
for this high-risk patient group.