Use and outcomes of dual antiplatelet therapy for acute coronary syndrome in patients with chronic kidney disease: insights from the Canadian Observational Antiplatelet Study (COAPT).

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) in CKD poses a challenge due to the increased bleeding and clotting tendencies, particularly since patients with CKD were underrepresented in randomized controlled trials. We examined the practice patterns of DAPT prescription stratified by the presence of CKD. The multicentre prospective Canadian Observational Antiplatelet Study (COAPT) enrolled patients with ACS between December 2011 and May 2013. The present study is a subgroup analysis comparing type and duration of DAPT and associated outcomes among patients with and without CKD (eGFR < 60 ml/min/1.73 m2, calculated by CKD-EPI). Patients with CKD (275/1921, 14.3%) were prescribed prasugrel/ticagrelor less (18.5% vs 25.8%, p = 0.01) and had a shorter duration of DAPT therapy versus 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. 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 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 evaluation, and establish a more tailored and evidence-based DAPT regimen for this high-risk patient group.

Ischemic and bleeding events in patients with myocardial infarction undergoing percutaneous coronary intervention who require oral anticoagulation: Insights from the Canadian observational AntiPlatelet sTudy.

BACKGROUND: Since the introduction of newer, more potent P2Y12 receptor inhibitors (P2Y12ris), practice patterns and associated clinical outcomes in patients with myocardial infarction (MI) undergoing percutaneous coronary intervention (PCI) and also requiring oral anticoagulation (OAC) have not been fully characterized. METHODS: The Canadian Observational Antiplatelet Study was a prospective, multicenter, longitudinal, observational study (26 hospitals, December 2011 to May 2013) describing P2Y12ri treatment patterns and outcomes in patients with ST-elevation and non-ST-elevation MI undergoing PCI. We describe the clinical characteristics, treatment patterns, bleeding, and ischemic outcomes over the 15-month follow-up within and between the subgroups of patients discharged on either dual-antiplatelet therapy (DAPT) (acetyl salicylic acid [ASA]+P2Y12ri) or triple therapy (ASA+P2Y12ri+OAC). RESULTS: Of the 2,034 patients at discharge, 86% (n = 1,757) were on DAPT, whereas 14% (n = 277) were on triple therapy (50% warfarin, 50% non-vitamin K OAC [NOAC]). The frequency of newer P2Y12ri use (prasugrel or ticagrelor) was similar in the DAPT and triple therapy groups (28% vs 26%, respectively). In the triple therapy group, NOAC use was higher in those receiving a new P2Y12ri compared to those receiving clopidogrel (75% vs 41%, respectively, P < .0001). The unadjusted and adjusted events of major cardiovascular event (MACE) and bleeding were higher in the triple therapy group. For patients on triple therapy, the bleeding or MACE events were not significantly different between those on clopidogrel versus those on ticagrelor or prasugrel. CONCLUSION: In this observational study of MI patients requiring PCI, 1 in 8 were discharged on triple antithrombotic therapy, of whom 26% were on newer P2Y12ris. Patients on triple therapy had higher risk at baseline, with higher unadjusted and adjusted MACE and bleeding events compared to those on DAPT alone. Among triple therapy-treated patients, there was no difference in the MACE and bleeding events regardless of the P2Y12ri used.

Baseline characteristics, adenosine diphosphate receptor inhibitor treatment patterns, and in-hospital outcomes of myocardial infarction patients undergoing percutaneous coronary intervention in the prospective Canadian Observational AntiPlatelet sTudy (COAPT).

BACKGROUND: Contemporary use of dual antiplatelet therapy and consistency with guideline recommendations in acute coronary syndrome patients undergoing percutaneous coronary intervention (PCI) have not been well characterized. METHODS: The COAPT was a prospective, observational, multicenter, longitudinal study of patients with myocardial infarction (MI) undergoing PCI. Baseline characteristics, treatment patterns, processes of care, factors associated with switching to and from novel adenosine diphosphate receptor inhibitors (ADPris), and in-hospital outcomes are described. RESULTS: Among 2,179 MI patients undergoing PCI during their index hospitalization, 1,328 (60.9%) had ST elevation. Initial ADPri use included clopidogrel in 1,812 (83.2%), prasugrel in 125 (5.7%), and ticagrelor in 242 (11.1%). At discharge, 1,597 patients (73.4%) were prescribed clopidogrel, 220 (10.1%) prasugrel, and 358 (16.5%) ticagrelor. Switching between ADPri therapies during the index hospitalization occurred in 15.3%, 22.4%, and 25.2% of patients initially started on clopidogrel, prasugrel, and ticagrelor, respectively. Most switches over the 15-month study period occurred during the index admission (16.8% of patients vs 4.4% switches postdischarge). Major adverse cardiovascular events occurred in 7.5% of patients during the index hospitalization. In-hospital bleeding events occurred in 6.0% of patients and most were mild. CONCLUSIONS: Despite randomized trial evidence and guideline recommendations, only a minority of Canadian MI patients undergoing PCI initially received or were discharged on one of the newer ADPri agents. These findings suggest an opportunity to improve upon the appropriate selection of the ADPris at index hospitalization and discharge in Canadian MI patients undergoing PCI.

Duration of dual antiplatelet therapy and associated outcomes following percutaneous coronary intervention for acute myocardial infarction: contemporary practice insights from the Canadian Observational Antiplatelet Study.

Aims: There is a paucity of real-world, contemporary data of practice patterns and clinical outcomes following dual-antiplatelet therapy (DAPT) in acute myocardial infarction (AMI) patients treated with percutaneous coronary intervention (PCI). Methods and results: The Canadian Observational Antiplatelet Study was a prospective, multicentre, cohort study examining adenosine diphosphate receptor antagonist use following PCI for AMI. We compared practice patterns, patient characteristics, and clinical outcomes in relation to DAPT duration (<6 weeks, 6 weeks to <6 months, 6 to <12, and ≥12 months). The primary outcome was the composite of non-fatal AMI, unplanned coronary revascularization, stent thrombosis, new or worsening heart failure, cardiogenic shock, or stroke. We identified 2034 patients with AMI treated with PCI. DAPT duration was <6 weeks in 5.2% of patients; 6 weeks to <6 months in 7.0%; 6 to <12 months in 12.6%; and ≥12 months in 75.3%. Patients who discontinued DAPT early had higher GRACE risk scores. Overall, mortality rate at 15 months was 2.5%. Compared with a duration of DAPT of ≥12 months, discontinuation of DAPT <6 weeks (P < 0.0001) and 6 weeks to <6 months (P = 0.02), but not 6 months to <12 months (P = 0.06), were independently associated with a higher incidence of the primary outcome among survivors. Conclusion: One-in-four patients with AMI treated with PCI discontinued DAPT prior to the guideline-recommended 12-month duration. Patients in whom DAPT was discontinued early were at higher baseline risk and had higher rates of non-fatal ischaemic events during follow up.

Does chronic Chlamydia pneumoniae infection increase the risk of myocardial injury? Insights from patients with non-ST-elevation acute coronary syndromes.

BACKGROUND: Cumulative evidence suggests a positive association between Chlamydia pneumoniae (Cpn) infection and risk of future coronary events among patients with stable coronary artery disease. However, its prognostic role in unstable coronary syndromes is less well defined. Because Cpn immunoglobulin A (IgA) may be a more reliable indicator of chronic infection than immunoglobulin G (IgG), we speculated that in patients with non-ST-elevation acute coronary syndromes (ACS), this marker might serve as a more useful prognostic tool. Accordingly, we evaluated plasma samples acquired at presentation in 178 patients with ACS for a possible association between Cpn IgA titer and biochemical evidence of myocardial injury. METHODS: Cpn IgG (positive if > or =1:32), and IgA titers (positive if > or =1:16) were measured by use of the microimmunofluorescence technique in 70 patients with ACS in whom myocardial injury developed associated with their presenting events (elevated CK-MB and/or troponin I); and in 108 patients with ACS without such injury. The odds ratios (ORs) for myocardial injury associated with consecutive antibody titers were determined for each of Cpn IgG and IgA. Multiple logistic regression was applied to adjust for key baseline characteristics. RESULTS: Median age of subjects was 64 years; 63% were male and 33% were smokers. The median antibody titers among those with and without myocardial injury respectively were as follows: IgG (1:128 vs 1:128), IgA (1:32 vs <1:16, P =.2). The adjusted ORs for myocardial injury associated with consecutive IgA titers were as follows: IgA > or =1:16, adjusted OR 1.49 (P =.22); > or =1:32, OR 1.95 (P =.04); > or =1:64, OR 1.37 (P =.38); > or =1:128, OR 0.77 (P =.55). No significant trend was found for any IgG titer. CONCLUSIONS: Among patients with non-ST-elevation ACS, a Cpn IgA > or =1:32 at presentation was associated with a significantly higher risk of myocardial injury complicating the presenting event.