SPECIAL CONSIDERATIONS
Risk of GI bleeding Patients who may be considered for shorter durations of DAT include those with a history of GI bleeding. Aggressive antithrombotic therapy can lead to rebleeding of the GI tract. GI bleeds occur in up to 2.3% of DAT patients. Risk factors include age older than 70 years, history of PUD, concurrent use of an NSAID, underlying liver disease, thrombocytopenia, or need for prolonged critical care due to MI complications. The occurrence of GI bleeds in DES patients increases length of hospital stay, inhospital mortality, and 6-month mortality.17 Unless bleeding becomes life-threatening, every effort should be made to continue DAT in DES patients.17 When hemodynamic instability does occur, urgent GI consultation with potential therapeutic intervention is recommended. Patients with a known history of PUD or gastroesophageal reflux and those deemed to be at high risk for GI bleeds should receive prophylaxis utilizing a proton pump inhibitor.
Pre-DES oral anticoagulation Other patients worthy of special consideration are those who are on an oral anticoagulation (OAC) regimen prior to DES implantation. The typical OAC regimen is daily warfarin, although heparin is often used until therapeutic levels of warfarin are achieved. Patients receive OAC most commonly for venous thromboembolism, cerebrovascular accident (CVA), prosthetic valve replacement, and atrial fibrillation. OAC decreases those patients' risk for everyday thrombotic events, including transient ischemic attack, CVA, and MI.
Previously, OAC and ASA were utilized as the post-PCI-S antithrombotic regimen of choice. However, numerous studies established the increased efficacy and safety of DAT over OAC and ASA,18,19 even in patients with a prior indication for OAC. The Stent Antithrombotic Regimen Study in 1998 established that patients receiving DAT after DES had significantly fewer events that correlate with thrombosis (death, emergency CABG, Q-wave MI, angiographically evident thrombosis) versus patients receiving only ASA or ASA and warfarin. A more recent meta-analysis established the increased safety and efficacy of DAT over OAC and ASA with regard to adverse cardiac events and hemorrhagic/vascular complications after PCI-S.18 Investigators reported a 50% decrease in nonfatal MI and a 71% reduction in need for repeat revascularization in the DAT patients. Cardiac death was also decreased by 27% in DAT patients.
Patients receiving OAC for reasons other than valve replacement should receive DAT in the post-stent implantation period to avoid an increased risk of nonfatal MI and need for repeat revascularization.18 Note that continuation of OAC in the poststent implantation period is efficacious, but patients may experience increased cardiac outcomes, including in-stent thrombosis. If you, as the treating PA prefer, OAC may be restarted with ASA, but the patient's international normalized ratio should be kept at the lower end of the therapeutic range.
Prosthetic heart valves Patients with mechanical prosthetic heart valves are the only subset of patients previously on OAC who are urged to continue this treatment regimen rather than DAT, as these patients were not adequately protected by antiplatelet agents alone.
Surgical candidates In patients who are scheduled for invasive procedures or surgeries in the next 12 months, BMS is recommended over DES per ACC/AHA/SCAI recommendations.16 Use of a BMS may avoid the need for antithrombotic therapy altogether.
Drug hypersensitivity Be aware that patients with a hypersensitivity to ASA or clopidogrel should undergo desensitization therapy prior to PCI, as no other agents have been deemed as efficacious and safe as this combination.
Third antiplatelet agent Additional studies have focused on use of a third antiplatelet agent following DES implantation. Patients receiving triple therapy have demonstrated a 33.2% decrease in late luminal loss at 6-month angiographic followup.20 These patients had less restenosis, reduced target-lesion revascularization, and fewer major adverse cardiac events. However, at present, the addition of a third agent is not routinely recommended.
SUMMARY
Although DES effectively reduces restenosis, a small but significant number of patients suffer complications of in-stent thrombosis. Thus, each patient's health history should be determined before recommending DES. Patients must understand the importance of post-implantation DAT and the need for continued DAT, potentially for life, in order to reduce complications. Current recommendations advocate at least 12 months of uninterrupted clopidogrel and ASA (lifelong ASA if tolerated). With each new generation of stents, patients experience fewer adverse outcomes and improved quality of life. For the present, DES remains a strong therapeutic option for patients with symptomatic CHD. JAAPA
Jessica Justice is a PA with Aria Health–Torresdale in Philadelphia, Pennsylvania. Christian Yacono works at Cardiology Consultants of Philadelphia, PC, also in Philadelphia. The authors have indicated no relationships to disclose relating to the content of this article.
DRUGS MENTIONED Aspirin
Clopidogrel (Plavix)
Heparin
Metformin
Paclitaxel
Sirolimus
Ticlopidine (Ticlid, generics)
Warfarin (Coumadin, generics)
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