Topic 6 Cardiac stents

What are the 2 types of cardiac stents?

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There are 2 types of cardiac stents:

• Bare metal stent

• Drug eluting stent

Bare metal stents were first developed in the 1980s. The risk of stent thrombosis in Bare metal stents is in the first 2 to 4 weeks.

Drug eluting stents were developed in the early 2000s. Nowadays, Drug eluting stents are used in preference over Bare metal stents. Drug eluting stents contain neointimal inhibiting and antiproliferative agents. However, late stent thrombosis is seen in Drug eluting stents.

Management of antiplatelet therapy in patients who have had cardiac stent placement in the past 12 months

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Following cardiac stent placement, patients are normally placed on dual antiplatelet therapy (aspirin and P2Y12 inhibitor) for at least 6 to 12 months. In patients who have cardiac stent inserted within the first 12 months, and are for surgery, the main problem is balancing the cardiac risk associated with holding antiplatelet therapy (stent thrombosis, acute coronary events, need for further repeat revascularization) versus the bleeding risk from continuing antiplatelet therapy.

In surgery associated with low risk of bleeding, dual antiplatelet therapy should be continued. In high bleeding risk surgery, American College of Cardiology (ACC) and American Heart Association (AHA) recommend delaying surgery for at least 6 months after either Bare metal stent or Drug eluting stent insertion.

In surgery which has greater urgency, elective surgery should be postponed for at least 1 month after Bare metal coronary stent placement and 3 months after Drug eluting stent placement. Dual antiplatelet therapy should be restarted postoperatively as soon as possible.

In patients who undergo surgery sooner than the minimum waiting period listed above and where P2Y12 inhibitor is suspended, monotherapy with aspirin should continue perioperatively. Bridging therapy, where short acting anticoagulation agent is substituted in place of held antiplatelet agents is not recommended, as there is a lack of evidence.

Childers et al published a systematic review in 2018, finding that there is insufficient evidence to guide the perioperative management of antiplatelet therapy in patients with coronary stents. This is compounded by lack of randomized control trials.

Therefore, it is important to liaise with the patient’s Cardiologist, when making decisions on preoperative management of antiplatelet therapy, in patients who have had cardiac stent placement in the first 12 months. Ideally, a multidisciplinary approach should be used, involving the surgeon and anesthetist as well.

Management of antiplatelet therapy in patients 12 months or more after Cardiac stent placement

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Following completion of dual antiplatelet therapy, the majority of patients with cardiac stent(s) are placed on monotherapy antiplatelet therapy (usually aspirin) lifelong.

Type of surgery, surgical bleeding risk and risk of stent thrombosis determines whether or not aspirin suspension preoperatively is required. In the vast majority of patients, after completion of dual antiplatelet therapy, it should be safe for aspirin to be held preoperatively. However, this should be ideally discussed with the patient’s cardiologist first.

Duration of suspension of antiplatelet agents

• Clopidogrel 5 days

• Prasugrel 7 days

• Ticagrelor 5 days

• Aspirin 5 to 7 day

Resources

Association Task Force on Clinical Practice Guidelines. J Thorac Cardiovasc Surg. 2016;2016(152):1243–75.

Childers CP, Maggard-Gibbons M, Ulloa JG, MacQueen IT, Miake-Lye IM, Shanman R, Mak S, Beroes JM, Shekelle PG. Perioperative management of antiplatelet therapy in patients undergoing non-cardiac surgery following coronary stent placement: a systematic review. Syst Rev. 2018 Jan 10;7(1):4. doi: 10.1186/s13643-017-0635-z. PMID: 29321066; PMCID: PMC5763575.

Gurajala I, Gopinath R. Perioperative management of patient with intracoronary stent presenting for noncardiac surgery. Ann Card Anaesth. 2016;19(1):122-131. doi:10.4103/0971-9784.173028

Levine GN, Bates ER, Bittl JA, Brindis RG, Fihn SD, Fleisher LA, Granger CB, Lange RA, Mack MJ, Mauri L, et al. ACC/AHA guideline focused update on duration of dual antiplatelet therapy in patients with coronary artery disease: a report of the American College of Cardiology/American Heart

Scafa Udriște A, Niculescu AG, Grumezescu AM, Bădilă E. Cardiovascular Stents: A Review of Past, Current, and Emerging Devices. Materials (Basel). 2021 May 12;14(10):2498. doi: 10.3390/ma14102498. PMID: 34065986; PMCID: PMC8151529.

Valgimigli M, Bueno H, Byrne RA, et al. 2017 ESC focused update on dual antiplatelet therapy in coronary artery disease developed in collaboration with EACTS: The Task Force for dual antiplatelet therapy in coronary artery disease of the European Society of Cardiology (ESC) and of the European Association for Cardio-Thoracic Surgery (EACTS). Eur Heart J 2018; 39:213.