Makindo Medical Notes.com

Related Subjects: |Atherosclerosis |Ischaemic heart disease |Assessing Chest Pain |ACS - General |ACS - STEMI |ACS - NSTEMI |ACS - GRACE Score |ACS - ECG Changes |ACS -Cardiac Troponins |ACS - Post MI arrhythmias |ACS: Right Ventricular Infarction

Liaise closely with cardiologists when stopping anti platelets soon after stenting. Risk of thrombosis higher with drug eluting stents. Usual period to remain on Clopidogrel is 1 year but policies change and check with cardiologists if unsure

About

• Elective PCI does not reduce mortality but can help reduce angina
• Coronary angiography has transformed from being a test selecting those for CABG to one where increasingly complex interventions are being performed.
• Cath labs, once the provision of teaching hospitals are now found at district hospitals as stents have allowed better management of angioplasty complications and less need for urgent cardiac surgery.

Stents

• Metallic scaffold that splints open the vessel. It can be impregnated with drugs to prevent local proliferation. Stents can reduce complications such as vessel dissection which can lead to vessel occlusion and MI. The main use is to treat recurrent or life-limiting anginal pain
• A fine guidewire is advanced from the radial (or femoral) artery to the coronary artery under radiographic control. The wire is placed through the area of stenosis and then dilated by a balloon. A stent is then deployed. This reduces the risk of local restenosis
• Drug-eluting stents: contain sirolimus or paclitaxel which prevents local endothelial proliferation and are favoured in diabetics and those with long/calcified lesions.
• Difficult cases are those where the target lesion is complex, long, eccentric or calcified, lies on a bend or within a tortuous vessel, involves a branch or contain a thrombus.
• Patients are usually given Dual antiplatelet therapy for 6-12 months

Indications: reduces mortality

• STEMI and Contraindication to thrombolysis: reduces mortality
• STEMI and Haemodynamic compromise
• STEMI and can be done within 90 minutes

Others

• High risk NSTEMI
• Unstable angina, High risk Exercise stress test
• Unexplained ischaemic cardiomyopathy
• Survived a Cardiac arrest - look for treatable/causative disease
• Significant Ventricular arrhythmias e.g. VT

Access to coronaries

• Femoral artery, Brachial artery, Radial artery

Protocol

• Written consent. The risk of death 1/1000 is the baseline which increases the more exotic the intervention. Other complications are bleeding, infection, damage to the artery used, bruising. Stroke is rare.
• Check pulses beforehand. Document. Particularly femoral, popliteal and DP/PT. Check FBC, platelets and U&E, Glucose.
• Acetylcysteine may be given to protect kidneys from IV radiocontrast in those suspected to be renally impaired. Check local advice.
• Fasting at least 6 hours. Some may give anxiolytic. Aspirin/Clopidogrel may be given pre-procedure.

Intervention

• Balloon Angioplasty: Inflated Balloon dilates narrowed artery. Arterial dissection is possible. Vessel closure acutely. There is intimal hyperplasia and restenosis is common. As a long procedure uncommonly done except in very small vessels.
• Bare metal stents: They are made of cobalt chrome alloys and inherently thrombogenic. Reduce restenosis and the need for revascularization. Needs Aspirin + Clopidogrel for a period of time and then Aspirin life long.
• Drug eluting stents: the eluted drug (antiproliferative agents sirolimus or paclitaxel) acts to reduce neointimal hyperplasia. Needs Aspirin. Clopidogrel is given for at least 1 year.
• Referral for CABG: Triple vessel, left main stem disease.

Post procedure Complications

• Bleeding from the wound. Apply pressure. Adjust anticoagulation as per local protocol.
• Bleeding retroperitoneal: subtle initially. The patient becomes gradually shocked with low BP and tachycardia. Transfuse. Consider CT abdomen. Discuss with cardiologists/haematologist reversing anticoagulants.
• Cold white leg - discuss with procedure operator/cardiologist. Involve vascular surgeons for possible embolectomy. Thrombosis or embolization or arterial dissection. Likely to need angiography.
• Vascular damage : pseudoaneurysm formation. Painful, expansile mass in the groin. Diagnose by USS. Vascular consult. AV fistula can develop. Involve vascular.
• Bleeding into thigh: Pressure overwound. Adjust anticoagulation. Transfuse and watch FBC
• STEMI : Inform cardiologist. May need repeat Angio and may be due to stent thrombosis. May be a rise in CKMB/Troponin post-procedure.
• Contrast induced renal failure - rise in creatinine. Hydrate. Monitor.
• Restenosis needing further PCI
• Stroke: involve stroke team urgently.