Chapter 20
Percutaneous Coronary Intervention
1. What does the term percutaneous coronary intervention mean?
2. Which patients with chronic stable angina benefit from PCI?
The goals of treatment in patients with coronary artery disease are to:
Prevent adverse outcomes such as cardiovascular death, myocardial infarction (MI), left ventricular (LV) dysfunctions, and arrhythmias.
3. Which patients with unstable angina/non–ST elevation myocardial infarction (UA/NSTEMI) should undergo a strategy of early cardiac catheterization and revascularization?
Two major strategies, conservative (medical therapy without an initial strategy of catheterization and revascularization) and early invasive, are employed in treating patients with UA/NSTEMI. The early invasive approach involves performing diagnostic angiography with intent to perform PCI along with administering the usual antiischemic, antiplatelet, and anticoagulant medications. Evidence from clinical trials suggests that an early invasive approach with UA/NSTEMI leads to a reduction in adverse cardiovascular outcomes, such as death and nonfatal MI, especially in high-risk patients. Several risk-assessment tools are available that assign a score based upon the patient’s clinical characteristics (e.g., TIMI and GRACE scores). Patients who present with UA/NSTEMI should be risk stratified to identify those who would benefit most from an early invasive approach. Patients with the following clinical characteristics indicative of high risk should be taken for early coronary angiography with intent to perform revascularization:
Recurrent angina or ischemia at rest or with low-level activities
Elevated cardiac biomarkers (troponin T or I)
New or presumably new ST segment deviation
Congestive heart failure [CHF], new or worsening mitral regurgitation, or hypotension
Reduced LV function (ejection fraction less than 40%)
Sustained ventricular tachycardia
High-risk findings from noninvasive testing
PCI within the last six months or prior coronary artery bypass graft (CABG)
High risk score as per risk-assessment tools (e.g., TIMI, GRACE)
4. What are the contraindications to PCI and the predictors of adverse outcomes?
Bleeding diathesis or other conditions that predispose to bleeding during antiplatelet therapy
Severe renal insufficiency unless the patient is on hemodialysis, or severe electrolyte abnormalities
Poor patient compliance with medications
A terminal condition that indicates short life expectancy such as advanced or metastatic malignancy
Other indications for open heart surgery
Failure of previous PCI or not amenable to PCI based upon previous angiograms
Patients with severe cognitive dysfunction or advanced physical limitations
Patients generally should not undergo PCI if the following conditions are present:
There is only a very small area of myocardium at risk.
There is no objective evidence of ischemia (unless patient has clear anginal symptoms and has not had a stress test).
There is a low likelihood of technical success.
The patient has left-main or multivessel CAD with high SYNTAX score and is a candidate for CABG.
There is insignificant stenosis (less than 50% luminal narrowing).
The patient has end-stage cirrhosis with portal hypertension resulting in encephalopathy or visceral bleeding.
Angiographic predictors of poor outcomes include the presence of thrombus, degenerated bypass graft, unprotected left main disease, long lesions (more than 20 mm), excessive tortuosity of proximal segment, extremely angulated lesions (more than 90 degrees), a bifurcation lesion with involvement of major side branches, or chronic total occlusion.
5. What are the major complications related to PCI?
Death: The overall in-hospital mortality rate is 1.27% ranging from 0.65% in elective PCI to 4.81% in ST elevation myocardial infarction (STEMI) (based on the National Cardiac Data Registry [NCDR] CathPCI database of patients undergoing PCI between 2004 and 2007).
MI: The incidence of PCI-related MI is 0.4% to 4.9%; the incidence varies depending on the acuity of symptoms, lesion morphology, definition of MI, and frequency of measurement of biomarkers.
Stroke: The incidence of PCI-related stroke is 0.22%. In-hospital mortality in patients with PCI-related stroke is 25% to 30% (based on a contemporary analysis from the NCDR).
Emergency CABG: The need to perform emergency CABG in the stent era is extremely low (between 0.1% and 0.4%).
Vascular complications: The incidence of vascular complications ranges from 2% to 6%. These include access-site hematoma, retroperitoneal hematoma, pseudoaneurysm, arteriovenous fistula, and arterial dissection. In randomized trials, closure devices were only beneficial in reducing time to hemostasis but did not reduce the incidence of vascular complications.