Chapter A11: Atlas of Percutaneous Revascularization

Percutaneous coronary intervention (PCI) is the most widely employed coronary revascularization procedure worldwide (Chap. 270). It is now applied to patients with stable angina; patients with acute coronary syndromes, including unstable angina and non-ST-segment elevation myocardial infarction (NSTEMI); and as a primary treatment strategy in patients with ST-segment elevation myocardial infarction (STEMI). PCI is also applicable to patients with either single-vessel or multivessel disease.

In this chapter, the use of PCI will be illustrated in a variety of commonly encountered clinical and anatomic situations, such as chronic total occlusion (CTO) of a coronary artery, bifurcation disease, acute STEMI, saphenous vein graft disease, left main coronary artery disease, multivessel disease, and stent thrombosis. In addition, the use of interventional techniques to treat structural heart disease will be shown, including closure of an atrial septal defect (ASD) and transcatheter aortic valve replacement (TAVR).

(Videos A11-1, A11-2, A11-3, A11-4, A11-5, A11-6, A11-7)

• An 81-year-old male with angina, New York Heart Association (NYHA) class IV congestive heart failure and inferoapicoposterior ischemia on an exercise technetium-99m scan.

• Diagnostic cardiac catheterization revealed a left dominant system with a totally occluded left circumflex (LCx) artery. The distal LCx filled via collaterals from the left anterior descending (LAD) artery, indicating chronicity of the total occlusion.

• Approximately 15–30% of all patients referred for cardiac catheterization will have a CTO of a coronary artery.

• CTO often leads to a surgical referral for complete revascularization.

• Incomplete revascularization due to an untreated CTO is associated with an increased mortality rate (hazard ratio = 1.36; 95% confidence interval [CI], 1.12–1.66, p <0.05).

• Successful PCI of a CTO leads to a 3.8–8.4% absolute reduction in mortality, symptom relief, and improved left ventricular function.

• Newer techniques, such as the retrograde approach to crossing total occlusions, are useful when the antegrade approach fails or is not feasible and there are well-developed collateral vessels.

(Case contributed with permission by Dr. Frederick G.P. Welt.)

(Fig. A11-1; Videos A11-8, A11-9, A11-10, A11-11, A11-12, A11-13, A11-14, A11-15, A11-16)

• A 52-year-old male with an acute coronary syndrome and a troponin I = 0.18 (upper limit of normal, <0.04).

• Diagnostic cardiac catheterization showed single-vessel coronary artery disease with a significant stenosis in the mid-LAD and a bifurcation lesion involving a large diagonal branch.

• Approximately 15–20% of PCIs will involve the treatment of bifurcation lesions.

• Bifurcation lesions require consideration of PCI strategies that protect side-branch patency.

• There are both one-stent and two-stent techniques to treat bifurcation lesions; the selection of technique depends on anatomic considerations, including plaque burden, angle of side-branch take-off, plaque shift during angioplasty, and side-branch distribution.

• Rates of target lesion revascularization and stent thrombosis are similar between one-stent and two-stent procedures.

(Figs. A11-2, A11-3, A11-4; Videos A11-17, A11-18, A11-19, A11-20, A11-21, A11-22)

• A 59-year-old male presented to the emergency room with 2 h of severe midsternal chest pressure.

• His systolic blood pressure was 100 mmHg, and he was tachycardic in sinus rhythm with a heart rate of 90–100 beats/min.

• His initial electrocardiogram (ECG) showed inferior ST-segment elevations with lateral ST-segment depressions.

• He was referred emergently to the cardiac catheterization laboratory for primary PCI.

• An acute STEMI occurs following plaque rupture that promotes thrombotic occlusion of a coronary artery.

• Despite successful revascularization of the epicardial coronary artery, microemboli liberated during balloon angioplasty and stenting may lead to persistent microvascular dysfunction. When present, microvascular dysfunction is associated with a larger infarct size, heart failure, malignant ventricular arrhythmias, and death.

• Manual thrombectomy is used to aspirate or remove thrombus in the vessel and limit distal embolization during angioplasty and stenting.

• Manual thrombectomy in primary PCI is associated with improved myocardial perfusion and a reduction in mortality.

• Adjunctive antiplatelet and antithrombin agents are important to aid in the resolution of intracoronary thrombus.

(Fig. A11-5; Videos A11-23, A11-24, A11-25, A11-26)

• A 62-year-old male with a history of chronic stable angina.

• A four-vessel coronary artery bypass grafting (CABG) surgery was performed 17 years earlier with a left internal mammary artery graft to the LAD, a right internal mammary artery graft to the right coronary artery (RCA), a saphenous vein graft to the first obtuse marginal branch, and a saphenous vein graft to the first diagonal branch.

• The patient had a recent increase in angina with exertion and was found to have lateral ischemia on an exercise technetium-99m scan.

• Diagnostic cardiac catheterization revealed a significant stenosis in the body of the saphenous vein graft to the first obtuse marginal branch.

• Saphenous vein grafts have a failure rate of up to 20% after 1 year and as high as 50% by 5 years.

• Graft failure (after >1 month) results from intimal hyperplasia and atherosclerosis.

• Saphenous vein graft PCI is associated with distal embolization of atherosclerotic debris and microthrombi leading to microvascular occlusion, reduced antegrade blood flow (the “no-reflow” phenomenon), and myocardial infarction.

• Embolic distal protection devices decrease the risk of distal embolization, as well as the incidence of no-reflow and myocardial infarction associated with saphenous vein graft interventions.

(Figs. A11-6 and A11-7; Videos A11-27, A11-28, A11-29, A11-30, A11-31, A11-32, A11-33, A11-34)

• An 89-year-old woman presented with a NSTEMI associated with 5-mm ST-segment depression in the apical leads occurring 2 weeks after hospitalization for a NSTEMI that was treated conservatively.

• Chronic obstructive lung disease, elderly age, and the patient’s refusal to consider cardiac surgery restricted the choice of therapeutic options to medical and/or percutaneous interventions.

• Diagnostic catheterization revealed a left dominant circulation with a heavily calcified 80% distal left main coronary artery stenosis extending into the LAD and into the proximal LCx coronary arteries. A 70% proximal LAD lesion was also present.

• After consultation with the patient, family, and a cardiac surgeon, PCI was performed with intraaortic balloon pump support and a temporary pacemaker in the right ventricle.

• Left main coronary artery disease occurs in 5–10% of patients with symptomatic coronary artery disease.

• In patients with left main coronary artery disease, revascularization with CABG has been shown to decrease mortality significantly over 5–10 years of follow-up.

• PCI with drug-eluting stents in selected cases has been shown to have equal in-hospital and 1-year death and myocardial infarction rates compared with CABG in the Synergy between PCI with Taxus and Cardiac Surgery (SYNTAX) trial. Long-term outcome differences between the two treatment strategies are comparable.

• Indications for PCI of left main coronary artery lesions are high-risk surgical patients and patients with protected left main coronary artery disease (i.e., prior CABG with patent bypass grafts). Patients who are good candidates for bypass surgery may also undergo a stenting procedure, but discussion with the patient, the interventional cardiologist, and the cardiac surgeon should be undertaken to determine the best treatment option in an individual case.

• Outcomes are better for patients with an isolated lesion in the ostium and body of the left main coronary artery where a single stent can be placed compared to bifurcation lesions that involve the ostium of the LAD and LCx.

(Videos A11-35, A11-36, A11-37, A11-38, A11-39, A11-40, A11-41, A11-42)

• A 58-year-old man presented with a NSTEMI.

• The patient has hyperlipidemia and type 2 diabetes mellitus treated with oral hypoglycemic agents.

• Diagnostic catheterization revealed two-vessel disease with a total occlusion of the second obtuse marginal branch that was felt to be responsible for the patient’s symptoms (culprit lesion). In addition, there was a high-grade stenosis in a large ramus intermedius branch, and the RCA had a significant stenosis in the midsegment of the vessel.

• Multivessel PCI is performed commonly and may be done in one setting or staged with two or more procedures.

• Acute and long-term studies of multivessel PCI have shown comparable rates of death and myocardial infarction when compared to CABG, but a higher incidence of repeat revascularization as a result of restenosis is associated with PCI.

• In the randomized Bypass Angioplasty Revascularization Investigation (BARI) and Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease (FREEDOM) trials, diabetic patients treated with PCI had a worse long-term mortality than diabetic patients treated with CABG. However, the BARI registry found that in selected diabetic patients with favorable anatomy, PCI can result in outcomes equal to those observed with CABG.

(Figs. A11-8 and A11-9; Videos A11-43, A11-44, A11-45, A11-46, A11-47)

• A 74-year-old man presented with a NSTEMI.

• The patient is morbidly obese with a prior history of hypertension, hyperlipidemia, diabetes mellitus type 2 treated with oral hypoglycemic agents, chronic obstructive pulmonary disease, and a cerebrovascular accident. He has a prior history of coronary artery disease that was treated with DES implantation in the LCx 9 months earlier.

• Diagnostic catheterization revealed two-vessel disease with in-stent restenosis in the LCx and proximal RCA disease.

• FFR is a functional assessment of the severity of a coronary stenosis and is calculated as the ratio between the pressure distal to a stenosis and pressure proximal to the stenosis (aortic pressure) at maximal hyperemia.

• The Fractional Flow Reserve versus Angiography for Multivessel Evaluation (FAME) study found that patients randomized to angiography-guided PCI had more adverse events (death, myocardial infarction, or repeat revascularization) than patients randomized to FFR-guided PCI.

• When compared to optimal medical therapy in the FAME II trial, FFR-guided PCI was associated with a lower rate of urgent revascularization.

(Figs. A11-10 and A11-11; Videos A11-48, A11-49, A11-50, A11-51)

• A 62-year-old male had a drug-eluting stent placed in a proximal LAD lesion to treat severe angina. He received dual antiplatelet therapy with aspirin and clopidogrel for 1 year and then discontinued clopidogrel per protocol.

• He remained asymptomatic until 15 months after the initial stent placement when he presented with severe chest pain due to an acute anterior STEMI.

• He was taken to the catheterization laboratory within 70 min of presentation, and his initial angiogram showed a total occlusion of the proximal LAD stent.

• Stent thrombosis is an infrequent (1–2%) but serious complication of stent placement. It occurs most commonly within the first month, but rarely can occur as late as 1 year (0.2–0.6%) with bare metal stents. Very late stent thrombosis (VLST), which occurs after 1 year, is very rare with bare metal stents but can occur with drug-eluting stents.

• Premature discontinuation of dual antiplatelet therapy is the most common cause of early and late stent thrombosis; however, the etiology of VLST is not clear.

• The majority of patients with stent thrombosis present with acute coronary syndromes or STEMI; this presentation is associated with a high mortality rate (10%).

• Treatment is immediate PCI with balloon angioplasty or re-stenting.

(Figs. A11-12, A11-13, A11-14, A11-15, A11-16; Videos A11-52, A11-53, A11-54, A11-55)

• A 75-year-old female with symptomatic aortic stenosis and a valve area of 0.58 cm² by transthoracic echocardiogram.

• Chronic obstructive pulmonary disease (forced expiratory volume in 1 s [FEV₁] = 0.54) and other comorbidities contributed to an unacceptably high cardiac surgical risk (calculated logistic Euroscore = 29.57%) for aortic valve replacement.

• She was referred for TAVR.

• The prevalence of calcific aortic stenosis is 2–3% in individuals aged ≥75 years.

• Symptomatic aortic stenosis is associated with an average survival of 2–3 years and an increased risk of sudden death; aortic valve replacement improves both symptoms and survival.

• In high-risk patients with severe aortic stenosis who are not surgical candidates, 1- and 5-year survival rates are ~62% and 38%, respectively.

• TAVR is approved in Europe and the United States as an alternative to surgical aortic valve replacement in high-risk patients.

(Case contributed with permission by Dr. Andrew C. Eisenhauer.)

(Figs. A11-17, A11-18, A11-19, A11-20, A11-21, A11-22, A11-23; Videos A11-56, A11-57, A11-58)

• A 48-year-old female with increased shortness of breath, exercise intolerance, and an 18-mm secundum ASD.

• Echocardiogram showed a dilated right atrium (RA) and right ventricle (RV) with evidence of right ventricular volume overload.

• A shunt ratio (Qp/Qs) of 2.3:1 was determined at cardiac catheterization.

• Based on her symptoms, evidence of right-side chamber dilation, and a moderately sized ASD, the patient was referred for percutaneous closure of the ASD.

• Unrepaired ASDs lead to signs and symptoms of increased pulmonary blood flow and right heart failure, dyspnea, exercise intolerance, fatigue, palpitations and atrial arrhythmias, and pulmonary infections.

• Percutaneous closure of an ASD may be recommended for individuals with a secundum ASD and evidence of RA and RV enlargement with or without symptoms.

• Percutaneous closure is contraindicated in patients with irreversible pulmonary arterial hypertension and no left-to-right shunt. It is not recommended for closure of sinus venosus, coronary sinus, or primum ASDs.

• After the atrial septal occluder device is placed, patients are treated with antiplatelet agents and use antibiotic prophylaxis for certain procedures for 6 months. Follow-up echocardiograms to assess for device migration or erosion, residual shunting, thrombus, or pericardial effusion are recommended at 1 day, 1 month, 6 months, 1 year, and periodically thereafter.

(Case contributed with permission by Dr. Andrew C. Eisenhauer.)