Case presentation

A 61-year-old woman with hypertension and a history of heavy tobacco abuse developed typical exertional angina 3 months prior to her presentation. Symptoms occurred during moderate exertion and resolved with rest. Medical therapy with beta-blockade and long-acting nitrates temporarily improved her symptoms, but she continued to report lifestyle-limiting angina and underwent an exercise stress test. During this test, she exercised for 7 minutes and developed chest discomfort associated with 1 to 2 mm downsloping ST-segment depression. Perfusion scintigraphy identified a moderate-sized inferolateral reversible defect. She was referred for catheterization.

Cardiac catheterization

Ventriculography demonstrated moderate hypokinesis of the inferior wall, but global function was normal with an estimated ejection fraction of 60%. The right coronary artery was completely occluded and the duration of the occlusion could not be precisely determined (Figure 36-1 and Video 36-1). In the left coronary artery, a severe stenosis was identified in the midsegment of the left circumflex artery (Figure 36-2 and Video 36-2), and a stenosis of at least moderate severity was seen in the midsegment of the left anterior descending artery (Figure 36-3 and Video 36-3). The presence of well-developed left to right collaterals and the duration of symptoms suggested that the right coronary artery was chronically occluded and at least 3 months old.

FIGURE 36-1 This is an LAO image of the right coronary artery demonstrating total occlusion.

FIGURE 36-2 A severe stenosis was present in the left circumflex artery (arrow).

FIGURE 36-3 This is an RAO image with cranial angulation of the left coronary artery demonstrating a moderate stenosis of the LAD (arrow) and extensive collateral circulation to the distal right coronary artery (double arrow).

The patient remained on the catheterization table and the findings were explained to her. After a lengthy discussion regarding the options of bypass surgery versus multivessel percutaneous coronary intervention, the patient chose percutaneous revascularization with the understanding that, if the operator could not successfully treat the chronically occluded right coronary artery, surgical revascularization would be necessary.

With this strategy in mind, the operator began with the right coronary artery. Procedural anticoagulation was accomplished with bivalirudin; the patient had already received pretreatment with 300 mg of clopidogrel the night before the procedure. After engaging a 6 French right Judkins guide catheter, the operator loaded a stiff-tipped 0.014 inch guidewire (Miracle Bros, 3, Asahi) into the lumen of a 2.5 mm diameter by 15 mm long, “over-the-wire,” compliant balloon catheter. The stiff-tipped guidewire easily crossed the occlusion and was advanced into the distal right coronary artery (Figure 36-4). The “over-the-wire” balloon was advanced distally and the stiff-tipped wire was removed and replaced by a floppy-tipped guidewire. Patency was restored after performing balloon angioplasty with the 2.5 mm balloon; however, the artery appeared diffusely diseased distally with an extensive dissection in the midsection (Figure 36-5 and Video 36-4). Multiple everolimus-eluting stents were placed, ranging in diameter from 2.5 mm distally to 3.5 mm proximally, covering 98 mm of length. The proximal and midsegments were postdilated with a 4.0 mm noncompliant balloon and an excellent final angiographic result was obtained (Figure 36-6 and Video 36-5).

FIGURE 36-4 A stiff-tipped angioplasty guidewire was used to cross the totally occluded segment of the right coronary artery.

FIGURE 36-5 Result after balloon angioplasty; there is extensive dissection and distal disease observed (arrow).

FIGURE 36-6 Final angiographic result after extensive stenting performed in the right coronary artery.

The procedure was stopped in order to conserve contrast volume and limit radiation exposure. The following day, the operator treated the circumflex artery with a 3.5 mm diameter everolimus-eluting stent without difficulty (Figure 36-7 and Video 36-6). Because the left anterior descending artery stenosis was of unclear significance, this lesion was assessed with a pressure wire to determine fractional flow reserve (Figure 36-8). Maximum vasodilation was achieved with an injection of 200 mcg of intracoronary adenosine and the fractional flow reserve was calculated to be 0.86, indicating that the lesion in the LAD was not hemodynamically significant; thus stenting was not performed (Figure 36-9).

FIGURE 36-7 Post-stent result in the left circumflex artery.

FIGURE 36-8 Location of the pressure wire transducer (arrow) in the left anterior descending artery.

FIGURE 36-9 These pressure tracings were recorded from the catheter tip (AO) and from the pressure transducer distal to a coronary stenosis in the left anterior descending artery (LAD) after maximal hyperemia created by an intracoronary injection of adenosine. Fractional flow reserve is defined as the ratio of mean distal coronary pressure to mean aortic pressure during maximal hyperemia, which in this case was 86 mmHg/100 mmHg or 0.86.

Postprocedural course

After an overnight observation without complication, she was discharged on lisinopril, aspirin, clopidogrel, and simvastatin. At a follow-up visit 2 months later, she reported no further angina.

Discussion

The management of multivessel coronary disease is controversial and challenging. First, the physician must decide whether to recommend bypass surgery or multivessel PCI. This often depends on numerous factors, including coronary anatomy, the technical feasibility of bypass surgery or PCI, completeness of revascularization, the presence of comorbid illness, and patient preference. If multivessel PCI is chosen, the physician is also faced with the problem of determining exactly which lesions require intervention.

This case is a good example of a typical patient with multivessel disease facing a decision regarding optimal revascularization strategy. Often, at least one lesion is complex, such as the chronic occlusion of the right coronary artery present in this case. The decision to proceed with surgery or multivessel PCI is often predicated on the complexity of the lesions. The presence of a chronic occlusion or a complex bifurcation lesion may be a “deal breaker” and push the physician to recommend surgery. On the other hand, comorbid illnesses that increase the risk of surgery or the presence of poor distal targets or nonviable myocardium usually cause the physician to lean toward percutaneous revascularization.

The decision regarding which vessels to revascularize is typically made by a visual assessment of the angiogram. While this approach is certainly acceptable for lesions that are severely stenotic, treatment of a lesion that is ambiguous or moderately narrowed but not actually flow-limiting exposes the patient to increased risk without providing any benefit. Recently, the strategy of fractional flow reserve guided revascularization has been shown to be superior to angiographic guided therapy in patients with multivessel coronary disease undergoing stenting.¹ In the case presented here, fractional flow reserve was very helpful and determined that the left anterior descending artery was non–flow-limiting and thus did not require treatment with a stent.

The controversy regarding multivessel intervention versus coronary bypass surgery has been debated for many years. In the balloon angioplasty era, numerous randomized controlled studies were performed comparing balloon angioplasty to bypass surgery; the largest study with the longest follow-up was the BARI trial.² Similar to other related trials, the BARI study found no difference in death or myocardial infarction between patients treated with balloon angioplasty versus those undergoing bypass surgery. The main difference, also observed in earlier trials, was that patients undergoing balloon angioplasty had a higher rate of repeat revascularization procedures compared to patients undergoing bypass surgery.

Additional randomized controlled trials were repeated in the bare-metal stent era^3–6 and the drug-eluting stent era.^7,8 Again, the rate of death or MI was similar for groups treated with bare-metal stents compared to those treated with bypass surgery. Although stents reduced the rate of restenosis compared to balloon angioplasty, and drug-eluting stents reduced restenosis rates compared to bare-metal stents, the stent-treated groups continued to have higher rates of repeat revascularization compared to the groups treated with bypass surgery. Of interest, in the large-scale, randomized SYNTAX trial, a higher rate of stroke was observed for patients treated with coronary bypass surgery compared to PCI (2.2% vs. 0.6%).⁸

In the end, the decision whether to revascularize a patient with multivessel coronary disease surgically or by a percutaneous approach is complex and depends on multiple factors, including coronary anatomy, the nature of the ischemic syndrome, compliance with medications (particularly long-term, dual antiplatelet therapy), comorbid illness, patient preference, and operator skill. This controversy will likely continue long into the future.