Case presentation

An unfortunate 54-year-old man experienced numerous complications from paraplegia as a result of a gunshot wound at age 18. He has a neurogenic bladder with an indwelling catheter, and underwent resection of the left proximal femur following hip disarticulation. He has had multiple debridement and surgical procedures on chronic sacral decubitus ulcers. The most recent surgery, performed 2 weeks earlier, consisted of a gluteal flap.

While recuperating from this surgery, he developed a left facial droop and left arm weakness and also reported profound dyspnea but no chest pain. The neurologic symptoms resolved after a few hours but dyspnea continued. An electrocardiogram found lateral lead ST depressions and serial troponins were elevated, peaking at 17.54 ng/mL. Echocardiography uncovered severely reduced left ventricular function and a chest X-ray revealed congestive heart failure. He was diagnosed with a non-ST segment elevation myocardial infarction and heart failure; the transient ischemic attack was thought possibly due to a cardiac embolism. Although cardiac catheterization was indicated, the plastic surgeons advised against lying on his back side because pressure on the graft might jeopardize the viability of the gluteal flap. His extensive past medical history is also notable for prior myocardial infarction, diabetes mellitus, dyslipidemia, nephrolithiasis, and depression.

He was treated medically with aspirin, clopidogrel, beta blockers, and nitrates, and ultimately became stable with no further cardiac or neurologic symptoms. Surgery recommended that he continue to avoid lying on his back side for at least 2 more weeks. His physician decided to postpone catheterization for about 4 weeks to allow his decubitus graft to heal. However, 2 weeks later, he developed acute-onset shortness of breath and was admitted with pulmonary edema. He was referred for cardiac catheterization.

Cardiac catheterization

Obtaining arterial access proved challenging as his longstanding paraplegia resulted in substantial lower extremity atrophy and contracture at the hip. The femoral pulses were barely palpable; however, the right femoral artery was finally accessed successfully using ultrasound guidance, and angiography showed a small, diseased external iliac (Figure 9-1). The right coronary artery was without significant disease (Figure 9-2). Upon engagement of the left coronary artery, the operator observed pressure damping and ventricularization. The left main stem was severely diseased at the ostium (Figures 9-3, 9-4 and Videos 9-1, 9-2). In addition, there was significant obstructive disease noted in the proximal left anterior descending (LAD) and circumflex (LCX) arteries.

FIGURE 9-1 The femoral and external iliac vessels were very small and diffusely diseased.

FIGURE 9-2 There was moderate atherosclerotic disease in the right coronary artery.

FIGURE 9-3 The ostium of the left main stem was severely narrowed (arrow) and there was a high grade lesion of the proximal LAD (double arrow).

FIGURE 9-4 There was also severe disease of the circumflex artery (arrow).

A cardiac surgeon reviewed his medical history and deemed him a very poor surgical candidate because of his substantial comorbidities. After discussion about the options of continuing medical therapy versus a high-risk percutaneous coronary intervention, the patient agreed to proceed with a stenting procedure of the left main stem as well as the LCX and LAD lesions, primarily because he clearly failed a course of medical therapy.

The operator inserted an 8 French sheath in the right femoral artery and procedural anticoagulation was achieved with bivalirudin; he had already been on clopidogrel therapy. An 8 French, left Judkins guide catheter was engaged and floppy-tipped guidewires passed into the LAD and LCX. The lesions in the LAD and LCX were treated successfully with balloon dilatation followed by placement of paclitaxel-eluting stents (Figure 9-5).

FIGURE 9-5 The LAD and LCX were stented first, with an excellent angiographic result.

In order to protect the circumflex artery, the operator chose to use a modified “crush stent” technique to treat the left main stem lesion. Two stents were positioned in the left main/LAD and LCX: a 3.0 mm diameter by 20 mm long paclitaxel-eluting stent in the left main into the LAD, and a 3.0 mm diameter by 12 mm long paclitaxel-eluting stent in the circumflex (Figure 9-6). The left circumflex stent was deployed first (Figure 9-7); following this, the stent catheter and wire was removed from the circumflex artery and the left main stent deployed (Figure 9-8). The operator re-crossed the circumflex stent with another 0.014 inch guidewire and simultaneously inflated two 3.0 mm diameter noncompliant balloons (“kissing balloons”) to high pressure (Figure 9-9). A 3.5 mm noncompliant balloon was used to postdilate the left main stem. The final angiographic result was excellent (Figures 9-10, 9-11 and Videos 9-3, 9-4). Intravascular ultrasound was used to assess stent deployment and showed excellent stent apposition and a widely patent lumen (Figure 9-12).

FIGURE 9-6 The initial step in managing the left main lesion is shown here. An 8 French guide catheter is engaged in the left main, and stents are positioned in the left main into the LAD and in the circumflex artery with the distal end of the circumflex stent at the ostium.

FIGURE 9-7 The LCX stent is deployed first.

FIGURE 9-8 After deploying the LCX stent, the stent catheter and guidewire were removed from the LCX and the left main/LAD stent deployed.

FIGURE 9-9 Final kissing balloons performed with noncompliant balloons.

FIGURE 9-10 Final angiographic result in the RAO caudal projection.

FIGURE 9-11 Final angiographic result in the RAO cranial projection.

FIGURE 9-12 Representative intravascular ultrasound image of the left main stem after stenting, showing excellent stent deployment.

Postprocedural course

He recovered uneventfully and was discharged 2 days later on aspirin, clopidogrel, simvastatin, and metoprolol. In follow-up 3 months later, he reported no symptoms of chest pain, dyspnea, or recurrent heart failure. Unfortunately, he continued to be limited due to his chronic sacral decubitus ulcer and experienced new areas of skin breakdown in another sacral location. He was again seen 18 months after the coronary intervention and remained symptom-free and without cardiac events.

Discussion

Left main stem disease is traditionally treated with bypass surgery, and this mode of revascularization is generally accepted as the standard of care for this high-risk subgroup. Percutaneous intervention of unprotected left main stem disease (i.e., without a patent bypass graft to one or more branches of the left coronary artery) has generally been reserved for patients too unstable for bypass or, as in this case, for patients who are not surgical candidates. However, there is a growing interest in and experience of treating this disease with stents instead of bypass surgery. Numerous registries and nonrandomized comparative trials have shown feasibility, relative safety, and efficacy of left main stenting using both bare-metal and drug-eluting stents.¹ These data suggest that left main stenting can be done, but do not answer the question of whether it should be done. Only randomized, controlled trials comparing left main PCI to bypass surgery can answer that question, and PCI would need to show equivalence to bypass surgery in order to gain a Class I recommendation.

Left main stem stenting is a high-risk lesion subset for several reasons. First, the left main stem supplies a very large vascular territory and there is the potential for cardiovascular collapse with ischemia, particularly if the left coronary is dominant, the right coronary is occluded, or left ventricular function is reduced. Patients with left main coronary disease often have other disease requiring revascularization; isolated involvement of the left main stem occurs in only 9% of patients with left main stem disease.² Often, this other disease is extensive or not amenable to percutaneous approaches, thus favoring surgical revascularization. Furthermore, left main stem disease involves the bifurcation in more than half the cases, introducing additional complexity and risk. Finally, the occurrence of either restenosis or stent thrombosis may be fatal events in patients with left main stents.

Several randomized controlled trials comparing bypass surgery to drug-eluting stents for treatment of left main disease are in progress or have been reported. A small series of 105 patients randomized to PCI versus surgery found similar anginal status at 12 months, but better left ventricular ejection fraction, shorter length of stay, and lower rate of adverse events at 12-month follow-up in the group randomized to stenting.³ The SYNTAX trial was a much larger randomized controlled trial that included patients with three-vessel or left main disease and compared stenting to bypass surgery.⁴ In the subgroup of patients with left main disease, patients treated with stents had similar rates of death and MI as patients treated with bypass surgery. Similar to the multivessel PCI versus CABG trials, patients treated with stents had a significantly higher rate of repeat revascularization. In the SYNTAX trial, the patients treated with bypass surgery had a higher rate of stroke.

Based on the SYNTAX trial, the most recently revised guidelines changed the classification of left main stenting from Class III to Class IIb, with several important caveats.⁵ Patients considered for left main stenting must have lesions suitable for PCI. Complex bifurcations and patients with multivessel disease are better served with surgery. Furthermore, the guidelines suggest that only experienced operators, backed-up by surgeons and competent support staff, should consider PCI of left main lesions.

There are several other issues and concerns relating to left main stenting. Regarding the choice of drug-eluting stent, based on the ISAR LEFT MAIN study, there does not appear to be a difference in outcomes in patients with left main disease treated with paclitaxel-eluting compared to sirolimus-eluting stents.⁶ Late stent thrombosis is a concern in this subgroup, as thrombosis of a left main stent would likely prove fatal. In the ISAR LEFT MAIN trial, no late thrombosis was seen beyond 30 days, alleviating this worry in this population. There is also uncertainty about how best to follow these patients after stenting. Many practitioners have advocated the performance of routine coronary angiography at 6 to 9 months; however, the most recent guidelines do not recommend this practice.

Selection of patients is clearly important in deciding on the optimal method of revascularization in this subgroup. In patients undergoing left main PCI, the most significant predictor of a major adverse event and repeat revascularization is bifurcation involvement.⁷ Treatment of bifurcation disease remains challenging, but nonbifurcation left main PCI has very favorable outcomes. The SYNTAX score can help choose the optimal revascularization strategy in patients with complex CAD including left main stem disease.⁸ This score takes into account disease complexity and the presence of additional disease; the higher the SYNTAX score, the better the outcome with CABG compared to PCI.