Case presentation

A healthy 58-year-old man with several risk factors for coronary disease, including hypertension and dysplipidemia, developed severe left-sided substernal chest pain while walking down his driveway to get the mail. The pain migrated to his left arm and was associated with diaphoresis and dyspnea. The discomfort continued all night and he presented to a community hospital the next morning with ongoing residual chest pain. His initial electrocardiogram showed T-wave inversion inferiorly and his initial troponin was already elevated at 2.7 ng/mL. He was admitted to the hospital with a diagnosis of non-ST segment elevation myocardial infarction and was treated with 300 mg clopidogrel, aspirin, unfractionated heparin, beta-blocker, and nitrates. He quickly became pain-free, and the cardiology consultant recommended urgent cardiac catheterization. The patient was at a facility that offered cardiac catheterization, had recently begun a percutaneous coronary interventional program, but did not have an open-heart surgery program; the nearest hospital offering open-heart surgery was 30 miles away.

Cardiac catheterization

The patient stayed at the community hospital and the procedure was scheduled with an experienced interventional cardiologist (who performed more than 200 interventions each year), whose primary practice was at a large university hospital with surgical backup. Left ventricular function appeared normal with no wall motion abnormalities. The right coronary artery had a severe stenosis in the proximal segment; this lesion appeared hazy, but there was normal TIMI flow in the artery (Figure 45-1 and Video 45-1). The left coronary angiogram was notable for a normal appearing circumflex artery and a moderate lesion in the midsegment of the left anterior descending (LAD) artery (Figures 45-2, 45-3). To further assess the hemodynamic significance of the LAD stenosis, the operator measured fractional flow reserve (FFR); this calculated to 0.84 and was therefore deemed not significant.

FIGURE 45-1 This is a left anterior oblique angiogram of the right coronary artery, showing the severe lesion with a hazy appearance in the proximal right coronary artery.

FIGURE 45-2 This is a representative image of the left coronary artery in the right anterior oblique caudal projection, showing no significant disease of the left circumflex artery.

FIGURE 45-3 There was a moderate stenosis noted in the mid-segment of the left anterior descending artery. This lesion was assessed by fractional flow reserve (FFR) using a pressure wire (arrow shows position of the pressure transducer); FFR was 0.84 and thus was not considered a significant lesion.

Based on the patient’s clinical syndrome and the angiogram, the disease in the right coronary artery appeared to represent the culprit lesion responsible for the acute coronary syndrome. The interventional cardiologist thought the lesion appeared fairly straightforward, without high-risk features that would necessarily preclude performance of a stenting procedure at a facility without surgical backup.

Thus, the interventionalist proceeded with PCI and placed a 6 French right Judkins guide catheter in the right coronary artery after procedural anticoagulation was achieved with bivalirudin. The operator first dilated the lesion with a 3.0 mm diameter by 20 mm long compliant balloon and then placed a 4.0 mm diameter by 28 mm long drug-eluting stent. As the operator was satisfied with the angiographic result in several views (Figures 45-4, 45-5 and Videos 45-2, 45-3), intravascular ultrasound was not performed and the case was terminated. The patient felt well with no chest pain or discomfort. Hemostasis was easily accomplished with a vascular closure device.

FIGURE 45-4 The left anterior oblique projection of the right coronary artery following stenting showed an excellent angiographic result.

FIGURE 45-5 The right anterior oblique projection of the right coronary artery following stenting showed an excellent angiographic result.

The patient had been moved off the cardiac catheterization laboratory table and onto a stretcher awaiting transfer to his hospital bed when he reported chest pain, diaphoresis, and nausea. The monitor leads showed marked ST-segment elevation and sinus bradycardia. Fearing acute stent thrombosis, the patient was immediately returned to the cardiac catheterization laboratory and the physician quickly regained arterial access and imaged the right coronary artery. The right coronary was completely occluded distal to the stent and there appeared to be a linear dissection beyond the distal end of the stent that was not apparent on the post-PCI films (Figure 45-6). At this point, the patient had ongoing severe chest pain and bradycardia but maintained an adequate arterial pressure.

FIGURE 45-6 This right coronary angiogram was obtained shortly after the patient noted the onset of severe chest pain associated with ST-segment elevation. The artery is now closed and there is a dissection flap at the distal end of the stent (arrow).

The operator administered atropine, unfractionated heparin, and eptifibatide, and attempted to open the artery. Gaining the true lumen proved extremely difficult, but finally the operator was able to insert floppy-tipped guidewires into both the posterior descending and the posterolateral branches (Figure 45-7). The angiogram revealed an extensive spiral dissection originating at the distal end of the stent and progressing to the bifurcation of the posterior descending and posterolateral branches. The operator placed bare-metal stents at the origin of both the posterolateral artery (Figure 45-8 and Video 45-5) and the posterior descending artery (Figure 45-9) and then placed bare-metal stents distal to proximal in an effort to cover the dissection flap (Figure 45-10). Once patency was restored, the patient no longer complained of chest discomfort, the bradycardia resolved, and the ST segments returned to normal. The final angiographic result after multiple stents were inserted is shown in Figure 45-11 and Video 45-6.

FIGURE 45-7 With great difficulty, wires were successfully placed in the posterior descending and posterolateral branches. Note the extensive spiral dissection (arrow).

FIGURE 45-8 Stenting of the posterolateral branch.

FIGURE 45-9 Angiogram after stenting the posterior descending artery.

FIGURE 45-10 Stents were placed distal to proximal in an effort to cover the entire dissection.

FIGURE 45-11 Final angiographic result after insertion of multiple stents.

Postprocedural course

Following the procedure, he was admitted to the coronary care unit for close observation and monitoring. Troponin I assays peaked at 58 ng/mL. He had no further chest pain but developed heart failure the night after the procedure that quickly responded to diuretics and was felt to be due to the excessive contrast load he received from the two procedures, particularly the second, more complex one. He was discharged 3 days later on aspirin, clopidogrel, metoprolol, and atorvastatin. At follow-up 2 months later, he had returned to all activities and remained free of symptoms.

Discussion

The unpredictable nature of balloon angioplasty characterizing the early era of percutaneous coronary intervention mandated the need for surgical backup for all coronary interventional procedures. Without the coronary stents, technology, and pharmacology we enjoy today, flow-limiting dissections, threatened or abrupt closure, and coronary perforations could only be managed surgically. During this early era, emergency bypass surgery was needed in up to 5% of balloon angioplasties. In the stent era, this has been reduced to less than 0.5%.^1–3

In the modern era, indications for emergency surgery include the presence of triple vessel disease (40% of cases), dissection or acute closure (43% of cases), perforation (8% of cases), and failure to cross the lesion (8% of cases).⁴ Unfortunately, as evidenced by the case presented here, there do not appear to be clear-cut risk factors that identify which patients are at increased risk for this complication.⁵ Clearly, patients requiring PCI of calcified, complex stenoses or chronic total occlusion should not undergo these procedures at institutions without surgical backup. However, the case shown here is an example of a patient with a very straightforward coronary lesion that was initially successfully treated percutaneously but would have required emergency bypass for an extensive dissection if the operator had not been fortunate or skilled enough to successfully treat the complication percutaneously.

Despite the low rate of emergency bypass surgery in the modern era, current professional guidelines continue to classify elective coronary interventional procedures without on-site surgical backup as a Class III indication.⁶ Emergency angioplasty performed to reperfuse an ST-segment elevation acute myocardial infarction is classified as a IIb indication, with multiple caveats as follows⁶:

These recommended guidelines remain controversial but have not been modified in the 2007 and 2009 PCI updates. Currently, many community hospitals throughout the nation perform elective PCI without on-site surgical backup and/or perform primary PCI for ST-segment elevation MI without adhering to these numerous stipulations. The number of such centers continues to grow.⁷ The most recent data from the National Cardiovascular Data Registry (NCDR) reported that 13% of participating hospitals perform PCI without on-site surgical backup, representing 2.8% of patients undergoing PCI in that registry.⁸ Although this data is not randomized and patients may have been carefully selected at the sites without surgical backup, the centers performing PCI without on-site surgical backup had similar rates of emergent CABG and risk-adjusted mortality when compared to centers with on-site surgical backup, despite lower annual PCI procedural volumes. Several other published reports suggest that elective PCI at centers without on-site surgical backup is safe and feasible.^9–11 However, a large report consisting of Medicare enrollees found a higher mortality for patients undergoing non-primary or rescue PCI at centers without on-site surgical backup.¹² Clearly, this issue will not be resolved until a large-scale, randomized trial is performed.

Although the risk is small, in the author’s experience, when emergency surgery is needed, it is needed desperately and it is needed immediately. Abrupt vessel closure of an artery supplying a large vascular territory will not be tolerated very long without serious morbidity or death. Similarly, a perforation that cannot be sealed in the cardiac catheterization laboratory is a true emergency requiring immediate attention. Stabilization for transfer to an institution miles away may not be possible in some cases. In addition, the delays involved in arranging for transfer and physically transporting a patient to another institution for emergency surgery will likely be associated with serious and potentially unnecessary morbidity. One study estimates that one in four patients referred for emergency bypass surgery after failed PCI would be placed at increased risk of harm if delays to surgery were present.¹³

This debate will likely continue, but if faced with the prospect of a similar procedure on his or her own heart, at what type of institution would the interventional cardiologist choose to have a coronary intervention performed?