December 1st, 2011
Heart Over Head or Head Over Heart?
A 52-year-old man presented with 3 episodes of transient dysarthria and right-sided facial numbness within a 2-week period. A carotid ultrasound revealed >70% stenosis of the left-internal carotid artery and 50%–69% stenosis of the right coronary artery.
At age 40, the man had been diagnosed with non-Hodgkin lymphoma, which was treated with cranial radiation and anthracyclines, followed by total-body irradiation and an allogeneic stem-cell transplant. His post-transplant course has been complicated by end-stage renal disease, requiring dialysis.
While being evaluated for renal transplantation last year, the patient had an echocardiogram and an exercise MIBI stress test. The echo showed an LV ejection fraction of 55% with no regional wall-motion abnormalities and no significant valvular disease. He exercised to a workload of 10 Mets without any chest pain or shortness of breath. His EKG, however, showed 1-mm horizontal ST depressions in leads V4–6. A subsequent cardiac catheterization revealed noncritical three-vessel coronary artery disease, and the patient was medically managed with aspirin, statins, and a beta-blocker.
As part of a perioperative assessment for left-carotid endarterectomy, the patient was again referred for an exercise MIBI. He exercised, without significant EKG changes, to a workload of 8.4 Mets, then stopped from fatigue. The MIBI images showed large reversible areas of ischemia in the mid-anterior, septal, apical, and lateral walls (summed stress score, 27); the post-stress reduction in LV ejection fraction was from 45% to 32%. The patient was again sent for a left-heart catheterization, which revealed small, diffusely diseased coronary vessels without any clear-cut focal lesions.
A CT angiogram of the neck and aortic arch revealed no acute intracranial abnormality. Severe narrowing of the proximal left-internal carotid artery, along an approximately 1-cm length and with heterogeneous density, was consistent with lipid/thrombus. The CT angiogram also revealed focal moderate narrowing of the proximal right-internal carotid artery, approximately 2 cm from the bifurcation; a circumferential plaque and luminal irregularity at the origin of the right-internal carotid artery; and “a web versus intimal” flap, approximately 1 cm from the carotid bifurcation.
1. Given the patient’s preoperative cardiac assessment, would you clear him for surgery?
2. Given the carotid imaging data, would you recommend carotid-artery stenting or endarterectomy?
3. How would you communicate the pros and cons of your decision to the patient and his family?
December 14, 2011
This middle-aged man is having TIAs due to unstable left common carotid disease and should be managed urgently. Revascularization has been shown to decrease the risk for subsequent stroke in this clinical setting; the greatest risk for stroke is in the first few days after presentation. A reasonable case could be made to admit this patient for heparin anticoagulation, particularly in light of the angiographic findings. However, the evidence base for acute anticoagulation in this setting is not robust.
Although the patient has provokable ischemia (which increases his operative risk), such situations can be managed effectively with medical therapy, as shown in the CARP trial. I also wonder about the accuracy of the stress-test findings 1 year apart, given how different they are. In fact, ACC/AHA guidelines do not recommend repeat testing within 3 years if there is no interval clinical change (and up to 5 years after revascularization). The widespread scintigraphic ischemia without EKG changes or hemodynamic compromise after >8 METs — and no change in angiographic appearance of the epicardial anatomy — would be unusual, even for microvascular angina. However, the >8 METs of work is reassuring regardless of the scintigraphic findings.
In light of the coronary and carotid angiographic results, I would proceed with surgical management (e.g., carotid endarterectomy [CEA]). Randomized trials of CEA versus carotid stenting have generally favored CEA (SPACE, EVA-3S, ICSS) or have shown that the two strategies are generally equivalent in the proper hands (SAPPHIRE, CAVATAS, and CREST). Despite distal protection devices, ipsilateral stroke is still an issue with stenting. The cumulative evidence to date has also been difficult to reconcile in light of variable rates of relevant outcomes. Probably the most important lesson from these trials and registries is that local expertise, whatever the technique, is the most overriding consideration when deciding on a method of revascularization. Moreover, in this patient on dialysis, long-term dual antiplatelet therapy has a substantial chance of being complicated by clinically important bleeding.
Therefore, I conclude:
1. This man’s operative risk is elevated but acceptable, as long as surgical expertise is available.
2. I favor CEA over carotid stenting, as discussed. If there is local expertise, stenting could be offered, with the limitations I described above.
3. I would explain to the patient and his family that the optimal approach is surgical (again, assuming the local expertise), albeit with some increased CV risk. Stenting could be offered as an alternative, but only if the patient (or family) refused operative therapy.
December 29, 2011
The patient’s anatomical features on CT angiography suggested a higher risk for periprocedural stroke with carotid stenting than with endarterectomy. However, surgery presented a greater risk for a periprocedural cardiac event. The patient was presented with the risks and benefits of both options. He chose surgery,which was performed successfully in the presence of aspirin and beta-blockade. He recovered from the procedure without any perioperative complications. Nevertheless, given his extensive coronary artery disease and lack of nonmedical treatment options, his candidacy for renal transplantation remains unclear.