He is active and has enjoyed excellent general health except for mild depression and gastroesophageal reflux disease. Three months ago, he developed throat discomfort when walking more than four minutes on level ground, without other symptoms. He also had one episode of throat discomfort with emotional stress. He saw his primary care physician and was referred for treadmill exercise stress testing. He completed 9 minutes and 59 seconds of the Bruce protocol to a peak heart rate of 90% predicted and blood pressure of 166/86 (12 METS), stopping due to his typical throat discomfort that began 4 minutes and 6 seconds into exercise. His ECG evolved 2-3 mm horizontal to upsloping ST-segment depressions in an inferior-apical distribution on a substrate of right bundle-branch block. Three-days later, he underwent repeat treadmill exercise testing with myocardial perfusion imaging (MPI), completing 10 minutes (12 METS). Throat pain began at 4 minutes and 15 seconds of exercise. Perfusion imaging demonstrated a small-to-moderate (not quantified) area of distal septal and apical ischemia without transient ischemic dilation. His left-ventricular systolic function was normal with an ejection fraction of 0.68. Medical therapy was initiated with aspirin 81 mg daily, metoprolol succinate 25 mg daily, and atorvastatin 10 mg daily. He was not previously aware of hyperlipidemia. There was no history of diabetes or hypertension.
He was referred for initial cardiology evaluation four weeks later, over which time he continued with Canadian Cardiovascular Society (CCS) Class III angina (throat discomfort). After discussion of his symptoms, risk, and treatment options, he elected to intensify his medical therapy. The dose of his beta-blocker was increased and long-acting nitrates were added, with additional instructions to use sublingual NTG prior to activities that would predictably precipitate angina. Despite strict heart rate and blood pressure control, his symptoms continued unabated and he expressed a strong preference to proceed with diagnostic angiography in anticipation of revascularization. Findings included right coronary artery dominance with no significant left-main disease, serial 90% proximal and mid left-anterior descending artery (LAD) stenoses, an 80% mid-left circumflex artery (LCx) lesion, and an 80% mid-right coronary artery (RCA) lesion. His coronary artery lesions were described as easily amenable to percutaneous coronary intervention (PCI). The SYNTAX score was not calculated but felt to be in a low-intermediate range. Other medical as well as revascularization options for angiographic three vessel disease were reviewed and discussed. He voiced a strong preference to avoid “open heart surgery.” A final decision was not made on the day of diagnostic angiography and the conversation was continued over the course of the next two days with the patient and members of the multi-disciplinary Heart Team.
At this point, which treatment choice would you recommend?
Show Answer
The correct answer is: C. Perform LAD PCI and re-evaluate the LCx and RCA lesions.
Discussion
A) While intensification of medical therapy may be a reasonable approach, the patient’s coronary anatomy is now known and demonstrates multi-vessel CAD with proximal LAD involvement. Given that he has not had an improvement in Class III symptoms despite strict heart rate and blood pressure control, and he has evidence of ischemia on non-invasive stress testing, it would be reasonable to pursue revascularization. Revascularization would be anticipated to improve symptoms and, possibly, prognosis. Assessment of coronary artery lesions with fractional flow reserve (FFR) to guide decision-making prior to surgical revascularization has not been evaluated.
B) While the patient has multi-vessel disease, it is not yet clear that revascularization of all of his lesions with PCI would be indicated. His stress test demonstrated an area of small-moderate distal apical and septal ischemia in an LAD distribution and the physiologic significance of his non-LAD disease is uncertain. The ESC guidelines recommend FFR testing of coronary lesions when assessment by non-invasive means does not clearly demonstrate ischemia in the distribution in question. Revascularization of his non-LAD lesions would be considered only for an FFR < 0.80 (See guideline Table 31).1
C) This is the single best answer for this specific case study given the several issues reviewed, including the patient's preferences, the opportunity provided to him to make an informed decision after discussion with the Heart Team, and the uncertainty of the physiologic significance of the non-LAD lesions. FFR assessment of the LCx and RCA lesions can be done at time of repeat catheterization and before planned LAD PCI.
D) The revascularization strategy for patients with three-vessel CAD including the proximal LAD involves a complex decision algorithm that should take into account patient risk factors and co-morbidities, patient preference, the experience of the surgical and interventional cardiology teams at the local institution, and the patient’s coronary anatomy (see guideline Figure 6).1 While CABG would be a reasonable option, he does not have diabetes and has voiced a personal preference not to undergo cardiac surgery. Efforts by the Heart Team should be made to review his options and present alternatives, risks, and benefits in as objective and dispassionate manner as possible, respecting his preferences and values.
Patient Follow-Up:
The patient returned for repeat catheterization. The anatomic findings were unchanged. FFR of the LCx and RCA lesions were 0.86 at both sites. He underwent single vessel PCI of the serial LAD lesions with three overlapping drug-eluting stents. At clinical follow-up, the patient felt that his symptoms had significantly improved, although he reported mild left-sided chest (not throat) discomfort when walking in cold weather. He was able to climb 10 flights of stairs without either throat or chest symptoms. Repeat exercise stress MPI through 11 minutes of the Bruce protocol (13 METS) precipitated mild chest discomfort albeit without evidence of ischemia by either ECG or radionuclide criteria. He continues to be managed medically with slight limitation of exercise tolerance in cold weather. The dose of his stain has been increased in accordance with recent guideline recommendations.
References
Task Force Members, Montalescot G, Sechtem U, Achenbach S, et al. 2013 ESC guidelines on the management of stable coronary artery disease: the Task Force on the management of stable coronary artery disease of the European Society of Cardiology. Eur Heart J 2013;34:2949-3003.
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