CardioExchange Archive

A 61-year-old man with a past medical history significant for hypertension, hyperlipidemia (LDL-C, 145 mg/dL; HDL-C, 38 mg/dL), and type 2 diabetes (HbA1c, 8.2) presents to his primary care physician after several months of exertional chest tightness that is associated with dyspnea and relieved by rest. His current medications include lisinopril at 20 mg/day, metoprolol succinate at 50 mg/day, simvastatin at 20 mg/day, and glyburide at 10 mg/day.

He is referred for an exercise treadmill test with myocardial perfusion imaging. He exercises for 8:08, achieving 10.2 METs and reaching 94% of peak HR goal, before stopping for mild chest tightness and fatigue. The imaging portion of the study reveals an estimated LVEF of 62% with moderate-sized, medium-intensity reversible perfusion defects in both the inferior and lateral walls.

Based on these results, the patient is referred for coronary angiography, which reveals 70% discrete lesion of the mid-LAD after the take-off of the first diagonal, 90% complex lesion of the mid-LCx, and 80% discrete lesion in the proximal RCA.

Questions for Discussion:

1.   How would you proceed at this point?

• Optimize medical therapy with intensification of glycemic, anti-hypertensive, and lipid-lowering therapies.
• Optimize medical therapy but also proceed with PCI and stenting of the RCA and LCx.
• Optimize medical therapy and proceed to PCI based on fractional flow reserve assessment.
• Optimize medical therapy and refer the patient for CABG surgery.

2.   What would constitute “optimal medical therapy” for this patient?

3.   Based on the patient’s clinical presentation, would you have performed the sequential testing as outlined in the vignette (i.e., stress test followed by coronary angiography), or would you have pursued a different management strategy?

Response:
James Fang, MD

Therapy for this patient is very much dependent on the goals of the patient as well as his physicians. Clearly, medical therapy needs to be intensified. The decision to catheterize the patient based on the stress test results would likely have been driven by a concern for multivessel ischemic heart disease, despite the good exercise tolerance, and by a perception that revascularization in this setting (with preserved ventricular function) improves survival. This decision of whether or not to revascularize depends on the ischemic burden. If the patient is not satisfied with his functional capacity and is limited by angina, I would offer revascularization. Contemporary revascularization trials suggest no significant mortality differences between CABG and PCI, even in the presence of DM. However, more procedures are likely with a PCI approach.

Medical management should consist of aggressive statin therapy to drive his LDL to <70 mg/dL, his HDL to >40 mg/dL, and his TG to <200 mg/dL. I suspect a potent statin will be necessary to achieve these levels — and if that isn’t effective, I would consider niacin, even though the trial results aren’t in yet. His HbA1c goal is unclear, particularly in light of the recent ACCORD data. I would personally target <7.5%, but this is a compromise based on the available data. Clearly, overly aggressive control has to be balanced against complications from hypoglycemia — an issue that has tempered the trials of glucose control in heart disease. The best way to control blood sugar is not clear from the diabetes trials, and most patients seem to require more than one class of oral hypoglycemic drug to reach good control. Finally, this patient’s beta-blocker dose is very modest and could be increased.

A case could certainly have been made to manage the patient medically, based purely on the stress test results. However, in the U.S., it is rare for a positive stress test to not lead to coronary angiography, despite good evidence that even patients with multivessel ischemic heart disease can be managed medically without sacrificing years of life.