Maintenance of Certification in Cardiology

Preparing for the American Board of Internal Medicine Maintenance of Certification

The following questions can assist candidates prepare for the Maintenance of Certification Exam in Endocrinology, Metabolism, and Diabetes. Feedback regarding these questions is welcomed and can be sent to

.

editor@cardiology-review.com

These questions were prepared by

Leslie S. H. Cho, MD.

Rosiglitazone and pioglitazone are both thiazolidinediones, which decrease glucose levels in type 2 diabetes by increasing sensitivity to insulin. In addition to their glucose-lowering ability, these agents have other effects mediated through the activation of the peroxisome proliferator-activated receptor (PPAR) gamma nuclear receptor. What are the effects of rosiglitazone and pioglitazone on triglyceride, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol levels?

1.

a) Both rosiglitazone and pioglitazone lower triglycerides and LDL while increasing HDL.

b) Both rosiglitazone and pioglitazone lower triglycerides and LDL, but pioglitazone increases HDL while rosiglitazone does not.

c) Rosiglitazone lowers LDL and increases triglycerides, whereas pioglitazone increases LDL and lowers triglycerides; however, neither agent has any effect on HDL.

d) Rosiglitazone increases LDL and triglycerides, whereas pioglitazone lowers LDL and increases triglycerides; neither agent has any effect on HDL.

e) Both rosiglitazone and pioglitazone increase LDL and cause a small increase in HDL; however, rosiglitazone increases triglycerides while pioglitazone lowers triglycerides.

2. According to the current American Diabetes Association (ADA) recommendation, in which diabetic patients should a baseline ankle-brachial index (ABI) be established?

a) Only in patients with intermittent claudication; there are no recommendations for asymptomatic diabetic patients.

b) All diabetic patients.

c) Only if a patient has had diabetes for more than 5 years.

d) Only if the patient has had other manifestations of cardiovascular disease.

e) All diabetic patients older than 50 years.

A 68-year-old patient with type 2 diabetes underwent coronary artery bypass graft (CAGB) surgery 2 years earlier and is on a regimen of metformin, glyburide, lisinopril, aspirin, and simvastatin. He comes to your office for a follow-up examination, and having heard the recent controversy surrounding diabetes treatment, would like to know what to do. In light of the ACCORD (Action to Control Cardiovascular Risk in Diabetes) and ADVANCE (Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation) trials, what is the current ADA recommendation regarding glycosylated hemoglobin (HgbA_1c) control for patients with cardiovascular disease?

3.

a) HgbA_1c ≤6.0%

b) HgbA_1c ≤6.5%

c) HgbA_1c ≤7.0%

d) HgbA_1c ≤7.5%

A 45-year-old woman with diabetes, coronary artery disease (CAD), and hypertension comes to your office for a follow-up examination. One year ago, she had a non-ST—segment elevation myocardial infarction (NSTEMI), for which she underwent coronary intervention with placement of a drug-eluting stent in the left anterior descending artery. She is on aspirin, 81 mg; clopidogrel, 75mg; atorvastatin, 80 mg; metformin, 1000 mg twice daily; and lisinopril, 5 mg daily. A fasting lipid panel reveals triglycerides of 150 mg/dL, LDL of 69 mg/dL, and HDL of 35 mg/dL. Her HgbA_1c is 6.2%. Her blood pressure is 120/70 mm Hg, with a heart rate of 62 beats per minute. The remainder of her examination is unremarkable. She wants aggressive risk-factor modification. What should you do next?

4.

a) No change in medication; she is optimally controlled.

b) Lower HgbA_1c to <6.0% by adding a thiazolidinedione or sulfonylurea.

c) Lower triglycerides by adding fenofibrate.

d) Increase HDL by adding niacin.

A 78-year-old man with recently diagnosed type 2 diabetes, CAD, and hypertension presents to the emergency department with NSTEMI. His only symptoms were shortness of breath and increased fatigue. Diagnostic catheterization shows 3-vessel disease with good distal targets and a left ventricular ejection fraction of 0.35. He was discharged to home with the option for undergoing multivessel percutaneous coronary intervention (PCI) or CABG surgery. He is asymptomatic but sedentary. In your opinion, which of the following is the better option for him?

5.

a) CABG surgery, but only if the internal mammary artery (IMA) is used.

b) Multivessel PCI using drug-eluting stents.

c) Multivessel PCI using bare-metal stents.

d) CABG surgery, regardless of whether an IMA or saphenous vein graft is used.

You are being consulted on the case of a 50-year-old man who has postural hypotension and exercise intolerance. He has had diabetes for over 10 years with variable control and is currently on insulin, aspirin, simvastatin, and lisinopril. The patient notes having undergone a dobutamine stress echocardiogram at an outside hospital, which showed a normal ejection fraction and no evidence of ischemia. He did not bring the echocardiogram reports with him. His examination is unremarkable except for resting tachycardia. The internist thinks he might have cardiovascular autonomic neuropathy. What test will you order next?

6.

a) Bedside electrocardiogram (ECG)

b) Cardiac magnetic resonance imaging

c) Cardiac catheterization

d) All of the above

ANSWERS

1. E

There has been much controversy about thiazolidinediones. Both rosiglitazone and pioglitazone increase LDL; however, rosiglitazone causes greater increase in LDL compared with pioglitazone. These agents both increase HDL minimally. Triglycerides are mildly increased by rosiglitazone and are reduced by pioglitazone.

2. E

The ADA consensus statement on peripheral arterial disease (PAD) recommends ABI in diabetic patients over the age of 50, regardless of symptoms, and ABI assessment should be considered in younger patient who have other PAD risk factors, such as smoking, hypertension, hyperlipidemia, or duration of diabetes ≥10 years.

3. C

The current ADA recommendation is to lower HgbA_1C to an average of ≤7.0%, which has been shown to reduce the microvascular and neuropathic complications of diabetes. The recently published ACCORD study, which showed a greater increase in mortality in the tight glycemic control group, had an HgbA_1c of ≤6.5% as the goal.

4. D

Although the patient’s diabetes, hypertension, LDL cholesterol levels, and triglycerides are under good control, her HDL cholesterol level is quite low. The ADA recommends an HDL of >50 mg/dL for women and >40 mg/dL for men with diabetes. Adding niacin would be an option. Because niacin can increase fasting glucose in diabetic patients, it is important to monitor the patient’s fasting glucose during her follow-up examinations.

5. A

According to the BARI (Bypass Angioplasty Revascularization Investigation) trial, which randomly assigned patients to CABG surgery or to percutaneous transluminal coronary angioplasty, CABG surgery had lower mortality overall if the IMA was used, but not if only saphenous vein grafts were used.

6. A

Cardiovascular autonomic neuropathy most likely contributes to the poor prognosis in diabetic patients with cardiovascular disease. The risk for this disorder increases with duration of diabetes and poor glycemic control. Tests to diagnose cardiovascular autonomic neuropathy assess parasympathetic and sympathetic function. Bedside ECG can be used to measure beat-to-beat heart rate variation during deep breathing, with various postural changes, and during the Valsalva maneuver. Cardiac radionuclide imaging with metaiodobenzylguanidine, a physiologic analogue of norepinephrine, can directly visualize the sympathetic nerve activity of the myocardium. Positron emission tomography using C-labeled hydroxyephedrine, a sympathetic neurotransmitter analogue, also can be used to evaluate cardiovascular autonomic neuropathy.