Discussion: Ratio of cholesterol to HDL

The patient was a 48-year-old man admitted to the coronary care unit complaining of substernal chest pain. During the 4 months preceding admission, he noted chest pain radiating to his neck and jaw during exercise or emotional upsets. The pain dissipated when he discontinued the activity or relaxed. The results of his physical examination were essentially normal except for a systolic murmur heard best at the apex of the precordium and radiating into the left axilla.

Studies

Results

Routine laboratory work

Within normal limits (WNL)

Cardiac enzyme studies

Creatine phosphokinase (CPK), p. 167

235 units/L (normal: 55–170 units/L)

CPK-MB, p. 171

12 ng/mL (normal: 0–3 ng/mL)

Lactic dehydrogenase (LDH), p. 293

120 units/L (normal: 90–200 units/L)

Serum aspartate aminotransferase (AST), p. 107

24 International units/L (normal: 5–40 International units/L)

Troponins, p. 451

18 ng/mL

Echocardiography, p. 820

Hypokinetic portion of the lateral left ventricle

Electrocardiography (EKG), p. 485

Evidence of left ventricular hypertrophy

Chest x-ray study, p. 956

WNL

Exercise stress test, p. 481

Positive: pain reproduced; ST segment depression noted on EKG (normal: negative)

Echocardiography, p. 820

Normal ventricular wall motion

Transesophageal echocardiography (TEE), p. 840

Mitral regurgitation, dilated left atrium

Lipoproteins, p. 304

HDL

29 mg/dL (normal: >45 mg/dL)

LDL

189 mg/dL (normal: 60–180 mg/dL)

VLDL

12 mg/dL (normal: 7–32 mg/dL)

Homocysteine, p. 269

16 mol/L

C-reactive protein (CRP), p. 165

22 mg/dL

Cardiac catheterization, p. 950

All WNL except:

Pressures

Left ventricular systolic pressure

140 mm Hg (normal: 90–140 mm Hg)

Aortic systolic pressure

130 mm Hg (normal: 90–140 mm Hg)

Ventricular-aortic pressure gradient

5 mm Hg (normal: 0)

Left ventricular function

Cardiac output

3.5 L/min (normal: 3–6 L/min)

End diastolic volume (EDV)

60 mL/m2 (normal: 50–90 mL/m2)

End systolic volume (ESV)

22 mL/m2 (normal: 25 mL/m2)

Stroke volume (SV)

38 mL/m2 (SV = EDV ? ESV)

Ejection fraction

0.63 (normal: 0.67 ± 0.07) Discussion: Ratio of cholesterol to HDL

Cineventriculography

Mitral regurgitation present, normal muscle function (normal: normal ventricle)

Analysis of O2 gas content, p. 98

No shunting (normal: no shunting)

Coronary angiography (coronary cineangiography), p. 950

90% narrowing of left coronary artery (normal: no narrowing)

Cardiac radio-nuclear scanning, p. 733

Scans normal showed localized area of decreased perfusion and poor muscle function in the myocardium during exercise

Cholesterol, p. 138

502 mg/dL (normal: <200 mg/dL)

Triglycerides, p. 447

198 mg/dL (normal: 40–150 mg/dL)

Diagnostic Analysis

Cardiac radio-nuclear scanning, EKG, and studies ruled out the possibility of MI. Troponins and serial cardiac enzyme indicated cardiac ischemia. Stress testing and a nucleotide scan indicated that the patient was having exercise-related myocardial ischemia (angina). Echocardiography indicated that the heart muscle at the site of ischemia was functioning poorly. Transesophageal echocardiography indicated that the patient had mitral regurgitation. Cardiac catheterization with cineventriculography demonstrated near-normal ventricular function, and coronary angiography indicated significant narrowing of the left coronary artery. Mitral regurgitation was also seen. The patient’s angina was then thought to be caused by the coronary artery disease. Open heart surgery was performed. The patient\’s mitral valve was replaced with a prosthesis, and an aortocoronary artery bypass graft was performed. Postoperatively, he had a large pericardial effusion. This diminished his heart function. He underwent pericardiocentesis, and his function improved. Because his serum lipids study showed type IIa hyperlipidemia, a low-cholesterol diet and cholesterol-lowering agents were prescribed. The other cardiac risk factors did indicate increased risk for coronary heart disease. Six months later he was asymptomatic and jogging 3 miles per day.

Questions:

1. Based on the ratio of cholesterol to HDL, what is the patient’s risk for coronary heart disease?

2. If these blood tests were drawn 1 year ago, what treatment would have been indicated? Discussion: Ratio of cholesterol to HDL