Cardiovascular Disease and Obesity

Definitions:
 

• Angioplasty: A surgical technique performed on patients  to widen an obstructed blood vessel. 
• PTT: Partial Thromboplastin Time is a test that examines coagulation factors in order to determine if blood is clotting normally.  
• Stenosis: A narrowing of a passageway in the body which obstructs blood flow.
• Cardiac Catheterization: A procedure in which a catheter is inserted into the heart's champers or vessels in order to diagnose and treat heart conditions. 
• Pulmonary Edema: A condition in which fluid builds up in the lungs. The condition is usually the result of heart failure.
• Stress Test: There are various types of stress tests. During a cardiac stress test medications are provided to the patient which cause the heart to mimic exercise and allows the physician to determine a patients level of risk for heart surgery. 
• Syncope: Loss of consciousness due to poor blood flow.

Pathophysiology: For each of the following disorders, describe etiology, clinical symptoms, medical treatment and diet therapy.

CAD:

Coronary Artery Disease is caused by a buildup of plaque inside the coronary arteries. There are several contributing factors to Coronary Artery Disease. Genetics contribute to a person’s likelihood of developing atherosclerosis. Some families may have a history of hyper-cholesteremia caused by genetic abnormalities. Age, sex, and a person's weight also play a role. Other factors include dis-lipidemia, hypertension, cigarette smoking, diabetes mellitus, and diet.

A patient with Atherosclerosis will not exhibit signs of the disease unless they begin to show signs of Ischemic Heart Disease, experience angina, or a heart attack. At this point, the patient’s lipid profile would be assessed using the ATP-III guidelines which include examination of hypertension and low HDL cholesterol.

Patients who have atherosclerosis are first encouraged to make lifestyle modifications including weight management, increased physical activity, and diet changes. Diet changes would include increasing fiber, plant stanols/sterols, n-3 fatty acids, and plant-based diets while decreasing saturated fatty acids, trans-fatty acids and cholesterol. If lifestyle modifications do not improve the condition drug treatment will begin. Drug treatment includes treatment with HMG CoA Reductase Inhibitors, Bile Acid Sequestrants, Nicotinic Acid, and/or Fibric Acids.

Currently, the Therapeutic Lifestyle Changes plan is widely accepted for treatment of atherosclerosis. The TLC plan includes a reduction in saturated and cholesterol and increased consumption of fiber and plant stanols/sterols.

CHF:

Congestive heart failure occurs when the heart can no longer eject blood properly or the ventricles can not fill with blood. The primary cause of CHF is Hypertension, dilated Cardiomyopathy, and Ischemic Heart Disease.

Depending upon the type of heart failure (left or right sided) symptoms vary but in general people may experience dyspnea, fatigue, weakness, exercise intolerance, and periphery edema.

Treatment of CHF includes treatment with diuretics, ACE inhibitors, beta-adrenergic blockers, digitalis, dopamine, dobutamine, levosimendan, nesiritide, and L-Name.

Diet therapy includes reduction in sodium intake and fluid intake and increased potassium intake.

Hypertension:

There are two types of hypertension including primary hypertension and secondary hypertension. The cause for primary hypertension is unknown. It is thought to be the result of several different lifestyle factors including diet, exercise, smoking, stress, and obesity. Genetics may also play a role. Secondary hypertension occurs as a result of another primary problem such as renal disease.

Both primary and secondary hypertension are classified based on blood pressure. A systolic blood pressure of 140-159 or a diastolic blood pressure of 80-89 is classified as hypertensive stage I. A systolic blood pressure of greater than or equal to 160 or a diastolic blood pressure of greater than 100 is classified as hypertensive stage II.

Patients who are hypertensive are first encouraged to make lifestyle modifications to reduce their blood pressure. If lifestyle modifications do not improve the condition drug treatment will begin. Drug treatment aims to improve blood pressure by altering cardiac output or peripheral resistance, causing vasodilation, or decreasing heart rate. Drugs from some of the following drug classes are used: loop diuretics, thiazides, carbonic anhydrase inhibitors, potassium-sparing diuretics, ACE-inhibitors, and Beta adrenergic blocking agents.

Diet therapy aims to improve several lifestyle factors which effect blood pressure. Sodium reduction, decreasing alcohol consumption, and increasing potassium, calcium, and magnesium intake are all components of diet therapy. DASH is a widely used comprehensive diet therapy for hypertension which has had proven results. The DASH diet reduces sodium intake and increases potassium, magnesium, calcium, and fiber intake.

List and discuss the risk factors associated with the incidence of CHD. Which of these factors can be modified?

Heredity/Genetics play a role in a persons risk of developing CHD. When hypercholesteremia runs in a family there may be increased risk for development of CHD. CHD develops over a number of years so as age increases so does a persons likelihood for developing CHD. As people age their arteries loose elasticity and control of vascular relaxation is also reduced. Sex plays a role as well. As women age they loose the protective effect of estrogen and are more likely to develop atherosclerosis. Therefore, as women age they are at increased risk for developing atherosclerosis and CHD. Cigarette smoking impairs endothelial relaxation and increases inflammatory markers which can further the development of atherosclerosis. High Blood Pressure can irritate an atherosclerotic lesion and possibly cause it to rupture. Blood Cholesterol levels. Other risk factors include Diabetes, obesity, high blood cholesterol, high LDLs, and low HDL. All of these risk factors besides Age, sex, heredity/genetics, and Diabetes can be modified.

Define cholesterol, VLDL, LDL, HDL and triglycerides. Identify normal blood values for healthy individuals and the relationship between elevated values and the incidence of CHD.

Cholesterol: Cholesterol is synthesized in the body and can also be found in food. It is a fat like substance that is necessary in order for the body to produce hormones, vitamin D, and bile acids. Cholesterol is transported in the blood attached to proteins such as VLDL, LDL, and HDL. When cholesterol blood levels are high they can cause damage to the body by building up in the body’s arteries and making it difficult for blood to flow properly. Normal Blood Values for Healthy Adults-
VLDL: Very Low Density Lipoproteins move cholesterol from the liver to the body’s tissues and organs. When VLDL levels are high it is indicative of higher amounts of cholesterol circulating in the blood stream which increases risk for CHD. Normal Blood Values for Healthy Adults-
LDL: Low Density Lipoproteins are made in the liver and they carry cholesterol from the liver to other parts of the body. When LDL levels are high it is indicative of higher amounts of cholesterol circulating in the blood stream which increases risk for CHD. Normal Blood Values for Healthy Adults- < 100 mg/dL.

HDL: High Density Lipoproteins are made in the liver and carry cholesterol from body tissues and organs back to the liver where they are broken down or recycled. High HDL levels are indicative of a healthier heart because HDL decreases cholesterol levels in the blood. Normal Blood Values for Healthy Adults-
Triglycerides: Triglycerides are the storage form of fat. High levels of triglycerides correspond with an increased risk for heart disease. Normal Blood Values for Healthy Adults-

Identify desired values for total cholesterol/HDL ratio and homocysteine levels, and C-Reactive Protein

The total cholesterol/HDL ration should be below 200. C Reactive Protein normal levels are  below 10mg/L. The normal levels for homocysteine are 5-15 micromoles per liter.

What is the relationship between body composition and CVD risk?

Excessive fat located deep within the abdomen and surrounding the intestines and liver is associated with increased CVD risk. This type of excess fat is known as abdominal obesity. Fat stored around the hips and thighs in contrast is not associated with CVD risk.

What measure(s) of body composition would be most practical to use in a clinical setting?

Body composition measured by weight and BMI are most practical for a clinical setting.

Medical Management

Describe the percutaneous transluminal coronary angioplasty procedure (PTCA). Comment on the success/complication rates for this procedure.

Percutaneous transluminal coronary angioplasty is performed on patients who have atherosclerosis in order to widen the blood vessel. The blood vessel is widened by inserting a catheter with a ballon at the tip using a balloon which is inserted into the vessel and then inflated. Inflating of the balloon presses down on the fatty tissue and widens the blood vessel. Often, a stent is placed in the area where the balloon was inflated to prevent further closure. This procedure is not without risks. The procedure can cause stroke, heart attack, death, and may increase serum levels of enzymes that can cause further complications later in life for the patient. Although these complications are somewhat rare the procedure may not be successful and the vessel may close again. Stent placement and special stents increase the success rate of the procedure.

Surgical Treatment

Describe the CABG procedure. Include information on success rate/complications including sternal wound infection.

In Coronary Artery Bypass Graft surgery grafted vessels are sewn to blocked arteries to bypass the blockage site and allow for proper blood flow. Complications from CABG are rare, however, heart attack, kidney failure, heart arrhythmias, and infection of the sternum can occur. Infection after surgery is the leading cause of mortality in patients undergoing a CABG procedure. Sternum infection happens to about 1% of patients and is the most common type of infection.

Describe the use of VAD devices in heart failure.

Ventricular assistance devices are used in patients who have experienced heart failure in order to help the heart pump blood. They are mechanical pumps that move blood out to the body’s vital organs. Blood flows from the hearts ventricles into the pump and then into the aorta. The VAD can supply continuous blood flow or can pump blood in a similar pattern to that of the heart.

Drug Therapy

Discuss the use of the following drugs. Include classification, mechanism of action, indication for use with the cardiac patient, effect of the drug on nutrient absorption and utilization, effect of nutrients on drug absorption and utilization.

Digoxin: Falls into the Digitalis class of drugs. It increases the strength of heart contractions and slows the electrical conduction between the atria and ventricles by altering function of the sodium potassium pump. It is used on patients with arrhythmias. Digoxin can cause hypokalemia. Patients taking this drug should avoid Saint Johns Wart.

Aspirin:  A salicylate drug. Aspirin blocks clot formation by preventing the formation of the chemical that causes platelets to clump. It is used to prevent and treat heart attack and stroke. Large amounts of aspirin can cause a loss of folate, vitamin C, and stomach bleeding which could cause a loss of iron. Patients taking aspirin should avoid natural products which affect coagulation including garlic, ginger, gingko, and horse chestnut.

Coumadin: Part of the class oral anticoagulant. It prevents clotting factors from forming and is used to prevent clot formation. Consuming too much vitamin K can reduce the effect of Coumadin.

Aldactone: Falls into the aldosterone antagonist class. Used to lower blood pressure. It interrupts aldosterone and increases sodium and water excretion. It can increase serum potassium levels and lower sodium levels. A person receiving aldactone should have their potassium intake monitored closely.

Mevacor/Lovostatin: Falls into the statin class. Used to reduce LDL cholesterol levels. It inhibits HMG-CoA reductase and thus reduces cholesterol. Grapefruit can inhibit the metabolism of this drug.

Lasix: A diuretic. Decreased blood volume by increasing urinary output and inhibiting renal sodium and water reabsorption. Used to decrease blood pressure. Can cause hypokalemia, hyperlipidemia, and hypertriglceridemia.

Streptokinase: Falls into the class Fibrinolytic Therapy. It works by interrupting prothrombin which reduces the ability of blood to clot. Used to treat blood clots.

Tissue plasminogen activator: A serene protease which catalyzes the conversion of plasminogen to plasmin which is an enzyme necessary for dissolving clots. It is used to treat heart attack and stroke.

Nutritional Management

Summarize the dietary recommendations in the NHLBI National Cholesterol Education Program (NCEP). Note the differences between Step I and Step II.

Step 1 and Step 2 have been revised so that the guidelines are the same for everyone therefore there is no designation between step one and step two: consume 25-35% of daily calories from fat with less than 7% of those calories coming from saturated fat and reduce cholesterol consumption to less than 200 milligrams per day.

What is the relationship of dietary cholesterol to serum cholesterol?

Cholesterol levels are mainly influenced by the cholesterol produced by the body, however, dietary cholesterol also impacts cholesterol levels. Excess dietary cholesterol is transported in the blood by lipoproteins to be deposited to other parts of the body. Therefore as dietary cholesterol increases to an amount above what is needed by the body for normal functioning serum cholesterol increases.

What is the relationship of saturated fat in the diet to serum cholesterol?

Saturated fat increases LDL levels which increases serum levels of cholesterol.

What effect, if any, does dietary fiber have on serum cholesterol levels?

Fiber can lower serum cholesterol levels.

What is the current research on monounsaturated fat relative to dietary management of CAD?

Monounsaturated fat can lower serum cholesterol levels but does not lower the extent of  coronary artery atherosclerosis (Degirolamo and Rudel, 2010).

List the predominant fat in each of the following (i.e. Saturated, Monunsaturated and Polyunsaturated).

Butter: Saturated fat 

Coconut oil: Saturated fat 

Palm oil: Saturated fat 

Olive oil: Monounsaturated fat 

Peanut oil: Monounsaturated fat

Canola oil: Monounsaturated fat 

Soybean oil: Polyunsaturated fat 

Safflower oil: Polyunsaturated fat

Sunflower oil: Monounsaturated fat

Flaxseed oil: Polyunsaturated fat

What role, if any, does omega 3 fatty acids play in the management of CAD? What are the recommended amounts of omega 3 fatty acids?

Omega 3 fatty acids are thought to reduce inflammation which can damage blood vessels and are also thought to decrease triglycerides, lower blood pressure, and reduce blood clotting. The American Heart Association and the American Dietetic Association recommends consuming fish high in omega 3 fatty acids 2x per week (450-500 mg EPA and DHA per day) to prevent heart disease (American Dietetic Association, 2007).

Explain the role that soy plays in the management of CHD. What are the recommended amounts of soy?

Experts have not been able to make a direct connection between CHD and soy. However, foods high in soy are low in saturated fat and high in fiber which does correlate with decreased risk for CHD. The American Dietetic Association put out a statement about functional foods in 2009 that stated that consuming a diet low in cholesterol, low in saturated fat, and containing 25g of soy protein a day might reduce the risk of CHD.

Explain the role of plant stanols in the management of CHD. What are the recommended amounts of stanols?

Plant stanols lower serum cholesterol and LDL cholesterol levels. 2-3 grams of plant sterols/stanols are recommended for consumption each day to lower cholesterol (American Dietetic Association Position Statement on Plant Stanol/Sterol Esters, 2002). 

What is the relationship of trans fats in the diet to serum cholesterol? Name four foods that contain trans fats.

Trans fats lower HDL cholesterol and raise LDL cholesterol levels and increase plaque build up. Trans fats can be found shortenings, margerines, fried foods, cookies, crackers, and other commercially baked foods that are partially hydrogenated.

List five suggestions for preparing meals for a person on a saturated fat/cholesterol restricted diet.

Increase fiber and whole grains

Substitute egg whites for whole eggs

Choose lean cuts of meat and trim visible fat before eating

Switch from cooking with butter to oils high in mono and polyunsaturated fatty acids such as olive oil

Switch to low fat dairy products

List five suggestions for a person on a saturated fat/cholesterol restricted diet to follow when dining out.

Read the nutrition facts panel and avoid foods that contain the words “partially hydrogenated.”

Avoid fried foods

Choose leaner cuts of meat like chicken or turkey or remove the skin from your meat

Make fruits, vegetables, and carbohydrates the centerpiece of your meal

When ordering eggs ask for an egg substitute or ask that your egg be prepared as egg whites only.

What precautions must be taken when prescribing salt substitutes?

Salt substitutes often contain potassium. Patients on renal dialysis are at risk for hyperkalemia. Use caution when prescribing salt substitutes to these patients to reduce the risk of hyperkalemia. Some salt substitutes may also not be appropriate for patients on specific medications. Ensure that there is not a possible interaction with the patient’s medical prescriptions before prescribing a salt substitute.

What are the possible benefits/negative effects of alcohol consumption by patients with CAD?

Increased alcohol consumption may increase the risk of developing hypertension. However, light and moderate alcohol consumption has been associated with a decreased risk of developing coronary heart disease.

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INTERN’S NAME: Melissa Cannon

INSTITUTION: Cooler-Goldwater

ROTATION AREA: CVD/Obesity

CHARTING TYPE: Not specified 

PRECEPTOR’S COMMENTS / CORRECTIONS OF CHARTING

The patient had trace edema at her feet. Typically a patient’s nutritional needs are not assessed when edema is present. However, in this case Michelle (the dietitian I worked with in completing this assessment) recommended using the patient’s actual body weight because she believed the contribution of extra fluid would be minimal. In calculating the patients nutritional needs I originally chose to use a 25-30ml range for the patient’s fluid status. Michelle recommended a lower range of 25-27 because the patient had heart complications in addition to the edema. The patient’s protein requirements were increased secondary to a sacral ulcer and the presence of edema. Michelle recommended that I go with a slightly lower range for calculating out the patients protein needs at 1 to 1.3g/kg as opposed to a larger range of 1-1.5g/kg.

INTERN’S COMMENTS ABOUT NUTRITIONAL INTERVENTION(S):

The patient was receiving Coumadin to prevent blood clots. I provided nutrition education to the patient on the importance of maintaining a steady vitamin K intake. The patient spoke Spanish and English and was provided with a Spanish/English handout. When first discussing the steady vitamin K intake the patient stated that she had never had anyone talk to her about the complications of Coumadin, however, about 2 minutes into our discussion she began to mention that she had previously had someone discuss the diet interactions of the medication with her. The encounter highlighted the importance of ensuring patient understanding. 

WAS THE NUTRITION INTERVENTION SUCCESSFUL? WHY/WHY NOT?:

The patient had a common misunderstanding that she was not supposed to consume foods high in Vitamin K. However, after our meeting she verbalized her understanding that she could continue to consume foods high in vitamin K as long as her intake remained steady. I was unable to follow up with the patient as she was discharged from the facility because she was not participating in her cardiac rehabilitation program.