Lipid-lowering therapy after an atherosclerotic event

Quantitative Extent of Atherosclerotic Plaque in the Major Epicardial Coronary Arteries in Patients with Fatal Coronary Heart Disease, in Coronary Endarterectomy Specimens, in Aorta-Coronary Saphenous Venous Conduits, and Means to Prevent the Plaques: A Review after Studying the Coronary Arteries for 50 Years

This review tries to answer the following 15 questions: Is atherosclerosis a systemic or a regional disease? Is atherosclerosis in any particular region focal or diffuse? What is the quantity of atherosclerotic plaques in endarterectomy specimens of the right coronary artery in patients undergoing coronary artery bypass grafting (CABG) compared to that in the right coronary artery in patients with fatal coronary artery disease? How do the units used for measuring arterial narrowing by angiography compare to the units used for measuring arterial narrowing at necropsy? What do atherosclerotic plaques consist of in coronary arteries in patients with fatal coronary disease? What is the quantity of atherosclerotic plaque in bypassed -vs- non-bypassed native coronary arteries in patients dying early (<60 days) or late (>60 days) after coronary artery bypass grafting? What is the frequency of acute coronary lesions and multi-luminal channels at necropsy in patients with unstable angina pectoris, sudden coronary death, and acute myocardial infarction? What is the mechanism of luminal widening by angioplasty in the coronary arteries? What observations suggest that atherosclerotic plaques are the result at least in part of organization of thrombi? Is atherosclerosis a multifactoral or a unifactoral disease? What characteristics distinguish carnivores and herbivores? What are reasonable guidelines for whom to treat with lipid-altering agents? What is the rule of 5 and the rule of 7 in statin therapy? What is the effect of lipid lowering drug therapy on coronary luminal narrowing? What are some requisites for a healthy life?

Preventing and arresting coronary atherosclerosis

The good news about coronary atherosclerosis is that it takes an awful lot of plaque before symptoms of myocardial ischemia occur. The bad news is that despite the need for large quantities of plaque for symptoms to occur, nevertheless nearly half of us in the United States eventually have the necessary quantity. Atherosclerosis is infrequently hereditary in origin. Most of us get atherosclerosis because we consume too much fat, cholesterol, and calories. The consequence is an elevated ( > 150 mg/dl) serum total cholesterol level, and the higher the number is above 150, the greater is the quantity of plaque deposited in our arteries. If the serum total cholesterol level can be prevented from rising to more than 150 mg/dl, plaques are not laid down; if elevated levels are lowered to 150 mg/dl, further plaque does not form, and parts of those present may vanish. A fruit-vegetarian-starch diet is necessary as a rule to achieve the 150 mg/dl level in most adults. Lipid-lowering drugs are required in the patients with familial hypercholesterolemia and in most patients with atherosclerotic events. The best news about atherosclerosis is that it can be prevented in those without the hereditary form, and it can be arrested by lowering elevated serum total (and LDL) cholesterol to the 150 mg/dl level.

Heart disease in the assessment and treatment of hypercholesterolemia: coronary artery disease and other atherosclerotic disease, family history, and left ventricular hypertrophy

There appears to be little doubt that lowering serum cholesterol for reduction of risk for coronary artery disease (CAD) events in patients with established CAD is cost-effective and can decrease the rate of CAD events, stabilize atherosclerotic plaque progression, and reduce CAD mortality and all-cause mortality. Meta-analysis of clinical trials conducted in patients with CAD has shown a 26% reduction in CAD events and a 9% reduction in total mortality. It was generalized from the results of nine major, recent angiographically monitored clinical trials that an improvement in obstruction was seen in 8% of control patients and 25% of treated patients. In the recently released report of the second Adult Treatment Panel (ATP II) of the U.S. National Cholesterol Education Program, atherosclerotic disease status joins low-density lipoprotein cholesterol (LDL-C) level as central to the diagnosis and treatment algorithm. The ATP II evaluation process is divided into two categories according to whether atherosclerotic disease is present, and a lower LDL-C target level--100 mg/dL (2.6 mmol/L)--is set for secondary prevention. Initial therapy when LDL-C is > or = 100 mg/dL in a patient with atherosclerotic disease is the Step Two Diet, weight control, exercise, and control of other risk factors. Drug therapy may be considered after a relatively short trial of hygienic therapy if LDL-C remains > or = 130 mg/dL (3.4 mmol/L). Other, selected aspects of heart disease for general consideration in assessing CAD risk are family history and the presence of left ventricular hypertrophy (LVH). Family history of premature CAD is included in the ATP II algorithm, with different age considerations by gender added. Although LVH is not part of ATP II risk assessment, its presence as defined by echocardiography increases CAD risk six- to eightfold in both men and women.

Morphologic findings in saphenous veins used as coronary arterial bypass conduits for longer than 1 year: necropsy analysis of 53 patients, 123 saphenous veins, and 1865 five-millimeter segments of veins

Certain clinical and necropsy findings are described in 53 patients who died from 13 to 185 months (mean 58) after a single aortocoronary bypass operation. Of the 53 patients, 32 (60%) died of a cardiac cause and of their 72 saphenous vein aortocoronary conduits, 36 (49%) were narrowed at some point more than 75% in cross-sectional area by atherosclerotic plaque; the remaining 21 patients (40%) died of a noncardiac cause and of their 50 saphenous vein conduits, 10 (20%) were narrowed at some point more than 75% in cross-sectional area by plaque. Thus the noncardiac mode of death in a large percentage of the patients suggests that the bypass operation prolonged life to a degree sufficient for another condition to develop. The 123 saphenous vein conduits were divided into 5 mm segments, and a histologic section was prepared from each. Of the 1104 five-millimeter segments in the 32 patients dying as a consequence of myocardial ischemia, 291 (26%) were narrowed more than 75% in cross-sectional area by plaque; in contrast, of the 761 five-millimeter segments of veins in the 21 patients with a noncardiac mode of death, 86 (11%) were narrowed more than 75% by plaque. Of the total 1865 five-millimeter segments of vein, only 395 (21%) were narrowed 25% or less in cross-sectional area by plaque. Thus, in patients dying late after coronary bypass the atherosclerotic process continues in all segments of the saphenous veins used as aortocoronary conduits. Therapy after the operation must be directed toward prevention of progression of the atherosclerosis in the "new" coronary "arteries."