Prevention of coronary heart disease with pravastatin in men with hypercholesterolemia. West of Scotland Coronary Prevention Study Group

Choosing the right lipid-regulating agent. A guide to selection

If dietary therapy and other lifestyle changes do not adequately normalise blood lipid levels, lipid-regulating drugs, as single-drug or combination-drug therapy, may be prescribed to supplement lifestyle changes. Evaluation of the individual patient's health and risk status, determination of the dyslipidaemia, definition of treatment goals and a clear understanding of the mechanisms and effects of lipid-regulating agents are necessary for optimisation of treatment. Although all the available lipid-regulating agents lower low density lipoprotein (LDL) cholesterol, the agents with the greatest LDL cholesterol-lowering effect are the bile acid sequestrants, which up-regulate the LDL receptor by the decrease in intrahepatic cholesterol caused by the interruption of enterohepatic circulation of cholesterol-rich bile acids, and the HMG-CoA reductase inhibitors, which partially inhibit HMG-CoA reductase. The agents with the greatest triglyceride-lowering effect are nicotinic acid, which decreases the production of very low density lipoprotein (VLDL) cholesterol and reduces the availability of free fatty acids in the circulation, and the fibric acid derivatives, which increase lipoprotein lipase activity and may also decrease the release of free fatty acids. Although the safety profile of the available lipid-regulating drugs has been established, patients should be monitored for potential adverse effects and interactions with concomitantly administered agents. When used correctly, lipid-regulating drug therapy is highly effective in the treatment of a variety of dyslipidaemias.

Jejunal permeability and hepatic extraction of fluvastatin in humans

OBJECTIVES

The primary objective was to investigate the effective permeability and the hepatic extraction of fluvastatin, a new 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor, during a jejunal perfusion in humans. The secondary objective was to investigate the relationship between human jejunal effective permeability values and physicochemical properties for four different drugs.

METHODS

Nine healthy male volunteers were included in the study, which consisted of two sequential study parts. In the first part, the jejunal effective permeability of fluvastatin, antipyrine, metoprolol, and atenolol was assessed with use of the regional jejunal perfusion approach (150 minutes, 2.0 ml/min). After a washout period of at least 5 days, the same subjects received an intravenous infusion of fluvastatin (20 minutes, 2.0 mg). Plasma samples were taken in both parts of the study and were analyzed for the content of fluvastatin.

RESULTS

The mean hepatic extraction of fluvastatin was 67% after the jejunal perfusion and 73% after the intravenous infusion. The half-life of fluvastatin was approximately 60 minutes after both administration routes. The jejunal effective permeability and the fraction absorbed both correlated (r2 = 0.968, p < 0.05; and r2 = 0.994, p < 0.05) with the partition coefficient (log D, pH 6.5) but not with the molecular size or the hydrogen bond number.

CONCLUSION

Fluvastatin is extracted by the liver to a large extent (about 70%) and has a short half-life after both oral and intravenous administration. In this study, the human jejunal effective permeability and the fraction absorbed for these four drugs were better predicted by log D (pH 6.5) than both the molecular size and the hydrogen bond number.

Predominance of dense low-density lipoprotein particles predicts angiographic benefit of therapy in the Stanford Coronary Risk Intervention Project

BACKGROUND

LDL particles differ in size and density. Individuals with LDL profiles that peak in relatively small, dense particles have been reported to be at increased risk of coronary artery disease. We hypothesized that response to coronary disease therapy in such individuals might differ from response in individuals whose profiles peak in larger, more buoyant LDL. We examined this hypothesis in the Stanford Coronary Risk Intervention Project, an angiographic trial that compared multifactorial risk-reduction intervention with the usual care of physicians.

METHODS AND RESULTS

For 213 men, a bimodal frequency distribution of peak LDL density (g/mL) determined by analytical ultracentrifugation was used to classify baseline LDL profiles as "buoyant mode" (density < or = 1.0378) or "dense mode" (density > 1.0378). Coronary disease progression after 4 years was assessed by rates of change (mm/y, negative when arteries narrow) of minimum artery diameter. Rates for buoyant-mode subjects were -0.038 +/- 0.007 (mean +/- SEM) in usual care (n = 65) and -0.039 +/- 0.010 in intervention (n = 56; P = .6). Rates for dense-mode subjects were -0.054 +/- 0.012 in usual care (n = 51) and -0.008 +/- 0.009 in intervention (n = 41, P = .007). Lipid changes did not account for this difference in angiographic response.

CONCLUSIONS

Different types of LDL profile may predict different-responses to specific therapies, perhaps because metabolic processes determine both LDL profiles and responses to therapies.

Prevention and regression of atherosclerosis: effects of HMG-CoA reductase inhibitors

OBJECTIVE

To review the current literature on the effects of hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors in secondary prevention and regression of atherosclerosis.

DATA SOURCES

A MEDLINE and journal search of recent studies evaluating the effects of lipid lowering with HMG-CoA reductase inhibitors on serum cholesterol as well as progression and regression of atherosclerotic coronary or carotid disease in patients with established atherosclerotic disease was conducted. Articles addressing the pathophysiology of atherosclerotic disease were identified by using the same sources.

STUDY SELECTION

All available studies evaluating the use of HMG-CoA reductase inhibitors in the progression and regression of coronary and carotid atherosclerosis were reviewed.

DATA SYNTHESIS

Lowering of total serum cholesterol, low-density lipoprotein cholesterol, and triglycerides, as well as increasing high-density lipoprotein cholesterol can be achieved with HMG-CoA reductase inhibitors. Aggressive lipid lowering has been demonstrated to alter progression of established atherosclerotic disease and, in some patients, actually induce regression of the atheroma. An unexpected finding of several trials was the early and significant reduction in clinical cardiac events. Other mechanisms by which clinical event reduction may be explained include plaque stabilization and restoration of endothelium vasodilation.

CONCLUSIONS

Aggressive lipid-lowering therapy using HMG-CoA reductase inhibitors appears to alter the natural progression and promote regression of atherosclerosis in selected patients with established coronary or carotid atherosclerosis. However, it is unlikely that regression of atherosclerosis alone is responsible for the marked reduction in clinical cardiac events seen in these trials.

Atherosclerosis and restenosis: reflections on the Lovastatin Restenosis Trial and Scandinavian Simvastatin Survival Study

Atherosclerosis is related to serum lipids, whereas restenosis after coronary angioplasty is probably not, reflecting different pathophysiologies. Nonetheless, treatment of lipid disorders is appropriate after angioplasty.

Postal questionnaire study of disability in the community associated with psoriasis

OBJECTIVE

To study the disability caused by psoriasis in patients recorded as having psoriasis by their general practitioner.

DESIGN

Postal questionnaire survey using the psoriasis disability index and SF-36.

SETTING

Five general practices in Cleveland.

SUBJECTS

Of 767 patients identified, 546 completed the questionnaire and 435 were eligible and gave informed consent.

MAIN OUTCOME MEASURES

Scores on SF-36 and psoriasis disability index.

RESULTS

The psoriasis disability index score was highly negatively correlated with all eight of the SF-36 health measures (P < 0.0001 for each), and the manual social classes scored higher than the non-manual social classes (P < 0.0001). The manual social class group scored significantly lower scores than the controls on all the SF-36 scales, and the non-manual group scored significantly lower for physical and mental role limitation (P < 0.0004 and P = 0.026), mental health (P < 0.0001), energy and vitality (P < 0.0004), and health perception (P < 0.0001). Also, the manual group had poorer health perception on five of the SF-36 variables when compared with the non-manual group.

CONCLUSIONS

Patients with psoriasis have an overall lower perception of their quality of life than healthy controls, and those in the lower social classes suffer a greater degree of disability from their disease than the higher social classes.

Lipid management: current diet and drug treatment options

Diet and drug therapy are two of the principal approaches to lipid management. The aim of both is to reduce low-density-lipoprotein (LDL) cholesterol to goal levels established by the National Cholesterol Education Program Expert Panel in its second report, based on a patient's short-term risk of a coronary event. In prescribing diet therapy, it is important to determine patients' willingness to initiate and adhere to dietary modifications, their skill at reading nutritional labels, adapting recipes, and ordering "heart-healthy" foods when eating out. Diet therapy should be directed at modifying dietary factors known to adversely influence blood cholesterol-saturated fats, cholesterol, and obesity. Diet therapy (with exercise) is not always adequate. High risk individuals with no overt coronary artery disease but with >/=2 risk factors, as well as patients with coronary artery disease, are potential candidates for drug therapy, depending on their LDL cholesterol levels. The "statins" are the drug of choice for patients with coronary disease and elevated LDL cholesterol or familial LDL-cholesterol abnormalities. These drugs increase high-density-lipoprotein (HDL) cholesterol and reduce LDL cholesterol, coronary artery disease, and total mortality. Bile acid resins lower LDL cholesterol and are often used to augment the effects of the statins and niacin. Niacin is particularly useful in the management of patients with combined hyperlipidemia and low HDL cholesterol levels. Gemfibrozil is effective in familial dysbetalipoproteinemia and is the drug of choice for patients with severely elevated serum triglycerides.

Pathogenic mechanisms of atherosclerosis: effect of lipid lowering on the biology of atherosclerosis

Numerous trials have demonstrated that cholesterol-lowering therapy leads to marked reductions in cardiovascular and overall mortality and in the need for coronary revascularization. Angiographic regression trials have shown that cholesterol lowering can reduce progression and, in some instances, achieve regression of coronary atherosclerotic lesions. However, recent studies have contradicted the traditional view that the clinical course of coronary artery disease is closely linked to the severity of coronary artery stenosis. It is now apparent that stenoses responsible for myocardial infarction or unstable angina are typically mild rather than severe. These observations suggest that regression may not be the principal mechanism by which cholesterol lowering affects cardiovascular risk. Two mechanisms---plaque stabilization and improved endothelial function-have been examined in this regard. Basic studies suggest that cholesterol lowering favorably alters those features of atherosclerosis that promote plaque stability. Recent clinical studies have clearly established that aggressive lipid-lowering therapy improves endothelial function and reduces myocardial ischemia in patients with hypercholesterolemia.

Review of cholesterol-lowering therapy: coronary angiographic and events trials

Coronary angiographic trials have demonstrated that the lowering of cholesterol slows the progression of atherosclerosis, enhances atherosclerotic regression, limits the formation of new lesions, and reduces the incidence of coronary events. Atherosclerotic progression has been shown to be associated with an increased risk of cardiac death, cardiac death plus nonfatal myocardial infarction (MI), and all coronary events. Most of the atherosclerotic regression trials were too small and of too short duration to demonstrate a significant difference in hard coronary events between patients receiving cholesterol-lowering intervention and controls. However, when data from these studies were pooled, total mortality was found to be reduced by 26% and the rate of nonfatal MI by 39% in actively treated patients. The first events trial to demonstrate clearly a reduction in overall mortality was the Scandinavian Simvastatin Survival Study (4S), in which lowering of serum cholesterol in patients with coronary artery disease (CAD) and hypercholesterolemia also reduced coronary mortality, fatal and nonfatal MI, sudden cardiac death, and the need for revascularization. Reductions in major coronary events were seen consistently in all subgroups of patients studied and regardless of concomitant therapy with aspirin, beta blockers, or calcium antagonists. Further evidence of the benefit of cholesterol-lowering therapy was provided by the West of Scotland Coronary Prevention Study (WOSCOPS), which evaluated men with hypercholesterolemia but no history of CAD. Those receiving active treatment had less overall mortality, lower risk of definite nonfatal MI or death from definite or suspected CAD, and less need for revascularization. The Cholesterol and Recurrent Events (CARE) Study recently showed that lipid-lowering therapy is also beneficial in CAD patients with less severe dyslipidemia.

Risk stratification in coronary artery disease and special populations

In patients with coronary artery disease (CAD), left ventricular (LV) function, the number of diseased vessels, and the severity of myocardial ischemia are important determinants of survival. These factors can be used to identify subsets of high-risk patients who are candidates for aggressive intervention. Among patients with LV dysfunction, those with left main CAD, three-vessel disease, and one- or two-vessel disease with inducible ischemia are at highest risk. High-risk subsets among those with preserved LV function include patients with left main CAD and those with inducible ischemia and either three-vessel disease or two-vessel disease with involvement of the proximal left anterior descending coronary artery. Thus, exercise testing, assessment of ventricular function and, in selected patients, coronary angiography to determine coronary anatomy are valuable tools in risk stratification. In the primary-care setting, patient characteristics such as gender, race, age, and concomitant medical conditions may also be most useful in identifying high-risk patients. Although women in general have some primary protection against premature CAD, especially prior to the menopause, coronary risk in women who have experienced a cardiovascular event is similar to that in men. Coronary mortality is increased in minority populations, and the presence of other risk factors, such as diabetes and hyperlipidemia, can further increase this risk. Up to 80% of diabetic patients die of cardiovascular disease, 75% of which is CAD. The risk in this population is exacerbated by the abnormalities in lipid metabolism associated with the diabetic state. CAD mortality increases with aging, but it is recommended that elderly patients with CAD also receive risk factor intervention, such as cholesterol-lowering therapy. Consideration of the impact of such therapy on quality of life is especially important in initiating such interventions in the older population.

The effect of pravastatin on coronary events after myocardial infarction in patients with average cholesterol levels. Cholesterol and Recurrent Events Trial investigators

BACKGROUND

In patients with high cholesterol levels, lowering the cholesterol level reduces the risk of coronary events, but the effect of lowering cholesterol levels in the majority of patients with coronary disease, who have average levels, is less clear.

METHODS

In a double-blind trial lasting five years we administered either 40 mg of pravastatin per day or placebo to 4159 patients (3583 men and 576 women) with myocardial infarction who had plasma total cholesterol levels below 240 mg per deciliter (mean, 209) and low-density lipoprotein (LDL) cholesterol levels of 115 to 174 mg per deciliter (mean, 139). The primary end point was a fatal coronary event or a nonfatal myocardial infarction.

RESULTS

The frequency of the primary end point was 10.2 percent in the pravastatin group and 13.2 percent in the placebo group, an absolute difference of 3 percentage points and a 24 percent reduction in risk (95 percent confidence interval, 9 to 36 percent; P = 0.003). Coronary bypass surgery was needed in 7.5 percent of the patients in the pravastatin group and 10 percent of those in the placebo group, a 26 percent reduction (P=0.005), and coronary angioplasty was needed in 8.3 percent of the pravastatin group and 10.5 percent of the placebo group, a 23 percent reduction (P=0.01). The frequency of stroke was reduced by 31 percent (P=0.03). There were no significant differences in overall mortality or mortality from noncardiovascular causes. Pravastatin lowered the rate of coronary events more among women than among men. The reduction in coronary events was also greater in patients with higher pretreatment levels of LDL cholesterol.

CONCLUSIONS

These results demonstrate that the benefit of cholesterol-lowering therapy extends to the majority of patients with coronary disease who have average cholesterol levels.

Serum lipid profiles in Malay mothers and neonates: a cross-sectional study

OBJECTIVE

Preliminary epidemiological data suggest that dyslipidaemia contributes significantly to rising mortality due to atherosclerosis in Peninsular Malays. The aim of this study was to determine whether abnormal serum lipid profiles are present at birth in this population.

METHODOLOGY

The patients were 487 non-diabetic Malay women who had an uncomplicated antenatal course and delivered healthy singleton babies at term. Cord blood and maternal post-partum venous blood samples were taken for assay of serum cholesterol and triglyceride concentrations using standard enzymatic methods.

RESULTS

Maternal total serum cholesterol concentrations (mean +/- SD; 7.5 +/- 2.5 mmol/L) were higher than in other reported series (range of published means 5.2-6.5 mmol/L) with a correspondingly low high-density lipoprotein (HDL): total cholesterol ratio. The mean cord blood total serum cholesterol (1.7 +/- 1.0 mmol/L) was consistent with previously reported population means (1.5-1.9 mmol/L) but there was a relatively high low-density lipoprotein (LDL)-cholesterol and depressed HDL: cholesterol ratio. Significant correlations between maternal and neonatal serum total (P = 0.038) and especially HDL-cholesterol (P < 0.001) were observed. Maternal and cord blood serum triglyceride levels were comparable to those in other series.

CONCLUSIONS

These cross-sectional data provide evidence that abnormal serum cholesterol profiles are found in pregnant Malay women and their neonates which may have implications for the prevalence of macrovascular disease in the Malay population.

Oligonucleotide ligation assay (OLA) for the diagnosis of familial hypercholesterolemia

More than half of all deaths in Western society are related to arteriosclerotic cardiovascular diseases. Inherited disturbances in the low-density-lipoprotein (LDL) receptor and similar lipid-related defects account for the majority of these deaths. Testing procedures thus far rely on total cholesterol, LDL cholesterol, high-density-lipoprotein cholesterol, and triglyceride determinations. These tests are not able to provide any genetic information. We have developed an oligonucleotide ligation assay (OLA) that enables us to screen for high-risk individuals by testing for 19 common mutations in the LDL receptor and the apolipoprotein B genes using an automated genotyping-based two-step protocol. The novel OLA uses oligomeric pentaethyleneoxide mobility modifiers. The automated test will be useful in screening large populations for genetic data to distinguish relative from absolute risk, as well as for cost-effective familial analysis.

Lipid management: an opportunity for pharmacy service

Pharmacists are ideally suited to perform lipid management services. For many patients, hyperlipidemia is a symptomless disorder that requires knowledgeable laboratory interpretation, application of treatment guidelines, and appropriate drug therapy selection and monitoring. With the recent availability of portable lipid analyzers, pharmacists have a great opportunity to use their skills in drug therapy management to assist patients and their physicians with lipid management directly in the clinic or pharmacy. Evidence exists that appropriate lipid therapy can improve patient outcomes and save lives, and that delegating this responsibility to a qualified health care practitioner is cost-effective.

Reduction of transient myocardial ischemia with pravastatin in addition to the conventional treatment in patients with angina pectoris. REGRESS Study Group

BACKGROUND

Lipid-lowering therapy reduces cardiac morbidity and mortality. Less is known about its potential anti-ischemic effect.

METHODS AND RESULTS

In a 2-year prospective randomized placebo-controlled study, the effect of pravastatin 40 mg on transient myocardial ischemia was assessed. Forty-eight-hour ambulatory ECGs with continuous ST-segment analysis were performed in 768 male patients with stable angina pectoris, documented coronary artery disease, and serum cholesterol between 4 and 8 mmol/L (155 and 310 mg/dL). During the trial, patients received routine antianginal treatment. In the patients randomized to pravastatin, transient myocardial ischemia was present at baseline in 28% and after treatment in 19%; in the placebo group, it was found in 20% and 23% of the patients, respectively (P = .021 for change in percentage between two treatment groups; odds ratio, 0.62; 95% CI, 0.41 to 0.93). Ischemic episodes decreased by 1.23 +/- 0.25 (SEM) episode with pravastatin and by 0.53 +/- 0.25 episode with placebo (P = .047). Under pravastatin, the duration of ischemia decreased from 80 +/- 12 minutes to 42 +/- 10 minutes (P = .017) and with placebo, from 60 +/- 13 minutes to 51 +/- 9 minutes (P = .56). The total ischemic burden decreased from 41 +/- 5 to 22 +/- 5 mm.min in the pravastatin group (P = .0058) and from 34 +/- 6 to 26 +/- 4 mm . min in the placebo group (P = .24). Adjusted for independent risk factors for the occurrence of ischemia, the effect of pravastatin on the reduction of risk for ischemia remained statistically significant (odds ratio, 0.45; 95% CI, 0.22 to 0.91; P = .026).

CONCLUSIONS

In men with documented coronary artery disease and optimal antianginal therapy, pravastatin reduces transient myocardial ischemia.

Rationale for effective treatment of hypercholesterolemia

The primary objective of treating hypercholesterolemia is to reduce the patient's risk of developing coronary artery disease (CAD). Reducing low-density lipoprotein (LDL) cholesterol levels to achieve National Cholesterol Education Program (NCEP) goal lipid levels greatly reduces this risk. Treatment of additional risk factors for CAD (high blood pressure, diabetes, smoking) should be addressed and modified as part of appropriate patient management, but a high LDL cholesterol level is a major risk factor. Therefore, to effectively modify morbidity and mortality, reaching and maintaining NCEP target lipid levels should be the goal of lipid-lowering therapy. Epidemiologic data indicate that most adults in the United States need <30% reduction in LDL cholesterol level to achieve their NCEP goal. Regardless of the intervention or therapeutic agent used, the results of numerous studies have demonstrated that reducing LDL cholesterol levels to NCEP goals will result in significant reduction of CAD risk.

Cost-effectiveness of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor therapy in the managed care era

More than $100 billion is spent in the United States each year on cardiovascular disease, primarily for hospitalizations and revascularization procedures. This is more than for any other disease state. As the clinical practice of medicine shifts from the paradigm of private practice to the managed care environment, cost-effectiveness is becoming increasingly important. A primary measure in analyzing cost-effectiveness is the cost-effectiveness ratio, or the dollar cost per unit of improvement for a given expenditure. This measure allows healthcare planners to compare completely different interventions. With approximately 52 million adult U.S. citizens having elevated low-density lipoprotein (LDL) cholesterol levels, lipid-lowering therapy---with diet or 3-hydroxy-3methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors---is an important consideration for primary care physicians and managed care providers. The National Health and Nutrition Examination Survey (NHANES) III indicates that 75-88% of adults who have coronary artery disease (CAD) risk factors or CAD require only a moderate (20--30%) reduction in LDL cholesterol levels to reach National Cholesterol Education Program goals. The clinical literature shows that all 4 of the currently available HMG-CoA reductase inhibitors can provide appropriate, moderate LDL cholesterol reductions within their recommended dosage ranges. For the majority of patients who need a 20--30% reduction in LDL cholesterol, fluvastatin 20 or 40 mg once daily provides the most cost-effective HMG-CoA therapy, expressed as cost of therapy per 1% LDL cholesterol reduction. For patients who need a >30% LDL cholesterol reduction, a high-dose HMG-CoA reductase inhibitor (e.g., simvastatin 20 or 40 mg/day) or a combination of a lower-dose HMG-CoA reductase inhibitor and a bile acid resin is the preferred initial therapy. Although a true cost-effectiveness analysis would incorporate morbidity and mortality data from clinical trials, analysis using intermediate endpoints, such as LDL cholesterol reduction, suggests that fluvastatin is the preferred initial HMG-CoA reductase inhibitor for the treatment of moderate hyperlipidemia.

Review of the major intervention trials of lowering coronary artery disease risk through cholesterol reduction

Results of primary and secondary prevention trials have shown that lowering total cholesterol and low-density lipoprotein (LDL) cholesterol leads to a reduction in both fatal and nonfatal ischemic events. The reduced coronary artery disease (CAD) risk associated with cholesterol lowering appears to be unrelated to the intervention used, whether it be a low-fat/low-cholesterol diet, partial ileal bypass surgery, or pharmacologic intervention with an agent such as a bile resin, a fibrate, or niacin. Data emerging on the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors have shown that this newest class of cholesterol-lowering agents also reduces the risk for CAD. The studies provide increasing evidence that high LDL cholesterol levels not only contribute to atherosclerotic plaque formation but also interfere with normal endothelial control of arterial vasomotor tone. Because the small amount of plaque regression observed on angiographic studies is not sufficient to explain the magnitude of CAD risk reduction associated with lowered levels of LDL cholesterol, these studies suggest that vasomotor control and plaque stabilization may have a greater impact on clinical events than the stenosis caused by atherosclerotic plaques.

Serum cholesterol concentration and death from suicide in men: Paris prospective study I

OBJECTIVE

To investigate whether low serum cholesterol concentration or changing serum cholesterol concentration is associated with risk of suicide in men.

DESIGN

Cohort study with annual repeat measurements of serum cholesterol concentration (for up to four years).

SETTING

Paris, France.

SUBJECTS

6393 working men, aged 43-52 in 1967-72, who had at least three measurements of serum cholesterol concentration.

MAIN OUTCOME MEASURES

Individual change over time in serum cholesterol concentration (estimated using within person linear regression method); death from suicide during average of 17 years' follow up after last examination.

RESULTS

32 men committed suicide during follow up. After adjustment for age and other factors, relative risk of suicide for men with low average serum cholesterol concentration (< 4.78 mmol/l) compared with those with average serum cholesterol concentration of 4.78-6.21 mmol/l was 3.16 (95% confidence interval 1.38 to 7.22, P = 0.007). Men whose serum cholesterol concentration decreased by more than 0.13 mmol/l a year had multivariate adjusted relative risk of 2.17 (0.97 to 4.84, P = 0.056) compared with those whose cholesterol remained stable (change of < or = 0.13 mmol/l a year).

CONCLUSION

Both low serum cholesterol concentration and declining cholesterol concentration were associated with increased risk of death from suicide in men. Although there is some evidence in favour of a concomitant rather than a causal effect for interpreting these associations, long term surveillance of subjects included in trials of lipid lowering treatments seems warranted.

Pravastatin reduces restenosis after coronary angioplasty of high grade stenotic lesions: results of SHIPS (SHIga Pravastatin Study)

We conducted a multicenter prospective, randomized, double-blind, placebo-controlled trial to test whether pravastatin, a hydroxymethyl glutaryl coenzyme A reductase inhibitor, can decrease restenosis after percutaneous transluminal coronary angioplasty (PTCA). Pravastatin 10 mg twice daily was begun at least 10 days prior to elective PTCA in patients with total cholesterol less than 280 mg/dl. The end-point was a between-group comparison of the frequency of restenosis defined as a more than 50% loss of the initial gain in diameter stenosis at the PTCA site at 3 months during follow-up by automated quantitative coronary arteriography. Of 207 patients randomly assigned to study groups, 139 patients underwent PTCA; 133 procedures were successful, and 124 patients underwent follow-up angiography at 3 months, and 179 lesions (85 pravastatin, 94 placebo) in 124 patients (62 pravastatin, 62 placebo) were analyzed. The two groups were comparable for baseline characteristics. Total cholesterol decreased by 19.6% in the pravastatin group (p < 0.001) but not in the placebo group. Although the restenosis rate was not different in the two groups (29.4% in pravastatin vs. 39.4% in placebo, p = 0.215) as a whole, it was reduced to about one fifth (8.8%) in the pravastatin group compared with 44.8% in the placebo group (p = 0.0011) when the comparison was restricted to high grade lesions (> or = 75% diameter stenosis, 34 lesions in pravastatin, 29 lesions in placebo). Pravastatin thus reduces restenosis after PTCA of high grade lesions.

Coronary bypass graft fate and patient outcome: angiographic follow-up of 5,065 grafts related to survival and reoperation in 1,388 patients during 25 years

OBJECTIVES

We sought to examine, angiographically, the longterm fate of a large number of mainly venous coronary bypass grafts and to correlate graft patency and disease with patient survival and reoperation.

BACKGROUND

Much is known about bypass graft patency and disease, but the precise relation between graft fate and patient outcome has not been substantiated and documented.

METHODS

A total of 1,388 patients underwent a first coronary artery bypass graft procedure at a mean age of 48.9 years, 234 had a second bypass procedure at a mean age of 53.3 years, and 15 had a third bypass procedure at a mean age of 58.2 years during the 25-year period from 1969 to 1994. Most were male military personnel or veterans; 12% were < or = 39 years old. Of 5,284 grafts placed, 91% were venous and 9% arterial. Angiograms were performed on 5,065 (98% of surviving) grafts early, on 3,993 grafts at 1 year and on 1,978 grafts at 5 years after operation; other examinations were also performed up to 22.5 years after operation, and 353 grafts were examined after > or = 15 years. Grafts were graded for patency and disease. The status of all patients was known at the study's end.

RESULTS

The perioperative mortality rate was 1.4% for an isolated first coronary bypass procedure, 6.6% for reoperation. Vein graft patency was 88% early, 81% at 1 year, 75% at 5 years and 50% at > or = 15 years; when suboptimal grafts, graded B, were excluded from calculation, the proportion of excellent grafts, graded A, decreased to 40% after > or = 12.5 years. After the early study, the vein graft occlusion rate was 2.1%/year. Internal mammary artery graft patency was significantly better but decreased with time. Vein graft disease appeared by 1 year and the rate accelerated by > or = 2.5 years, involving 48% of grafts at 5 years and 81% at > or = 15 years; 44% of the latter grafts were narrowed > 50%. Survival of all patients was 93.6% at 5 years. 81.1% at 10 years, 62.1% at 15 years, 46.7% (150 patients) at 20 years and 38.4% (25 patients) at 23 years after operation. Survival decreased as age increased, but curves approximated "normal" life expectancy for older patients. Survival curves at all ages showed a steeper decline after 7 years. The rate of reoperation increased between 5 years and 10 to 14 years, then decreased to stable levels. Coronary atheroembolism from vein grafts was the major cause of morbidity and mortality associated with reoperation. Vein graft patency and disease were temporally and closely related to reoperation and survival.

CONCLUSIONS

Coronary bypass graft disease and occlusion are common after coronary artery bypass grafting and increase with time. They are major determinants of clinical prognosis, specifically measured by reoperation rate and survival. Intraoperative graft atheroembolism was a major reoperation hazard. Reoperation is definitely worthwhile but entails identifiable risks that must be dealt with.

Effects of cigarette smoking on the angiographic evolution of coronary atherosclerosis. A Canadian Coronary Atherosclerosis Intervention Trial (CCAIT) Substudy. CCAIT Study Group

BACKGROUND

Although smoking increases both the risk of developing coronary disease and the risk of coronary events in patients with known coronary atherosclerosis, the effect of smoking on the evolution of coronary atherosclerosis as assessed by serial angiography is poorly defined.

METHODS AND RESULTS

Ninety smokers with coronary atherosclerosis shown on a recent angiogram and with fasting cholesterol levels between 220 and 300 mg/dL were enrolled in a randomized, double-blind, placebo-controlled trial of cholesterol-lowering therapy, along with 241 nonsmokers and exsmokers. Lovastatin at a mean dose of 36 mg/d lowered total and LDL cholesterol by 21 +/- 11% and 29 +/- 11%, respectively, but these levels changed by < 2% in placebo-treated patients. Coronary arteriography was repeated after 2 years in 72 smokers and their 557 lesions were measured blindly with an automated quantitative system, along with 1752 lesions in 227 nonsmokers. Coronary change score, the per-patient mean of the minimal lumen diameter changes for all qualifying lesions, worsened by 0.16 +/- 0.16 mm in smokers and by 0.07 +/- 0.15 mm in nonsmokers in the placebo group (P < .001). Lovastatin-treated smokers had less worsening (0.07 +/- 0.15 mm) than placebo-treated smokers (P = .024). One or more coronary lesions progressed in 16 of 34 lovastatin-treated smokers and in 28 of 38 placebo-treated smokers (47% versus 74%, P < .001). In the placebo group, new coronary lesions developed in 21 of 38 smokers and in 28 of 115 nonsmokers (55% versus 24%, P < .001); fewer lovastatin-treated smokers developed new lesions (15% versus 55%, P < .001).

CONCLUSIONS

Smoking accelerates coronary progression and new lesion formation as assessed by serial quantitative coronary arteriography. Lovastatin slows the progression of coronary atherosclerosis and prevents the development of new coronary lesions in smokers.

Yield of laboratory tests for case-finding in the ambulatory general medical examination

PURPOSE

To examine the diagnostic and therapeutic yield of frequently obtained laboratory tests for case-finding in the comprehensive ambulatory medical examination.

PATIENTS AND METHODS

A prospective cohort study was conducted in four Mayo Clinic general internal medicine divisions that provide care to community, regional, and geographically distant patients. The main outcome measurements were the diagnostic yield and therapeutic yield of the complete blood count, chemistry panel, lipid profile, thyroid tests, and urinalysis ordered for case-finding.

RESULTS

Overall, 1,508 laboratory tests consisting of 7,008 individual components were obtained for case-finding in the 531 patients (mean age 63 +/- 14 years; 57% female). Thirty-six percent (544 of 1508) of the tests were abnormal, of which 6% (33 of 544) were repeated and 9% (47 of 544) led to further investigations. The 1,508 case-finding tests had a diagnostic yield of 4.8% (73 new diagnoses) and a therapeutic yield of 4.0% (60 new therapies). The therapeutic yield of each test ordered for case-finding was as follows: lipid profile (16.5%), chemistry panel (2.8%), complete blood count (0.9%), urinalysis (0.8%), and thyroid tests (0.7%). Therapeutic yield was not associated with patient's age, gender, or referral distance but was approximately twice as high in new patients compared with established patients.

CONCLUSIONS

The majority of treatments for conditions identified by case-finding laboratory tests resulted from the lipid profile. The therapeutic yield of the chemistry panel was low, and the therapeutic yield of the complete blood count, thyroid tests, and urinalysis were all less than 1%. The low therapeutic yield of many routine laboratory tests ordered for case-finding should be provided to patients, physicians, and managed care organizations to set priorities for case-finding and screening.

Cost-effective treatment of coronary artery disease--the new imperative

Large lipid-lowering clinical trials have demonstrated a significant reduction in cardiovascular events and the need for cardiovascular procedures. These clinical and point trials used relatively weak treatment modalities, and when the cost savings of the reduced number of events is balanced against the estimated cost of treatment, the average difference is approximately $1,500 per patient per year. Arteriographic trials have used similar or more aggressive lipoprotein therapy over shorter periods of time. Estimates of cost savings from reduced clinical events balanced against the cost of treatment in these studies indicate a wide spectrum of estimated patient costs. These estimates range between a cost of $2,273 per patient per year to a cost savings of (-)$901 per patient per year. Extrapolation to the United States population with coronary artery disease (CAD) suggests that greater than one billion dollars per year could be saved if patients with CAD received similar treatment and responded in a similar manner.

Hyperlipidemia. When does treatment make a difference?

A high serum cholesterol level is regarded as a major contributor to the development of coronary atherosclerosis. Screening for hyperlipidemia should begin no later than age 35 for men and age 45 for women. Individuals with additional risk factors for coronary artery disease should be screened earlier. When values are not within a desirable range, further assessment should be done by determining high-density lipoprotein and triglyceride levels. The initial approach to treatment of hyperlipidemia includes diet, exercise, and weight loss. Smoking should be proscribed. When nonpharmacologic intervention fails, "statins" are increasingly being selected as agents of first choice. Recommendations for the busy practitioner include consistently identifying the hyperlipidemic patient, setting target goals for lipid values, addressing modifiable risk factors, and providing appropriate pharmacologic intervention (eg, aspirin, antioxidants, and beta blockers in patients with established disease; angiotensin-converting enzyme inhibitors in patients with systolic dysfunction; estrogen replacement in selected patients) and treatment to attain target goals in lowering cholesterol.

Cost effectiveness of lowering cholesterol concentration with statins in patients with and without pre-existing coronary heart disease: life table method applied to health authority population

OBJECTIVES

To estimate the cost effectiveness of statins in lowering serum cholesterol concentration in people at varying risk of fatal cardiovascular disease and to explore the implications of changing the criteria for intervention on cost and cost effectiveness for a purchasing authority.

DESIGN

A life table method was used to model the effect of treatment with a statin on survival over 10 years in men and women aged 45-64. The costs of intervention were estimated from the direct costs of treatment, offset by savings associated with a reduction in coronary angiographies, non-fatal myocardial infarctions, and revascularisation procedures. The robustness of the model to various assumptions was tested in a sensitivity analysis.

SETTING

Population of a typical district health authority.

MAIN OUTCOME MEASURE

Cost per life year saved.

RESULTS

The average cost effectiveness of treating men aged 45-64 with no history of coronary heart disease and a cholesterol concentration > 6.5 mmol/l for 10 years with a statin was 136,000 pounds per life year saved. The average cost effectiveness for patients with pre-existing coronary heart disease and a cholesterol concentration > 5.4 mmol/l was 32,000 pounds. These averages hide enormous differences in cost effectiveness between groups at different risk, ranging from 6000 pounds per life year in men aged 55-64 who have had a myocardial infarction and whose cholesterol concentration is above 7.2 mmol/l to 361,000 pounds per life year saved in women aged 45-54 with angina and a cholesterol concentration of 5.5-6.0 mmol/l.

CONCLUSIONS

Lowering serum cholesterol concentration in patients with and without preexisting coronary heart disease is effective and safe, but treatment for all those in whom treatment is likely to be effective is not sustainable within current NHS resources. Data on cost effectiveness data should be taken into account when assessing who should be eligible for treatment.