Lifestyle Heart Trial - LHT

Description:

Lifestyle changes for 1 year angiographic progression in CAD.

Hypothesis:

Whether patients outside hospital can be motivated to make and sustain comprehensive lifestyle changes to cause a regression of coronary atherosclerosis.

Study Design

Study Design:

Patients Screened: 193
Patients Enrolled: 94
Mean Follow Up: 12 months
Female: 3

Patient Populations:

35-75 years of age
Male or female
Residence in the greater San Francisco area
No other life-threatening illnesses
No myocardial infarction (MI) during the preceding 6 weeks
No history of receiving streptokinase (SK) or alteplase
Not currently receiving lipid-lowering drugs
One-, two-, or three-vessel coronary artery disease (defined as any measurable coronary atherosclerosis in a non-dilated or non-bypassed coronary artery)
Left ventricular ejection fraction greater than 25%
Not scheduled to have coronary artery bypass grafting
Permission granted by patient's cardiologist and primary care physician
Angiographically documented coronary artery disease

Primary Endpoints:

Percent diameter coronary stenosis after intervention minus before intervention, levels of HDL-cholesterol, levels of apolipoproteins A-I and B, ratio of total/HDL cholesterol, ratio of LDL/HDL cholesterol, frequency of angina, duration of angina, reduction/increase in the severity of angina

Drug/Procedures Used:

Low-fat vegetarian diet (10% of calories as fat), moderate aerobic exercise, stress management training, stopping smoking, and group support.

Principal Findings:

In the experimental group:
Total cholesterol fell by 24.3%
LDL-cholesterol fell by 37.4%
91% reduction in the frequency of angina
42% reduction in the duration of angina
28% reduction in the severity of angina
Average % stenosis regressed from 40.0 to 37.8 (p = 0.001, two tailed)

In the control group:
165% increase in the frequency of angina
95% increase in the duration of angina
39% increase in the severity of angina
Average % stenosis progressed from 42.7 to 46.1 (p = 0.001, two tailed) group

Neither group had significant changes in apolipoprotein A-I.

The average % stenosis decreased from 40.0 to 37.8.

When only lesions >50% were analyzed, the average % diameter stenosis regressed from 61.1 to 55.8 in the experimental group, but progressed from 61.7 to 64.4 (p = 0.03, two tailed).

The average lesion change scores (% diameter coronary stenosis after intervention minus before intervention) in the experimental group were in the direction of regression of coronary atherosclerosis in 18 of 22 patients (82%) including the one woman, in the direction of slight progression in 3 patients, and in the direction of substantial progression in 1 patient with poor adherence. In contrast, the average lesion change scores in the control group were in the direction of progression of coronary atherosclerosis in 10 and 1 showed no change.

Interpretation:

After a year, patients in the experimental group showed significant overall regression of coronary atherosclerosis as measured by quantitative arteriography.

Since coronary atherosclerosis occurs over decades, it is surprising to find larger changes in only one year. Perfusion is a fourth-power function of coronary artery diameter, so even a small amount of regression in a critically stenosed artery has a large effect on myocardial perfusion and overall functional status.

In contrast, patients in the usual-care control group who were making less comprehensive lifestyle changes showed significant overall progression of coronary atherosclerosis. This finding suggests that conventional recommendations for patients with coronary artery disease (such as 30% fat diet) are not sufficient to bring about regression in many patients.

References:

1. Lancet 1990;336:129-133. Final Results

Keywords: Life Style, Myocardial Infarction, Diet, Vegetarian, Exercise, Apolipoprotein A-I, Constriction, Pathologic, Smoking, Streptokinase, Coronary Angiography, Coronary Stenosis, Stroke Volume, Tissue Plasminogen Activator, Coronary Artery Bypass


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