Long-term trial results ‘support intensive lipid control’
MedWire News: The longest follow-up of a lipid-atherosclerosis intervention trial to date supports the longevity benefits of intensive intervention to control lipid levels, say researchers.
Twenty-five-year results from the Program on the Surgical Control of the Hyperlipidemias (POSCH) trial showed gains in survival, both overall and free from cardiovascular disease, and life expectancy with surgery to decrease low-density lipoprotein (LDL) cholesterol versus control treatment.
POSCH was the first lipid-atherosclerosis trial to demonstrate unequivocally that LDL cholesterol reductions decreased the incidence of coronary heart disease death and myocardial infarction (MI), the researchers note in the Annals of Surgery.
The secondary, clinical/arteriographic intervention trial included 838 survivors of a single MI who were randomly assigned to receive dietary instruction with or without partial ileal bypass surgery.
The operation, dating back to 1973, resulted in a 23.3% reduction in total plasma cholesterol and a 37.7% reduction in LDL cholesterol at 5 years among patients receiving surgery versus dietary advice only.
Over 25 years of follow-up, there was a statistically significant survival difference between the groups using the logrank statistic, which takes into account differences in cumulative survival.
Surgical patients had an estimated 18% reduced risk for death and a 1-year increase in restricted mean survival compared with control patients.
The survival probability at 25 years was 0.57 with surgery versus 0.51 in the control group, equating to the survival of an additional six surgical patients out of 100.
There was a significant increase in cardiovascular deaths in the control group, with a trend toward increased cancer deaths that was not significant.
Patients with an ejection fraction of 50% or more experienced particular benefits from surgery, with a relative probability for survival of 0.61 versus 0.51 with control treatment and 1.7 years greater life expectancy over 25 years.
Henry Buchwald and colleagues, from the University of Minnesota in Minneapolis, USA, conclude: “These new POSCH findings substantiate the lipid-atherosclerosis theory as evidenced based, and support the long-term longevity benefits of aggressive intervention to control lipid levels.”
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By Anita Wilkinson