Statins reduce heart disease deaths by 28 percent in men with high “bad” cholesterol
07 Sep 2017 --- Statins reduce deaths from coronary heart disease by 28 percent in men with high levels of “bad” cholesterol, according to the longest-ever study of its kind. The study, by Imperial College London and the University of Glasgow, focused specifically on men with high levels of low-density lipoprotein (LDL) and no other risk factors or signs of heart disease.
Previous research had shown the benefit of statins for reducing high cholesterol and heart disease risk amongst different patient populations, according to the Imperial College London press release. However, until now there has been no conclusive evidence from trials for current guidelines on statin usage for people with very high levels of low-density lipoprotein (LDL) cholesterol (above 190mg/dL) and no established heart disease.
After studying mortality over a 20-year period, researchers led by Professor Kausik Ray at Imperial showed that 40mg daily of pravastatin, a relatively weak type of statin, reduced deaths from heart disease in participants by more than a quarter.
Findings provide evidence for proactive treatment
“For the first time, we show that statins reduce the risk of death in this specific group of people who appear largely healthy except for very high LDL levels,” says senior author Ray from Imperial’s School of Public Health. “This legitimizes current guidelines which recommend treating this population with statins.”
In addition, the findings challenge current approaches to treating younger patients with LDL elevations with a “watch and wait” approach. Instead, the authors say even those with slightly elevated cholesterol are at higher long-term risk of heart disease, and that the accumulation of modest LDL reductions over time will translate into large mortality benefits.
“Our findings provide the first trial-based evidence to support the guidelines for treating patients with LDL above 190mg/dL and no signs of heart disease,” Ray adds. “They also suggest that we should consider prescribing statins more readily for those with elevated cholesterol levels above 155 mg/dl and who also appear otherwise healthy.”
The paper was published on September 5 in the journal Circulation. It follows on from a five-year 1995 study in which researchers observed the long-term effects of statins on patients involved in the West of Scotland Coronary Prevention Study (WOSCOPS) trial. The researchers took into account the original five-year study and followed the patients for a further 15 years.
The WOSCOPS study gave the first conclusive evidence that treating high LDL in men with pravastatin for five years significantly reduces the risk of heart attack or death from heart disease compared with placebo. Statins were subsequently established as the standard treatment for primary prevention in people with elevated cholesterol levels.
Now, researchers have completed analyses of the 15-year follow up of 5,529 men, including 2,560 with LDL cholesterol above 190 mg/dL of the original 6,595, chosen because they had no evidence of heart disease at the beginning of the present study.
Pravastatin reduces mortality
Participants were aged 45 to 64 years. During the five-year initial trial, they were given pravastatin or placebo. Once the trial ended the participants returned to their primary care physicians, and an additional 15-year period of follow-up ensued.
The 5,529 men were split into two groups: those with “elevated” LDL (between 155 and 190mg/dL) and those with “very high” LDL (above 190mg/dL). The standard “ideal” level of LDL for high-risk patients is below 100mg/dL, according to the Imperial College London press release, but this varies depending on individual risk factors.
The researchers found that giving pravastatin to men with “very high” LDL reduced 20-year mortality rates by 18 percent. Statins also reduced the overall risk of death by coronary heart disease by 28 percent, and they reduced the risk of death by other cardiovascular disease by 25 percent among those with very high LDL cholesterol.
The 15-year follow up also meant the researchers could compare patients’ original predicted risk of heart disease with actual observed risk. According to the risk equations for cardiovascular disease, 67 percent of patients included in the WOSCOPS trial with LDL above 190mg/dL would have less than a 7.5 percent risk of heart disease by year 10, and thus would not have been treated with statins based on that risk.
However, the present study shows that in fact, this group actually had a 7.5 percent risk by year five, and meaning its 10-year risk was 15 percent. Following statin therapy, this group’s 10-year risk was reduced compared with those that were given placebo during the trial.
“This is the strongest evidence yet that statins reduce the risk of heart disease and death in men with high LDL,” Ray concludes. “Our study lends support to LDL’s status as a major driver of heart disease risk, and suggests that even modest LDL reductions might offer significant mortality benefits in the long-term. Our analysis firmly establishes that controlling LDL over time translates to fewer deaths in this population.”
Nutritional solutions to heart disease also continue to be proposed, with randomized controlled trials that lowered intake of dietary saturated fat and replaced it with polyunsaturated vegetable oil having reduced cardiovascular disease by approximately 30 percent – similar to that achieved by statins. The dangers of low “good” cholesterol also shouldn’t be ignored, according to a study earlier this year. The study found that young heart attack parents were more likely to have low “good” cholesterol than high “bad” cholesterol.
