Statins are effective in decreasing mortality in people with pre-existing cardiovascular disease. Pre-existing disease can have many manifestations. Defining illnesses include a prior heart attack, stroke, stable or unstable angina, aortic aneurysm, or other arterial ischemic disease, in the presence of atherosclerosis. They are also advocated for use in people at high risk of developing coronary heart disease. On average, statins can lower LDL cholesterol by 1.8 mmol/l (70 mg/dl), which translates into an estimated 60% decrease in the number of cardiac events (heart attack, sudden cardiac death) and a 17% reduced risk of stroke after long-term treatment. A greater benefit is observed with high-intensity statin therapy. They have less effect than the fibrates or niacin in reducing triglycerides and raising HDL-cholesterol ("good cholesterol").