A systematic review 1 including 66 RCTs with a total of 173 160 subjects was abstracted in DARE. Cholesterol reduction rates ranged from 22.86% for statins (range 12.8% to 32%) to 3.07% for n-3 long chain fatty acids and precursors. Coronary heart disease mortality according to intervention was as follows: HMG-CoA reductase inhibitors, RR 0.69 (95% CI 0.59 to 0.80, no heterogeneity); resins, RR 0.71 (95% CI 0.51 to 0.99, significant heterogeneity); all other interventions, no statistical significance. For overall mortality the RR for HMG-COA reductase inhibitors was 0.79 (95% CI 0.71 to 0.89) and (according to small trials) for n-3 fatty acids 0.68 (95% CI 0.53 to 0.88). Treatment with hormones was associated with borderline increase in overall mortality (RR 1.09, 95% CI 1.00 to 1.20).
A systematic review 2 including 17 studies with a total of 21 303 subjects was abstracted in DARE.
Patients who received statin treatment for hypercholesterolemia demonstrated a 20% to 30% reduction in death and major cardiovascular events compared with patients who received placebo. Studied treatments included (n=number of studies) lovastatin 20/40 mg (n=5), pravastatin 15/20/40 mg (n=10) and simvastatin 20 mg (n=3) versus placebo.
The results in different outcomes were as follows:
All-cause mortality (n = 14), the OR was 0.76 (95% CI: 0.67, 0.86) in favour of receiving statin treatment. NNT = 67.
Fatal MI (n = 14), the OR was 0.61 (95% CI: 0.48, 0.78) in favour of receiving statin treatment. NNT = 166.
Non-fatal MI (n = 13), the OR was 0.66 (95% CI: 0.57, 0.77) in favour of receiving statin treatment. NNT = 43.
Fatal stroke (n = 10), the OR was 0.77 (95% CI: 0.57, 1.04) that was not statistically significant. NNT = 500.
Non-fatal stroke (n = 7), the OR was 0.69 (95% CI: 0.54, 0.88) in favour of receiving statin treatment. NNT = 143.
Angina (n = 12), the OR was 0.70 (95% CI: 0.65, 0.76) in favour of receiving statin treatment. NNT = 24.
Withdrawals (n = 11), the OR was 0.80 (95% CI: 0.61, 1.04) which was not statistically significant. NNT not reported.
Sensitivity analyses revealed no significant differences in results. The advantage of statins was generally present across study types and statin treatment types and for patients with less severe dyslipidemias. The benefit in clinical outcomes was noticeable as early as 1 year.
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