Seventy-five trials (n=10,757) were included in the review: 60 trials from the previous OHRC review and 15 trials published since. One hundred and forty head-to-head comparisons were made between different statin types. Fifty-one studies (68%) were graded B or better for methodological quality. Three trials adequately reported appropriate methods of allocation concealment. The authors stated that attrition rates were similar for both groups across the trials.
Of statins that could decrease LDL-C by 30% to 40%, statistically significant differences were found for the comparisons: atorvastatin 10mg and lovastatin 40mg (WMD 7.00, 95% CI 2.87 to 11.13; n=89), atorvastatin 10mg and lovastatin 80 mg (WMD -10.00, 95% CI -15.25 to -4.75; n=84), atorvastatin 10mg and simvastatin 20mg (WMD 2.17, 95% CI 1.20 to 3.14,;n=5,075), lovasatin 80mg and simvastatin 20mg (WMD 13.00, 95% CI 7.36 to 18.64; n=60) and fluvastatin 80mg and lovastatin 80mg (WMD -9.00, 95% CI -17.01 to -0.99; n=52).
Significant differences were also observed for statins shown to reduce LDL-C by 20% to 30%: fluvastatin 40mg and lovastatin 20mg (WMD -4.81, 95% CI -7.25 to -2.36; n=496), fluvastatin 40mg and pravastatin 40mg (WMD -9.37, 95% CI -14.50 to -4.24; n=87), fluvastatin 40mg and simvastatin 10mg (WMD -4.01, 95% CI -4.77 to -3.26; n=300), simvastatin 10mg and lovastatin 20mg (WMD -3.50, 95% CI -4.70 to -2.31;n=1,773), simvastatin 10mg and pravastatin 20mg (WMD -3.87, 95% CI -4.62 to -3.12; n=945) and simvastatin 10mg and pravastatin 40mg (WMD 2.27, 95% CI 0.31 to 4.23; n=421). Significant statistical heterogeneity was found only for the comparison of pravastatin 40mg and simvastatin 10mg (p=0.07).
Atorvastatin at 80mg was observed to confer statistically significant benefits in one trial of protection against unstable angina (3.8% compared to 5.1%) and revascularisation (16.3% compared to 18.8) than pravastatin at 40mg. Atorvastatin at the same dose was associated with fewer myocardial infarctions, peripheral arterial disease and revascularisations than simvastatin at 20mg.
The authors reported that the studies that evaluated rosuvastatin reported a higher adverse event rate than other comparison arms. Incidence of raised ALT/AST levels was less than 1% in most trials.