Population Characteristics and Study Quality of Included Trials , by Combination Therapy Agent and Potency Comparison Long-Term Clinical Outcomes We found insufficient evidence to compare long-term clinical outcomes ( mortality , acute coronary events , cerebrovascular events , and revascularization procedures ) for all combination therapy and statin intensity comparisons .
Figure 1 presents an evidence map of studies that evaluated these
Atherosclerotic cardiovascular disease ( ASCVD ) affects more than 15 million Americans ( 1 ) and is the leading cause of death for both men and women in the United States ( 2 ) .
Trials have demonstrated reductions in low-density lipoprotein ( LDL ) cholesterol levels ( 3 ) and decreased ASCVD risk with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor ( statin ) monotherapy ( 4 ) .
Over the past decade , statins have often been used in combination with other lipid-modifying agents .
Recently , several high-profile r and omized , controlled trials ( RCTs ) have evaluated add-on therapy ( 57 ) , wherein statin monotherapy is compared with the combination of the same statin dose and another lipid-modifying agent .
Add-on combination therapy can lead to superior lipid outcomes , but studies have not shown decreased rates of cardiovascular death , myocardial infa rct ion , revascularization , or stroke ( 57 ) .
Therefore , the 2013 American College of Cardiology ( ACC ) and American Heart Association ( AHA ) guidelines recommend moderate- or high-intensity statin monotherapy as the first-line strategy for ASCVD risk reduction among patients with LDL cholesterol levels of 4.91 mmol/L or greater ( 190 mg/dL ) , preexisting ASCVD , diabetes mellitus ( DM ) , or estimated 10-year ASCVD risk of 7.5 % or greater ( 8) .
Adverse effects are more common with higher-intensity statin regimens ( 9 ) , and musculoskeletal adverse events occur frequently among patients with the C variant in the SLCO1B1 gene ( 10 ) .
The 2013 ACC/AHA guidelines suggest that clinicians consider moderated combination therapy with a lower-intensity statin and another lipid-modifying medication among high-risk patients ( LDL cholesterol level 4.91 mmol/L [ 190 mg/dL ] , preexisting ASCVD , or DM ) who are intolerant of or unresponsive to statins ( evidence grade E : expert opinion ) ( 8) .
Yet , it is unclear whether this strategy results in similar ASCVD risk reductions and fewer adverse effects compared with higher-intensity statin monotherapy .
A 2009 systematic review that examined these questions found insufficient evidence to weigh benefits and risks of moderated combination therapy ( 12 ) .
We aim ed to compare the effectiveness , safety , and tolerability of moderated combination therapy of statin with another lipid-modifying medication ( bile acid sequestrant , ezetimibe , fibrate , niacin , or -3 fatty acid ) with those of higher-intensity statin monotherapy among high-risk patients .
We sought to compare the long-term clinical benefits and short-term lipid effects of moderated combination therapy with those of higher-intensity statin monotherapy , as well as to determine whether these regimens differ in rates of adherence and harms .
Given the recent release of the 2013 ACC/AHA guidelines ( 8) , we narrowed the scope of this manuscript to focus on evidence most relevant to high-risk population s for whom combination therapy might be considered .
Prior studies have suggested schemes to group statins on the basis of their reported LDL cholesterol reduction ( 17 , 18 ) , which are similar to the strategy used by the ACC/AHA committee ( 8) .
Safety and efficacy of ezetimibe added to atorvastatin versus up titration of atorvastatin to 40 mg in Patients > or = 65 years of age (from the ZETia in the ELDerly [ZETELD] study).
Few clinical studies have focused on the efficacy of lipid-lowering therapies  in patients > or = 65 years of age . The percentage of change from baseline in low-density lipoprotein ( LDL ) cholesterol and the percentage of patients achieving prespecified LDL cholesterol levels after 12 weeks of ezetimibe 10 mg plus atorvastatin versus up titration of atorvastatin were assessed in subjects > or = 65 years old with hyperlipidemia and at high risk of coronary heart disease . After stabilization of atorvastatin 10-mg therapy , 1,053 patients , > or = 65 years old , at high risk of coronary heart disease , with and without atherosclerotic vascular disease and a LDL cholesterol level that was not < 70 or < 100 mg/dl , respectively , were r and omized to receive ezetimibe added to atorvastatin 10 mg for 12 weeks versus up titration to atorvastatin 20 mg for 6 weeks followed by up titration to atorvastatin 40 mg for an additional 6 weeks . Ezetimibe added to atorvastatin 10 mg result ed in significantly greater changes at week 6 in LDL cholesterol ( p < 0.001 ) , significantly more patients with atherosclerotic vascular disease achieving a LDL cholesterol level of < 70 mg/dl ( p < 0.001 ) , and significantly more patients without atherosclerotic vascular disease achieving a LDL cholesterol level of < 100 mg/dl ( p < 0.001 ) at weeks 6 and 12 compared to atorvastatin 20 mg or atorvastatin 40 mg . In addition , ezetimibe plus atorvastatin 10 mg result ed in significantly greater changes at week 6 in total cholesterol , triglycerides , non-high-density lipoprotein ( HDL ) cholesterol , apolipoprotein B ( all p < 0.001 ) , and HDL cholesterol ( p = 0.021 ) compared with atorvastatin 20 mg and significantly greater changes at week 12 in LDL cholesterol , non-HDL cholesterol , apolipoprotein A-I ( p = 0.001 ) , total cholesterol , apolipoprotein B ( p < 0.030 ) , and HDL cholesterol ( p < 0.001 ) compared with atorvastatin 40 mg . Both treatments were generally well tolerated , with comparable safety profiles . In conclusion , adding ezetimibe to atorvastatin 10 mg produced significantly greater favorable changes in most lipids at 6 and 12 weeks and significantly greater attainment of prespecified LDL cholesterol levels than doubling or quadrupling the atorvastatin dose in patients > or = 65 years old at high risk for coronary heart disease
Population Characteristics and Study Quality of Included Trials , by Combination Therapy Agent and Potency Comparison Long-Term Clinical Outcomes We found insufficient evidence to compare long-term clinical outcomes ( mortality , acute coronary events , cerebrovascular events , and revascularization procedures ) for all combination therapy and statin intensity comparisons .
Figure 1 presents an evidence map of studies that evaluated these
Atherosclerotic cardiovascular disease ( ASCVD ) affects more than 15 million Americans ( 1 ) and is the leading cause of death for both men and women in the United States ( 2 ) .
Trials have demonstrated reductions in low-density lipoprotein ( LDL ) cholesterol levels ( 3 ) and decreased ASCVD risk with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor ( statin ) monotherapy ( 4 ) .
Over the past decade , statins have often been used in combination with other lipid-modifying agents .
Recently , several high-profile r and omized , controlled trials ( RCTs ) have evaluated add-on therapy ( 57 ) , wherein statin monotherapy is compared with the combination of the same statin dose and another lipid-modifying agent .
Add-on combination therapy can lead to superior lipid outcomes , but studies have not shown decreased rates of cardiovascular death , myocardial infa rct ion , revascularization , or stroke ( 57 ) .
Therefore , the 2013 American College of Cardiology ( ACC ) and American Heart Association ( AHA ) guidelines recommend moderate- or high-intensity statin monotherapy as the first-line strategy for ASCVD risk reduction among patients with LDL cholesterol levels of 4.91 mmol/L or greater ( 190 mg/dL ) , preexisting ASCVD , diabetes mellitus ( DM ) , or estimated 10-year ASCVD risk of 7.5 % or greater ( 8) .
Adverse effects are more common with higher-intensity statin regimens ( 9 ) , and musculoskeletal adverse events occur frequently among patients with the C variant in the SLCO1B1 gene ( 10 ) .
The 2013 ACC/AHA guidelines suggest that clinicians consider moderated combination therapy with a lower-intensity statin and another lipid-modifying medication among high-risk patients ( LDL cholesterol level 4.91 mmol/L [ 190 mg/dL ] , preexisting ASCVD , or DM ) who are intolerant of or unresponsive to statins ( evidence grade E : expert opinion ) ( 8) .
Yet , it is unclear whether this strategy results in similar ASCVD risk reductions and fewer adverse effects compared with higher-intensity statin monotherapy .
A 2009 systematic review that examined these questions found insufficient evidence to weigh benefits and risks of moderated combination therapy ( 12 ) .
We aim ed to compare the effectiveness , safety , and tolerability of moderated combination therapy of statin with another lipid-modifying medication ( bile acid sequestrant , ezetimibe , fibrate , niacin , or -3 fatty acid ) with those of higher-intensity statin monotherapy among high-risk patients .
We sought to compare the long-term clinical benefits and short-term lipid effects of moderated combination therapy with those of higher-intensity statin monotherapy , as well as to determine whether these regimens differ in rates of adherence and harms .
Given the recent release of the 2013 ACC/AHA guidelines ( 8) , we narrowed the scope of this manuscript to focus on evidence most relevant to high-risk population s for whom combination therapy might be considered .
Prior studies have suggested schemes to group statins on the basis of their reported LDL cholesterol reduction ( 17 , 18 ) , which are similar to the strategy used by the ACC/AHA committee ( 8) .