New data prompt update to ACC guidance on nonstatin LDL lowering

The American College of Cardiology Task Force on Expert Consensus Decision Pathways has released a “focused update” for the 2016 ACC Expert Consensus Decision Pathway (ECDP) on the role of nonstatin therapies for LDL-cholesterol lowering in the management of atherosclerotic cardiovascular disease (ASCVD) risk.

The update was deemed by the ECDP writing committee to be desirable given the additional evidence and perspectives that have emerged since the publication of the 2016 version, particularly with respect to the efficacy and safety of proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitors for the secondary prevention of ASCVD, as well as the best use of ezetimibe in addition to statin therapy after acute coronary syndrome.

Dr. Donald M. Lloyd-Jones

The ECDP algorithms endorse the four evidence-based statin benefit groups identified in the 2013 guidelines (adults aged 21 and older with clinical ASCVD, adults aged 21 and older with LDL-C of 190 mg/dL or greater, adults aged 40-75 years without ASCVD but with diabetes and with LDL-C of 70-189 mg/dL, and adults aged 40-75 without ASCVD or diabetes but with LDL-C of 70-189 mg/dL and an estimated 10-year risk for ASCVD of 7.5% or greater) and assume that the patient is currently taking or has attempted to take a statin, they noted.

Among the changes in the 2017 focused update are:

• Consideration of new randomized clinical trial data for the PCSK9 inhibitors evolocumab and bococizumab. Namely, they included results from the cardiovascular outcomes trials FOURIER (Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk) and SPIRE-1 and SPIRE-2 (Studies of PCSK9 Inhibition and the Reduction of Vascular Events), which were published in early 2017.
• An adjustment in the ECDP algorithms with respect to thresholds for consideration of net ASCVD risk reduction. The 2016 ECDP thresholds for risk reduction benefit were percent reduction in LDL-C with consideration of absolute LDL-C level in patients with clinical ASCVD, baseline LDL-C of 190 mg/dL or greater, and primary prevention. In patients with diabetes with or without clinical ASCVD, clinicians were allowed to consider absolute LDL-C and/or non-HDL-cholesterol levels. In the 2017 ECDP update, the thresholds are percent reduction in LDL-C with consideration of absolute LDL-C or non-HDL-C levels for patients in each of the four statin benefit groups. This change was based on the inclusion criteria of the FOURIER trial, the ongoing ODYSSEY Outcomes trial (Evaluation of Cardiovascular Outcomes after an Acute Coronary Syndrome During Treatment with Alirocumab), and the SPIRE-2 trial, all of which included non-HDL-C thresholds. “In alignment with these inclusion criteria, the 2017 Focused Update includes both LDL-C and non-HDL-C thresholds for evaluation of net ASCVD risk-reduction benefit when considering the addition of nonstatin therapies for patients in each of the four statin benefit groups” the update explained.
• An expansion of the threshold for consideration of net ASCVD risk-reduction benefit from a reduction of LDL C of at least 50%, as well as consideration of LDL-C less than 70 mg/dL or non-HDL-C less than 100 mg/dL for all patients (that is, both those with and those without comorbidities) who have clinical ASCVD and baseline LDL-C of 70-189 mg/dL. The 2016 ECDP had different thresholds for those with versus those without comorbidities. This change was based on findings from the FOURIER trial and the IMPROVE-IT (Improved Reduction of Outcomes: Vytorin Efficacy International Trial).“Based on consideration of all available evidence, the consensus of the writing committee members is that lower LDL-C levels are safe and optimal in patients with clinical ASCVD due to [their] increased risk of recurrent events,” they said.
• An expanded recommendation on the use of ezetimibe and PCSK9 inhibition. The 2016 ECDP stated that “if a decision is made to proceed with the addition of nonstatin therapy to maximally tolerated statin therapy, it is reasonable to consider the addition of ezetimibe as the initial agent and a PCSK9 inhibitor as the second agent.” However, based on the FOURIER findings, the ongoing ODYSSEY Outcomes trial, and the IMPROVE-IT trial, the 2017 Focused Update states that, if such a decision is made in patients with clinical ASCVD with comorbidities and baseline LDL-C of 70-189 mg/dL, it is reasonable to weigh the addition of either ezetimibe or a PCSK9 inhibitor in light of “considerations of the additional percent LDL-C reduction desired, patient preferences, costs, route of administration, and other factors.” The update also spells out considerations that may favor the initial choice of ezetimibe versus a PCSK9 inhibitor (such as requiring less than 25% additional lowering of LDL-C, an age of over 75 years, cost, and other patient factors and preferences) .
• Additional factors, based on the FOURIER trial results and inclusion criteria, that may be considered for the identification of higher-risk patients with clinical ASCVD. The 2016 ECDP included on this list diabetes, a recent ASCVD event, an ASCVD event while already taking a statin, poorly controlled other major ASCVD risk factors, elevated lipoprotein, chronic kidney disease, symptomatic heart failure, maintenance hemodialysis, and baseline LDL-C of at least 190 mg/dL not due to secondary causes. The 2017 update added being 65 years or older, prior MI or nonhemorrhagic stroke, current daily cigarette smoking, symptomatic peripheral artery disease with prior MI or stroke, history of non-MI related coronary revascularization, residual coronary artery disease with at least 40% stenosis in at least two large vessels, HDL-C less than 40 mg/dL for men and less than 50 mg/dL for women, high-sensitivity C-reactive protein greater than 2 mg/L, and metabolic syndrome.