Acute arterial events across all vascular territories in the FOURIER trial

Background

In the FOURIER (Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Patients With Elevated Risk) trial, adding the PCSK9 inhibitor evolocumab to statin therapy reduced low-density lipoprotein cholesterol (LDL-C) and cardiovascular risk. Although atherosclerotic coronary, cerebrovascular, and peripheral vascular events share a related pathobiology, the effect of aggressive LDL-C lowering with PCSK9 inhibition on the risk of acute arterial events across all three vascular beds is not well-described.

Purpose

To assess the efficacy of evolocumab on acute arterial events in all vascular territories including coronary, cerebral, and peripheral vascular beds.

Methods

In the FOURIER trial, patients (n=27,564) with stable atherosclerotic cardiovascular disease and LDL-C ≥70 mg/dL on a statin were randomly assigned to evolocumab versus placebo and followed for a median of 2.2 years (1.8–2.5). Acute arterial events were defined as a composite of coronary (coronary heart disease [CHD] death, myocardial infarction [MI], or urgent coronary revascularization), cerebrovascular (ischemic stroke, transient ischemic attack [TIA], or urgent cerebral revascularization), or peripheral vascular (acute limb ischemia, major amputation, or urgent peripheral revascularization) events. Cox proportional-hazard models were used to assess the efficacy of evolocumab on these outcomes. Landmark and total event analyses were also done.

Results

Of the 2,210 first acute arterial events occurring during follow-up, 74% were coronary, 22% were cerebrovascular, and 4% were peripheral vascular. Evolocumab reduced the risk of a first acute arterial event by 19% (HR 0.81, 95% CI 0.74–0.88; P<0.001), with significant individual reductions in acute coronary (HR 0.83; 95% CI 0.75–0.91; P<0.001), acute cerebrovascular (HR 0.77; 95% CI 0.65–0.92; P=0.004), and acute peripheral vascular (HR 0.58; 95% CI 0.38–0.88; P=0.01) events (Figure, top). The magnitude of the risk reduction with evolocumab tended to increase over time, with a 16% reduction (HR 0.84; 95% CI 0.75–0.96) in the first year followed by a 24% reduction (HR 0.76; 95% CI 0.67–0.85) thereafter (Figure, bottom). There were 3,780 total acute arterial events (first plus recurrent), with a 22% reduction with evolocumab (incidence rate ratio [RR] 0.78; 95% CI 0.70–0.87). Evolocumab prevented 496 total acute arterial events as compared to 222 first events.

Conclusions

The addition of the PCSK9 inhibitor evolocumab to statin therapy reduced the risk of acute arterial events across all vascular territories with a robust effect over time. These findings indicate a pan-vascular impact of aggressive lipid-lowering therapy on these acute and clinically meaningful events.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): The FOURIER trial was supported by Amgen.