Lipoprotein(a) Blood Levels and Cardiovascular Risk Reduction With Icosapent Ethyl.

BACKGROUND: Elevated lipoprotein(a) (Lp[a]) concentrations are associated with increased cardiovascular event risk even in the presence of well-controlled low-density lipoprotein cholesterol levels, but few treatments are documented to reduce this residual risk. OBJECTIVES: The aim of this post hoc analysis of REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial) was to explore the cardiovascular benefit of icosapent ethyl (IPE) across a range of Lp(a) levels. METHODS: A total of 8,179 participants receiving statin therapy with established cardiovascular disease or age ≥50 years with diabetes and ≥1 additional risk factor, fasting triglyceride 1.69 to 5.63 mmol/L, and low-density lipoprotein cholesterol 1.06 to 2.59 mmol/L were randomized to receive 2 g twice daily of IPE or matching placebo. Relationships between continuous baseline Lp(a) mass concentration and risk for first and total (first and subsequent) major adverse cardiovascular events (MACE) were analyzed, along with the effects of IPE on first MACE among those with Lp(a) concentrations ≥50 or <50 mg/dL. RESULTS: Among 7,026 participants (86% of those randomized) with baseline Lp(a) assessments, the median concentration was 11.6 mg/dL (Q1-Q3: 5.0-37.4 mg/dL). Lp(a) had significant relationships with first and total MACE (P < 0.0001), while event reductions with IPE did not vary across the range of Lp(a) (interaction P > 0.10). IPE significantly reduced first MACE in subgroups with concentrations ≥50 and <50 mg/dL. CONCLUSIONS: Baseline Lp(a) concentration was prognostic for MACE among participants with elevated triglyceride levels receiving statin therapy. Importantly, IPE consistently reduced MACE across a range of Lp(a) levels, including among those with clinically relevant elevations.

Can machine learning bring cardiovascular risk assessment to the next level? A methodological study using FOURIER trial data.

Aims: Through this proof of concept, we studied the potential added value of machine learning (ML) methods in building cardiovascular risk scores from structured data and the conditions under which they outperform linear statistical models. Methods and results: Relying on extensive cardiovascular clinical data from FOURIER, a randomized clinical trial to test for evolocumab efficacy, we compared linear models, neural networks, random forest, and gradient boosting machines for predicting the risk of major adverse cardiovascular events. To study the relative strengths of each method, we extended the comparison to restricted subsets of the full FOURIER dataset, limiting either the number of available patients or the number of their characteristics. When using all the 428 covariates available in the dataset, ML methods significantly (c-index 0.67, P-value 2e-5) outperformed linear models built from the same variables (c-index 0.62), as well as a reference cardiovascular risk score based on only 10 variables (c-index 0.60). We showed that gradient boosting-the best performing model in our setting-requires fewer patients and significantly outperforms linear models when using large numbers of variables. On the other hand, we illustrate how linear models suffer from being trained on too many variables, thus requiring a more careful prior selection. These ML methods proved to consistently improve risk assessment, to be interpretable despite their complexity and to help identify the minimal set of covariates necessary to achieve top performance. Conclusion: In the field of secondary cardiovascular events prevention, given the increased availability of extensive electronic health records, ML methods could open the door to more powerful tools for patient risk stratification and treatment allocation strategies.

Efficacy and Safety of Long-Term Evolocumab Use Among Asian Subjects　- A Subgroup Analysis of the Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk (FOURIER) Trial.

BACKGROUND: There are concerns that Asian patients respond differently to some medications. This study evaluated the efficacy and safety of evolocumab among Asian vs. other subjects in the FOURIER trial, which randomized stable atherosclerosis patients to receive either evolocumab or placebo.Methods and Results:Effects of adding evolocumab vs. placebo to background statin therapy on low-density lipoprotein cholesterol (LDL-C) reductions, cardiovascular outcomes, and adverse events were compared among 27,564 participants with atherosclerotic disease, according to self-reported Asian (n=2,723) vs. other (n=24,841) races followed for a median of 2.2 years in the FOURIER trial. The primary endpoint was a composite of cardiovascular death, myocardial infarction, stroke, hospitalization for unstable angina, or coronary revascularization. At randomization, Asians had slightly lower LDL-C (median 89 [IQR 78-104] mg/dL vs. 92 [80-109] mg/dL; P<0.001) and were much less likely to be on a high-intensity statin (33.3% vs. 73.3%; P<0.001). Evolocumab lowered LDL-C more in Asians than in others (66% vs. 58%; P<0.001). The effect of evolocumab on the primary endpoint was similar in Asians (HR, 0.79; 95% CI, 0.61-1.03) and others (HR, 0.86; 95% CI, 0.79-0.93; P interaction=0.55). There was no excess of serious adverse events with evolocumab among Asians over others. CONCLUSIONS: Use of evolocumab robustly lowers LDL-C and is equally efficacious in lowering the risk of cardiovascular events and safe in Asians as it is in others.

Stroke Prevention With the PCSK9 (Proprotein Convertase Subtilisin-Kexin Type 9) Inhibitor Evolocumab Added to Statin in High-Risk Patients With Stable Atherosclerosis.

Background and Purpose- The PCSK9 (proprotein convertase subtilisin-kexin type 9) monoclonal antibody evolocumab lowered LDL (low-density lipoprotein) cholesterol by 59% to 0.8 (0.5-1.2) mmol/L and significantly reduced major vascular events in the FOURIER trial (Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk). Herein, we report the results of a prespecified analysis of cerebrovascular events in the overall trial population and in patients stratified by prior stroke. Methods- FOURIER was a randomized, double-blind trial comparing evolocumab versus placebo in patients with established atherosclerosis, additional risk factors, and LDL cholesterol levels ≥1.8 (or non-HDL [high-density lipoprotein] ≥2.6 mmol/L) on statin therapy. The median follow-up was 2.2 years. We analyzed the efficacy of evolocumab to reduce overall stroke and stroke subtypes, as well as the primary cardiovascular composite end point by subgroups according to a history of stroke. Results- Among the 27 564 patients, 469 (1.7%) experienced a total of 503 strokes of which 421 (84%) were ischemic. Prior ischemic stroke, diabetes mellitus, elevated CRP (C-reactive protein), history of heart failure, older age, nonwhite race, peripheral arterial disease, and renal insufficiency were independent predictors of stroke. Evolocumab significantly reduced all stroke (1.5% versus 1.9%; hazard ratio, 0.79 [95% CI, 0.66-0.95]; P=0.01) and ischemic stroke (1.2% versus 1.6%; hazard ratio, 0.75 [95% CI, 0.62-0.92]; P=0.005), with no difference in hemorrhagic stroke (0.21% versus 0.18%; hazard ratio, 1.16 [95% CI, 0.68-1.98]; P=0.59). These findings were consistent across subgroups, including among the 5337 patients (19%) with prior ischemic stroke in whom the hazard ratios (95% CIs) were 0.85 (0.72-1.00) for the cardiovascular composite, 0.90 (0.68-1.19) for all stroke, and 0.92 (0.68-1.25) for ischemic stroke (P interactions, 0.91, 0.22, and 0.09, respectively, compared with patients without a prior ischemic stroke). Conclusions- Inhibition of PCSK9 with evolocumab added to statin in patients with established atherosclerosis reduced ischemic stroke and cardiovascular events in the total population and in key subgroups, including those with prior ischemic stroke. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT01764633.

Predicting Benefit From Evolocumab Therapy in Patients With Atherosclerotic Disease Using a Genetic Risk Score: Results From the FOURIER Trial.

BACKGROUND: The ability of a genetic risk score to predict risk in established cardiovascular disease and identify individuals who derive greater benefit from PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibition has not been established. METHODS: We studied 14 298 patients with atherosclerotic cardiovascular disease from the FOURIER trial (Further Cardiovascular Outcomes Researh With PCSK9 Inhibition in Subjects With Elevated Risk). A 27-single-nucleotide polymorphism genetic risk score defined low (quintile 1), intermediate (quintiles 2-4), and high (quintile 5) genetic risk. Patients were also categorized by major atherosclerotic risk factors including diabetes mellitus, hypertension, low-density lipoprotein cholesterol ≥100 mg/dl, and smoking; multiple (≥2) risk factors was considered high clinical risk. Outcomes consisted of major coronary events (coronary heart death, myocardial infarction, or coronary revascularization) and major vascular events (major coronary events and ischemic stroke). Median follow-up was 2.3 years. RESULTS: After we adjusted for clinical factors, the genetic risk score was associated with risk for both major vascular events (Ptrend=0.005) and major coronary events (Ptrend<0.0001). Individuals with intermediate and high genetic risk scores had 1.23- and 1.65-fold increased hazard for major coronary events, respectively. Elevated genetic risk was additive to major atherosclerotic risk factors and identified patients more likely to benefit from evolocumab. There was no benefit for major vascular events in patients without multiple clinical risk factors or high genetic risk (hazard ratio [HR], 1.02; absolute risk reduction [ARR], -0.2%, P=0.86). In contrast, there was a 13% relative risk reduction (HR, 0.87 [0.75-0.998], P=0.047) and a 1.4% ARR in patients with multiple clinical risk factors but without high genetic risk and a 31% relative risk reduction (HR, 0.69 [0.55-0.86], P=0.0012), and 4.0% ARR in patients with high genetic risk, irrespective of clinical risk (Ptrend for HR=0.017, ARR Ptrend=0.004). Patients with high genetic risk who received evolocumab had event rates similar to patients with a low burden of both genetic and clinical risk. CONCLUSION: Patients without multiple clinical risk factors or high genetic risk had a low event rate and did not appear to derive benefit from evolocumab over 2.3 years. Conversely, patients with multiple clinical risk factors but without high genetic risk had intermediate risk and intermediate risk reduction. Patients with high genetic risk, regardless of clinical risk, had a high event rate and derived the greatest relative and absolute benefit from evolocumab, which mitigated this risk.

Lipoprotein(a), PCSK9 Inhibition, and Cardiovascular Risk.

BACKGROUND: Lipoprotein(a) [Lp(a)] may play a causal role in atherosclerosis. PCSK9 (proprotein convertase subtilisin/kexin 9) inhibitors have been shown to significantly reduce plasma Lp(a) concentration. However, the relationship between Lp(a) levels, PCSK9 inhibition, and cardiovascular risk reduction remains undefined. METHODS: Lp(a) was measured in 25 096 patients in the FOURIER trial (Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk), a randomized trial of evolocumab versus placebo in patients with established atherosclerotic cardiovascular disease (median follow-up, 2.2 years). Cox models were used to assess the independent prognostic value of Lp(a) and the efficacy of evolocumab for coronary risk reduction by baseline Lp(a) concentration. RESULTS: The median (interquartile range) baseline Lp(a) concentration was 37 (13-165) nmol/L. In the placebo arm, patients with baseline Lp(a) in the highest quartile had a higher risk of coronary heart disease death, myocardial infarction, or urgent revascularization (adjusted hazard ratio quartile 4: quartile 1, 1.22; 95% CI, 1.01-1.48) independent of low-density lipoprotein cholesterol. At 48 weeks, evolocumab significantly reduced Lp(a) by a median (interquartile range) of 26.9% (6.2%-46.7%). The percent change in Lp(a) and low-density lipoprotein cholesterol at 48 weeks in patients taking evolocumab was moderately positively correlated ( r=0.37; 95% CI, 0.36-0.39; P<0.001). Evolocumab reduced the risk of coronary heart disease death, myocardial infarction, or urgent revascularization by 23% (hazard ratio, 0.77; 95% CI, 0.67-0.88) in patients with a baseline Lp(a) >median, and by 7% (hazard ratio, 0.93; 95% CI, 0.80-1.08; P interaction=0.07) in those ≤median. Coupled with the higher baseline risk, the absolute risk reductions, and number needed to treat over 3 years were 2.49% and 40 versus 0.95% and 105, respectively. CONCLUSIONS: Higher levels of Lp(a) are associated with an increased risk of cardiovascular events in patients with established cardiovascular disease irrespective of low-density lipoprotein cholesterol. Evolocumab significantly reduced Lp(a) levels, and patients with higher baseline Lp(a) levels experienced greater absolute reductions in Lp(a) and tended to derive greater coronary benefit from PCSK9 inhibition. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01764633.

Inflammatory and Cholesterol Risk in the FOURIER Trial.

BACKGROUND: In the FOURIER trial (Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Patients With Elevated Risk), the PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitor evolocumab reduced low-density lipoprotein cholesterol (LDL-C) and cardiovascular risk. It is not known whether the efficacy of evolocumab is modified by baseline inflammatory risk. We explored the efficacy of evolocumab stratified by baseline high-sensitivity C-reactive protein (hsCRP). We also assessed the importance of inflammatory and residual cholesterol risk across the range of on-treatment LDL-C concentrations. METHODS: 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). The effects of evolocumab on the primary end point of cardiovascular death, myocardial infarction, stroke, hospitalization for unstable angina or coronary revascularization, and the key secondary end point of cardiovascular death, myocardial infarction, or stroke were compared across strata of baseline hsCRP (<1, 1-3, and >3 mg/dL). Outcomes were also assessed across values for baseline hsCRP and 1-month LDL-C in the entire trial population. Multivariable models adjusted for variables associated with hsCRP and 1-month LDL-C were evaluated. RESULTS: A total of 7981 (29%) patients had a baseline hsCRP<1 mg/L, 11 177 (41%) had a hsCRP 1 to 3 mg/L, and 8337 (30%) had a hsCRP >3 mg/L. Median (interquartile range) baseline hsCRP was 1.8 (0.9-3.6) mg/L and levels were not altered by evolocumab (change at 48 weeks of -0.2 mg/dL [-1.0 to 0.4] in both treatment arms). In the placebo arm, patients in higher baseline hsCRP categories experienced significantly higher 3-year Kaplan-Meier rates of the primary and key secondary end points: 12.0%, 13.7%, and 18.1% for the primary end point (Ptrend<0.0001) and 7.4%, 9.1%, and 13.2% for the key secondary end point (Ptrend<0.0001) for categories of <1, 1 to 3, and >3 mg/dL, respectively. The relative risk reductions for the primary end point and key secondary end point with evolocumab were consistent across hsCRP strata (P-interactions>0.15 for both). In contrast, the absolute risk reductions with evolocumab tended to be greater in patients with higher hsCRP: 1.6%, 1.8%, and 2.6% and 0.8%, 2.0%, and 3.0%, respectively, for the primary and key secondary end points across hsCRP strata. In adjusted analyses of the association between LDL-C and hsCRP levels and cardiovascular risk, both LDL-C and hsCRP were independently associated with the primary outcome (P<0.0001 for each). CONCLUSIONS: LDL-C reduction with evolocumab reduces cardiovascular events across hsCRP strata with greater absolute risk reductions in patients with higher-baseline hsCRP. Event rates were lowest in patients with the lowest hsCRP and LDL-C. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01764633.