Polyunsaturated Fatty Acid Impact on Clinical Outcomes in Acute Coronary Syndrome Patients With Dyslipidemia: Subanalysis of HIJ-PROPER

Role of serum n-6 polyunsaturated fatty acids in the development of acute coronary syndromes

n-3 polyunsaturated fatty acids (PUFAs) have an inhibitory effect on the development of coronary artery disease (CAD). However, whether n-6 PUFAs, dihomo-gamma-linolenic acid (DGLA), and arachidonic acid (AA) play a role in the development of CAD remains unclear. This study investigated the association between PUFAs and the risk of developing acute coronary syndrome (ACS) using the lipid and PUFAs data of patients who received percutaneous coronary intervention (PCI) for either non-emergent conditions (staged group) or ACS (ACS group). We retrospectively evaluated 433 patients who underwent PCI between 2014 and 2021. The patients were divided into the ACS group (n = 18) and the staged group (n = 132). The lipid and PUFA values of each patient between the two groups were compared. Moreover, to investigate the correlation between n-6 PUFA levels and ACS, the effects of confounding factors such as the use of strong statins and low-density lipoprotein cholesterol (LDL-C) levels were adjusted. The ACS group had higher n-6 PUFAs levels than the staged group (DGLA: 36.8 µg/mL vs 29.6 µg/mL; AA: 203.3 µg/mL vs 145.8 µg/mL). Furthermore, the analysis of covariance adjusted for LDL-C levels showed a significant difference between the two groups in terms of DGLA and AA levels. The n-3 PUFA levels did not significantly differ between the staged and ACS groups. Moreover, the ACS group had higher DGLA and AA levels and lower n-3 PUFAs/AA ratios than the staged group. Therefore, excess n-6 PUFAs may be a risk factor for ACS.

Greater Change in the Eicosapentaenoic Acid to Arachidonic Acid Ratio Is Associated With Decreased Incidence of Cardiovascular Events in Acute Coronary Syndrome Patients With Elevated Triglyceride Levels

BACKGROUND

This study investigated whether the percentage change (%Δ) in the eicosapentaenoic acid to arachidonic acid (EPA/AA) ratio is associated with cardiovascular event rates among acute coronary syndrome (ACS) patients receiving contemporary lipid-lowering therapy other than polyunsaturated fatty acids (PUFAs).Methods and Results:This post hoc subanalysis of the HIJ-PROPER study included PUFA-naïve patients for whom EPA/AA ratio data were available at baseline and after 3 months. Patients were categorized into 2 groups based on the median %ΔEPA/AA ratio: Group 1, change less than the median; and Group 2, change greater than or equal to the median. The 3-year rates of the primary endpoint, a composite of all-cause death, non-fatal myocardial infarction, non-fatal stroke, and unstable angina pectoris, were compared between the 2 groups. The median %ΔEPA/AA ratio in Groups 1 and 2 was -26.2% (n=482 patients [49.9%]) and 42.2% (n=483 patients [50.1%]), respectively. At the 3-year follow-up, the occurrence of the primary endpoint was significantly lower in Group 2 than in Group 1 (29/483 [6.0%] vs. 53/482 [11.0%]; hazard ratio 0.53, 95% confidence interval 0.33-0.82; P=0.005). The same trend was observed after adjusting for patient factors (P=0.02).

CONCLUSIONS

Among ACS patients receiving contemporary lipid-lowering therapy other than PUFAs, a greater change in the EPA/AA ratio was associated with a lower incidence of cardiovascular events.

Effect of Ezetimibe + Pitavastatin on Cardiovascular Outcomes in Patients with ST-Segment Elevation Myocardial Infarction (from the HIJ-PROPER Study)

Lipid-lowering therapy is necessary to reduce cardiovascular event rates in patients with ST-segment elevation myocardial infarction (STEMI). This study aimed to evaluate the effect of intensive lipid-lowering therapy, which comprised pitavastatin and ezetimibe, on patients with STEMI. We therefore undertook a post hoc subanalysis of the HIJ-PROPER study's data that examined the clinical outcomes of the patients with dyslipidemia and STEMI (n = 880) who received pitavastatin and ezetimibe therapy (intensive lipid-lowering therapy group) or pitavastatin monotherapy (standard lipid-lowering therapy group), and we evaluated their cardiovascular events. The primary end point was a composite of all-cause death, nonfatal myocardial infarction, nonfatal stroke, unstable angina, and ischemia-driven revascularization. During the median 3.4-year follow-up period, the cumulative rates of the primary end point were 31.9% and 39.7% in the intensive lipid-lowering therapy and standard lipid-lowering therapy groups, respectively (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.62 to 0.97; p = 0.02). Compared with the standard lipid-lowering therapy group, the intensive lipid-lowering therapy group had significantly lower all-cause death (6.9% vs 3.2%; HR, 0.45; 95% CI, 0.23 to 1.84; p = 0.01) and nonfatal stroke (2.9% vs 1.6%; HR, 0.77; 95% CI, 0.62 to 0.97; p = 0.02) rates. Patients with pitavastatin and ezetimibe therapy, as compared with pitavastatin monotherapy, had a lower cardiovascular event in STEMI patients. In conclusion, adding ezetimibe to statin therapy may be beneficial for patients with dyslipidemia and STEMI.

The Effects of Lipid-Lowering Therapy on Serum Eicosapentaenoic Acid to Arachidonic Acid Ratio: An HIJ-PROPER Sub-Analysis

BACKGROUND

Controversy remains regarding the influence of lipid-lowering therapy on the eicosapentaenoic acid/arachidonic acid ratio.

OBJECTIVE

This study aimed to clarify the effects of lipid-lowering therapy on the eicosapentaenoic acid/arachidonic acid ratio in patients with acute coronary syndrome (ACS).

METHODS

This was a post hoc sub-analysis of the Heart Institute of Japan-PRoper level of lipid-lowering with pitavastatin and ezetimibe in ACS study. We compared the eicosapentaenoic acid/arachidonic acid ratio changes from baseline to the 3-month follow-up after contemporary lipid-lowering therapy with pitavastatin + ezetimibe therapy and pitavastatin mono-therapy.

RESULTS

Among patients with ACS and dyslipidemia, the eicosapentaenoic acid/arachidonic acid increased significantly in the pitavastatin mono-therapy group (0.40 ± 0.26 to 0.46 ± 0.34, P < .0001) but did not increase in the pitavastatin + ezetimibe group (0.37 ± 0.22 to 0.38 ± 0.27, P = .18). When the analysis was limited to patients who received 2 mg/day of pitavastatin during the follow-up period, these trends in changes of the eicosapentaenoic acid/arachidonic acid ratio remained unchanged. Multivariate analysis showed that ezetimibe use (P = .005; β = 0.09), ST-elevation myocardial infarction (P = .04; β = -0.01), and baseline low-density lipoprotein cholesterol (LDL-C) level (P = .0003; β = 0.12) were independent predictors of the percentage change in the eicosapentaenoic acid/arachidonic acid ratio. These trends were similar even when the analysis was limited to patients who did not take statins at enrollment.

CONCLUSION

Standard lipid-lowering therapy with pitavastatin mono-therapy improved the eicosapentaenoic acid/arachidonic acid ratio for patients with ACS. Intensive lipid-lowering therapy with pitavastatin + ezetimibe did not improve the eicosapentaenoic acid/arachidonic acid ratio, although LDL-C decreased significantly. Inhibition of the improvement in the eicosapentaenoic acid/arachidonic acid ratio by adding ezetimibe may affect cardiovascular disease prognosis.

Polyunsaturated Fatty Acid Impact on Clinical Outcomes in Acute Coronary Syndrome Patients With Dyslipidemia: Subanalysis of HIJ-PROPER

Background

This study aimed to examine the impact of baseline eicosapentaenoic acid (EPA) to arachidonic acid (AA) ratio on clinical outcomes of patients with acute coronary syndrome.

Methods and Results

In the HIJ‐PROPER (Heart Institute of Japan Proper Level of Lipid Lowering With Pitavastatin and Ezetimibe in Acute Coronary Syndrome) study, 1734 patients with acute coronary syndrome and dyslipidemia were randomly assigned to pitavastatin+ezetimibe therapy or pitavastatin monotherapy. We divided the patients into 2 groups based on EPA/AA ratio on admission (cutoff 0.34 μg/mL as median of baseline EPA/AA ratio) and examined their clinical outcomes. The primary end point comprised all‐cause death, nonfatal myocardial infarction, nonfatal stroke, unstable angina pectoris, or ischemia‐driven revascularization. Percentage reduction of low‐density lipoprotein cholesterol and triglyceride from baseline to follow‐up was similar regardless of baseline EPA/AA ratio. Despite the mean low‐density lipoprotein cholesterol level during follow‐up being similar between the low‐ and high‐EPA/AA groups, the mean triglyceride levels during follow‐up were significantly higher in the low‐ than in the high‐EPA/AA group. After 3 years of follow‐up, the cumulative incidence of the primary end point in patients with low EPA/AA was 27.2% in the pitavastatin+ezetimibe group compared with 36.6% in the pitavastatin‐monotherapy group (hazard ratio 0.69; 95% CI, 0.52‐0.93; P=0.015). However, there was no effect of pitavastatin+ezetimibe therapy on the primary end point in patients with high EPA/AA (hazard ratio 0.92; 95% CI, 0.70‐1.20; P=0.52).

Conclusions

Among acute coronary syndrome patients who have dyslipidemia and low EPA/AA ratio, adding ezetimibe to statin decreases the risk of cardiovascular events compared with statin monotherapy.

Clinical Trial Registration

URL: http://www.umin.ac.jp/ctr. Unique identifier: UMIN000002742