Effectiveness of low-density lipoprotein cholesterol reduction with lipid lowering therapy for secondary prevention amongst older individuals: a nationwide cohort study

BACKGROUND

Data about the clinical benefit from initial low-density lipoprotein cholesterol (LDL-C) reduction with lipid lowering treatment for secondary prevention and risk of major vascular events amongst older as compared with younger individuals treated during routine clinical care are limited. We investigated this in a nationwide cohort.

METHODS

Individuals aged ≥ 50 years with a first-time hospitalisation for a cardiovascular event (index event, including acute coronary syndrome, non-haemorrhagic stroke, transient ischaemic attack and coronary revascularisation), 1 January 2008 to 31 October 2018, who subsequently used lipid lowering treatment, and had an LDL-C measurement before and after the event were included. Hazard ratios (HRs) for major vascular events per 1 mmol/L reduction in LDL-C were estimated for the included 21,751 older and 22,681 younger individuals (≥/<70 years old) using Cox regression.

RESULTS

LDL-C lowering was associated with a 12% lower risk of major vascular events in older individuals per 1 mmol/L reduction in LDL-C (HR 0.88, 95% confidence interval [CI] 0.84-0.93), with no significant difference compared with the risk reduction amongst younger individuals (HR 0.88, 95% CI 0.83-0.93; P-value for difference between age groups: 0.86). The risk reduction was more pronounced when post hoc restricting, as a proxy for compliance, to new users with an LDL-C reduction above the lowest decile for both older (0.81, 95% CI 0.73-0.90) and younger (0.81, 95% CI 0.72-0.91) individuals.

CONCLUSIONS

This study strongly supports a similar relative clinical benefit of LDL-C reduction with lipid lowering treatment for secondary prevention of major vascular events amongst individuals aged ≥70 and <70 years.

LDL-C Reduction With Lipid-Lowering Therapy for Primary Prevention of Major Vascular Events Among Older Individuals

BACKGROUND

Reducing low-density lipoprotein (LDL) cholesterol with lipid-lowering therapy has consistently been shown to lower the risk of cardiovascular disease in primary prevention trials where the majority of individuals are aged <70 years. For older individuals, however, evidence is less clear.

OBJECTIVES

In this study, the authors sought to compare the clinical effectiveness of lowering LDL cholesterol by means of lipid-lowering therapy for primary prevention of cardiovascular disease among older and younger individuals in a Danish nationwide cohort.

METHODS

We included individuals aged ≥50 years who had initiated lipid-lowering therapy from January 1, 2008, to October 31, 2017, had no history of atherosclerotic cardiovascular disease, and had a baseline and a within-1-year LDL cholesterol measurement. We assessed the associated risk of major vascular events among older individuals (≥70 years) by HRs per 1 mmol/L reduction in LDL cholesterol compared with younger individuals (<70 years).

RESULTS

For both the 16,035 older and the 49,155 younger individuals, the median LDL cholesterol reduction was 1.7 mmol/L. Each 1 mmol/L reduction in LDL cholesterol in older individuals was significantly associated with a 23% lower risk of major vascular events (HR: 0.77; 95% CI: 0.71-0.83), which was equal to that of younger individuals (HR: 0.76; 95% CI: 0.71-0.80; P value for difference = 0.79). Similar results were observed across all secondary analyses.

CONCLUSIONS

Our study supports a relative clinical benefit of lowering LDL cholesterol for primary prevention of major vascular events in individuals aged ≥70 years similarly as in individuals aged <70 years.

Secretory phospholipase A(2)-IIA and cardiovascular disease: a mendelian randomization study

OBJECTIVES

This study sought to investigate the role of secretory phospholipase A2 (sPLA2)-IIA in cardiovascular disease.

BACKGROUND

Higher circulating levels of sPLA2-IIA mass or sPLA2 enzyme activity have been associated with increased risk of cardiovascular events. However, it is not clear if this association is causal. A recent phase III clinical trial of an sPLA2 inhibitor (varespladib) was stopped prematurely for lack of efficacy.

METHODS

We conducted a Mendelian randomization meta-analysis of 19 general population studies (8,021 incident, 7,513 prevalent major vascular events [MVE] in 74,683 individuals) and 10 acute coronary syndrome (ACS) cohorts (2,520 recurrent MVE in 18,355 individuals) using rs11573156, a variant in PLA2G2A encoding the sPLA2-IIA isoenzyme, as an instrumental variable.

RESULTS

PLA2G2A rs11573156 C allele associated with lower circulating sPLA2-IIA mass (38% to 44%) and sPLA2 enzyme activity (3% to 23%) per C allele. The odds ratio (OR) for MVE per rs11573156 C allele was 1.02 (95% confidence interval [CI]: 0.98 to 1.06) in general populations and 0.96 (95% CI: 0.90 to 1.03) in ACS cohorts. In the general population studies, the OR derived from the genetic instrumental variable analysis for MVE for a 1-log unit lower sPLA2-IIA mass was 1.04 (95% CI: 0.96 to 1.13), and differed from the non-genetic observational estimate (OR: 0.69; 95% CI: 0.61 to 0.79). In the ACS cohorts, both the genetic instrumental variable and observational ORs showed a null association with MVE. Instrumental variable analysis failed to show associations between sPLA2 enzyme activity and MVE.

CONCLUSIONS

Reducing sPLA2-IIA mass is unlikely to be a useful therapeutic goal for preventing cardiovascular events.