Complementary prediction of cardiovascular events by estimated apo- and lipoprotein concentrations in the working age population. The Health 2000 Study

Validation of the role of apolipoproteins in coronary artery disease patients with impaired kidney function for prognosis: a prospective cohort study in China

OBJECTIVE

This study aims to evaluate the relationship between apolipoproteins (ApoA1, ApoB, and the ApoB/A1 ratio) and the incidence of major adverse cardiovascular events (MACE) in patients with coronary artery disease (CAD) and impaired kidney function, assessing their potential role in secondary prevention.

METHOD

A prospective cohort of 1,640 patients with impaired kidney function who underwent percutaneous coronary intervention in China was analyzed. Patients were categorized based on the measurements of ApoA1, ApoB, and ApoB/A1 ratio. MACE, defined as a composite of all-cause mortality, cardiovascular death, nonfatal myocardial infarctions, strokes, and unplanned revascularizations, was tracked post-procedure, with statistical analyses including Kaplan-Meier survival curves and Cox regression models to identify associations with apolipoproteins. Subgroup analyses according to kidney function were conducted.

RESULT

During a median follow-up of 3.1 years, 324 MACE events were observed. Multivariable Cox regression analyses illustrated higher levels of ApoB and the ApoB/A1 ratio were significantly associated with increased MACE incidence (adjusted HR [95%CI] 1.668[1.044-2.666]; adjusted HR [95%CI] 2.231[1.409-3.533], respectively), while lower ApoA1 levels correlated with a higher risk (adjusted HR [95%CI] 0.505[0.326-0.782]). ROC curve analyses indicated comparable predictive performances to traditional risk factors like LDL cholesterol. Subgroup analysis revealed that the above association was not statistically significant in the moderate-to-severe renal impairment CAD patients (eGFR < 45 mL/min/1.73 m2).

CONCLUSION

Our findings illustrate that apolipoproteins, specifically ApoA1 and ApoB, along with their ratio, are significant predictors of major adverse cardiovascular events in CAD patients with impaired kidney function. These results emphasize the need for incorporating apolipoprotein measurements in secondary prevention strategies for this high-risk population.

Apolipoprotein and peripheral artery disease: Mendelian randomization analysis

BACKGROUND

The prevalence of peripheral arterial disease (PAD) is on the rise globally, leading to adverse clinical outcomes. Our aim was to investigate the causal relationship between apolipoprotein and PAD, as well as the potential mediating role of smoking, diabetes, hypertension, myocardial infarction, and ischemic stroke.

METHODS

We employed two-sample Mendelian randomization (TSMR) to assess the causal effect of apoB/A1 on the risk of PAD and potential mediators (smoking, diabetes mellitus, hypertension, myocardial infarction, and ischemic stroke), as well as the causal effect of those mediators on PAD. The use of multivariate MR (MVMR) allowed us to explore and quantify the mediating role of these factors in the causal association between apoB/A1 and the risk of PAD.

RESULTS

Our MR analysis showed that each standard deviation increase in apoB/A1 increased the risk of PAD by 46% (OR = 1.460, 95% CI: 1.255-1.697, P = 8.74E-07). Hypertension, myocardial infarction, and ischemic stroke were ultimately recognized as the mediators of the causal relationship between apoB/A1 and PAD, explaining 7.5%, 19.7%, and 62.5% of the causal effect, respectively, and the proportion combined of the three together was 81%.

CONCLUSIONS

These studies demonstrated that elevated apoB/A1 increases the risk of developing PAD and that this association may be mediated by hypertension, myocardial infarction, and ischemic stroke.

Association of apolipoprotein levels with all-cause and cardiovascular mortality

AIMS

Research has shown that apolipoproteins (Apos) are potential indicators of heart health and death. We investigated the associations of Apo levels with all-cause and cardiovascular mortality.

METHODS AND RESULTS

We systematically searched the Cochrane Library, PubMed, and Web of Science for English language studies up to 28 November 2022. We used Stata 17.0 to summarize the estimated effects with 95% confidence intervals (CIs). We also conducted subgroup analyses according to study location, year of publication, individual age, follow-up years, and sample size. Moreover, we performed a sensitivity analysis to evaluate bias in our study. This study included 23 studies with 152 854 individuals in total. The level of ApoA was negatively related to cardiovascular mortality [odds ratio (OR) = 0.69, 95% CI = 0.52-0.93]. An increased ratio of ApoB/A1 was a risk factor for cardiovascular mortality (OR = 2.13, 95% CI = 1.48-3.07) and all-cause mortality (OR = 2.05, 95% CI = 1.52-2.77). The level of ApoB was positively related to cardiovascular mortality (OR = 1.12, 95% CI = 0.85-1.47), but the difference was not statistically significant. However, the associations between ApoB or ApoA1 and all-cause mortality were not obvious. Our subgroup analyses showed that the location, year of publication, individual age, and follow-up years of the studies affected the heterogeneity of our study to varying degrees. The sensitivity analysis showed that our results were almost robust, apart from excluding the article by Nomikos (OR = 0.77, 95% CI = 0.65-0.92) and Zeng (OR = 0.77, 95% CI = 0.65-0.91), when investigating the relationship between ApoA1 and all-cause mortality.

CONCLUSION

In this study, we found that Apo levels were linked to cardiovascular and all-cause mortality. Our study strengthens the evidence on the association between the level of Apos and cardiac health and may provide ideas for regulating the level of Apos to promote public health.

Serum Cholesterol Levels and Risk of Cardiovascular Death: A Systematic Review and a Dose-Response Meta-Analysis of Prospective Cohort Studies

Introduction: Numerous studies have demonstrated that abnormal levels of cholesterol are associated with a high attributable risk for the occurrence of cardiovascular disease (CVD). However, there has been no comprehensive study to investigate the relationship between serum cholesterol levels and cardiovascular mortality. Therefore, we conducted a systematic review and dose-response meta-analysis. Methods: A systematic literature search of key databases, including EMBASE and MEDLINE, was conducted and included all the published epidemiological studies that contained estimates of the hazard ratios (HR) of serum cholesterol of CVD mortality. Data extraction, eligibility, and assessment of the risk of bias were assessed by two reviewers independently. All published risk estimates were hazard ratios and analyzed by quantitative meta-analysis using a random-effects model and dose-response relationships of serum cholesterol with CVD mortality. Results: A total of 14 independent reports, including 1,055,309 subjects and 9457 events, were analyzed. The pooled HR (95% CI) was 1.27 (95% CI, 1.19–1.36) for total cholesterol, 1.21 (95% CI, 1.09–1.35) for low-density lipoprotein cholesterol (LDL-C), and 0.60 (95% CI, 0.50–0.72) for high-density lipoprotein cholesterol (HDL-C). We observed a linear association between serum cholesterol (TC, HDL-C) levels and CVD mortality in this meta-analysis. Conclusions: Serum total cholesterol and LDL-C level is associated with increased CVD mortality, but HDL-C level is inversely associated with CVD mortality.

A dose-response meta-analysis to evaluate the relationship between high-density lipoprotein cholesterol and all-cause and cardiovascular disease mortality

PURPOSE

Previous studies have not fully described the relationship between high-density lipoprotein cholesterol (HDL-C) and death risks from all cause and cardiovascular disease (CVD). This study quantitatively evaluates HDL-C-mortality associations.

METHODS

Embase and PubMed databases were searched for relevant articles published up to 1 June 2019. Random-effects models were used to pool relative risks (RRs) and 95% confidence intervals (CIs). We used restricted cubic splines to model the dose-response association.

RESULTS

We identified 32 prospective cohort studies including 369,904 participants and 33,473 total deaths (9426 CVD deaths). Compared to the lowest HDL-C levels, all cause and CVD mortality risks were reduced by 18% (RR 0.82; 95% CI, 0.73-0.93) and 36% (0.64, 0.46-0.89), respectively, for the highest HDL-C levels. All cause and CVD mortality risks were reduced by 15% (0.85, 0.79-0.92) and 23% (0.77, 0.69-0.87), respectively, with each 1 mmol/L increment of HDL-C. We found evidence of nonlinear and negative dose-response associations of HDL-C with all cause and CVD mortality (P_nonlinearity < 0.001), and the lowest death risks from all cause and CVD were observed at approximately 1.34 and 1.55 mmol/L, respectively.

CONCLUSION

HDL-C is inversely associated with all cause and CVD mortality risks under approximately 2.05 and 2.33 mmol/L, respectively. Optimal doses require investigation via clinical practice or high-quality research.

Serum apolipoprotein A-I concentration differs in coronary and peripheral artery disease

Coronary artery and peripheral artery diseases represent different clinical outcomes of atherosclerosis and despite sharing common risk factors the ultimate reasons determining disease presentation are still unclear. The present study sought to define and compare the serum lipid and apolipoprotein profiles of patients undergoing coronary artery bypass grafting and those treated invasively for symptomatic lower extremity peripheral artery disease. Altogether 218 coronary and 280 peripheral artery disease patients treated between 2013 and 2014 in the Tampere University Hospital, Tampere, Finland, with available lipid measurements within two years prior to the intervention were retrospectively analysed. The Extended Friedewald formula neural network model was used to obtain apolipoprotein and lipoprotein subfraction values. Patients undergoing coronary artery bypass surgery had a clear male predominance (82% versus 53%, p < 0.001), lower median age (69 versus 74 years, p < 0.001) and a lower prevalence of smoking (18% versus 32%, p = 0.001) and pulmonary disease (12% versus 20%, p = 0.023) compared to peripheral artery disease patients. There were some differences in the serum lipid profiles between the study groups in the univariable analyses. When controlling for the statistically significant differences in age, sex, urgency of treatment and comorbidities between the groups in a multivariable logistic regression model, higher serum concentrations of apolipoprotein A-I were significantly and independently associated with coronary artery disease (OR 1.11 for 0.01 g/L increase, p = 0.044). In conclusion, patients undergoing coronary artery bypass grafting appear to have higher apolipoprotein A-I levels when compared to patients treated for peripheral artery disease.

Extended Serum Lipid Profile Predicting Long-Term Survival in Patients Treated for Abdominal Aortic Aneurysms

BACKGROUND

Individuals treated for abdominal aortic aneurysms (AAAs) are high-risk patients in whom better risk prediction could improve survival. Contemporary serum lipid parameters, such as apolipoproteins and lipoprotein subfractions, may improve or complement the prognostic value of traditional serum lipids. The aim of this study was to ascertain the extended serum lipid profiles, long-term prognosis and their association in AAA patients.

METHODS

Altogether 498 patients treated for AAAs and with available serum lipid values were retrospectively analysed. Contemporary lipid parameters were estimated using a neural network model, the extended Friedewald formula.

RESULTS

Younger age, smoking and urgent or emergency surgery were associated with an unfavourable, and coronary disease and previous stroke with a favourable lipid profile. In multivariable analysis-in addition to advanced age, aneurysm rupture, smoking, pulmonary disease and diabetes-high triglycerides and traditional LDL cholesterol were significant independent risk factors for mortality, HR 1.84 (95% CI 1.20-2.81) and 1.79 (95% CI 1.18-2.73), respectively, while higher EFW-IDL cholesterol was associated with better survival, HR 0.31 (95% CI 0.19-0.65). Including serum lipid parameters improved the prediction of 5-year survival (NRI = 17.7%, p = 0.016).

CONCLUSIONS

Extended serum lipid parameters complement risk prediction of patients treated for AAAs. An unfavourable lipid profile is associated with treatment of AAA earlier in life and with inferior long-term survival.

Effect of Metformin Treatment on Lipoprotein Subfractions in Non-Diabetic Patients with Acute Myocardial Infarction: A Glycometabolic Intervention as Adjunct to Primary Coronary Intervention in ST Elevation Myocardial Infarction (GIPS-III) Trial

Objective

Metformin affects low density lipoprotein (LDL) and high density (HDL) subfractions in the context of impaired glucose tolerance, but its effects in the setting of acute myocardial infarction (MI) are unknown. We determined whether metformin administration affects lipoprotein subfractions 4 months after ST-segment elevation MI (STEMI). Second, we assessed associations of lipoprotein subfractions with left ventricular ejection fraction (LVEF) and infarct size 4 months after STEMI.

Methods

371 participants without known diabetes participating in the GIPS-III trial, a placebo controlled, double-blind randomized trial studying the effect of metformin (500 mg bid) during 4 months after primary percutaneous coronary intervention for STEMI were included of whom 317 completed follow-up (clinicaltrial.gov Identifier: NCT01217307). Lipoprotein subfractions were measured using nuclear magnetic resonance spectroscopy at presentation, 24 hours and 4 months after STEMI. (Apo)lipoprotein measures were obtained during acute STEMI and 4 months post-STEMI. LVEF and infarct size were measured by cardiac magnetic resonance imaging.

Results

Metformin treatment slightly decreased LDL cholesterol levels (adjusted P = 0.01), whereas apoB remained unchanged. Large LDL particles and LDL size were also decreased after metformin treatment (adjusted P<0.001). After adjustment for covariates, increased small HDL particles at 24 hours after STEMI predicted higher LVEF (P = 0.005). In addition, increased medium-sized VLDL particles at the same time point predicted a smaller infarct size (P<0.001).

Conclusion

LDL cholesterol and large LDL particles were decreased during 4 months treatment with metformin started early after MI. Higher small HDL and medium VLDL particle concentrations are associated with favorable LVEF and infarct size.