High Lipoprotein(a) Levels are Associated With Long-Term Adverse Outcomes in Acute Myocardial Infarction Patients in High Killip Classes

High Lipoprotein(a) Levels as a Predictor of Major Adverse Cardiovascular Events in Hospitalized-Acute Myocardial Infarction Patients

Background

Risk stratification models with incorporation of biochemical markers have received attention recently. In acute myocardial infarction (AMI) one such marker is lipoprotein(a) (Lp(a)). Lp(a) has prothrombotic and proinflammatory properties. High levels of Lp(a) probably contribute to the additional adverse effects in AMI, as it enhances the damaging effect of acute thrombosis. This study aimed to evaluate serum Lp(a) as a predictor of major adverse cardiovascular events (MACE) in hospitalized-acute myocardial infarction patients.

Methods

A prospective cohort study was conducted at Sanglah Hospital, Denpasar, during June–August 2018, among 66 people by consecutive sampling. Samples that met the inclusion and exclusion criteria were examined for serum Lp(a) at the time of admission and the occurrence of MACE during hospitalization was observed. Data regarding serum Lp(a), demography, smoking history, dyslipidemia, hypertension, diabetes mellitus, and MACE were collected. Log rank test and Cox proportional hazards regression were conducted with SPSS version 20 for Windows.

Results

During observation, MACE occurred in 25 (38%) patients, including cardiogenic shock in 7 (10.6%) patients, heart failure in 20 (30.3%) patients, cardiovascular death in 5 (7, 6%) patients, malignant arrhythmias in 5 (7.6%) patients, and postinfarction angina in 5 (7.6%) patients. After the Log rank test, a significant difference in survival was observed (p = 0.001) between groups of high Lp(a) (survival rate of 60.6 hours; 95% CI 43.3–77.9) and low Lp(a) (average survival of 104.3 hours, 95% CI 91.4–117.2). The hazard ratio of high Lp(a) against MACE was 4.63 (p=0.002), and it increased to 4.69 in multivariate analysis with Cox proportional hazards regression test (p=0.003).

Conclusion

The high level of Lp(a) in AMI patients was a risk factor for the occurrence of MACE during hospitalization. Patients with high Lp(a) also had worse survival compared to patients with low Lp(a).

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Lipoprotein(a) as a marker for predicting coronary collateral circulation in patients with acute myocardial infarction

Aim: The aim of the present study was to examine the predictive value of lipoprotein(a) (Lp[a]) levels for coronary collateral circulation (CCC) in patients with acute myocardial infarction (AMI). Method & methods: A total of 409 consecutive patients with AMI were enrolled for this study. Patients were divided into two groups according to rentrop grades assessed by coronary angiography: bad (n = 277) and good CCC group (n = 132). Result: Patients with bad CCC had a higher level of Lp(a) than that with good CCC (median Lp[a] 219.1 vs 122.0 mg/l). The area under the receiver-operating characteristic curves of Lp(a) in predicting bad CCC was 0.647 (95% CI: 0.592–0.702) with the cut-off value of 199.0 mg/l. Conclusion: Our data firstly suggested that Lp(a) might be a useful marker for CCC after AMI.

Prognostic Value of Lipoprotein(a) Levels in Patients Undergoing Coronary Angiography for Premature Acute Coronary Syndromes

Little is known about the association between lipoprotein(a) [Lp(a)] levels and future ischemic cardiovascular events in patients with premature acute coronary syndrome (ACS). A total of 1464 consecutive patients who underwent coronary angiography for premature ACS (males <45 years and females <55 years) were enrolled in this study. Patients were divided into quartiles according to serum Lp(a) levels (Q1: ≤11.1 nmol/L; Q2: 11.1-27.7 nmol/L; Q3: 27.7-79.3 nmol/L; and Q4: >79.3 nmol/L). Major adverse cardiovascular events (MACEs) increased with Lp(a) quartiles after 2-year follow-up (among quartiles, respectively; P = .001). Kaplan-Meier curves revealed significant differences in event-free survival rates among Lp(a) quartile groups ( P = .001). Multivariate Cox proportional hazards regression analysis indicated that serum Lp(a) level was an independent predictor of MACE either as a continuous variable (hazard ratio [HR]: 1.002, 95% confidence interval [CI]: 1.001-1.004; P = .009) or as a categorical variable (HR: 1.443, 95% CI: 1.074-1.937; P = .015). Furthermore, Lp(a) levels (as a variable) significantly improved the prognostic value for MACE. These findings suggest that Lp(a) measurement has value for cardiovascular risk stratification in patients with premature ACS.

Prognostic value of lipoprotein (a) level in patients with coronary artery disease: a meta-analysis

Background

Elevated lipoprotein (a) is recognized as a risk factor for incident cardiovascular events in the general population and established cardiovascular disease patients. However, there are conflicting findings on the prognostic utility of elevated lipoprotein (a) level in patients with coronary artery disease (CAD).Thus, we performed a meta-analysis to evaluate the prognostic value of elevated lipoprotein (a) level in CAD patients.

Methods and results

A systematic literature search of PubMed and Embase databases was conducted until April 16, 2019. Observational studies reporting the prognostic value of elevated lipoprotein (a) level for cardiac events (cardiac death and acute coronary syndrome), cardiovascular events (death, stroke, acute coronary syndrome or coronary revascularisation), cardiovascular death, and all-cause mortality in CAD patients were included. Pooled multivariable adjusted risk ratio (RR) and 95% confidence interval (CI) for the highest vs. the lowest lipoprotein (a) level were utilized to calculate the prognostic value. Seventeen studies enrolling 283,328 patients were identified. Meta-analysis indicated that elevated lipoprotein (a) level was independently associated with an increased risk of cardiac events (RR 1.78; 95% CI 1.31–2.42) and cardiovascular events (RR 1.29; 95% CI 1.17–1.42) in CAD patients. However, elevated lipoprotein (a) level was not significantly associated with an increased risk of cardiovascular mortality (RR 1.43; 95% CI 0.94–2.18) and all-cause mortality (RR 1.35; 95% CI 0.93–1.95).

Conclusions

Elevated lipoprotein (a) level is an independent predictor of cardiac and cardiovascular events in CAD patients. Measurement of lipoprotein (a) level has potential to improve the risk stratification among patients with CAD.

Electronic supplementary material

The online version of this article (10.1186/s12944-019-1092-6) contains supplementary material, which is available to authorized users.

South Asian Cardiovascular Disease & Cancer Risk: Genetics & Pathophysiology

South Asians (SAs) are at heightened risk for cardiovascular disease as compared to other ethnic groups, facing premature and more severe coronary artery disease, and decreased insulin sensitivity. This disease burden can only be partially explained by conventional risk factors, suggesting the need for a specific cardiovascular risk profile for SAs. Current research, as explored through a comprehensive literature review, suggests the existence of population specific genetic risk factors such as lipoprotein(a), as well as population specific gene modulating factors. This review catalogues the available research on cardiovascular disease and genetics, anthropometry, and pathophysiology, and cancer genetics among SAs, with a geographical focus on the U.S. A tailored risk profile will hinge upon population customized classification and treatment guidelines, informed by continued research.

Potential of lipoproteins as biomarkers in acute myocardial infarction

Acute myocardial infarction (AMI), commonly known as heart attack, is a medical emergency that is potentially fatal if not promptly and properly managed. The early diagnosis of AMI is critically important for the timely institution of pharmacotherapy to prevent myocardial damage and preserve cardiac function. Ischemic insults during AMI cause myocardial tissue damage, releasing the cardiac muscle protein troponin T into the blood stream. Therefore, serum troponin T levels are used as a sensitive and specific indicator of myocardial injury for diagnosing AMI. However, there remains a requirement for developing technologies for more accurate biomarkers or signatures for AMI diagnosis or prognosis. Previous studies have implicated impaired lipid metabolism as a causative factor in AMI development. Lipoproteins are important constituents of lipid metabolism; their levels in the blood stream are a convenient biomarker tool for monitoring lipid metabolism. This review summarizes recent findings (data of studies from 2001 to 2016) regarding the biomarker potentials of various lipoproteins, including low-density lipoprotein, oxidized low-density lipoprotein, high-density lipoprotein, lipoprotein-a, and remnant lipoprotein, for the risk stratification of AMI.

Association of lipoprotein(a) with long-term mortality following coronary angiography or percutaneous coronary intervention

BACKGROUND

There is no consistent evidence to suggest the association of plasma lipoprotein(a) (Lp[a]) with long-term mortality in patients undergoing coronary angiography (CAG) or percutaneous coronary intervention (PCI).

HYPOTHESIS

Level of Lp(a) is associated with long-term mortality following CAG or PCI.

METHODS

We enrolled 1684 patients with plasma Lp(a) data undergoing CAG or PCI between April 2009 and December 2013. The patients were divided into 2 groups: a low-Lp(a) group (Lp[a] <16.0 mg/dL; n = 842) and a high-Lp(a) group (Lp[a] ≥16.0 mg/dL; n = 842).

RESULTS

In-hospital mortality was not significantly different between the high and low Lp(a) groups (0.8% vs 0.5%, respectively; P = 0.364). During the median follow-up period of 1.95 years, the high-Lp(a) group had a higher long-term mortality than did the low-Lp(a) group (5.8% vs 2.5%, respectively; P = 0.003). After adjustment of confounders, multivariate Cox regression analysis revealed that a higher Lp(a) level was an independent predictor of long-term mortality (hazard ratio: 1.96, 95% confidence interval: 1.07-3.59, P = 0.029).

CONCLUSIONS

Our data suggested that an elevated Lp(a) level was significantly associated with long-term mortality following CAG or PCI. However, additional larger multicenter studies will be required to investigate the predictive value of Lp(a) levels and evaluate the benefit of controlling Lp(a) levels for patients undergoing CAG or PCI.

The relationship between Lp(a) and CVD outcomes: a systematic review

Robust associations between lipoprotein(a) [Lp(a)] and CVD outcomes among general populations have been published in previous studies. However, associations in high risk primary prevention and secondary prevention populations are less well defined. In order to investigate this further, a systematic review was performed including prospective studies, which assessed the relationship between Lp(a) and CVD outcomes using multivariable analyses. Additional information was gathered on Lp(a) assays, multivariable modelling and population characteristics. Literature searches from inception up to December 2015 retrieved 2850 records. From these 60 studies were included. Across 39 primary prevention studies in the general population (hazard ratios ranged from 1.16 to 2.97) and seven high risk primary prevention studies (hazard ratios ranged from 1.01 to 3.7), there was evidence of a statistically significant relationship between increased Lp(a) and an increased risk of future CVD. Results in 14 studies of secondary prevention populations were also suggestive of a modest statistically significant relationship (hazard ratios ranged from 0.75 to 3.7).Therefore current evidence would suggest that increased Lp(a) levels are associated with modest increases in the risk of future CVD events in both general and higher risk populations. However, further studies are required to confirm these findings.

Factors affecting outcome of primary percutaneous coronary intervention for acute myocardial infarction

BACKGROUND

Primary percutaneous coronary intervention (PCI) is the main treatment for patients with ST-segment elevation myocardial infarction (STEMI). We investigated factors affecting the major complications of this procedure.

METHODS

This case-control study assessed 200 patients receiving primary PCI for STEMI. Effects of some factors including age, sex, coronary artery risk factors, left ventricular function, thrombolysis in myocardial infarction (TIMI) flow, and number of involved vessels on major adverse cardiac events (MACE) were studied.

RESULTS

Two thirds of patients were male but sex had no significant effect on MACE. Similarly, age, hypertension, and hyperlipidemia did not significantly affect the incidence of MACE. However, Killip class, left ventricular ejection fraction, diabetes, TIMI flow, and type of involved vessels had significant relations with the incidence of MACE.

CONCLUSION

According to our findings, factors such as diabetes, left ventricular function, left anterior descending artery involvement, and low TIMI flow are risk factors of MACE.