Elevated low-density lipoprotein cholesterol: An inverse marker of morbidity and mortality in patients with myocardial infarction

BACKGROUND

The incidence of atherosclerotic cardiovascular disease increases with levels of low-density lipoprotein cholesterol (LDL-C). Yet, a paradox may exist where lower LDL-C levels at myocardial infarction (MI) are associated with poorer prognoses.

OBJECTIVE

To assess the association between LDL-C levels at MI with risk factor burden and cause-specific outcomes.

METHODS

Statin-naive patients hospitalized for a first MI and registered in SWEDEHEART were included. Data were linked to Swedish registers. Primary outcomes were all-cause mortality and nonfatal MI. Associations between LDL-C and outcomes were assessed using adjusted proportional hazards models.

RESULTS

Among 63,168 patients (median age, 66 years), the median LDL-C level was 3.0 mmol/L (interquartile range 2.4-3.6). Patient age and comorbidities increased as LDL-C decreased. During a median follow-up of 4.5 years, 10,236 patients died, and 4973 had nonfatal MI. Patients with the highest LDL-C had a lower risk of mortality (hazard ratio [HR] 0.75; 95% confidence interval [CI] 0.71-0.80). The risk of hospitalization for pneumonia, hip fracture, chronic obstructive pulmonary disease, and new cancer diagnosis was lower with higher LDL-C (HR range, 0.40-0.81). Patients with the highest LDL-C had a greater risk of recurrent MI (HR 1.16; 95% CI 1.07-1.26).

CONCLUSIONS

Patients with the highest LDL-C levels at MI had the lowest incidence of mortality and morbidity. This seems to reflect lower age at MI, less underlying morbidities, paired with the modifiability of LDL-C. However, supporting the causal association between LDL-C and ischemic heart disease, elevated LDL-C was simultaneously associated with an increased risk of nonfatal MI.

Comparison of Three Different Methods of Transfection for the Production of Recombinant Adenovirus Expressing Human Carcinoembryonic Antigen Gene

Adenoviral vectors (AdVs) are widely used as a gene delivery vehicle and vaccine design due to their genetic stability, transfer capacity of large genes, production at high titers, and remarkable efficacy of transduction. One of the most important applications of AdVs is in cancer immunotherapy. Tumor-associated antigens are overexpressed in cancer cells; however, they cannot induce immune responses sufficiently. Therefore, the immune system must be stimulated against these antigens to kill the cancer cells. This study described the construction steps of a recombinant AdV expressing human carcinoembryonic antigen (CEA) gene. Furthermore, in order to achieve a high titer of the virus, an efficient transfection was required. Three various transfection reagents were compared to achieve the best method of transfection. Carcinoembryonic antigen was cloned into the pAdV and transfected into the A293 cells using three different reagents, including polyethylenimine (PEI), calcium phosphate, and DMRIE-C. The PEI had the highest transfection efficiency, which was selected for the transfection of the recombinant plasmid. It has low toxicity for cells and is suitable for large-scale transfection. The virus produced in this study can be applied as a vaccine in cancer immunotherapy for stimulating the immune system against CEA-expressing tumors.

Distribution of cardiovascular disease risk according to SCORE2 and potential need for cholesterol and blood pressure lowering therapy in apparently healthy middle-aged individuals

Background

The 2021 European Society of Cardiology (ESC) prevention guidelines recommend the Systemic Coronary Risk Estimation 2 algorithm (SCORE2) to estimate the 10-year risk of cardiovascular disease (CVD) events to guide pharmacological treatment for primary prevention in apparently healthy individuals aged 40–69 years.

Purpose

To assess the distribution of CVD risk according to SCORE2 and the proportion of individuals who could be eligible for pharmacological treatment of blood cholesterol and blood pressure in an apparently healthy middle-aged population in Sweden.

Methods

We used data from the Swedish Cardiopulmonary Bioimage Study (SCAPIS) which used population registers to randomly recruit individuals aged 50–64 years at six Swedish study sites. Information was collected from the study participants through clinical examinations, national registries, and questionnaires. We excluded individuals with previously known atherosclerotic CVD, diabetes mellitus, or chronic kidney disease with eGFR <60 mL/min/1.73 m2. The SCORE2 algorithm designed for countries with moderate baseline CVD risk was used to categorize study participants' 10-year CVD risk as low-moderate (<5% risk); high (5-<10% risk); and very-high (≥10% risk). The proportions of the population who could be eligible, according to the 2021 ESC prevention guidelines, for pharmacological treatment of LDL-cholesterol (LDL-C) were assessed. Treatment thresholds for LDL-C according to SCORE2 risk were ≥1.8 mmol/L (high risk) and ≥1.4 mmol/L (very-high risk). Treatment threshold for hypertension was defined as a blood pressure ≥140/90 mmHg regardless of CVD risk.

Results

SCAPIS included 30,082 individuals. After exclusion criteria were applied 26,877 individuals remained (median age 57.2 years; 52.8% women). The median 10-year risk of CVD according to SCORE2 was 5.0 (interquartile range 3.0, 7.0) %. In total, 47.5% were classified as low-moderate risk, 45.9% as high risk, and 6.6% as very-high risk, with men having higher risk than women (figure). Almost all of those with high and very-high risk had LDL-C levels above the treatment thresholds. As such, according to the guidelines, lipid-lowering treatment should be considered (high risk) or was generally recommended (very-high risk) in 51.7% of the total population (Figure 1). The proportion of individuals with blood pressure ≥140/90 mmHg was 21.9%. The self-reported use of lipid-lowering therapy among low-moderate, high risk, and very-high risk individuals was 3.1%, 6.9%, and 6.3%, respectively. The use of blood pressure lowering therapy was 13.1% for those with blood pressure <140/80 mmHg and 29.2% for those ≥140/90 mmHg.

Conclusions

In this population-based study of nearly 27,000 apparently healthy middle-aged individuals in Sweden, around half of the individuals could be eligible for LDL-C-lowering therapy and around one in five could be eligible for antihypertensive therapy according to the 2021 ESC prevention guidelines.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): SCAPIS funding: The Swedish Heart-Lung Foundation and Knut and Alice Wallenberg Foundation.

Low-density lipoprotein cholesterol reduction and statin intensity in myocardial infarction patients and major adverse outcomes: a Swedish nationwide cohort study

Aims 

Clinical trials have demonstrated that a reduction in low-density lipoprotein cholesterol (LDL-C) reduces cardiovascular (CV) events. This has, however, not yet been shown in a real-world setting. We aimed to investigate the association between LDL-C changes and statin intensity with prognosis after a myocardial infarction (MI).

Methods and results 

Patients admitted with MI were followed for mortality and major CV events. Changes in LDL-C between the MI and a 6- to 10-week follow-up visit were analysed. The associations between quartiles of LDL-C change and statin intensity with outcomes were assessed using adjusted Cox regression analyses. A total of 40 607 patients were followed for a median of 3.78 years. The median change in LDL-C was a 1.20 mmol/L reduction. Patients with larger LDL-C reduction (1.85 mmol/L, 75th percentile) compared with a smaller reduction (0.36 mmol/L, 25th percentile) had lower hazard ratios (HR) for all outcomes (95% confidence interval): composite of CV mortality, MI, and ischaemic stroke 0.77 (0.70–0.84); all-cause mortality 0.71 (0.63–0.80); CV mortality 0.68 (0.57–0.81); MI 0.81 (0.73–0.91); ischaemic stroke 0.76 (0.62–0.93); heart failure hospitalization 0.73 (0.63–0.85), and coronary artery revascularization 0.86 (0.79–0.94). Patients with ≥50% LDL-C reduction using high-intensity statins at discharge had a lower incidence of all outcomes compared with those using a lower intensity statin.

Conclusions 

Larger early LDL-C reduction and more intensive statin therapy after MI were associated with a reduced hazard of all CV outcomes and all-cause mortality. This supports clinical trial data suggesting that earlier lowering of LDL-C after an MI confers the greatest benefit.

Intra-arterial transplantation of neural stem cells improve functional recovery after transient ischemic stroke in adult rats

OBJECTIVES

The neural stem cell transplantation has been proposed as alternative therapy to promote functional recovery after various neurological disorders. The aim of this study was to evaluate the effect of intra-arterial transplantation of adult neural stem cells on improving local brain ischemia injuries.

MATERIALS AND METHODS

In this study, 32 male Wistar rats were used. Ischemia was induced using a middle cerebral artery obstruction with monofilament nylon suture. Neural stem cells were isolated from subventricular zone of the rat brain. 24 hours after local ischemia, the cells were labeled with DiI and transplanted intra-articularly. Evaluation of neurological movement deficits was performed using a neurological deficit score. The transplanted neural stem cells differentiation into neurons and astrocytes was assessed by immunohistochemistry.

RESULTS

The results indicated that lesion volumes in the ischemic control, PBS and the treatment groups were 31.5, 29.8 and 14.7 % respectively. Our results also showed that the number of eosinophilic neurons and also neurological impairment in the treatment group was significantly reduced compared to the control and PBS groups.

CONCLUSION

The results suggested that intra-arterial transplantation of neural stem cells 24 hours after ischemia, led to a decrease in the volume of brain ischemic lesion and improved neurological outcomes (Fig. 7, Ref. 23).

Efficacy of Crocus sativus L. on reduction of cadmium-induced toxicity on spermatogenesis in adult rats

Cadmium is a toxic heavy metal element, which probably cause infertility by impairment in spermatogenesis. The present work aimed (i) to study the toxic effect of cadmium on spermatogenesis in rat, as well as (ii) the protective effect of Crocus sativus L. on cadmium-intoxicated rats. Cadmium chloride was administered intraperitoneally during 16 days at intervals of 48 h between subsequent treatments. Crocus sativus L. was pre-treated in both of control and cadmium-injected rats. Animals were sacrificed on day 17 after the first treatment. The left cauda epididymis was removed and immediately immersed into Hank's balanced salt solution for the evaluation of sperm count and viability, and left testis was fixed in 10% formalin for histological evaluation. Following contamination with cadmium, a decrease was observed in the number and viability of cauda epididymis sperm, which were increased by Crocus sativus L. pre-treatment (P < 0.05). In addition, cadmium decreased both cell proliferation and Johnsen Scores in the seminiferous tubules, which were reversed by Crocus sativus pre-treatment (P < 0.05). Furthermore, cadmium-induced decrease in the amount of free serum testosterone as well as an increase in lipid peroxidation activity in the testicular tissue was reversed by Crocus sativus L. (P < 0.05). These findings may support the concept that Crocus sativus L. can improve the cadmium toxicity on spermatogenesis.