CARDIOVASCULAR AND SURVIVAL PARADOXES IN DIALYSIS PATIENTS: The Cholesterol Paradox Is Flawed; Cholesterol Must Be Lowered in Dialysis Patients

The Lipid Paradox is present in ST-elevation but not in non-ST-elevation myocardial infarction patients: Insights from the Singapore Myocardial Infarction Registry

Lowering low-density lipoprotein (LDL-C) and triglyceride (TG) levels form the cornerstone approach of cardiovascular risk reduction, and a higher high-density lipoprotein (HDL-C) is thought to be protective. However, in acute myocardial infarction (AMI) patients, higher admission LDL-C and TG levels have been shown to be associated with better clinical outcomes - termed the 'lipid paradox'. We studied the relationship between lipid profile obtained within 72 hours of presentation, and all-cause mortality (during hospitalization, at 30-days and 12-months), and rehospitalization for heart failure and non-fatal AMI at 12-months in ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) patients treated by percutaneous coronary intervention (PCI). We included 11543 STEMI and 8470 NSTEMI patients who underwent PCI in the Singapore Myocardial Infarction Registry between 2008-2015. NSTEMI patients were older (60.3 years vs 57.7 years, p < 0.001) and more likely to be female (22.4% vs 15.0%, p < 0.001). In NSTEMI, a lower LDL-C was paradoxically associated with worse outcomes for death during hospitalization, within 30-days and within 12-months (all p < 0.001), but adjustment eliminated this paradox. In contrast, the paradox for LDL-C persisted for all primary outcomes after adjustment in STEMI. For NSTEMI patients, a lower HDL-C was associated with a higher risk of death during hospitalization but in STEMI patients a lower HDL-C was paradoxically associated with a lower risk of death during hospitalization. For this endpoint, the interaction term for HDL-C and type of MI was significant even after adjustment. An elevated TG level was not protective after adjustment. These observations may be due to differing characteristics and underlying pathophysiological mechanisms in NSTEMI and STEMI.

Association Between Total Cholesterol and 5 year Mortality in Patients with Carotid Artery Stenosis and Poststroke Functional Dependence

BACKGROUND

Aggressive lipid-lowering treatment reduces the risk of cardiovascular events, but remains controversial in stroke patients. We investigate the influence of total cholesterol level on 5-year outcomes of ischemic stroke patients with high-grade internal carotid artery (ICA) stenosis and poststroke functional dependence.

METHODS

One-hundred and ninety-six acute ischemic stroke patients with high-grade ICA stenosis and modified Rankin Scale score ≥ 3 upon discharge were enrolled and prospectively observed for 5 years. Patients were divided into 2 groups according to total cholesterol level at admission: ≥200 mg/dL or <200 mg/dL. Demographic features, vascular risk factors, co-morbidities, and outcomes were compared between the 2 groups.

RESULTS

117 (59.7%) patients had higher and 79 (40.3%) patients had lower total cholesterol levels. The prevalence of older age and atrial fibrillation was significantly higher in patients with lower total cholesterol; the prevalence of diabetes mellitus was higher in patients with higher total cholesterol. After adjusting for the established clinical predictors of adverse outcomes, the multivariate Cox regression revealed that lower total cholesterol level is a significant predictor of 5-year mortality (HR (hazard ratio) = 1.88, 95% CI (confidence interval) = 1.09-3.23, P = .023).

CONCLUSIONS

Lower total cholesterol level is associated with increased risk of 5-year mortality in ischemic stroke patients with high-grade ICA stenosis and post-stroke functional dependence. Aggressive treatment of hyperlipidemia should be carefully considered in these patients although it could reduce the risk of atherosclerotic cardiovascular diseases and stroke recurrence in some stroke patients.

Does marital status contribute to the explanation of the hypercholesterolemia paradox in relation to long term mortality in myocardial infarction? Findings from the MONICA/KORA Myocardial Infarction Registry

OBJECTIVE

A recent study found long-term mortality after first acute myocardial infarction (AMI) to be particularly reduced among married individuals with hypercholesterolemia. This study explores, whether statin treatments during the last week prior to AMI offer an explanation to this phenomenon.

METHODS

Data were retrieved 2000-2008 from the population-based KORA myocardial infarction registry, located in Bavaria, Germany. The sample included 3162 individuals, alive 28days after first AMI, who received statins both in hospital and at discharge. Associations with long-term mortality were examined via multivariable Cox regression. Among patients with hypercholesterolemia, individuals with and without prior statin treatment were each tested against the reference group "neither (hypercholesterolemia nor statin)" and tested for interaction with "marital status".

RESULTS

Among patients with and without prior statins, hazard ratio (HR) 0.66, 95% confidence interval (CI) 0.46-0.93 and HR 0.72, 95% CI 0.55-0.94, were observed, respectively. Mortality reductions diminished after introduction of the following interaction terms with marital status: HR 0.49, p 0.042 for patients with and HR 0.77, p 0.370, for patients without prior statins.

CONCLUSIONS

Prior statin treatments appear to be an underlying factor for long-term mortality reduction in married AMI-survivors with hypercholesterolemia. Confirmation of our results in further studies is warranted.

Low cholesterol is associated with mortality from cardiovascular diseases: a dynamic cohort study in Korean adults

This study was conducted to evaluate the association of single serum total cholesterol (TC) measurement with cardiovascular diseases (CVD) deaths in Korean adults. The study subjects were taken from the multi-site collaborative dynamic prospective cohort for epidemiologic investigation on cancer risk in residents nearby nuclear power plants in Korea. A total of 12,740 adults aged 40 to 69 yr who underwent a mass screening examination were followed up from 1993 to 2008. Occurring CVD deaths were confirmed by the death certificates in the National Statistical Office, Korea. Groups with the lowest group having TC < 160 mg/dL as well as the highest group having >= 240 mg/dL were associated with higher CVD mortality in Cox proportional hazards analysis adjusting for age, sex, smoking and drinking status, body mass index, level of blood pressure, triglyceride and high density lipoprotein cholesterol. The distribution of adjusted hazard ratios showed the U-shaped curve. Based on the results of this study, caution should be taken in prescribing statins for primary prevention among people at low cardiovascular risk in Korean adults.