Immediate effect of intensive atorvastatin therapy on lipid parameters in patients with acute coronary syndrome

Sex Differences in the Risk of Developing Acute Coronary Syndrome in Patients With Sleep Disorders: A Population-Based Cohort Study

Studies that focus on the relationship between sex and the risk of acute coronary syndrome (ACS) are scant. The current study investigated the effects of sex differences in the risk of developing ACS in patients with sleep disorders (SDs). This longitudinal population-based cohort study evaluated the incidence and risk of ACS development in 40,232 men and 65,519 women newly diagnosed with SDs between 2002 and 2008 from the Longitudinal Health Insurance Database. The follow-up period began from the entry date and ended on the date of an ACS event or December 31, 2010. Univariable and multivariable Cox proportional hazard regression models were conducted to estimate the sex differences in the risk of ACS. Men with SDs exhibited an increased incidence of ACS compared with women with SDs in all age- and comorbidity-specific subgroups. After covariates were adjusted, the men with SDs exhibited a 1.48-fold adjusted hazard ratio (aHR) of ACS compared with the women with SDs (95% confidence interval [CI] = 1.36-1.60). After age group stratification, the men with SDs in the young adult group exhibited the highest risk of subsequent ACS development compared with the women with SDs (aHR = 2.07, 95% CI = 1.69-2.55), followed by those in middle-aged adults (aHR = 1.52, 95% CI = 1.32-1.76) and older adults groups (aHR = 1.24, 95% CI = 1.11-1.39). This study determined that men with SDs, particularly young men, are at a higher risk of subsequent ACS development compared with women with SDs.

Mycoplasma pneumonia increases the risk of acute coronary syndrome: a nationwide population-based cohort study

BACKGROUND

Studies investigating the epidemiological relationship between Mycoplasma pneumonia (MP) and the subsequent development of acute coronary syndrome (ACS) are scant. We conducted a nationwide longitudinal cohort study in Taiwan to explore whether MP patients are at an increased risk of developing ACS.

METHODS

This study investigated the incidence and risk factors for ACS in 12 152 newly diagnosed MP patients from the Taiwan National Health Insurance Research Database between 2004 and 2011. The control group consisted of 48 600 individuals without MP. The follow-up period ran from the time of initial MP diagnosis to the date of an ACS event, censoring, or 31 December 2011. We analyzed the risk of ACS by using Cox proportional hazard regression models, including variables for sex, age and comorbidities.

RESULTS

The incidence of ACS was higher in MP patients than in comparison cohort (3.08 vs. 2.42 per 1000 person-years). The hazard ratio of developing ACS increased 37% in MP patients compared with that in the comparison cohort after adjustment for covariates. The effect of MP on subsequent ACS development appeared to 12 months after infection.

CONCLUSION

This nationwide study determined that compared with the general population, MP patients exhibited a 37% increase in the risk of subsequently developing ACS. Clinicians should be aware of this risk in MP patients and provide appropriate cardiovascular management in addition to MP treatment.

Increased risk of acute coronary syndrome among leptospirosis patients: A nationwide cohort analysis

BACKGROUND

Studies on the association between leptospirosis and acute coronary syndrome (ACS) are lacking. Therefore, this study identifies the effects of leptospirosis on the risks of developing ACS with a nationwide retrospective cohort study.

METHODS

We identified adult patients aged ≥20 years who were newly diagnosed with leptospirosis. We also randomly selected a comparison cohort from the general population by using a propensity score matching method. We analyzed the risks of ACS by using Cox proportional hazard regression models.

RESULTS

Among the 23.74 million people in the cohort, 3690 patients with leptospirosis (68% men, mean age of 52.2 years) and 3690 controls were followed for 13,677 and 15,652 person-years, respectively. The overall incidence of ACS was higher in the leptospirosis cohort than in the nonleptospirosis cohort (4.68 vs 3.71 per 1000 person-years), with a hazard ratio (HR) of 1.69 (95% confidence interval [CI]=1.12-2.56). Men exhibited a 1.88-fold greater HR of ACS than women did (95% CI=1.20-2.94). The risk of developing ACS was highest for leptospirosis patients aged ≥65 years (HR=7, 51% CI=4.35-12.9) compared with patients aged ≤49 years.

CONCLUSION

Leptospirosis is not a previously identified risk factor for ACS. The findings of this nationwide retrospective cohort study indicate that leptospirosis may become an independent risk factor for ACS. Future research to investigate the mechanism is warranted.

Adult asthmatics increase the risk of acute coronary syndrome: A nationwide population-based cohort study

OBJECTIVES

Few studies have examined the risk of acute coronary syndrome (ACS) in asthmatics. We investigate the effects of asthma on the risk of ACS development in an Asian population.

METHODS

Asthma patients aged ≥ 18 years were identified, and asthma-free controls were randomly selected from the general population and frequency-matched according to age, sex, index year, and baseline comorbidity by using the National Health Insurance Research Database. Both cohorts were followed up until the end of 2011 to measure the incidence of ACS. The risk of ACS was analyzed using Cox proportional hazards regression models.

RESULTS

We observed the asthmatic patients for 97,506 person-years and followed the nonasthmatic people for 193,423 person-years. The incidence density rate of ACS increased in all groups of the asthmatic patients compared with those of the controls when the data were stratified according to sex, age, and comorbidities. The hazard ratio (HR) of ACS was 1.66-fold greater in the asthmatic cohort than in the nonasthmatic cohort, after adjusting for sex, age, and comorbidities (95% confidence interval [CI]: 1.31-2.11). The adjusted HR of developing ACS increased substantially as age and the frequency of asthmatic exacerbation and hospitalization increased.

CONCLUSIONS

Asthma is an independent risk factor of ACS, and poor control of asthma increases the risk of ACS development in a dose-dependent manner.

Scrub typhus increases the risk of developing acute coronary syndrome: a nationwide cohort study

BACKGROUND

Studies investigating the epidemiological relationship between scrub typhus and the subsequent development of acute coronary syndrome (ACS) are lacking. Therefore, we conducted a nationwide longitudinal cohort study in Taiwan to explore whether patients with scrub typhus are at an increased risk of developing ACS.

METHODS

This study investigated the incidence and risk factors for ACS in 5215 patients newly diagnosed with scrub typhus from the Taiwan National Health Insurance Research Database between 2000 and 2011. The comparison cohort contained 20 860 persons from the general population without scrub typhus. The follow-up period ran from the time of the initial diagnosis for scrub typhus to the date of an ACS event, censoring, or 31 December 2011. We used Cox proportional hazard regression models to analyse the risk of ACS by including the variables of sex, age and comorbidities.

RESULTS

The incidence of ACS was higher in patients with scrub typhus than in the comparison cohort (3.10 vs 1.92 per 1000 person-years). The HR of developing ACS increased by 37% in patients with scrub typhus after adjusting for age, sex and comorbidities. Men, increased age, hypertension, diabetes, hyperlipidaemia, chronic obstructive pulmonary disease and coronary artery disease were identified as independent risk factors of developing ACS after controlling for covariates. The prominent effect of scrub typhus on subsequent ACS development appeared within 1 year after infection.

CONCLUSIONS

This nationwide study determined that patients with scrub typhus exhibited a 37% increase in the risk of subsequently developing ACS compared with that of the general population.

Rheumatoid arthritis and risk of acute myocardial infarction--a nationwide retrospective cohort study

OBJECTIVES

Rheumatoid arthritis (RA) imposes substantial social costs, including an increased risk of work-related disability and accelerated cardiovascular diseases. The aim of the study is to determine the risk of acute myocardial infarction (AMI) associated with RA in a nationwide retrospective cohort study.

METHODS

Using the catastrophic illness registry of the Taiwan National Health Insurance Research Database (NHIRD), we identified patients with RA from 1998 to 2010. We also randomly selected non-RA controls frequency-matched by age, sex, and index year from the general population free of RA. The risk of AMI was analyzed using Cox proportional hazards regression models including sex, age, and comorbidities.

RESULTS

From a total of 23.74 million people in the cohort, 29,260 RA patients and 117,040 controls were followed for 193,987 and 792,254 person-years, respectively. The incidence density rate increased in all groups of RA patients than those of the controls. RA patients had a 1.33-fold higher overall incidence of AMI than controls, with an adjusted hazard ration of 1.38. Although the overall adjusted hazard ratio of AMI increased with age, the age-specific RA patients to controls incidence rate ratio was higher for younger RA patients. Subjects with comorbidities of hypertension, diabetes hyperlipidemia, CVA, COPD, or ESRD had increased risk of AMI. Subjects with ESRD had the highest hazard of AMI.

CONCLUSION

This nationwide retrospective cohort study indicates that AMI risk increased by 38% in RA patients compared to the general population. Comorbidities increase the AMI risk independently.

Alteration in lipoprotein-associated phospholipase A2 levels during acute coronary syndrome and its relationship to standard biomarkers

BACKGROUND

Lipoprotein-associated phospholipase A2 (Lp-PLA2) probably plays an important role in the development of acute coronary syndrome (ACS); elevated levels of Lp-PLA2 are associated with a poorer prognosis in patients with ischemic heart disease. Alterations of Lp-PLA2 levels during ACS and its relationship to standard biomarkers are, however, unclear.

FINDINGS

Fifty-one consecutive ACS patients were enrolled in the study. All were managed with early invasive strategy and according to the current guidelines for pharmacotherapy; intensive statin therapy was started in all patients at admission. Serum levels of Lp-PLA2, LDL-cholesterol (LDL), troponin l (Tnl), and C-reactive protein (CRP) were assessed at admission (D0), on the first morning (D1), and on the second morning of hospitalization (D2). Mean serum levels of Lp-PLA2 (ng/mL) decreased from 264.6±19.1 at D0, to 193.2±14.4 at D1 (P < 0.001 vs. D0) and 189.8±22.6 at D2 (P = 0.002 vs. D0; P = not significant vs. D1). Alterations in Lp-PLA2 levels significantly correlated with changes in LDL (r = 0.43; P = 0.008). On the other hand, no relationship between Lp-PLA2 and Tnl or CRP was found.

CONCLUSIONS

Initially, serum levels of Lp-PLA2 were significantly elevated in ACS patients, but decreased within the first 24 hours after admission and subsequently remained stable. Lp-PLA2 levels correlated with LDL levels but not with Tnl or CRP levels. Our results demonstrated dynamic alterations in Lp-PLA2 levels during the early stages of ACS and, therefore, indirectly support the hypothesis of an active role for Lp-PLA2 in the pathogenesis of ACS.

Influence of atorvastatin and carboxymethylated glucan on the serum lipoprotein profile and MMP activity of mice with lipemia induced by poloxamer 407

The effects of atorvastatin and carboxymethylated β-glucan (CMG) on the lipoprotein-cholesterol (LP-C) and lipoprotein-triglyceride (LP-TG) fractions and subfractions at the early stage of murine hyperlipidemia, and its pleiotropic anti-inflammatory effects, were studied. Atorvastatin and CMG were administered in ICR male mice with acute lipemia induced with a single injection of poloxamer 407 (P-407). A novel small-angle X-ray scattering method for the determination of fractional and subfractional composition of LP-C and LP-TG was used. In P-407-treated animals, there was a drastic increase of total cholesterol and especially TG. Atorvastatin decreased both the total cholesterol and TG, but not to control levels. CMG primarily decreased TG and was not as potent as atorvastatin. P-407 increased atherogenic LDL-C (IDL-C and LDL1–3-C subfractions) and very low-density lipoprotein-C (VLDL-C) (VLDL1–2-C and VLDL3–5-C subfractions) fractions, with an increase of the total anti-atherogenic HDL-C fraction (HDL2-C subfraction). Atorvastatin treatment of lipemia was followed by a decrease in the total LP-C, total LDL-C (LDL1–3-C subfraction), and the LDL1–3-TG subfraction. Additionally, atorvastatin treatment resulted in an increase in the serum matrix metalloproteases activity both in control and P-407-treated mice. In general, high-dose atorvastatin therapy exerts its lipid-lowering and pleiotropic effects in the early stages of acute lipemia induced in mice by treatment with P-407.

Statins as first-line therapy for acute coronary syndrome?

It has repeatedly been shown that statins decrease morbidity and mortality in patients with atherosclerosis, thus supporting their use for the primary and secondary prevention of ischemic heart disease. Different pathological pathways that are triggered in the setting of acute coronary syndrome (ACS), such as endothelial dysfunction, activation of inflammatory and coagulation cascades, and thrombus formation, are known to be inhibited by statins, thereby justifying the use of these agents in patients with ACS. Several recent prospective controlled clinical trials have demonstrated the safety and, in some cases, the efficacy of statins when administered early after ACS. An increasing number of publications have reported, however, that statins may confer a beneficial effect not only in early secondary prevention, but also in the direct treatment of ACS (ie, when statins are administered as first-line treatment in clinically unstable patients). This therapeutic option is supported by the following: numerous experimental studies demonstrating a protective effect of statins under conditions of acute ischemia; analysis of different registries and trials, which has demonstrated a more favourable prognosis for statin-treated patients at the time of acute myocardial ischemia; and small clinical trials reporting a lower periprocedural infarction rate during coronary intervention or lower levels of several prognostic biomarkers, in addition to a lower incidence of cardiovascular events associated with statin therapy. Nevertheless, confirmation of this hypothesis in large prospective controlled clinical trials will be necessary before the implementation of statins as first-line therapy in unstable patients with ACS, irrespective of blood cholesterol levels.