Clinical and economic impact of coronary artery bypass graft and percutaneous coronary intervention in young individuals with acute coronary syndromes and multivessel disease: A real-world comparison in a middle-income country

Background

In recent decades, the world watched a dramatic increase in the incidence of acute coronary syndromes (ACS) among young individuals (≤55 years-old) and a relative decrease in the elderly. The management of ACS in young patients with multivessel disease still needs to be elucidated, as these individuals maintain a long life expectancy.

Research Question

To compare clinical outcomes and care costs in individuals with premature ACS and multivessel disease undergoing coronary artery bypass graft surgery (CABG) or percutaneous coronary intervention (PCI).

Methods and Results

Participants included all individuals ≤55 years-old admitted with ACS to public hospitals in Brasília (Brazil) between 2013 and 2015 and who underwent cardiac catheterization with SYNTAX score ≥23 or Duke category 6. Outcomes were adjudicated with death certificates and data from medical records. The primary outcome was the occurrence of major adverse cardiovascular events (MACE), defined as death due to cardiovascular causes, recurrent hospitalizations due to cardiovascular ischemic events, and incident heart failure New York Heart Association III-IV. As secondary outcome we assessed indirect and direct costs by evaluating the cost of lost productivity (in international dollars (Int$) per year) due to illness and death, outpatient costs and costs with new hospitalizations. Multivariate and principal components (PC) adjusted analyzes were performed.

Results

Among 1,088 subjects (111 CABG and 977 PCI) followed for 6.2 years (IQR: 1.1), 304 primary events were observed. MACE was observed in 20.7% of the CABG group and 28.8% of the PCI group (p = 0.037). In multivariate analyses, PCI was associated with a hazard ratio (HR) = 1.227 (95% CI: 1.004–1.499; p = 0.0457) for MACE, and in PC-adjusted HR = 1.268 (95% CI: 1.048–1.548; p = 0.0271) compared with CABG. Despite direct costs were equivalent, the cost due to the loss of labor productivity was higher in the PCI group (Int$ 4,511 (IQR: 18,062)/year vs Int$ 3,578 (IQR: 13,198)/year; p = 0.049], compared with CABG.

Conclusions

Among young individuals with ACS and multivessel disease, surgical strategy was associated with a lower occurrence of MACE and lower indirect costs in the long-term.

AGEs accumulation is related to muscle degeneration and vascular calcification in peritoneal dialysis patients

BACKGROUND

Patients with chronic kidney disease (CKD) are affected by dynapenia, sarcopenia, and vascular calcification. Advanced glycation end products (AGEs) may accumulate in peritoneal dialysis (PD) patients and favor sarcopenia via changes in collagen cross-linking, muscle protein breakdown, and the calcification of arterial smooth muscle cells via p38-MAPK activation. The aim of this study is to explore the relationships between AGEs, muscle degeneration, and coronary artery calcification.

METHODS

This was a clinical observational study in patients with CKD undergoing PD, in which serum and skin AGEs (AGEs-sAF), cumulative glucose load, muscle strength and functional tests, muscle ultrasounds with elastography, coronary artery calcium (CAC) quantification, and muscle density by multislice computed tomography were measured.

RESULTS

27 patients aged 48±16 years, dialysis vintage of 27±17 months, had AGEs-sAF levels of 3.09±0.65 AU (elevated in 13 [87%] patients), grip strength levels of 26.2±9.2 kg (11 [42%] patients with dynapenia), gait speed of 1.04±0.3 m/s (abnormal in 14 [58%] patients) and "timed-up-and-go test" (TUG) of 10.5±2.2s (abnormal in 7 [26%] patients). Correlations between AGEs-sAF levels and femoral rectus elastography (R=-0.74; p=0.02), anterior-tibialis elastography (R= -0.68; p=0.04) and CAC (R=0.64; p=0.04) were detected. Cumulative glucose load correlated with femoral rectal elastography (R=-0.6; p=0.02), and serum glycated hemoglobin concentrations correlated with psoas muscle density (R= -0.58; p=0.04) and CAC correlated with psoas muscle density (R=0.57; p=0.01) and lumbar square muscle density (R=-0.63; p=0.005).

CONCLUSIONS

The study revealed associations between AGEs accumulation and lower muscle stiffness/density. Associations that linked muscle degeneration parameters with vascular calcification were observed.

Serum potassium levels provide prognostic information in symptomatic heart failure beyond traditional clinical variables

Aims

Despite of recent advances in the pharmacological treatment, heart failure (HF) maintains significant morbidity and mortality rates. While serum potassium disorders are common and associated with adverse outcomes, the exact recommended potassium level for patients with HF are not entirely established. We aimed to investigate the prognostic role of potassium levels on a cohort of patients with symptomatic chronic HF.

Methods and results

Patients with symptomatic chronic HF were identified at the referral to 6 min walking test (6MWT) and were prospectively followed up for cardiovascular events. Clinical and laboratorial data were retrospectively obtained. The primary endpoint was the composite of cardiovascular death, hospitalization due to HF, and heart transplantation. The cohort included 178 patients with HF with the mean age of 51 ± 12.76 years, 39% were female, 85% of non‐ischaemic cardiomyopathy, and 38% had New York Heart Association Class III with a relatively high Meta‐Analysis Global Group in Chronic Heart Failure (MAGGIC) score (12.91 ± 6.6). The mean left ventricular ejection fraction was 39.98 ± 15.79%, and the mean 6MWT distance was 353 ± 136 m. After a median follow‐up of 516 days, there were 22 major cardiovascular events (4 cardiovascular deaths, 13 HF admissions, and 5 heart transplants). Patients were stratified according to cut‐point level of serum potassium of 4.7 mmol/L to predict combined cardiac events based on receiver operating characteristic analysis. Individuals with higher potassium levels had worse renal function (glomerular filtration rate, K ≤ 4.7: 102.8 ± 32.2 mL/min/1.73 m² vs. K > 4.7: 85.42 ± 36.2 mL/min/1.73 m², P = 0.004), higher proportion of New York Heart Association Class III patients (K ≤ 4.7: 28% vs. K > 4.7: 48%, P = 0.0029), and also higher MAGGIC score (K ≤ 4.7: 12.08 ± 5.7 vs. K > 4.7: 14.9 ± 7.9, P = 0.0089), without significant differences on the baseline pharmacological HF treatment. Both potassium levels [hazard ratio (HR) 4.26, 95% confidence interval (CI) 1.59–11.421, P = 0.003] and 6MWT distance (HR 0.99, 95% CI 0.993–0.999, P = 0.01) were independently associated with the primary outcome. After adjustments for MAGGIC score and 6MWT distance, potassium levels > 4.7 mmol/L maintained a significant association with outcomes (HR 3.57, 95% CI 1.305–9.807, P = 0.013). Patients with K > 4.7 mmol/L were more likely to present clinical events during the follow‐up (log rank = 0.005). Adding potassium levels to the model including 6MWT and MAGGIC significantly improved the prediction of events over 2 years (integrated discrimination index 0.105, 95% CI 0.018–0.281, P = 0.012 and net reclassification index 0.447, 95% CI 0.077–0.703, P = 0.028).

Conclusions

Potassium levels were independently associated with worse outcomes in patients with chronic symptomatic HF, also improving the accuracy model for prognostic prediction when added to MAGGIC score and 6MWT distance. The potassium levels above 4.7 mmol/L might identify those patients at an increased risk of cardiovascular events.

Machine Learning Improves the Identification of Individuals With Higher Morbidity and Avoidable Health Costs After Acute Coronary Syndromes

OBJECTIVES

Traditional risk scores improved the definition of the initial therapeutic strategy in acute coronary syndrome (ACS), but they were not designed for predicting long-term individual risks and costs. In parallel, attempts to directly predict costs from clinical variables in ACS had limited success. Thus, novel approaches to predict cardiovascular risk and health expenditure are urgently needed. Our objectives were to predict the risk of major/minor adverse cardiovascular events (MACE) and estimate assistance-related costs.

METHODS

We used a 2-step approach that: (1) predicted outcomes with a common pathophysiological substrate (MACE) by using machine learning (ML) or logistic regression (LR) and compared with existing risk scores; (2) derived costs associated with noncardiovascular deaths, dialysis, ambulatory-care-sensitive-hospitalizations (ACSH), strokes, and MACE. With consecutive ACS individuals (n = 1089) from 2 cohorts, we trained in 80% of the population and tested in 20% using a 4-fold cross-validation framework. The 29-variable model included socioeconomic, clinical/lab, and coronarography variables. Individual costs were estimated based on cause-specific hospitalization from the Brazilian Health Ministry perspective.

RESULTS

After up to 12 years follow-up (mean = 3.3 ± 3.1; MACE = 169), the gradient-boosting machine model was superior to LR and reached an area under the curve (AUROC) of 0.891 [95% CI 0.846-0.921] (test set), outperforming the Syntax Score II (AUROC = 0.635 [95% CI 0.569-0.699]). Individuals classified as high risk (>90th percentile) presented increased HbA1c and LDL-C both at <24 hours post-ACS and 1-year follow-up. High-risk individuals required 33.5% of total costs and showed 4.96-fold (95% CI 3.71-5.48, P < .00001) greater per capita costs compared with low-risk individuals, mostly owing to avoidable costs (ACSH). This 2-step approach was more successful for finding individuals incurring high costs than predicting costs directly from clinical variables.

CONCLUSION

ML methods predicted long-term risks and avoidable costs after ACS.

Walking performance is associated with coronary artery calcification in very old adults

BACKGROUND

Coronary artery calcification (CAC) scores have good predictive value for atherosclerosis-related outcomes in the geriatric population. The low availability of cardiac computed tomography is an obstacle to assess CAC in clinical practice. Thus, clinical signs with a good degree of association with CAC can help to estimate cardiovascular risk, particularly in low-income populations.

OBJECTIVES

To assess whether clinical, biochemical and functional measures explain the CAC scores in older individuals.

METHODS

We characterized 89 non-institutionalized older volunteers (≥ 80 years old) by means of a comprehensive biochemical and anthropometric evaluation along with assessments of CAC scores determined by computerized tomography, and tested their association with walking speed test (WS) and handgrip strength (HS) performance.

RESULTS

Analyses of variance showed that body mass index (BMI) and waist circumference (WC) differed significantly (p ≤ 0.01 and p ≤ 0.03; respectively) across quartiles, so that subsequent tests were adjusted for anthropometry. ANCOVA revealed that the two lower quartiles of CAC had better performance in WS compared to the third and fourth quartiles (p ≤ 0.04). Multinomial logistic regression analysis showed that WS scores exhibit enough power (R² = 0.379, p = 0.05) to explain CAC scores. There were no significant differences for HS between quartiles (p = 0.87).

CONCLUSION

WS is associated and explain CAC scores, and may be useful to stratify atherosclerotic burden in apparently healthy very old individuals regardless of body composition.

P4626Neuronal nitric oxide sintetase polymorphism increases sympathetic activity and recurrent cardiovascular events after myocardial infarction

Background

The expression and activity of neuronal nitric oxide sintetase (nNOS) in central and peripheral nervous system attenuate the sympathetic response and promote other cardioprotective effects in animal models. However, in humans those effects are uncertain. Recently, a polymorphism at the sequence rs41279104 G/T has been associated with a reduced expression of nNOS, but its clinical impact has never been studied in the context of ST elevation myocardial infarction (STEMI) in humans.

Purpose

We investigated the impact of the T allele at rs41279104 in sympathetic activation after STEMI and its influence in the incidence of recurrent major cardiovascular events (MACE). We sought to determine a pathway to autonomic nervous system modulation during STEMI and its possible clinical impact.

Methods

297 patients were admitted in the first 24h (D1) after STEMI and followed prospectively. Blood samples and an electrocardiogram were obtained upon D1 and fifth day (D5). We assessed glycosylated hemoglobin, glucose, insulin, C-peptide, lipid profile and nitric oxide (NOx) plasma levels. We genotyped rs41279104 and grouped patients according to carrier status (GT+TT vs. GG). The heart rate variability was obtained with a 15min electrocardiogram recording and processed into spectral analysis variables including low (LF) and high frequencies (HF) and LF/HF ratio. Flow-mediated dilation (FMD) was performed after 30 days. Clinical follow–up was carried over until two years after MI and the endpoint was a composite of major cardiovascular events (MACE) consisting of fatal MI, non-fatal MI, unstable angina with hospitalization and cardiac sudden death.

Results

T-allele carriers showed a decreased parasympathetic activity and an increased sympathetic activity between D1 and D5 (ΔLF −68.43 (median) [IQR −324.76 to −6.29] vs −4.49 [−190.29 to 72.03], p<0.001; ΔHF −19.40 [−185.55 to 6.21] vs −10.73 [−79.53 to 137.53], p=0.004; ΔLF/HF 0.07 [−2.32 to 1.44] vs −0.11 [−1.14 to 0.96], p<0.001). Decreased FMD (6.9±4.7 vs 7.5±4.9, p=0.046) was also detected among T-allele carriers. In the Cox -regression analysis adjusted by sex, age, betablocker use and mean simvastatin dose, T-allele carriers had a relative risk for MACE of 2.112 (95% CI: 1.133–3.938; p=0.019).

Conclusions

The presence of the T allele at nNOS gene rs41279104 sequence is associated with increased sympathetic tone at acute phase of STEMI and a higher incidence of recurrent MACE.

Effect of Loading Dose of Atorvastatin Prior to Planned Percutaneous Coronary Intervention on Major Adverse Cardiovascular Events in Acute Coronary Syndrome: The SECURE-PCI Randomized Clinical Trial

IMPORTANCE

The effects of loading doses of statins on clinical outcomes in patients with acute coronary syndrome (ACS) and planned invasive management remain uncertain.

OBJECTIVE

To determine if periprocedural loading doses of atorvastatin decrease 30-day major adverse cardiovascular events (MACE) in patients with ACS and planned invasive management.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, double-blind, placebo-controlled, randomized clinical trial conducted at 53 sites in Brazil among 4191 patients with ACS evaluated with coronary angiography to proceed with a percutaneous coronary intervention (PCI) if anatomically feasible. Enrollment occurred between April 18, 2012, and October 6, 2017. Final follow-up for 30-day outcomes was on November 6, 2017.

INTERVENTIONS

Patients were randomized to receive 2 loading doses of 80 mg of atorvastatin (n = 2087) or matching placebo (n = 2104) before and 24 hours after a planned PCI. All patients received 40 mg of atorvastatin for 30 days starting 24 hours after the second dose of study medication.

MAIN OUTCOMES AND MEASURES

The primary outcome was MACE, defined as a composite of all-cause mortality, myocardial infarction, stroke, and unplanned coronary revascularization through 30 days.

RESULTS

Among the 4191 patients (mean age, 61.8 [SD, 11.5] years; 1085 women [25.9%]) enrolled, 4163 (99.3%) completed 30-day follow-up. A total of 2710 (64.7%) underwent PCI, 333 (8%) underwent coronary artery bypass graft surgery, and 1144 (27.3%) had exclusively medical management. At 30 days, 130 patients in the atorvastatin group (6.2%) and 149 in the placebo group (7.1%) had a MACE (absolute difference, 0.85% [95% CI, -0.70% to 2.41%]; hazard ratio, 0.88; 95% CI, 0.69-1.11; P = .27). No cases of hepatic failure were reported; 3 cases of rhabdomyolysis were reported in the placebo group (0.1%) and 0 in the atorvastatin group.

CONCLUSIONS AND RELEVANCE

Among patients with ACS and planned invasive management with PCI, periprocedural loading doses of atorvastatin did not reduce the rate of MACE at 30 days. These findings do not support the routine use of loading doses of atorvastatin among unselected patients with ACS and intended invasive management.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01448642.

Diacerein improves left ventricular remodeling and cardiac function by reducing the inflammatory response after myocardial infarction

BACKGROUND

The inflammatory response has been implicated in the pathogenesis of left ventricular (LV) remodeling after myocardial infarction (MI). An anthraquinone compound with anti-inflammatory properties, diacerein inhibits the synthesis and activity of pro-inflammatory cytokines, such as tumor necrosis factor and interleukins 1 and 6. The purpose of this study was to investigate the effects of diacerein on ventricular remodeling in vivo.

METHODS AND RESULTS

Ligation of the left anterior descending artery was used to induce MI in an experimental rat model. Rats were divided into two groups: a control group that received saline solution (n = 16) and a group that received diacerein (80 mg/kg) daily (n = 10). After 4 weeks, the LV volume, cellular signaling, caspase 3 activity, and nuclear factor kappa B (NF-κB) transcription were compared between the two groups. After 4 weeks, end-diastolic and end-systolic LV volumes were reduced in the treatment group compared to the control group (p < .01 and p < .01, respectively). Compared to control rats, diacerein-treated rats exhibited less fibrosis in the LV (14.65%± 7.27% vs. 22.57%± 8.94%; p < .01), lower levels of caspase-3 activity, and lower levels of NF-κB p65 transcription.

CONCLUSIONS

Treatment with diacerein once a day for 4 weeks after MI improved ventricular remodeling by promoting lower end-systolic and end-diastolic LV volumes. Diacerein also reduced fibrosis in the LV. These effects might be associated with partial blockage of the NF-κB pathway.

Arterial tissue and plasma concentration of enzymatic-driven oxysterols are associated with severe peripheral atherosclerotic disease and systemic inflammatory activity

INTRODUCTION

Cholesterol undergoes oxidation via both enzymatic stress- and free radical-mediated mechanisms, generating a wide range of oxysterols. In contrast to oxidative stress-driven metabolites, enzymatic stress-derived oxysterols are scarcely studied in their association with atherosclerotic disease in humans.

METHODS

24S-hydroxycholesterol (24S-HC), 25-hydroxycholesterol (25-HC), and 27-hydroxycholesterol (27-HC) were assessed in plasma and arteries with atherosclerotic plaques from 10 patients (54-84 years) with severe peripheral artery disease (PAD) as well as arteries free of atherosclerotic plaques from 13 individuals (45-78 years, controls).

RESULTS

Plasma 25-HC was higher in PAD individuals than in controls (6.3[2] vs. 3.9[1.9] ng/mgCol; p = 0.004). 24S-HC and 27-HC levels were, respectively, five- and 20-fold higher in the arterial tissue of PAD individuals than in those of the controls (p = 0.016 and p = 0.001). Plasma C-reactive protein correlated with plasma 24-HC (r = 0.51; p = 0.010), 25-HC (r = 0.75; p < 0.001), 27-HC (r = 0.48; p = 0.015), and with tissue 24S-HC (r = 0.4; p = 0.041) and 27-HC (r = 0.46; p = 0.023).

CONCLUSION

Arterial intima accumulation of 27-HC and 24S-HC is associated with advanced atherosclerotic disease and systemic inflammatory activity in individuals with severe PAD.

The I405V and Taq1B polymorphisms of the CETP gene differentially affect sub-clinical carotid atherosclerosis

Background

Cholesteryl ester transfer protein (CETP) plays a major role in lipid metabolism, but studies on the association of CETP polymorphisms with risks of cardiovascular disease are inconsistent. This study investigated whether the CETP gene I405V and Taq1B polymorphisms modified subclinical atherosclerosis in an asymptomatic Brazilian population sample.

Methods

The polymorphisms were analyzed using polymerase chain reaction in 207 adult volunteers. Serum lipid profiles, oxLDL Ab titers, C-reactive protein and tumor necrosis factor-α concentrations and CETP and phospholipid transfer protein (PLTP) activities were determined, and common carotid artery intima-media thickness (cIMT) was measured using ultrasonography.

Results

No differences in cIMT were observed between the presence or absence of the minor B2 and V alleles in either polymorphism. However, inverse correlations between mean cIMT and CETP activity in the presence of these polymorphisms were observed, and positive correlations of these polymorphisms with PLTP activity and oxLDL Ab titers were identified. Moreover, logistic multivariate analysis revealed that the presence of the B2 allele was associated with a 5.1-fold (CI 95%, OR: 1.26 – 21.06) increased risk for cIMT, which was equal and above the 66^th percentile and positively interacted with age. However, no associations with the V allele or CETP and PLTP activities were observed.

Conclusions

None of the studied parameters, including CETP activity, explained the different relationships between these polymorphisms and cIMT, suggesting that other non-determined factors were affected by the genotypes and related to carotid atherosclerotic disease.

In comparison to the myocardial perfusion scintigraphy, a treadmill stress test is a viable, efficient and cost effective option to predict cardiovascular events in elderly patients

OBJECTIVE

To define the prognostic value and cost-effectiveness of the treadmill stress test (TST) in comparison to the dipyridamole myocardial perfusion scintigraphy (DIP), in individuals > or = 75 years of age.

METHODS

Consecutive and prospective assessment of 66 patients (40% male) aged 81 +/- 5 years of which 57% were hypertensive, 38% had dyslipidemia and 28% were diabetics. The Bruce protocol was adapted for a tilt treadmill and the TST prognostic value was obtained using the Duke treadmill score.

RESULTS

The TST duration, recommended maximum heart rate percentage and double product at peak exercise were respectively: 7 +/- 3 minutes, 95 +/- 9% and 24,946 +/- 4,576 (bpm x mmHg). The TST and DIP presented similar positive results for myocardial ischemia (21% vs 15%, respectively). The correlation between the tests was 88% (Kappa 0.63, p<0.01). During 685 +/- 120 days of follow-up, nine major events occurred: 6 deaths, 2 acute coronary syndromes and 1 myocardial revascularization. The variables associated with the major events were: age (83 +/- 6 vs 80 +/- 4 years; p=0.048), male gender (78% vs 33%; p=0.02), ST segment depression (1 +/- 1 mm vs 0.25 +/- 0.6 mm; p= 0.01), high or intermediate risk determined by the Duke treadmill score - combined in one group (44% vs 2%; p=0.001) and abnormal DIP (44% vs 10%, p= 0.02).

CONCLUSION

For this elderly population, the TST was an efficient and viable option with a similar diagnostic value in comparison to the DIP. However, the TST was more accurate in the prediction of major events and offers a lower cost.

Endothelial nitric oxide synthase gene variant modulates the relationship between serum cholesterol levels and blood pressure in the general population: New evidence for a direct effect of lipids in arterial blood pressure

BACKGROUND

A causal relationship between plasma cholesterol and blood pressure remains poorly understood. It has been postulated that the decrease in nitric oxide (NO) availability is a potential mechanism by which hypercholesterolemia may stimulate blood pressure elevation. However, evidence supporting the role of the L-arginine-NO pathway on the relationship between hypertension and hypercholesterolemia is still lacking.

METHODS AND RESULTS

We tested for an association of the expressed NO synthase (eNOS) Glu298Asp gene variant and plasma levels of lipids and lipoproteins in the determination of systolic blood pressure levels in a 1577 individuals randomly selected from the general population. Significant interactions could be disclosed either between the Glu298Asp gene variant and total-cholesterol (p = 0.02), log-transformed triglycerides (p = 0.004) or non-HDL-cholesterol (p = 0.003) in the determination of systolic blood pressure. In addition, although the presence of the AspAsp genotype did not significantly increase the risk of hypertension in individuals in the 50% lowest percentile of total-cholesterol, presence of this genotype significantly increased the risk of hypertension in individuals in the 50% highest percentile. Finally, in a multiple logistic regression model adjusting for age, sex, diabetes, ethnicity, smoking status and BMI, the AspAsp genotype significantly increased the risk of hypertension only in individuals with total-cholesterol above 209 mg/dL (p = 0.05, odds ratios (OR) = 2.0).

CONCLUSION

Taken together, these results provide evidence supporting the role of the eNOS Glu298Asp gene variant in modulating blood pressure through a relationship with lipid levels.

Hyperlipidemia related to the use of HIV-protease inhibitors: natural history and results of treatment with fenofibrate

Hyperlipidemia has been frequently recorded as a side effect of treating HIV patients with protease inhibitors (PI). This study was initiated to analyze the modifications on blood lipids in HIV-patients receiving PI and the safety and efficacy of the treatment with fenofibrate. Total (TC) and HDL-cholesterol, triglycerides (TG), and CD(4)(+) T-cell counts were measured in 30 HAART-naive patients (Group I) before and after PI introduction. In a second phase of the study, the effects of fenofibrate on lipids, CPK, CD(4)(+), and viral load were determined in 13 patients (Group II) with elevated TC or TG. In Group I, 60% of the patients showed TC or TG elevations. Average increments of 31% and 146% in TC and TG respectively (p<0.0006 and p<0.0001) were observed. In Group II, fenofibrate treatment was associated with decrements of 6.6% (TC) and 45.7% (TG) (p=0.07 and 0.0002) and no modifications on CPK, CD(4)(+), and viral load. In conclusion, hyperlipidemia is common during the treatment of HIV with protease inhibitors, and fenofibrate appears to be an effective and safe choice for its treatment.

Cholesterol lowering with statins reduces exercise-induced myocardial ischemia in hypercholesterolemic patients with coronary artery disease

Coronary flow reserve is mainly influenced by the combination of luminal stenosis and vascular dilation capacity. Thus, after statin treatment, the reduction of ischemic threshold in patients submitted to exercise testing could be intensely influenced by angiographic severity. In this study, we verify the effect of statin treatment on exercise-induced myocardial ischemia in hypercholesterolemic patients with a broad range of coronary angiographic severities. Patients with 2 consecutive positive exercise tests, coronary stenosis > or =70%, total cholesterol > or =300 mg/dl, and triglycerides < or =200 mg/dl were randomly assigned to a 16-week treatment period with either diet alone (n = 39) or diet plus statins (simavastatin, n = 31 and pravastatin, n = 10). Statin-treated patients had a significant variation in total cholesterol (-46% vs -2.7%; p <0.01), low-density lipoprotein cholesterol (-58% vs 0.8%; p <0.01), and high-density cholesterol (+28% vs -6%; p <0.05) in comparison with the diet-only group. After 16 weeks of treatment, 36 patients (92%) in the diet group still had positive exercise tests, whereas only 7 patients (15%) of the statin group had a positive test (p <0.01). The proportion of positive tests was significantly reduced in subgroups of patients with 1-, 2-, or 3-vessel disease. Regarding the severity of coronary stenosis, the proportion of positive tests was significantly reduced in patients with stenosis between 70% and 90% and in patients with stenosis > or =90%. Moreover, the proportion of positive tests tended to decrease to a greater extent in patients with mild coronary disease. In conclusion, cholesterol-lowering treatment with statins reduces exercise-induced myocardial ischemia in hypercholesterolemic patients with mild or severe epicardial coronary stenosis.

Triglyceride and lipoprotein (a) are markers of coronary artery disease severity among postmenopausal women

OBJECTIVE

After menopause, some women manifest coronary artery disease (CAD) with highly variable angiographic severity. For these women, postmenopausal appearing of some CAD risk factors may have differently influenced the CAD risk and severity. In this study, we attempt to unravel differences in the frequency or intensity of CAD risk factors among postmenopausal women with different angiographic severity.

METHODS

We studied 182 postmenopausal women (64+/-6 years) who underwent coronary angiography to investigate thoracic pain. Subjects with no detectable coronary lesions at angiography were recruited to the non-obstructive group and patients with CAD were grouped in one-vessel or multi-vessel groups. We compared clinical variables as the body mass index (BMI), age at menopause, age, hypertension, diabetes and cigarette smoking, and lipid measurements as plasma levels of total cholesterol, triglyceride, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, apolipoprotein (apo) A1, apo B and lipoprotein(a) (Lp(a)).

RESULTS

Comparing to the non-obstructive group, Lp(a) was twofold higher in the one-vessel group and threefold higher in the multi-vessel group and triglycerides were 34% higher in the one-vessel group and 50% higher in the multi-vessel group. No further difference was found among the three groups. After multivariate logistic regression analysis, triglyceride (odds ratio: 1.01; P=0.0013) and Lp(a) (odds ratio: 1.006; P<0.0001) were independently indicative of the presence of obstructive CAD.

CONCLUSIONS

We found that both Lp(a) and triglycerides constitute useful markers of CAD severity among postmenopausal women.

Etofibrate but not controlled-release niacin decreases LDL cholesterol and lipoprotein (a) in type IIb dyslipidemic subjects

Etofibrate is a hybrid drug which combines niacin with clofibrate. After contact with plasma hydrolases, both constituents are gradually released in a controlled-release manner. In this study, we compared the effects of etofibrate and controlled-release niacin on lipid profile and plasma lipoprotein (a) (Lp(a)) levels of patients with triglyceride levels of 200 to 400 mg/dl, total cholesterol above 240 mg/dl and Lp(a) above 40 mg/dl. These patients were randomly assigned to a double-blind 16-week treatment period with etofibrate (500 mg twice daily, N = 14) or niacin (500 mg twice daily, N = 11). In both treatment groups total cholesterol, VLDL cholesterol and triglycerides were equally reduced and high-density lipoprotein cholesterol was increased. Etofibrate, but not niacin, reduced Lp(a) by 26% and low-density lipoprotein (LDL) cholesterol by 23%. The hybrid compound etofibrate produced a more effective reduction in plasma LDL cholesterol and Lp(a) levels than controlled-release niacin in type IIb dyslipidemic subjects.

Effect of pravastatin on plasma removal of a chylomicron-like emulsion in men with coronary artery disease

The speed of the plasma removal of chylomicrons, the lipoproteins that carry dietary lipids absorbed in the intestine, may influence atherogenesis. Thus, the effects of a 30-day pravastatin or placebo treatment on the plasma kinetics of chylomicron-like emulsions were evaluated in 25 patients with coronary artery disease who were not hypertriglyceridemic in a randomized, single-blinded study. Eleven patients (53 +/- 4 years, 10 men) received pravastatin 40 mg/day and 14 received placebo (52 +/- 3 years, 13 men). Emulsions labeled with triolein ((3)H-TO) and cholesteryl oleate ((14)C-CO) to assess lipolysis and clearance of chylomicron and remnants, respectively, were injected intravenously in a bolus after a 12-hour fast. Blood samples were collected during 60 minutes to determine radio isotope decaying curves and fractional catabolic rates. Subjects were studied at baseline and after the treatment period. Compared with placebo (data expressed as mean +/- SEM), pravastatin treatment increased the (14)C-CO fractional catabolic rates (70 +/- 45% vs 18 +/- 10%, p = 0.01), reduced total cholesterol (-21 +/- 3% vs -3 +/- 2% p = 0.0001), low-density lipoprotein (LDL) cholesterol (-25 +/- 5% vs 4 +/- 6%, p = 0.0001), and apolipoprotein B levels (-22 +/- 3% vs -7 +/- 3% p = 0.01). (3)H-TO fractional catabolic rates, plasma triglycerides, very-low-density lipoprotein (VLDL) cholesterol and high-density lipoprotein (HDL) cholesterol variations did not differ between the groups. The fractional catabolic rate of (14)C-CO was inversely correlated with plasma apolipoprotein B levels (r = -0.7, p = 0.04). This suggests that besides reducing LDL cholesterol, pravastatin also increases chylomicron remnant clearance, with possible antiatherogenic implications.