High oxidized LDL and elevated plasma homocysteine contribute to the early reduction of myocardial flow reserve in healthy adults

Effect of Atherogenic Index of Plasma on Pre-Percutaneous Coronary Intervention Thrombolysis in Myocardial Infarction Flow in Patients With ST Elevation Myocardial Infarction

Dyslipidemia is an important risk factor for cardiovascular morbidity and mortality. Although low-density lipoprotein (LDL) is primarily responsible, the importance of triglyceride (TG) and high-density lipoprotein (HDL) has also been recognized. The present study investigated the effect of the atherogenic index of plasma (AIP), in which atherogenic and protective lipoproteins were evaluated together, on the initial flow in patients with ST elevation myocardial infarction. AIP was calculated as log(TG/HDL-cholesterol). Patients included in the study (n = 1535) were divided into Thrombolysis in Myocardial Infarction (TIMI) flow grade 0 and >0. AIP was found to be significantly different between 2 groups (.55 ± .23 vs .67 ± .21; P < .001). AIP was an independent predictor for pre-intervention TIMI flow (Odds Ratio: 2.778). A moderate correlation was found between TIMI frame count measurements, calculated in patients with TIMI 2-3, and AIP (Pearson correlation coefficient: .63, P < .001). In the receiver operating characteristic analysis, AIP showed the highest area under curve (AUC) compared with other lipid parameters for predicting vascular patency. The AUC of AIP was .634, the cut-off value was .59, and the sensitivity and specificity were 67.6% and 68.4%, respectively (P < .001). In conclusion, AIP was found to be an important marker affecting pre-percutaneous coronary intervention TIMI flow.

Plasma lipids in patients with inflammatory bowel disease : Observations on the associations between lipid indices and coronary flow reserve

BACKGROUND AND AIMS

Patients with inflammatory bowel disease (IBD) are at increased risk for coronary artery disease (CAD), even after adjusting for traditional risk factors for atherosclerosis. While inflammation is widely regarded as the pathophysiologic link between IBD and CAD, the exact mechanisms are largely unknown. This study was conducted to investigate the association of lipid parameters and indices with coronary flow reserve and markers of inflammation in IBD patients.

METHODS

A total of 73 patients with IBD and 26 healthy controls were enrolled. Patients in the IBD arm were either in remission or had mild disease activity. Lipid parameters, C‑reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were analyzed using standard laboratory techniques. Coronary flow reserve (CFR) was measured using two-dimensional echocardiography.

RESULTS

Both CRP and ESR were higher and CFR was significantly lower in IBD patients, but there were no differences in terms of lipid parameters or indices; however, patients with IBD and a CFR <2.0 had significantly higher triglyceride (TG) level (155.0 (80.0) mg/dl vs. 108.0 (68.0) mg/dl, p < 0.001) and there was a strong trend towards lower high-density lipoprotein (HDL) cholesterol (40.0 (8.5) mg/dl vs. 45.0 (10.0) mg/dl, p = 0.05) level in the latter group when compared to patients with a CFR ≥2.0. The atherogenic index of plasma (AIP), measured as log(TG/HDL-C) had the best predictive value for CFR in IBD group and was an independent predictor of CFR after multivariate adjustment for confounders (unstandardized coefficient: -0.75, 95% CI: (-1.13)-(-0.37)), β = -0.41, p = <0.001).

CONCLUSION

The atherogenic index of plasma is a marker for reduced CFR in IBD patients and could be useful to screen those at risk for early atherogenesis and CAD.

Atherogenesis: hyperhomocysteinemia interactions with LDL, macrophage function, paraoxonase 1, and exercise

Despite great strides in understanding the atherogenesis process, the mechanisms are not entirely known. In addition to diet, cigarette smoking, genetic predisposition, and hypertension, hyperhomocysteinemia (HHcy), an accumulation of the noncoding sulfur-containing amino acid homocysteine (Hcy), is a significant contributor to atherogenesis. Although exercise decreases HHcy and increases longevity, the complete mechanism is unclear. In light of recent evidence, in this review, we focus on the effects of HHcy on macrophage function, differentiation, and polarization. Though there is need for further evidence, it is most likely that HHcy-mediated alterations in macrophage function are important contributors to atherogenesis, and HHcy-countering strategies, such as nutrition and exercise, should be included in the combinatorial regimens for effective prevention and regression of atherosclerotic plaques. Therefore, we also included a discussion on the effects of exercise on the HHcy-mediated atherogenic process.

PET/CT challenge for the non-invasive diagnosis of coronary artery disease

This review will focus on the clinical potential of PET/CT for the characterization of cardiovascular diseases. We describe the technical challenges of combining instrumentation with very different imaging performance and discuss the clinical applications in the field of cardiology.

Clinical utility of estimated glomerular filtration rate in patients undergoing gated SPECT

BACKGROUND

Chronic kidney disease is a major risk factor for coronary artery disease (CAD). The aim of the study was to examine the association between estimated glomerular filtration rate (GFR), presence of CAD, and prognosis in patients with reversible perfusion defects at gated single-photon emission computed tomography (g-SPECT).

METHODS

Six hundred fifty-eight subjects who had undergone stress/rest g-SPECT for evaluation of myocardial ischemia were divided into two groups according to the presence of CAD, defined by a 70% diameter stenosis in at least one major vessel or principal side branch at coronary angiography.

RESULTS

GFR was lower in patients with CAD and after adjusting for several clinical characteristics through multivariate logistic regression analysis, reduced (<60 mL/min/1.73 m(2)) GFR remained a significant predictor of CAD (HR 1.80, 95% CI 1.04 to 3.12, P = .036). In addition, reduced GFR was associated with a greater extent of myocardial ischemia, assessed through the summed difference score, as well as with an increase in both total and cardiac mortality.

CONCLUSIONS

In patients with a positive g-SPECT scan, GFR is an accurate marker of CAD and is directly correlated to the extent of myocardial ischemia. Furthermore, reduced GFR had an adverse impact on survival in this particular population.

Coronary reactivity, homocysteine and methylenetetrahydrofolate reductase gene variation in young men during pravastatin therapy

High plasma homocysteine (Hcy) has been linked to impaired endothelial function. We investigated whether treatment with pravastatin affects the Hcy levels. Moreover, we studied whether the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism affects coronary vasomotion at baseline and during the treatment with pravastatin. Fifty-one healthy, mildly hypercholesterolemic men (mean age 35+/-4 years) attended this randomised, double-blind, placebo-controlled study. The volunteers were randomised into groups with 6-month treatment with pravastatin (40 mg/day, n=25) or placebo (n=26). Coronary blood flow measurements with positron emission tomography at rest and during adenosine infusion as well as biochemical analyses were done at baseline and at the end of the treatment period. The Hcy concentration decreased significantly during the pravastatin therapy (-0.81+/-1.46 micromol/l, p=0.01), but not during placebo (0.02+/-2.39 micromol/l, p=0.97). The MTHFR polymorphism did not affect the Hcy concentration or coronary flow indices. Neither did the MTHFR polymorphism modulate the effects of pravastatin on coronary vasomotion. In conclusion, a 6-month therapy with pravastatin decreases Hcy concentration in Finnish healthy young men. The MTHFR genotype is neither a determinant of baseline coronary flow indices nor does it modulate the effect of pravastatin on coronary reactivity.

Low serum adiponectin is associated with high circulating oxidized low-density lipoprotein in patients with type 2 diabetes mellitus and coronary artery disease

Decrease in adiponectin level, a common feature in patients with type 2 diabetes mellitus, is considered to predict cardiovascular events. Elevated oxidized low-density lipoprotein (oxLDL), formed within the arterial wall, is commonly seen as part of the atherogenic profile. We investigated the association of adiponectin and oxLDL in 58 patients with type 2 diabetes mellitus and ischemic coronary artery disease. In addition to adiponectin, the serum lipid profile (including oxLDL), plasminogen activator inhibitor 1, high-sensitivity C-reactive protein, and whole-body glucose uptake determined by euglycemic-hyperinsulinemic clamp were evaluated. The average adiponectin level was 7.1 +/- 3.5 microg/mL and was higher in female than in male patients (P = .011). Adiponectin level correlated with whole-body glucose uptake (P = .037) and high-density lipoprotein (HDL) cholesterol concentration (P = .007) and was inversely associated with oxLDL (P = .005), triglycerides (P = .010), and plasminogen activator inhibitor 1 (P = .004). No association was found between adiponectin and high-sensitivity C-reactive protein or LDL cholesterol levels. In multiple linear regression analysis, adiponectin contributed to oxLDL concentration, whereas total cholesterol, LDL and HDL cholesterol, and triglycerides did not. In conclusion, our results suggest that low adiponectin concentration indicates increased oxidative state in the arterial wall, which further supports previous data on the role of adipose tissue in atherogenesis.

Modulation by homocysteine of the iberiotoxin-sensitive, Ca2+ -activated K+ channels of porcine coronary artery smooth muscle cells

We evaluated the acute effect of homocysteine on the iberiotoxin-sensitive, Ca(2+)-activated K(+) (BK(Ca)) channels of the porcine coronary artery smooth muscle cells. NS 1619 (1 to 30 microM) caused a concentration-dependent enhancement of the BK(Ca) amplitude (recorded using the whole-cell, membrane-rupture configuration) only with an elevated [Ca(2+)](i) of approximately 444 nM, but not with [Ca(2+)](i) of approximately 100 nM. Homocysteine (30 microM) caused a small inhibition ( approximately 16%) of the BK(Ca) amplitude ([Ca(2+)](i)= approximately 444 nM), and a greater inhibition ( approximately 77%) was observed with 100 microM NADH present in the pipette solution. The inhibition persisted after washing. With NADPH (100 microM), a smaller magnitude of inhibition ( approximately 34%) of the BK(Ca) amplitude was recorded. The NS 1619-mediated enhancement of the BK(Ca) amplitude (with elevated [Ca(2+)](i) plus NADH in the pipette) was attenuated by homocysteine. The homocysteine-mediated inhibition of the BK(Ca) amplitude was suppressed by Tiron (10 mM) or diphenylene iodonium (30 nM), applied alone, but not by superoxide dismutase (500 U/ml) and catalase (500 U/ml). Generation of superoxide (O(2)(-)) of the smooth muscle cells (with NADH presence), measured using the lucigenin-enhanced chemiluminescence, was markedly increased by angiotensin II (100 nM) and homocysteine (30 microM). The chemiluminescence signal was sensitive to apocynin (300 microM) or Tiron, applied alone, but not to superoxide dismutase and catalase. In conclusion, our results demonstrate that acute homocysteine application inhibits the iberiotoxin-sensitive BK(Ca) channels (with elevated [Ca(2+)](i) and NADH present) which is probably caused by the NADH oxidase activation and the concomitant generation of intracellular superoxide.

Lowered levels of serum albumin and HDL-cholesterol in children with a recent mild infection

BACKGROUND

Infections are associated with atherogenic changes in serum.AIM. To elucidate effects of recent infections on risk factors for coronary heart disease in children.

SUBJECTS AND METHODS

In 1983 and again 3 years later, 2458 individuals aged 9, 12, 15, 18 and 21 years were investigated. In 1986, 106 subjects had symptoms of infection during the past 2 weeks before their follow-up visit. Their serum albumin and lipid concentrations were compared to those in 1983 when these individuals probably were healthy. An age- and sex-matched healthy control group from the cohort 1986 was chosen for comparison. For cholesterol age, sex and body mass index specific Z-scores in addition to actual values were used in statistical comparisons.

RESULTS

Serum albumin was 42 g/L in subjects with positive history of infection and 46 g/L in healthy controls (P<0.0001). HDL-cholesterol and the ratio of HDL- to total cholesterol were lower with increasing evidence of infection. Elevated serum C-reactive protein (CRP) or orosomucoid grouped the subjects with high and low serum HDL-cholesterol concentrations better than history of infection alone.

CONCLUSION

A mild infection lowers serum HDL-cholesterol and serum albumin concentrations, which both favour atherogenesis.

Do young women with polycystic ovary syndrome show early evidence of preclinical coronary artery disease?

BACKGROUND

It is thought that women with polycystic ovary syndrome (PCOS) are at increased risk of developing cardiovascular diseases.

METHODS

In this study, we used transthoracic echocardiography to measure coronary flow reserve (CFR) in 28 women with PCOS and in 26 healthy women.

RESULTS

The PCOS and the control groups were similar in terms of age (27.1 +/- 4.5 versus 28.8 +/- 4.4 years) and BMI (26.6 +/- 5.7 versus 24.7 +/- 4.4 kg/m2). Fasting insulin levels and homeostasis model assessment insulin resistance index were higher in the PCOS group. LH, the LH/FSH ratio, total testosterone, free testosterone and androstenedione were higher in the PCOS group. FSH, estradiol, prolactin, progesterone, cholesterol, triglyceride and high-sensitive C-reactive protein were similar between the two groups, but homocysteine levels were higher in the PCOS group. Baseline diastolic peak f low velocity (DPFV) (25.0 +/- 4.6 versus 23.3 +/- 2.7 cm/s, P > 0.05), hyperaemic DPFV (71.2 +/- 12.8 versus 73.0 +/- 12.9 cm/s, P > 0.05) and CFR (2.8 +/- 0.8 versus 3.2 +/- 0.8 cm/s, P > 0.05) of the left anterior descending coronary artery were similar between the two groups.

CONCLUSION

We conclude that in young women with PCOS and without cardiovascular risk factors, CFR is preserved.

Short-term changes in inflammatory response protein (hsCRP) do not parallel with changes in coronary vasoreactivity in obese men

AIM

Obese subjects are characterized by increased high-sensitivity C-reactive protein (hsCRP) and coronary vascular resistance. Clucocorticoids suppress inflammation, a possible cardioprotective effect. We tested the short-term anti-inflammatory effect of dexamethasone (dx) on these parameters in obese subjects.

METHODS

Coronary vascular resistance was quantitated basally and during adenosine infusion with or without simultaneous euglycemic hyperinsulinemic clamp (insulin infusion rate of 1 mU/kg/min) in 11 obese and 19 age-matched nonobese males using positron emission tomography and (15)O-water. Each subject was studied both with and without previous dx treatment for 2 days (2 mg/day).

RESULTS

Before dx treatment, hsCRP concentration was significantly higher in obese than in nonobese subjects (1.55+/-1.73 vs 0.32+/-0.32 mg/l, P = 0.005). In addition, coronary vascular resistances were higher (P < 0.05) in obese than in nonobese subjects at baseline (139+/-36 vs 117+/-22) and during adenosine infusion without (32+/-7 vs 26+/-7) or with simultaneous clamp (26+/-8 vs 21+/-5 mmHg min g/ ml). Dx treatment decreased significantly hsCRP concentration in obese but not in nonobese subjects, leading to similar hsCRP concentrations between the groups (0.45+/-0.43 vs 0.26+/-0.42 mg/l, respectively, P = 0.3). Dx had no effect on coronary vascular resistances (NS).

CONCLUSIONS

Obese subjects are characterized by high hsCRP, which can be normalized by dx. However, despite this, coronary vascular resistances did not decrease in obese subjects. Short-term changes in inflammatory response protein appear not to parallel with changes in coronary vasoreactivity in obese men.

Approach to the patient with chest pain and nonobstructive coronary artery disease

Patients with chest pain and nonobstructive coronary artery disease (NOCAD) utilize a significant part of our health care resources. Their diagnosis and treatment can often be difficult and time consuming. A simple classification system and stepwise diagnostic approach may help to reduce unnecessary testing. Also, utilization of a chest pain clinic may be beneficial for these patients.