Adipokines and Inflammatory Markers in Acute Myocardial Infarction Patients with and without Obstructive Sleep Apnea: A Comparative Analysis

An association has been suggested between acute myocardial infarction (AMI) and obstructive sleep apnea (OSA). Considering the role of adipose-tissue-derived inflammatory mediators (adipokines) and the shared risk factor of obesity in OSA and AMI, this study aimed to investigate the involvement of adipokines in AMI patients with and without OSA. Serum levels of adipokines and inflammatory mediators were quantified, and home respiratory polygraphy was conducted. A total of 30 AMI patients and 25 controls were included. Patients with AMI exhibited elevated levels of resistin (7.4 vs. 3.7 ng/mL), interleukin-6 (8.8 vs. 1.3 pg/mL), and endothelin-1 (3.31 vs. 1.8 pg/mL). Remarkably, AMI patients with concomitant OSA exhibited higher levels of resistin (7.1 vs. 3.7 ng/mL), interleukin-6 (8.9 vs. 1.3 pg/mL), endothelin-1 (3.2 vs. 1.8 pg/mL), creatin kinase (1430 vs. 377 U/L), creatine kinase-MB (64.6 vs. 9.7 ng/mL), and troponin T (2298 vs. 356 pg/mL) than their non-OSA counterparts. Leptin showed a correlation with OSA severity markers. OSA was associated with greater cardiac damage in AMI patients. Our findings underscore that adipokines alone are not sufficient to discriminate the risk of AMI in the presence of OSA. Further research is necessary to determine the potential mechanisms contributing to exacerbated cardiac damage in patients with both conditions.

Differential expression of osteopontin, and osteoprotegerin mRNA in epicardial adipose tissue between patients with severe coronary artery disease and aortic valvular stenosis: association with HDL subclasses

BACKGROUND

Previous studies suggest a relationship of the epicardial adipose tissue (EAT) with progression and calcification of the atherosclerotic plaque; however, it is unknown if this tissue expresses genes that may participate on these processes and if the expression of these genes is regulated by high-density lipoprotein (HDL) subclasses.

METHODS

To explore this possibility, we determined the mRNA expression by qPCR of a pro-calcifying gene (osteopontin (OPN)), and two anti-calcifying genes (osteoprotegerin (OPG) and osteonectin (ON)), in biopsies of EAT obtained from 15 patients with coronary artery disease (CAD) determined by angiography, and 15 patients with diagnostic of aortic valve stenosis but without CAD as control group. We determined the distribution and composition of HDL subclasses by electrophoresis and their statistical relationship with the gene expression in EAT.

RESULTS

EAT from CAD patients showed a higher expression level of OPN and OPG than control group, whereas ON expression was similar between groups. Large HDL subclasses were cholesterol-poor in CAD patients as estimated by the cholesterol-to-phospholipid ratio. A linear regression model showed an independent association of OPN expression with HDL3a-cholesterol, and OPG expression with the relative proportion of HDL3b protein. Logistic analysis determined that OPN expression was positively associated with the presence of atherosclerotic plaque CONCLUSION: OPN, ON, and OPG genes are transcribed in EAT; to the exception of ON, the level of expression was different in CAD patients and control group, and correlated with some HDL subclasses, suggesting a new role of these lipoproteins.

Increased HDL Size and Enhanced Apo A-I Catabolic Rates Are Associated With Doxorubicin-Induced Proteinuria in New Zealand White Rabbits

The catabolism and structure of high-density lipoproteins (HDL) may be the determining factor of their atheroprotective properties. To better understand the role of the kidney in HDL catabolism, here we characterized HDL subclasses and the catabolic rates of apo A-I in a rabbit model of proteinuria. Proteinuria was induced by intravenous administration of doxorubicin in New Zealand white rabbits (n = 10). HDL size and HDL subclass lipids were assessed by electrophoresis of the isolated lipoproteins. The catabolic rate of HDL-apo A-I was evaluated by exogenous radiolabelling with iodine-131. Doxorubicin induced significant proteinuria after 4 weeks (4.47 ± 0.55 vs. 0.30 ± 0.02 g/L of protein in urine, P < 0.001) associated with increased uremia, creatininemia, and cardiotoxicity. Large HDL2b augmented significantly during proteinuria, whereas small HDL3b and HDL3c decreased compared to basal conditions. HDL2b, HDL2a, and HDL3a subclasses were enriched with triacylglycerols in proteinuric animals as determined by the triacylglycerol-to-phospholipid ratio; the cholesterol content in HDL subclasses remained unchanged. The fractional catabolic rate (FCR) of [(131)I]-apo A-I in the proteinuric rabbits was faster (FCR = 0.036 h(-1)) compared to control rabbits group (FCR = 0.026 h(-1), P < 0.05). Apo E increased and apo A-I decreased in HDL, whereas PON-1 activity increased in proteinuric rabbits. Proteinuria was associated with an increased number of large HDL2b particles and a decreased number of small HDL3b and 3c. Proteinuria was also connected to an alteration in HDL subclass lipids, apolipoprotein content of HDL, high paraoxonase-1 activity, and a rise in the fractional catabolic rate of the [(131)I]-apo A-I.

[Phosphodiesterase-5 inhibitors for the treatment of pulmonary arterial hypertension]

In experimental and clinical cardiology, phosphodiesterase type 5 (PDE-5) inhibitors have brought scientific interest as a therapeutic tool in pulmonary arterial hypertension (PAH) management in recent years. Phosphodiesterases are a superfamily of enzymes that inactivate cyclic adenosine monophosphate and cyclic guanosine monophosphate, the second messengers of prostacyclin and nitric oxide. The rationale for the use of PDE-5 inhibitors in PAH is based on their capacity to overexpresss the nitric oxide pathway pursued inhibition of cyclic guanosine monophosphate hydrolysis. By increasing cyclic guanosine monophosphate levels it promotes vasodilation, antiproliferative and pro-apoptotic effects that may reverse pulmonary vascular remodeling. There is also evidence that these drugs may directly enhance right ventricular contractility through an increase in cyclic adenosine monophosphate mediated by the inhibition of the cyclic guanosine monophosphate -sensitive PDE-3. Sildenafil, tadalafil and vardenafil are 3 specific PDE-5 inhibitors in current clinical use, which share similar mechanisms of action but present some significant differences regarding potency, selectivity for PDE-5 and pharmacokinetic properties. Sildenafil received approval in 2005 by the Food and Drug Administration and the European Medicines Agency and tadalafil in 2009 by the Food and Drug Administration and the European Medicines Agency for the treatment of PAH in patients classified as NYHA/WHO functional class II and III. In Mexico, sildenafil and tadalafil were approved by Comisión Federal de Protección contra Riesgos Sanitarios for this indication in 2010 and 2011, respectively.

[Clinical implications and prognostic significance of the study on the circadian variation of heart rate variability in patients with severe pulmonary hypertension]

BACKGROUND

A reduction of heart rate variability (HRV) is currently considered an independent risk factor for morbidity, mortality and severity of severalcardiac disease, however, the dynamic sympathovagal modulation on HRV during 24 hr in primary pulmonary hypertension (PPH) had not been described.

METHODS

24 hr Holter monitoring (HA) were recorded in 32 patients (mean age 34, +/-12, 90% female) with severe primary pulmonary hypertension (mean pulmonary pressure, 90:t:12 mm Hg), and in 34 patients (mean age 36 +/-14, 60% female) with Eisenmenger syndrome (ES) secondary to septal ventricular defect or atent ductus arteriosus. A control group (n=44) paired for age, gender and arterial pulmonary pressure was included. HRV time and spectral parameters (mean, SDNN, SDANN, rMSSD, PNN50, LF, HF and LF/HF ratio) were analyzed during three periods: 24 hr; day (8-22:00), night (23-07:00) and also every hour of recording at 5 min-intervals). After detection of sympatho-vagal balance 15 patients were randomized, Treprostinil (prostaglandin) was administered to 6 patients and subcutaneous placebo to 9.

RESULTS

HRV frequency parameters during 24 hr HM were significantly different among groups. LF/HF (day) 5.9:1:12.5:1:1P.001 and LF/HF night) 2.8:tlvs.1.5:l:.8.034. Sympathovagal modulation on 24 hr HRV showed that heart rate circadian rhythm is clearly altered in both PPH and ES, but the sympathetic tone in PPH is higher at l 24 hr. (p < .05), after administering treprostinil a recovery of sympathovagal balance was observed

CONCLUSIONS

Autonomic cardiac disturbance is clearly present in PPH and ES. The circadian rhythm of HRV is first lost due to an increase of sympathetic tone. These changes may be markers of autonomic disbalance that favor the development of arrhythmias and sudden death. The sympathovagal balance in PPH could be considered an important risk marker.

Utility of Transesophageal Echocardiography in Diagnosis of a Left Atrial Myxoma with Regional Pulmonary Venous Obstruction

A case of a 57-year-old patient with regional pulmonary edema secondary to obstruction of the right lower pulmonary vein by a left atrial myxoma is described. Diagnosis was established by transesophageal echocardiography.