Journal of Hypertension: Open Access

Nitric oxide (NO) is one of the most important vasodilator molecules produced by endothelium and presents plenty of cardiovascular actions. It has already been established that deficiency in NO/cGMP signaling pathway is involved in pathophysiological mechanisms of many cardiovascular diseases. In this context, the use of NOreleasing drugs appears to be an effective alternative to replace the deficient endogenous NO and mimic the role of this molecule in the body. Organic nitrates represent the oldest class of NO donors that have been clinically applied. Considering that tolerance can occur when these drugs are used chronically, the search for new compounds of this class with lower tolerance potential is increasing. Here we briefly discuss the mechanisms involved in nitrate tolerance and highlight some achievements from our group in the development of new organic nitrates and their preclinical application in cardiovascular disorders.

Background: In patients with atrial septal defect (ASD) and severe pulmonary arterial hypertension (PAH), diastolic pulmonary arterial pressure (DPAP) correlates closely with pulmonary vascular resistance (PVR) and can reflect the severity of pulmonary vascular disease. However, it is unclear whether DPAP has potential to become a prognostic indicator for closure of ASD with severe PAH. Objectives: This study was performed to investigate the prognostic implication of DPAP in patients with ASD and severe PAH. Methods: Among 232 patients with ASD and severe PAH (systolic pulmonary arterial pressure (SPAP)≥70 mm Hg measured with right heart catheterization), 85 patients (21M/64F) undergoing closure of ASD were followed up. Doppler-calculated SPAP was recorded to identify the normalized post-operative PAP (SPAP<40 mm Hg). According to the cut-off value of DPAP from a ROC curve, two subsets were classified: low-DPAP (<25 mm Hg, n=31) and high-DPAP (≥25 mm Hg, n=54). Results: After closure of ASD, normalization of PAP occurred in 71% of patients with low-DPAP and 7.4% of patients with high-DPAP (P<0.001). Upon adjustment for PVR and SPAP/systolic aortic pressure, the hazard ratio of post-operative persistent PAH for high-DPAP was 4.48 (95%CI: 2.04-9.81, P<0.001). The follow-up (3.6 ± 1.3 years) demonstrated that normalized post-operative PAP tended to occur in patients with low-DPAP (Log Rank, P<0.001). Conclusions: In patients with ASD and severe PAH, low-DPAP has the potential to become a predictor for the normalized post-operative PAP.

Background: Homocysteine (Hcy) has been considered as an independent risk factor for coronary artery disease (CAD). Folic acid and vitamin B12 are two vital regulators in Hcy metabolic process. We evaluated the associations between Hcy and the categories of CAD as well as the levels of folic acid and vitamin B12.

Methods: Hcy, folic acid and vitamin B12 from 292 CAD patients, including 73 acute myocardial infarction (AMI), 116 unstable angina pectoris (UAP), 103 stable angina pectoris (SAP), and 100 non-CAD controls were measured, and the data were analyzed by SPSS software.

Results: Hcy concentrations of AMI patients were the highest, and UAP patients were second, and SAP patients were the third higher, which were significantly higher than controls (p<0.01). Compared to SAP patients, patients with AMI and UAP had higher Hcy levels with approximately average elevated (4-5) μmol/L, while SAP patients were more higher Hcy with approximately 8 μmol/L than controls. However, the levels of folic acid and vitamin B12 had opposite results, whose levels in AMI group had the lowest, while in controls had the highest. There were strongly moderate negative correlations between Hcy and folic acid (r=-0.67, p<0.001) and vitamin B12 (r=-0.56, p<0.001).

Conclusions: The present study confirms that high Hcy levels are closely associated with the categories of CAD as well as low status of folic acid and vitamin B12.

In the month of Ramadan, many Muslims fast during the day and significant changes in sleeping and eating patterns occur that may affect blood pressure. In the current study, we aimed to evaluate the effect of fasting on blood pressure. The study was performed in June 2014 in Yazd, a city in the center of Iran. Sixteen patients with controlled or mild hypertension on medical therapy underwent 24 hour blood pressure monitoring before the month of Ramadan and again while fasting during Ramadan. The differences in mean systolic and diastolic blood pressure before and during Ramadan were recorded. It was observed that the mean systolic, diastolic, and mean blood pressure, before and during Ramadan were not significantly different (131 vs. 128 mmHg, P=0.141, 70 vs. 68 mmHg P=0.144 and 99 vs. 96.4 mmHg, P=0.085 respectively). There were no significant differences in changes of blood pressure, throughout the day before and during fasting period of Ramadan. It was concluded that the patients with controlled or mild hypertension on antihypertensive therapy can observe their fasting during Ramadan without significant changes in blood pressure.