Coronary revascularization and quality of life

Qualidade de Vida de pacientes submetidos à revascularização do miocárdio

OBJETIVO: Determinar o impacto da cirurgia de revascularização do miocárdio na Qualidade de Vida dos pacientes; analisar e comparar dimensões da Qualidade de Vida antes e após a intervenção cirúrgica; comparar variáveis sociodemográficas e clínicas aos aspectos de depressão e ansiedade, pré e pós-operatórios. MÉTODOS: Estudo descritivo exploratório no qual foram incluídos 78 pacientes no pré e pós-operatório. Foram utilizados instrumentos de pesquisa internacionais e validados para avaliar a qualidade de vida e os aspectos de depressão e ansiedade. RESULTADOS: Houve melhora significativa em todos os domínios da Qualidade de Vida, depressão e ansiedade (p=0,05). Domínios físico e social do 36-Item Short-Form Health Survey apresentaram menor pontuação dos escores (13,46 e 3,03, respectivamente), bem como o domínio social do instrumento Macnew (3,03). CONCLUSÃO: Cirurgia de revascularização ocasionou impacto positivo na Qualidade de Vida desses pacientes.

Antihypertensive effects exerted by enalapril in mild to moderate hypertension are not associated with changes in the circulating levels of nitric oxide-related markers

PURPOSE

The antihypertensive effects of angiotensin-converting enzyme inhibitors (ACEi) are explained, at least in part, by enhanced bradykinin-dependent nitric oxide (NO) formation and decreased angiotensin II-induced oxidative stress and vasoconstriction. We examined for the first time whether treatment with enalapril increases the plasma levels of markers of NO formation and decreases oxidative stress in mild to moderate hypertensive patients.

METHODS

Eighteen untreated hypertensive patients were treated with enalapril 10 mg/day (n=10) or 20 mg/day (n=8) for 60 days. Eighteen normotensive healthy controls were followed for the same period. Venous blood samples were collected at baseline and after 30/60 days of treatment with enalapril. Plasma NOx (nitrites + nitrates) concentrations were determined by using the Griess reaction. Plasma nitrite and whole blood nitrite concentrations were determined by using an ozone-based chemiluminescence assay. Plasma thiobarbituric acid-reactive species (TBARS) and 8-isoprostane concentrations were determined by a fluorimetric method and by ELISA, respectively.

RESULTS

Treatment with enalapril decreased blood pressure in hypertensive patients. However, we found no significant changes in plasma NOx, nitrite, whole blood nitrite, and in the levels of markers of oxidative stress in both normotensive controls and hypertensive patients treated with enalapril.

CONCLUSIONS

Our data show that enalapril 10-20 mg/day does not affect the concentrations of relevant markers of NO formation or markers of oxidative stress in mild to moderately hypertensive subjects, despite satisfactory blood pressure control. Our findings do not rule out the possibility that ACEi may produce such effects in more severely hypertensive patients treated with higher doses of ACEi.

Systolic blood pressure and subjective well-being in patients with coronary artery disease

BACKGROUND

Limited information exists regarding the association between subjective well-being (SWB) and systolic blood pressure (SBP) among hypertensive patients with coronary artery disease (CAD).

HYPOTHESIS

We tested the hypothesis that there is an association between SBP and SWB.

METHODS

We studied 22,576 hypertensive CAD patients > or = 50 years old in the INternational VErapamil SR-Trandolapril Study (INVEST), a randomized, blinded-endpoint trial of antihypertensive therapy in stable CAD patients. At each study visit, patients rated their SWB in the previous 4 weeks as "excellent," "good," "fair," or "poor" prior to SBP recordings. The outcome measure was SWB of "fair" or "poor." A longitudinal analysis using generalized estimating equations was performed to assess the association between SBP and odds of reporting fair/poor SWB, controlling for baseline SWB of fair/poor and angina reported during the study.

RESULTS

Patients with higher SBP had higher odds of reporting fair/poor SWB. Specifically, compared with patients with SBP of < or = 120, patients with SBP 140-150 > 150 - < or = 160 and > 160 had about 90% and 2.5 times greater odds of feeling fair/poor, respectively (adjusted odds ratio [OR]: 1.5990, 95% confidence interval [CI]: 1.81-2.00 and adjusted OR: 2.53, 95% CI: 2.41-2.66). Those who reported angina in the 4 wks prior to a protocol visit had 2.2 times greater odds of reporting fair/poor SWB (adjusted OR: 2.2, 95% CI: 2.13-2.27). Female gender, black race, history of smoking, diabetes, myocardial infarction, stroke, and cancer also increased the odds of reporting fair/poor SWB.

CONCLUSIONS

Among hypertensive CAD patients, higher on-treatment SBP is associated with greater odds of fair/poor SWB during follow-up.

Asymmetric dimethylarginine, oxidative stress, and vascular nitric oxide synthase in essential hypertension

We reported impaired endothelium-derived relaxation factor/nitric oxide (EDRF/NO) responses and constitutive nitric oxide synthase (cNOS) activity in subcutaneous vessels dissected from patients with essential hypertension (n = 9) compared with normal controls (n = 10). We now test the hypothesis that the patients in this study have increased circulating levels of the cNOS inhibitor, asymmetric dimethylarginine (ADMA), or the lipid peroxidation product of linoleic acid, 13-hydroxyoctadecadienoic acid (HODE), which is a marker of reactive oxygen species. Patients had significantly (P < 0.001) elevated (means +/- SD) plasma levels of ADMA (P(ADMA), 766 +/- 217 vs. 393 +/- 57 nmol/l) and symmetric dimethylarginine (P(SDMA): 644 +/- 140 vs. 399 +/- 70 nmol/l) but similar levels of L-arginine accompanied by significantly (P < 0.015) increased rates of renal ADMA excretion (21 +/- 9 vs. 14 +/- 5 nmol/mumol creatinine) and decreased rates of renal ADMA clearance (18 +/- 3 vs. 28 +/- 5 ml/min). They had significantly increased plasma levels of HODE (P(HODE): 309 +/- 30 vs. 226 +/- 24 nmol/l) and renal HODE excretion (433 +/- 93 vs. 299 +/- 67 nmol/micromol creatinine). For the combined group of normal and hypertensive subjects, the individual values for plasma levels of ADMA and HODE were both significantly (P < 0.001) and inversely correlated with microvascular EDRF/NO and positively correlated with mean blood pressure. In conclusion, elevated levels of ADMA and oxidative stress in a group of hypertensive patients could contribute to the associated microvascular endothelial dysfunction and elevated blood pressure.

Role of asymmetric dimethylarginine for angiotensin II-induced target organ damage in mice

The aim of the present study was to investigate the role of the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) and its degrading enzyme dimethylarginine dimethylaminohydrolase (DDAH) in angiotensin II (ANG II)-induced hypertension and target organ damage in mice. Mice transgenic for the human DDAH1 gene (TG) and wild-type (WT) mice (each, n = 28) were treated with 1.0 microg kg(-1) min(-1) ANG II, 3.0 microg kg(-1) min(-1) ANG II, or phosphate-buffered saline over 4 wk via osmotic minipumps. Blood pressure, as measured by tail cuff, was elevated to the same degree in TG and WT mice. Plasma levels of ADMA were lower in TG than WT mice and were not affected after 4 wk by either dose of ANG II in both TG and WT animals. Oxidative stress within the wall of the aorta, measured by fluorescence microscopy using the dye dihydroethidium, was significantly reduced in TG mice. ANG II-induced glomerulosclerosis was similar between WT and TG mice, whereas renal interstitial fibrosis was significantly reduced in TG compared with WT animals. Renal mRNA expression of protein arginine methyltransferase (PRMT)1 and DDAH2 increased during the infusion of ANG II, whereas PRMT3 and endogenous mouse DDAH1 expression remained unaltered. Chronic infusion of ANG II in mice has no effect on the plasma levels of ADMA after 4 wk. However, an overexpression of DDAH1 alleviates ANG II-induced renal interstitial fibrosis and vascular oxidative stress, suggesting a blood pressure-independent effect of ADMA on ANG II-induced target organ damage.

Dimethylarginine dimethylaminohydrolase (DDAH): expression, regulation, and function in the cardiovascular and renal systems

Asymmetric (N(G),N(G))-dimethylarginine (ADMA) inhibits nitric oxide (NO) synthases (NOS). ADMA is a risk factor for endothelial dysfunction, cardiovascular mortality, and progression of chronic kidney disease. Two isoforms of dimethylarginine dimethylaminohydrolase (DDAH) metabolize ADMA. DDAH-1 is the predominant isoform in the proximal tubules of the kidney and in the liver. These organs extract ADMA from the circulation. DDAH-2 is the predominant isoform in the vasculature, where it is found in endothelial cells adjacent to the cell membrane and in intracellular vesicles and in vascular smooth muscle cells among the myofibrils and the nuclear envelope. In vivo gene silencing of DDAH-1 in the rat and DDAH +/- mice both have increased circulating ADMA, whereas gene silencing of DDAH-2 reduces vascular NO generation and endothelium-derived relaxation factor responses. DDAH-2 also is expressed in the kidney in the macula densa and distal nephron. Angiotensin type 1 receptor activation in kidneys reduces the expression of DDAH-1 but increases the expression of DDAH-2. This rapidly evolving evidence of isoform-specific distribution and regulation of DDAH expression in the kidney and blood vessels provides potential mechanisms for nephron site-specific regulation of NO production. In this review, the recent advances in the regulation and function of DDAH enzymes, their roles in the regulation of NO generation, and their possible contribution to endothelial dysfunction in patients with cardiovascular and kidney diseases are discussed.