Iván Godoy

Enalapril Attenuates Downregulation of Angiotensin-Converting Enzyme 2 in the Late Phase of Ventricular Dysfunction in Myocardial Infarcted Rat

The early and long-term effects of coronary artery ligation on the plasma and left ventricular angiotensin-converting enzyme (ACE and ACE2) activities, ACE and ACE2 mRNA levels, circulating angiotensin (Ang) levels [Ang I, Ang-(1-7), Ang-(1-9), and Ang II], and cardiac function were evaluated 1 and 8 weeks after experimental myocardial infarction in adult Sprague Dawley rats. Sham-operated rats were used as controls. Coronary artery ligation caused myocardial infarction, hypertrophy, and dysfunction 8 weeks after surgery. At week 1, circulating Ang II and Ang-(1-9) levels as well as left ventricular and plasma ACE and ACE2 activities increased in myocardial-infarcted rats as compared with controls. At 8 weeks post-myocardial infarction, circulating ACE activity, ACE mRNA levels, and Ang II levels remained higher, but plasma and left ventricular ACE2 activities and mRNA levels and circulating levels of Ang-(1-9) were lower than in controls. No changes in plasma Ang-(1-7) levels were observed at any time. Enalapril prevented cardiac hypertrophy and dysfunction as well as the changes in left ventricular ACE, left ventricular and plasmatic ACE2, and circulating levels of Ang II and Ang-(1-9) after 8 weeks postinfarction. Thus, the decrease in ACE2 expression and activity and circulating Ang-(1-9) levels in late ventricular dysfunction post-myocardial infarction were prevented with enalapril. These findings suggest that in this second arm of the renin-angiotensin system, ACE2 may act through Ang-(1-9), rather than Ang-(1-7), as a counterregulator of the first arm, where ACE catalyzes the formation of Ang II.

Pleiotropic effects of atorvastatin in heart failure: role in oxidative stress, inflammation, endothelial function, and exercise capacity.

BACKGROUND Increased oxidative stress, a common feature in chronic heart failure, has been associated with inflammation, endothelial dysfunction, and extracellular matrix degradation. Statins have known anti-inflammatory and anti-oxidant effects; however, their role in chronic heart failure is still controversial. METHODS This was a prospective study of 38 patients with stable systolic chronic heart failure. Patients received a 4-week placebo course, followed by atorvastatin 20 mg/day for 8 weeks. Oxidative stress, inflammation and remodeling markers, brachial artery flow-mediated vasodilation, and 6-minute walk test were evaluated at baseline, 4, and 8 weeks. RESULTS Mean age was 58 +/- 12. Mean left ventricular ejection fraction was 27% +/- 12%. No significant differences were observed between measurements at baseline and after placebo. Atorvastatin induced a significant decrease of matrix metalloproteinase-9 activity, high-sensitivity C-reactive protein, tumor necrosis factor-alpha, interleukin-6, and malondialdehyde, and a significant increase of endothelial superoxide dismutase activity when compared with placebo. No differences in tissue inhibitor of matrix metalloproteinase and matrix metalloproteinase-2 activities were observed. Atorvastatin use was associated with an improved flow-dependent brachial vasodilation and exercise capacity in the 6-minute walk test. CONCLUSIONS In chronic heart failure patients, atorvastatin therapy is associated with a decrease of inflammation and extracellular matrix remodeling, improving both endothelial function and exercise capacity.

Assessment of Left Atrial Function in Hypertrophic Cardiomyopathy and Athlete's Heart: A Left Atrial Myocardial Deformation Study

Background: Hypertrophic cardiomyopathy (HCM) is a common cause of sudden death in athletes and differentiating this condition from the nonpathological “athletes heart” remains a challenge. The development of pathological left ventricular hypertrophy (LVH) is associated with left atrial (LA) dilatation and dysfunction. LA strain and strain rate by two‐dimensional (2D) speckle tracking are novel indices of LA function and might contribute to differentiate physiological from pathological LVH among athletes with underdiagnosed HCM. Methods: We evaluated 20 patients with nonobstructive HCM, 20 highly trained athletes and 20 healthy controls matched for age, gender, and body surface area. All patients underwent a transthoracic echocardiogram with evaluation of LA strain: s‐wave (LASs); and strain rate: s‐wave (LASRs) and a‐wave (LASRa). Results: LV mass index, LA volume index, and ejection fraction were comparable between patients with HCM and athletes. Patients with HCM had a significantly lower LASs (19 + 8% vs. 43 + 8%, P < 0.01), LASRs (0.7 + 0.2 s‐1 vs. 1.6 + 0.2 s‐1, P < 0.01), and LASRa (–0.8 + 0.1 s‐1 vs. –1.4 + 0.3 s‐1, P < 0.01) compared to athletes. Among hypertrophic subjects, independent predictors of hypertrophy related to HCM were LASs and E/é ratio. Conclusions: LA myocardial deformation is significantly impaired in patients with HCM compared to athletes and healthy controls. LA strain and strain rate assessed by 2D speckle tracking should be incorporated in the evaluation of trained athletes with LVH and LA dilatation.

Angiotensin-(1-9) reverses experimental hypertension and cardiovascular damage by inhibition of the angiotensin converting enzyme/Ang II axis.

Background: Little is known about the biological effects of angiotensin-(1–9), but available evidence shows that angiotensin-(1–9) has beneficial effects in preventing/ameliorating cardiovascular remodeling. Objective: In this study, we evaluated whether angiotensin-(1–9) decreases hypertension and reverses experimental cardiovascular damage in the rat. Methods and results: Angiotensin-(1–9) (600 ng/kg per min for 2 weeks) reduced already-established hypertension in rats with early high blood pressure induced by angiotensin II infusion or renal artery clipping. Angiotensin-(1–9) also improved cardiac (assessed by echocardiography) and endothelial function in small-diameter mesenteric arteries, cardiac and aortic wall hypertrophy, fibrosis, oxidative stress, collagen and transforming growth factor type &bgr; − 1 protein expression (assessed by western blot). The beneficial effect of angiotensin-(1–9) was blunted by coadministration of the angiotensin type 2(AT2) receptor blocker PD123319 (36 ng/kg per min) but not by coadministration of the Mas receptor blocker A779 (100 ng/kg per min). Angiotensin-(1–9) treatment also decreased circulating levels of Ang II, angiotensin-converting enzyme activity and oxidative stress in aorta and left ventricle. Whereas, Ang-(1–9) increased endothelial nitric oxide synthase mRNA levels in aorta as well as plasma nitrate levels. Conclusion: Angiotensin-(1–9) reduces hypertension, ameliorates structural alterations (hypertrophy and fibrosis), oxidative stress in the heart and aorta and improves cardiac and endothelial function in hypertensive rats. These effects were mediated by the AT2 receptor but not by the angiotensin-(1–7)/Mas receptor axis.

Enalapril restores depressed circulating insulin-like growth factor 1 in patients with chronic heart failure

BACKGROUND Congestive heart failure (CHF) is characterized by increased activity of the renin-angiotensin system. Recent experimental studies have shown that infusion of angiotensin II results in depressed plasma levels of insulin-like growth factor 1 (IGF-1) and weight loss. We have previously reported that stable patients with CHF have decreased activity of the growth hormone (GH)-IGF1 axis. We have hypothesized, therefore, that angiotensin-converting enzyme (ACE) inhibition therapy should restore GH-IGF1 activity in CHF patients. METHODS AND RESULTS Nine patients with stable CHF who were taking digitalis and diuretics, New York Heart Association functional class III were studied before and after 8 weeks of therapy with Enalapril (10 mg twice daily). We measured IGF1 levels, radionuclide left ventricular ejection fraction (EF) and peak oxygen consumption (PVO2). We found that 7 of 9 patients had abnormally low levels of IGF1 (0.2-0.5 mU/ml). IGF1 levels reverted to normal after Enalapril therapy (0.36 +/- 0.03 to 0.8 +/- 0.14 mU/ml, P = .004). This was associated with a significant increase in EF (27.4 +/- 1.1 to 31.4 +/- 0.9%) and PVO2 (14.8 +/- 1.2 to 18.6 +/- 1.5 ml/kg/min) values (P < .05). CONCLUSION Chronic ACE inhibition therapy restored previously reduced IGF1 plasma levels in patients with CHF, most likely by reducing angiotensin II activity.

Serum uric acid correlates with extracellular superoxide dismutase activity in patients with chronic heart failure.

Increased serum uric acid has been identified as an independent risk factor for cardiovascular disease. However, because of its antioxidant capacity, uric acid may play a beneficial role in endothelial function. This paradoxical relationship between uric acid and endothelial function in chronic heart failure patients remains poorly understood. Thirty‐eight chronic heart failure patients (New York Heart Association functional class II–III, mean age 58±10 years and mean left ventricular ejection fraction 25±8%) and twelve age‐and‐sex‐matched healthy controls were studied. Chronic heart failure patients showed higher uric acid levels (7.3±2.3 mg/dL vs. 6.1±0.2 mg/dL, p<0.05) and lower extracellular superoxide dismutase activity (136±36 U ml−1 min−1 vs. 203±61 U ml−1 min−1, p<0.01) and endothelium‐dependent vasodilatation (4.0±1.6% v. 9.1±3.0%, p<0.01) when compared with control subjects. In chronic heart failure patients, correlations between both uric acid levels and extracellular superoxide dismutase activity (r=0.45; p<0.01), and uric acid and endothelium‐dependent vasodilatation (r=0.35; p=0.03) were detected. These correlations were not observed in healthy individuals, suggesting a positive effect of uric acid on endothelial function partially mediated by modulation of extracellular superoxide dismutase activity in chronic heart failure.

Xanthine-oxidase inhibitors and statins in chronic heart failure: effects on vascular and functional parameters.

BACKGROUND Increased oxidative stress in heart failure (HF) leads to inflammation and endothelial dysfunction (ED). Both statins and allopurinol have known anti-oxidant properties, but their utility in HF has not been fully assessed. METHODS This investigation was a prospective, double-blind, double-dummy study, performed between March 2007 and June 2009. Seventy-four HF patients, with New York Heart Association (NYHA) Class II or III status and left ventricular ejection fraction (LVEF) <40%, were included. Patients received placebo during 4 weeks and were then randomized to receive 4 weeks of either atorvastatin 20 mg/day plus placebo (ATV+PLA group) or atorvastatin 20 mg/day orally plus allopurinol 300 mg/day orally (ATV+ALLO group). Malondialdehyde (MDA), extracellular superoxide dismutase (ecSOD) activity and uric acid (UA) levels, among others, were determined at baseline and after 4 weeks of treatment. ED was assessed by flow-dependent endothelial-mediated vasodilation (FDD), and functional capacity by 6-minute walk test (6MWT). RESULTS Thirty-two patients were randomized to ATV+PLA and 38 to ATV+ALLO. Mean age was 59 ± 2 years, 82% were male, and 22% had an ischemic etiology. Hypertension was present in 60% and diabetes in 15% of those studied. No significant differences were observed between baseline measurements and after placebo. After 4 weeks of treatment, both groups showed a significant decrease on MDA (0.9 ± 0.1 to 0.8 ± 0.1 and 1.0 ± 0.5 to 0.9 ± 0.1 μmol/liter, p = 0.88), UA (7.4 ± 0.4 to 6.8 ± 0.3 and 7.2 ± 0.4 to 5.0 ± 0.3 mg/dl, p < 0.01) and FDD (3.9 ± 0.2% to 5.6 ± 0.4% and 4.6 ± 0.3% to 7.1 ± 0.5%, p = 0.07) with increased ecSOD activity (109 ± 11 to 173 ± 13 and 98 ± 10 to 202 ± 16, U/ml/min, p = 0.41) and improved 6MWT (447 ± 18 to 487 ± 19 and 438 ± 17 to 481 ± 21 m, p = 0.83), with all values for ATV+PLA and ATV+ALLO, respectively; p-values are for comparison between groups after treatment. CONCLUSION Short-term ATV treatment in heart failure (HF) patients reduces oxidative stress and improves FDD and functional capacity. These beneficial effects are not strengthened by the addition of allopurinol.

Markedly increased Rho-kinase activity in circulating leukocytes in patients with chronic heart failure

BACKGROUND The small guanosine triphosphatase Rho and its target Rho-kinase have significant roles in experimental remodeling and ventricular dysfunction, but no data are available on Rho-kinase activation in patients with heart failure (HF). We hypothesized that, in patients with chronic HF, Rho-kinase in circulating leukocytes is activated and related to left ventricular (LV) remodeling and dysfunction. METHODS Accordingly, Rho-kinase activity, assessed by the levels of phosphorylated to total myosin light chain phosphatase 1 (MYPT1-P/T) in circulating leukocytes, and echocardiographic LV function data were compared between patients with HF New York Heart Association functional class II or III due to systolic dysfunction (n = 17), healthy controls (n = 17), and hypertensive patients without HF (n = 17). RESULTS In the control subjects, mean MYPT1-P/T ratio was 1.2 ± 0.2 (it was similar in the hypertensive patients without HF), whereas in patients with HF, it was significantly increased by >100-fold (P < .001). Both MYPT1-P/T and log MYPT1-P/T ratios were inversely correlated with ejection fraction (r = -0.54, P < .03 and r = -0.86, P < .001, respectively). Furthermore, in patients with HF with LV end-diastolic diameter <60 mm, MYPT1-P/T ratio was 35.8 ± 18.1, whereas it was significantly higher in patients with LV diameter ≥60 mm (P < .05). CONCLUSIONS Rho-Kinase activity is markedly increased in patients with stable chronic HF under optimal medical treatment, and it is associated with pathologic LV remodeling and systolic dysfunction. Mechanisms of Rho-kinase activation in patients with HF, its role in the progression of the disease, and the direct effect of Rho-kinase inhibition need further investigation.

Levels of plasma angiotensin-(1-7) in patients with hypertension who have the angiotensin–I-converting enzyme deletion/deletion genotype

In patients with hypertension who have the DD-ACE genotype (higher angiotensin-converting enzyme [ACE] activity), plasma levels of angiotensin-(1-7) are 4 times lower than in patients with the II-ACE genotype (lower ACE levels). Angiotensin II levels are similar in both groups.

Blood Pressure After Recent Stroke: Baseline Findings From the Secondary Prevention of Small Subcortical Strokes Trial

BACKGROUND Hypertension is the most powerful risk factor for stroke. The aim of this study was to characterize baseline blood pressure in participants in the Secondary Prevention of Small Subcortical Strokes trial. METHODS For this cross-sectional analysis, participants were categorized by baseline systolic blood pressure (SBP) < 120, 120-139, 140-159, 160-179, and ≥ 180 mm Hg and compared on demographic and clinical characteristics. Predictors of SBP < 140 mm Hg were examined. RESULTS Mean SBP was 143±19 mm Hg while receiving an average of 1.7 antihypertensive medications; SBP ≥ 140 mm Hg for 53% and ≥ 160 mm Hg for 18% of the 3,020 participants. Higher SBP was associated with a history of hypertension and hypertension for longer duration (both P < 0.0001). Higher SBPs were associated with more extensive white matter disease on magnetic resonance imaging (P < 0.0001). There were significant differences in entry-level SBP when participants were categorized by race and region (both P < 0.0001). Black participants were more likely to have SBP ≥ 140 mm Hg. Multivariable logistic regression showed an independent effect for region with those from Canada more likely (odds ratio = 1.7; 95% confidence interval, 1.29, 2.32) to have SBP < 140 mm Hg compared with participants from United States. CONCLUSIONS In this cohort with symptomatic lacunar stroke, more than half had uncontrolled hypertension at approximately 2.5 months after stroke. Regional, racial, and clinical differences should be considered to improve control and prevent recurrent stroke.