18F-FDG PET/CT brain glucose metabolism as a marker of different types of depression comorbidity in chronic systolic heart failure patients

Background/Introduction

Depression comorbidity is an important issue in heart failure (HF) disease. Results from the recent prospective randomized trial MOOD-HF did not provide a rationale for the indiscriminate use of antidepressants in depressed HF patients.

Purpose

The study investigated whole-brain and regional-brain glucose metabolism in HF patients with 18F-FDG PET/CT and its association with depression comorbidity.

Methods

Twenty-nine hospitalized patients with symptomatic systolic HF disease (LVEF<40%), NYHA class II-IV and mean age of 55.5±12.0 years participated in the study. All patients had echocardiography, blood sampling, HF-adapted and psychometric questionnaires before discharge and a brain 18F-FDG PET/CT scan after discharge. Semi-automated PET/CT image analysis was performed on all patients and 30 matched controls. The metabolic index SUVmean was calculated for the whole-brain and three brain regions (prefrontal cortex, amygdala and hippocampus), implicated in depression pathogenesis. A standardized SUVmean was also estimated by dividing depression-related regional-brain SUVmean with the whole-brain SUVmean.

Results

HF patients had lower average whole-brain SUVmean (3.90±1.49 vs 5.10±1.35, p=0.001), average regional-brain SUVmean (4.57±2.31 vs 9.96±3.58, p<0.001) and average standardized SUVmean (1.28±0.60 vs 2.07±1.32, p<0.001) compared to controls.

Whole-brain SUVmean had a statistically significant correlation to patient age (r=−0.39, p=0.031), NYHA class (p=0.027), LVEF in the major group of 21 NYHA III-IV patients (p=0.018), diabetes comorbidity (p=0.001), creatinine levels (r=−0.49, p=0.005) and depression (r=−0.36, p=0.049). Regional-brain SUVmean was correlated to whole-brain SUVmean (r=0.53, p=0.002) and depression (r=0.46, p=0.011). The standardized SUVmean, in particular, was found to be a robust index that could differentiate HF patients with “epiphenomenal” (>0.93) or “real” (≤0.93) depression.

Conclusion

HF patients with more severe disease showed whole-brain and regional-brain hypometabolism in 18F-FDG PET/CT scan, which is consistent with impaired cerebral perfusion.

Depressed HF patients (Beck Depression Inventory score >13) exhibited different metabolic patterns that could be used to differentiate between “epiphenomenal” and “real” depression. Namely, presence of whole-brain hypometabolism suggested “epiphenomenal” depression. Absence of whole-brain hypometabolism suggested “real” depression. When the pattern of whole-brain hypometabolism included significant relative, depression-related regional hypometabolism (standardized SUVmean ≤0.93), “real” depression was the most likely diagnosis. The distinction is important, as different types of comorbid depression suggest different treatment approach.

Summarizing figure

Funding Acknowledgement

Type of funding source: None

Relationship between iNOS expression and aortic cell proliferation and apoptosis in an elastase-induced model of aorta aneurysm and the effect of 1400 W administration

BACKGROUND

In the present study, we employed an elastase infusion-dependent abdominal aortic aneurysm (AAA) model to examine inducible nitric oxide synthase (iNOS) expression in relation to cellular proliferation and apoptosis in this pathologic condition. Furthermore, we employed N-(3-(aminomethyl)benzyl)acetamidine (1400 W), a previously shown selective iNOS inhibitor, to further explore this relationship.

METHODS

Adult male Wistar rats were randomized into separate groups. Group A served as a control and received an intra-aortic saline infusion, while groups B, C, and D received an intra-aortic elastase infusion according to standard protocols. The animals in group C were administered postoperatively the highly selective iNOS inhibitor, 1400 W, while rats in group D received regularly the same compound preoperatively and postoperatively. The animals were killed at postoperative days 7 and 14. Aorta diameter and nitric oxide (NO), nitrite/nitrate, and MDA levels were measured. iNOS expression was assessed by immunohistochemistry and Western blot analysis, while Ki-67 immunohistochemistry and TUNEL assay were used to evaluate cellular proliferation and apoptosis, respectively.

RESULTS

Increased iNOS and NO levels accompanied aneurysm development in groups B, C, and D, but these levels were significantly lower in groups C and D, compared with group B. Interestingly, very low but detectable levels of iNOS were found in the control group, indicating a basal constitutive level. Cell growth parameters were augmented in group B compared with group A. In contrast, groups C and D exhibited a significant decrease of the cellular growth parameters but did not attain normal values.

CONCLUSIONS

iNOS-derived NO is associated with the cellular growth parameters of the vessel cells, predominantly smooth muscle cells. Selective iNOS blockage ameliorates the cellular remodeling in AAAs.

Increased risk for coronary heart disease in blue-collar workers at a military industrial plant in Greece?

OBJECTIVE

To test the hypothesis that blue-collar workers have a higher prevalence of risk factors for Coronary Heart Disease than white-collar workers.

METHODS

A cross-sectional study of 262 employees (208 males, 54 females, mean age: 50,65 years) was made of a Greek military industrial plant. Blood samples were taken and analyzed for lipids, lipoprotein levels and glucose levels; arterial blood pressure and body mass index (BMI) were also recorded. Smoking habits were ascertained by the use of a self-administered questionnaire.

RESULTS

White-collar workers had significantly higher mean levels of total and LDL cholesterol than blue-collar workers. No significant differences were found regarding arterial blood pressure, BMI, glucose, triglycerides and HDL cholesterol levels. Both groups reported similarly high rates of smoking. Multivariate analysis confirmed an independent association of abnormal levels of total and LDL cholesterol with white-collar occupation.

CONCLUSION

These findings partly contradict the current pattern of CHD risk factors in Western workforces. Possible interpretations, as well as the limitations of the study, are discussed.

Conformational and biological studies for a pair of novel synthetic AT1 antagonists: stereoelectronic requirements for antihypertensive efficacy

One of the major systems which interferes with the disease of hypertension, is the Renin Angiotensin Aldosterone System (RAS). The octapeptide hormone angiotensin II is the active product of RAS which causes vasoconstriction when binds to the AT(1) receptor. In the last years, there has been a development of drugs which block the Angiotensin II from binding the AT(1) receptor and are called AT(1) antagonists. In an effort to comprehend their stereoelectronic features, a study has been initiated to compare the conformational properties of drugs already marketed for the treatment of hypertension and others which are designed and synthesized in our laboratory possessing structural characteristics necessary for antihypertensive activity. In this study, two synthetic non-peptide AT(1) antagonists, are structurally elucidated and their conformational properties and bioactivity are compared to the prototype and first approved drug of this category in the market; losartan (trade name: COZAAR).

Impaired baroreflex sensitivity and sympathovagal balance in syndrome X

Alterations of autonomic nervous control of cardiac function have been described in syndrome X. The characteristics, however, of the autonomic control of the cardiovascular system in patients with syndrome X have not been adequately studied; thus, the aim of the present study was to investigate the role of baroreceptor sensitivity and sympathovagal balance in syndrome X. The study group included 12 patients with syndrome X, 12 age- and sex-matched control patients with coronary artery disease, and 12 age- and sex-matched controls with no evidence of heart disease. Baroreceptor sensitivity was evaluated by calculating the regression line relating phenylephrine-induced increases in systolic blood pressure to the attendant changes in the RR interval. Sympathovagal balance was assessed by using heart rate variability in the time and frequency domain and measuring plasma norepinephrine at rest and during incremental bicycle exercise. Baroreceptor sensitivity was significantly reduced in syndrome X compared with that in control normal subjects (7.4 +/- 1.2 vs 16.8 +/- 2.3 ms/mm Hg; p < 0.02). This was associated with a significantly lower percentage of adjacent normal RR intervals that differ by >50 ms, lower root-mean-square of the difference of adjacent RR intervals, and lower logarithmic value of the high-frequency component in patients with syndrome X compared with normal subjects. A nonsignificant trend toward lower baroreceptor sensitivity was found in patients with syndrome X compared with control ischemic patients (7.4 +/- 2 vs 12.2 +/- 1.3 ms/mm Hg). A nonsignificant trend toward a higher value of the low- to high-frequency ratio was also observed in patients with syndrome X than in both control groups. No difference was detected in norepinephrine levels either at rest or during exercise or in the exercise-induced norepinephrine increase between the 3 groups. No difference was also observed between ischemic patients and normal subjects in either baroreceptor sensitivity or heart rate variability measurements. A significant correlation (r = 0.80, p < 0.01) was found between baroreceptor sensitivity and the high-frequency component in normal controls but not for other measurements of autonomic function in the 3 groups. In conclusion, patients with syndrome X have an altered autonomic control of the cardiovascular system characterized by impaired baroreceptor sensitivity and reduced heart rate variability. Abnormal autonomic regulation of the cardiovascular system may be of pathophysiologic importance in syndrome X.

Ablation therapy of type I atrial flutter may eradicate paroxysmal atrial fibrillation

In patients with paroxysms of atrial fibrillation preceded by episodes of atrial flutter on Holter monitoring, eradication of the flutter circuit may also abolish the episodes of atrial fibrillation. At electrophysiology study, these patients are identified by documentation of simultaneous flutter of the right atrium and fibrillation of the left atrium.

A case of Adamantiadis-Behçet's syndrome presenting as myocardial infarction

We report a case of a 27-year-old man who presented with an acute myocardial infarction. When he was hospitalized one month later to evaluate this recent event, he developed clinical findings consistent with the diagnosis of Adamantiadis-Behçet's syndrome. We believe that the myocardial infarction was due to coronary arteritis, because there were no risk factors for coronary disease present.

Intravenous atenolol in elderly patients in the early phase of acute myocardial infarction

The aim of this study was to assess the hemodynamic response to intravenous atenolol in elderly patients with acute myocardial infarction. We studied 14 elderly men, aged 64-85 years, and 14 younger men, aged 29-48 years, in the early postfibrinolytic phase of acute myocardial infarction. All the patients were in Killip class I. A triple-lumen Swan-Ganz thermodilution catheter was introduced into the right heart chambers. The patients received 5 mg intravenous atenolol over 5 minutes. All hemodynamic parameters were measured before and 10 minutes after atenolol. The hemodynamic characteristics and the location and extent of acute myocardial infarction were the same in both groups before atenolol. The hemodynamic changes after atenolol administration were the same in the two groups, but the stroke volume and cardiac indexes decreased to a greater extent in the elderly (p = .01 and p = .0001, respectively). These results indicate that intravenous atenolol in the early postfibrinolytic phase of acute myocardial infarction is safe in Killip class I elderly patients, although the cardiac and stroke volume indexes decrease, and the increase in the total systemic resistance is more in older than in younger patients.

Painless myocardial ischemia in chronic hemodialysed patients: a real event?

We investigated the incidence of painless (silent) myocardial ischemia, manifested as S-T segment deviation, by Holter ECG monitoring in patients with chronic renal failure undergoing regular hemodialysis. Forty-five patients underwent Holter ECG monitoring for a continuous 48-hour period covering dialysis and the intermediate period of everyday activity at home. ECG criteria for ischemia were found in 15.5% of patients mainly during and immediately after dialysis with a simultaneous increase of R,S,R + S amplitude. There was no correlation of S-T segment deviation with the existence of cardiac dysfunction and coronary artery disease proved by hemodynamic and angiographic studies. It is concluded that hemodialysis itself seems to play an important role in the genesis of the above ECG findings, possibly by means of serum K and Mg changes.

c-AMP and ANP levels in VVI and DDD pacing with different AV delays during daily activity and exercise

Nine patients (three males) mean age 68 +/- 8 years, having complete heart block, and paced in the DDD mode were examined in VVI and DDD pacing with 100 and 150 ms atrioventricular delays (AVD) during rest and exercise. Plasma atrial natriuretic peptide (ANP) and cyclic AMP (c-AMP) were measured at rest and at peak exercise test. ANP plasma levels at rest were significantly higher in VVI pacing compared to 150 AVD (P less than 0.03). On exercise, ANP release was statistically increased only in DDD with 150 ms AVD, while in VVI it remained in high levels at exercise but no significant change was found (p:ns). c-AMP during rest was unchanged in any pacing mode or AVD, but on exercise DDD pacing with short AVD (100 ms) released lower c-AMP plasma levels, than at rest (p:ns). DDD pacing with long AVD (150 ms) during exercise produced statistically higher c-AMP plasma levels (P less than 0.05) than at rest. Also in VVI pacing the c-AMP plasma levels were statistically higher than at rest (P less than 0.02). Adrenergic activity seems to be lower during exercise in DDD pacing with shorter AVD (100 ms) than in DDD with 150 ms AVD or VVI pacing. No difference was found in c-AMP plasma levels at rest. ANP release was also found to be lower at exercise in DDD pacing with short AVD (100 ms) than in DDD with 150 ms AVD. ANP plasma levels at rest were statistically higher in VVI pacing.

On the explanation of the M-mode echocardiographic image of an atrial myxoma

Two experimental models were used to simulate the motion of a valve leaflet and atrial myxoma in order to investigate the echocardiographic images produced. Both support the view that an endogenous contrast effect, i.e. surfaces of different acoustic densities that are produced as a result of turbulence in a fluid medium and give rise to echo images, contributes to the echocardiographic M-mode appearance of the atrial mass.

Cardiac arrhythmias in chronic renal failure? Holter monitoring during dialysis and everyday activity at home

25 patients undergoing regular haemodialysis for chronic renal failure underwent Holter ECG monitoring for a continuous 48-hour period covering dialysis and the intermediate period of everyday activity at home. A low dialysate potassium concentration (1.7 mEq/l) was used. Clinically significant arrhythmias (greater than 100 ventricular extrasystoles/24 h) were found in only 1 patient and there were no complex ventricular arrhythmias. Benign atrial arrhythmias occurred in 22 patients (88%). Haemodialysis had no influence on type or frequency of arrhythmias.