Sinus node function after cardiac surgery: is impairment specific for the maze procedure?

BACKGROUND: Maze surgery is a final solution for intractable atrial fibrillation (AF), but an adverse effect on postoperative sinus node function has been reported. Whether this also applies to other types of cardiac surgery is unclear. METHODS: We assessed postoperative rhythm by means of repeated exercise tolerance testing, ambulatory electrocardiography, and non-invasive testing of autonomic function between 1 and 12 months after four types of cardiac surgery. Fourteen patients without structural cardiac disease and medically refractory AF underwent the maze III procedure, 11 patients with mitral valve disease and preoperative AF underwent valvar surgery combined with a (simplified) maze III procedure, and 8 patients with mitral valve disease in sinus rhythm (SR) underwent isolated valvar surgery. The control group consisted of eight patients with sinus rhythm who underwent coronary artery bypass surgery (CABG). RESULTS: One month after surgery, the chronotropic response to exercise was depressed, mean heart rate was high, and heart rate variability (HRV) was low, especially after maze III, combined surgery, and isolated valvar surgery. Twelve months after surgery, moderate improvements were observed. After CABG, considerably fewer abnormalities were observed, and HRV parameters recovered to a large extent. Non-invasive testing of autonomic function indicated disturbed vagal modulation of heart rate in all three groups with atrial incision. CONCLUSION: Thus, attenuation of HRV and vagal modulation of sinus node function are not confined to maze surgery but also apply to isolated mitral valve surgery. Atrial incision therefore appears to be crucial and presumably produces autonomic nervous damage followed by partial reinnervation. Nevertheless, cardiac surgery in general seems initially to impair sinus node function with partial recovery in the consecutive 12 months.     

Survival of HIV-1 and HIV-2 perinatally infected children in The Gambia

BACKGROUND: The risk of mother-to-child transmission (MTCT) of HIV-2 is much lower than that of HIV-1, but the long-term prognosis of perinatally infected HIV-2 children is unknown. We re-visited children who were part of a large MTCT study in The Gambia (conducted during 1993-1997), in order to compare the long-term survival of children perinatally infected with HIV-2 with that of seronegative and of HIV-1 infected children. METHODS: Five to eight years' follow-up of a cohort of children born to HIV-negative, HIV-1 positive, and HIV-2 positive mothers. RESULTS: Seven hundred and seventy-four children were followed up for a median of 6.6 years. Of 17 perinatally HIV-1 infected children, three were still alive on 1 July 2001, two had been lost to follow-up, and 12 had died. The median survival was 2.5 years. Of eight HIV-2 infected children five were still alive, none were lost to follow-up and three had died. The mortality hazards ratio of both HIV-1 [9.9; 95% confidence interval (CI), 5.2-19], and of HIV-2 infected children (3.9; CI, 1.2-12) was significantly increased compared with children of seronegative mothers. The mortality hazards ratio of HIV uninfected children of HIV-1 or HIV-2 infected mothers was not significantly increased compared to that of children of seronegative mothers (P = 0.17 and P = 0.5 respectively). CONCLUSIONS: Children with perinatally acquired HIV-2 infection have a higher mortality than children of seronegative mothers. Guidelines for treatment of HIV-1 infected children should be used for treatment of HIV-2 infected children.     

Effect of revascularization on mortality associated with an elevated white blood cell count in acute coronary syndromes

Inflammation is increasingly recognized as having an important role in patients with acute coronary syndromes. We sought to determine whether an elevated white blood cell (WBC) count would predict subsequent mortality and whether revascularization would have a protective effect. We analyzed data from 10,480 patients with acute coronary syndromes enrolled in the PURSUIT trial who had a WBC count measured on admission. WBC count values were stratified by quartiles, and death rates at 6 months were examined in univariate and multivariate analyses. Propensity analysis was performed to assess the effect of revascularization on the relation between WBC count and mortality. In the lowest quartile of WBC count, mortality was 4.0%; it was 5.8% in the second quartile, 6.7% in the third quartile, and 8.0% in the fourth quartile (p <0.001). In a multivariable model incorporating baseline demographic and clinical variables, an increasing WBC count was a significant predictor of death, with a hazard ratio of 1.07 per 1,000/microl increment in WBC count (p <0.001). Furthermore, the interaction term between mortality due to an elevated WBC count and benefit of in-hospital revascularization was significant (hazard ratio 0.94, p = 0.032), suggesting that the excess risk due to an elevated WBC count was attenuated by revascularization. An elevated WBC count at hospital admission, although only a crude index of inflammation, nevertheless is an independent predictor of death at 6 months in patients with acute coronary syndromes. This finding supports a pivotal role for inflammation in acute coronary syndromes. Importantly, this study suggests that in-hospital revascularization may mitigate some of the excess risk due to inflammation.     

The Prognostic Value of Right Ventricular Deformation Imaging in Early Arrhythmogenic Right Ventricular Cardiomyopathy

Objectives

The aim of this study was to investigate the prognostic value of echocardiographic deformation imaging in arrhythmogenic right ventricular cardiomyopathy (ARVC) to optimize family screening protocols.

Interorgan synthesis of arginine is down-regulated in tumor-bearing mice undergoing surgical trauma

Renal de novo arginine production has been suggested to be crucial for regulation of arginine production in disease. We investigated how the interorgan pathway for de novo arginine production is affected by the presence of malignant tumor and/or surgical trauma. Controls and methylcholanthrene-sarcoma-bearing mice were studied, both with and without undergoing laparotomy (n = 9-13 per group). One day after laparotomy, amino acid fluxes across the hindquarter, intestine, liver, and kidney were studied. In contrast to healthy mice, the liver of tumor-bearing mice took up citrulline (9 +/- 3 vs 1 +/- 2 nmol/[10 g min], P < .05), simultaneous with attenuated renal arginine output (4 +/- 3 vs 12 +/- 2 nmol/[10 g min], P < .05), despite increased intestinal conversion of glutamine to citrulline (15 +/- 3 vs 8 +/- 1 nmol/[10 g min], P < .05). In tumor-bearing mice undergoing surgery, intestinal citrulline output decreased (from 15 +/- 3 to 8 +/- 2 nmol/[10 g min], P < .05) and renal arginine output remained close to zero despite increased renal citrulline uptake (from 6 +/- 2 to 12 +/- 2 nmol/[10 g min], P < .05). In conclusion, the interorgan pathway for de novo arginine production was differently regulated depending on the pathophysiological situation. In methylcholanthrene-sarcoma-bearing mice, decreased de novo arginine production was accompanied by the presence of hepatic citrulline uptake, whereas tumor-bearing mice subjected to surgical trauma showed concomitant decreased intestinal citrulline output.     

Prognostic significance of left anterior hemiblock in patients with suspected coronary artery disease

OBJECTIVES: This study was designed to assess the functional and prognostic significance of left anterior hemiblock (LAHB) in patients with no history of myocardial infarction referred for dobutamine stress echocardiography (DSE). BACKGROUND: The significance of isolated LAHB in patients with suspected coronary artery disease (CAD) is unclear. METHODS: We studied 1,187 patients with suspected CAD and no history of myocardial infarction who underwent DSE and were followed for occurrence of cardiac death. RESULTS: Left anterior hemiblock was detected on baseline electrocardiogram in 159 patients (13%). Ischemia occurred more frequently in patients with LAHB (43% vs. 33%, p = 0.02). During a mean follow-up of 5.0 +/- 2.5 years, 125 patients (11%) died of cardiac causes. The annual cardiac death rate was 4.9% in patients with LAHB and 1.9% for patients without (p < 0.0001). Patients with both LAHB and an abnormal DSE had the highest annual cardiac death rate (6.3%). In a Cox multivariable analysis, independent predictors of cardiac death were age, smoking, history of heart failure, diabetes, and ischemia. Left anterior hemiblock was independently associated with increased risk of cardiac death among patients with normal DSE (hazard ratio 1.8, 95% confidence interval 1.1 to 3.8) and in patients with abnormal DSE (hazard ratio 1.7, 95% confidence interval 1.1 to 2.7). CONCLUSIONS: In patients with suspected CAD referred for stress testing, LAHB is associated with increased risk of cardiac death. This risk is persistent after adjustment for major clinical data and abnormalities on the stress echocardiogram. Therefore, isolated LAHB should not be considered a benign electrocardiographic abnormality in these patients.     

C‐reactive protein during and after myocardial infarction in relation to cardiac injury and left ventricular function at follow‐up

Background

Acute myocardial infarction (MI) invokes a large inflammatory response, which contributes to myocardial repair.

Hypothesis

We investigated whether C‐reactive protein (CRP) measured during MI vs at 1 month follow‐up improves the prediction of left ventricular (LV) function.

Methods

We prospectively enrolled 131 consecutive patients with acute MI and without non‐cardiovascular causes of inflammation. We correlated admission and peak levels of CRP during hospitalization and high‐sensitivity (hs) CRP at 1 month follow‐up with markers of cardiac injury. Clinical follow‐up and echocardiography for LV function were performed at a mean of 17 months.

Results

Median CRP levels were 1.89 mg/L on admission with MI, peaked to 12.10 mg/L during hospitalization and dropped to 1.24 mg/L at 1 month. Although admission CRP levels only weakly correlated with ejection fraction in the acute phase of MI (coefficient ?0.164, P = 0.094), peak CRP was significantly related to ejection fraction (coefficient ?0.4, P < 0.001), hsTroponin T (0.389, P < 0.001), and white blood cell count (0.389, P < 0.001). hsCRP at 1 month was not related to the extent of acute cardiac injury. These findings were replicated in an independent cohort of 57 patients. Peak CRP predicted LV dysfunction at follow‐up (OR 11.0, 3.1‐39.5 per log CRP, P < 0.001), persisting after adjustment for infarct size (OR 5.1, 1.1‐23.6, P = 0.037), while hsCRP at 1 month was unrelated to LV function at follow‐up.

Conclusions

hsCRP 1 month post‐MI does not relate to acute cardiac injury or LV function at follow‐up, but we confirm that peak CRP is an independent predictor of LV dysfunction at follow‐up.

     

The multi-ligand somatostatin analogue SOM230 inhibits ACTH secretion by cultured human corticotroph adenomas via somatostatin receptor type 5

OBJECTIVE: Currently, there is no effective medical treatment for patients with pituitary-dependent Cushing's disease. A novel somatostatin (SS) analogue, named SOM230, with high binding affinity to SS receptor subtypes sst(1), sst(2), sst(3) and sst(5) was recently introduced. We compared the in vitro effects of the sst(2)-preferring SS analogue octreotide (OCT) and the multi-ligand SOM230 on ACTH release by human and mouse corticotroph tumour cells. METHODS: By quantitative RT-PCR the sst subtype expression level was determined in human corticotroph adenomas. In vitro, the inhibitory effect of OCT and SOM230 on ACTH release by dispersed human corticotroph adenoma cells and mouse AtT20 corticotroph adenoma cells was determined. In addition, the influence of dexamethasone on the responsiveness to OCT and SOM230 was studied. RESULTS: Corticotroph adenomas expressed predominantly sst(5) mRNA (six out of six adenomas), whereas sst(2) mRNA expression was detected at significantly lower levels. In a 72 h incubation with 10 nmol/l SOM230, ACTH release was inhibited in three out of five cultures (range -30 to -40%). Ten nmol/l OCT slightly inhibited ACTH release in only one of five cultures (- 28%). In AtT20 cells, expressing sst(2), sst(3) and sst(5), SOM230 inhibited ACTH secretion with high potency (IC(50) 0.2 nmol/l). Dexamethasone (10 nmol/l) pre-treatment did not influence the sensitivity of the cells to the inhibitory effect of SOM230, suggesting that sst(5) is relatively resistant to negative control by glucocorticoids. CONCLUSIONS: The selective expression of sst(5) receptors in corticotroph adenomas and the preferential inhibition of ACTH release by human corticotroph adenoma cells by SOM230 in vitro, suggest that SOM230 may have potential in the treatment of patients with pituitary-dependent Cushing's disease.     

The Cardiology Audit and Registration Data Standards (CARDS), European data standards for clinical cardiology practice.

AIMS: Systematic registration of data from clinical practice is important for clinical care, local, national and international registries, and audit. Data to be collected for these different purposes should be harmonized. Therefore, during Ireland's Presidency of the European Union (EU) (January to June 2004), the Department of Health and Children worked with the European Society of Cardiology, the Irish Cardiac Society, and the European Commission to develop data standards for clinical cardiology. The Cardiology Audit and Registration Data Standards (CARDS) Project aimed to agree standards for three modules of cardiovascular health information systems: acute coronary syndromes (ACS), percutaneous coronary interventions (PCI), and clinical electrophysiology (pacemakers, implantable cardioverter defibrillators, and ablation procedures). METHODS AND RESULTS: Data items from existing registries and surveys were reviewed to derive draft data standards (variables, coding, and definitions). Variables common to the three modules include demographics, risk factors, medication, and discharge and follow-up data. Modules about a procedure contain variables on the lesion, the device, and medication during the procedure. The ACS module includes presenting symptoms, reperfusion and acute treatments, and procedures in hospital and at follow-up. CONCLUSIONS: The data standards were discussed and adopted at a conference involving EU member states in Cork, Ireland, in May 2004. After a pilot study, the standards will be disseminated to stakeholders throughout Europe.