Usefulness of T-wave loop and QRS complex loop to predict mortality after acute myocardial infarction

The aim of the study was to assess whether parameters based on the T-wave loop and QRS loop predict mortality, and cardiac mortality in particular, during follow-up of consecutive survivors of acute myocardial infarction (AMI). Patients with AMI (n = 437), treated according to contemporary guidelines, underwent digital high-resolution electrocardiography in orthogonal Frank leads (X, Y, Z) 5 to 14 days after AMI. Several T-wave and QRS loop parameters, such as the width and height of the loops and their ratio, T-wave loop dispersion (TWLD), QRS loop dispersion, and co-sine of the angle between the main vectors of the T-wave and QRS loops (TCRT), were calculated using a custom-made software package. During an average follow-up period of 43 +/- 14 months, 53 patients (12%) died. Of these 53 deaths, 35 were cardiac. TWLD and TCRT were the T-wave loop/QRS loop parameters that best predicted for cardiac mortality on univariate comparison (35.4 +/- 5.62 vs 32.8 +/- 2.87 for TWLD, p < 0.001 and -0.135 +/- 0.665 vs -0.657 +/- 0.518 for TCRT, p < 0.001, alive vs cardiac death, respectively). After adjustment for clinical risk markers in the Cox regression analysis, TWLD still significantly predicted for cardiac mortality (p < 0.05); however, TCRT had lost its predictive power. TWLD did not have significant univariate or multivariate association with noncardiac mortality. In conclusion, TWLD that describes the shape of the T-wave loop is a specific predictor of cardiac death and independent of the clinical risk markers in the current treatment era of patients with AMI.     

Amyloid and metabolic positron emission tomography imaging of cognitively normal adults with Alzheimer's parents

This study examines the relationship between fibrillar beta-amyloid (Aβ) deposition and reduced glucose metabolism, a proxy for neuronal dysfunction, in cognitively normal (NL) individuals with a parent affected by late-onset Alzheimer's disease (AD). Forty-seven 40–80-year-old NL received positron emission tomography (PET) with ¹¹C-Pittsburgh compound B (PiB) and 18F-fluoro-2-deoxy-d-glucose (FDG). These included 19 NL with a maternal history (MH), 12 NL with a paternal history (PH), and 16 NL with negative family history of AD (NH). Automated regions of interest, statistical parametric mapping, voxel-wise intermodality correlations, and logistic regressions were used to examine cerebral-to-cerebellar PiB and FDG standardized uptake value ratios across groups. The MH group showed higher PiB retention and lower metabolism in AD regions compared with NH and PH, which were negatively correlated in posterior cingulate, frontal, and parieto-temporal regions (Pearson r ≤ −0.57, p ≤ 0.05). No correlations were observed in NH and PH. The combination of Aβ deposition and metabolism yielded accuracy ≥ 69% for MH vs. NH and ≥ 71% for MH vs. PH, with relative risk = 1.9–5.1 (p values < 0.005). NL individuals with AD-affected mothers show co-occurring Aβ increases and hypometabolism in AD-vulnerable regions, suggesting an increased risk for AD.     

Preoperative alterations in correlation properties and complexity of R-R interval dynamics predict the risk of atrial fibrillation after coronary artery bypass grafting in patients with preserved left ventricular function

Introduction: We evaluated whether there are constant preoperative alterations in nonlinear R–R interval dynamics that associate with the risk of postoperative atrial fibrillation in patients with preserved left ventricular function. Methods: We analyzed mean normal‐to‐normal R–R intervals, short‐term scaling exponent of detrended fluctuation analysis (DFA α₁), approximate entropy and entropy of symbolic dynamics (SymDyn En) from 10‐minute ECG recordings during rest, paced breathing, and passive tilt performed 1 day before surgery in 67 elective coronary artery bypass grafting patients. Results: Nineteen patients developed postoperative atrial fibrillation. The preoperative DFA α₁ was constantly lower in patients developing postoperative atrial fibrillation than in patients remaining in sinus rhythm (P = 0.016); during spontaneous breathing, the DFA α₁ was 0.93 ± 0.33 in patients with atrial fibrillation and 1.13 ± 0.24 in patients with sinus rhythm. The entropy of symbolic dynamics was higher during the spontaneous breathing in patients with atrial fibrillation than in patients with sinus rhythm (4.72 ± 0.51 vs 4.36 ± 0.51, P = 0.012). Higher short‐term scaling exponent of detrended fluctuation analysis during the spontaneous breathing period reduced the risk of postoperative atrial fibrillation (OR 0.31 for an interquartile increase in DFA α₁, 95% CI 0.13–0.78), while higher entropy of symbolic dynamics increased it (OR 3.16 for an interquartile increase in SymDyn En, 95% CI 1.23–8.10), independently of age and clinical risk factors. Conclusion: The preoperatively altered nonlinear R–R interval dynamics were independent predictors of postoperative atrial fibrillation and might become a useful tool for the risk assessment of atrial fibrillation.     

Lack of CD44 variant 6 expression in rectal cancer invasive front associates with early recurrence

AIM: To investigate the prognostic value of CD44 variant 6 (CD44v6), a membranous adhesion molecule, in rectal cancer.METHODS: Altogether, 210 rectal cancer samples from 214 patients treated with short-course radiotherapy (RT, n = 90), long-course (chemo) RT (n = 53) or surgery alone (n = 71) were studied with immunohistochemistry for CD44v6. The extent and intensity of membranous and cytoplasmic CD44v6 staining, and the intratumoral membranous staining pattern, were analyzed.RESULTS: Membranous CD44v6 expression was seen in 84% and cytoplasmic expression in 81% of the cases. In 59% of the tumors with membranous CD44v6 expression, the staining pattern in the invasive front was determined as “front-positive” and in 41% as “front-negative”. The latter pattern was associated with narrower circumferential margin (P = 0.01), infiltrative growth pattern (P < 0.001), and shorter disease-free survival in univariate survival analysis (P = 0.022) when compared to the “front-positive” tumors.CONCLUSION: The lack of membranous CD44v6 in the rectal cancer invasive front could be used as a method to identify patients at increased risk for recurrent disease.     

Relationship of Modic type 1 change with disc degeneration: a prospective MRI study

Objective  The objective was to study the natural course of Modic type 1 change (M1) in relation to lumbar disc degeneration. Materials and methods  Twenty-four chronic low back pain (LBP) patients with M1 on lumbar spine were selected from 1,015 patients with magnetic resonance imaging from a follow-up study lasting for 18–74 months. Exclusion criteria were any other specific back disorder, age ≥60 years, or a recent spine operation. The association between the development of M1 and degenerative disc changes was studied using multivariate modeling (complex samples logistic regression). Results  At baseline, 20 of 28 (71%) disc spaces with M1 had a decreased disc height (DH) and 16 of 28 (57%) a dark nucleus pulposus, but ten of 28 (36%) a very dark annulus fibrosus and a paradoxically bright nucleus pulposus albeit decreased DH. During follow-up, DH decreased in 13 of 28 (46%) and signal intensity of nucleus pulposus (DSI) in eight of 28 (29%) disc spaces with M1, but it increased in four (14%) discs. In those without M1, only few changes occurred. The larger the M1, the more likely was the DH low or decreased further. Both the presence and changes in M1 were associated with a decrease in DH and changes in DSI and bulges. Conclusion  The degenerative process in discs with adjacent M1 seems to be accelerated and leads to advanced and deforming changes with special morphologic features. M1 may be a sign of a pathologic degenerative process in the discovertebral unit.