Trends of Increasing Medical Radiation Exposure in a Population Hospitalized for Cardiovascular Disease (1970-2009)

Abstract Background: High radiation doses employed in cardiac imaging may increase cancer frequency in exposed patients after decades. The aim of this study was to evaluate the relative trends in medical radiation exposure in a population hospitalized for cardiovascular disease. Methods and Results: An observational single-center study was conducted to examine 16,431 consecutive patients with heart disease admitted to the Italian National Research Council Institute of Clinical Physiology between January 1970 and December 2009. In all patients, the cumulative estimated effective dose was obtained from data mining of electronic records of hospital admissions, adopting the effective dose typical values of the American Heart Association 2009 statement and Mettler\u27s 2008 catalog of doses. Cumulative estimated effective dose per patient in the last 5 years was 22 (12-42) mSv (median, 25th-75th percentiles), with higher values in ischemic heart disease (IHD), 37 (20-59) vs non-IHD, 13 (8-22) mSv, p,0.001. Trends in radiation exposure showed a steady increase in IHD and a flat trend in non-IHD patients, with variation from 1970-74 to 2005-2009 of +155% for IHD (p,0.001) and 21% in non-IHD (NS). The relative contribution of different imaging techniques was remodeled over time, with nuclear cardiology dominating in 1970s (23% of individual exposure) and invasive fluoroscopy in the last decade (90% of individual exposure). Conclusion: A progressive increase in cumulative estimated effective dose is observed in hospitalized IHD patients. The growing medical radiation exposure may encourage a more careful justification policy regarding ionizing imaging in cardiology patients applying the two main principles of radiation protection: appropriate justification for ordering and performing each procedure, and careful optimization of the radiation dose used during each procedure

Interpretation of the "obesity paradox": A 30-year study in patients with cardiovascular disease

Background: Several epidemiological reports indicate that the body mass index (BMI) is inversely related with mortality, in spite of the notion that obesity is a recognized cardio-metabolic risk factor. The aim of the study was to evaluate the independent impact of overweight and obesity on long-term mortality in a large cohort of patients with heart disease (HD). Methods: The study included 10,446 patients hospitalized in the last three decades for ischemic (60%) or nonischemic HD and followed-up for 10 years. The relationship between BMI and total or cardiovascular mortality was analyzed in the whole cohort, and in age-stratified categories (≤65 and >65 years). Considering that survival in HD patients has improved after the introduction of revascularization, beta-blockers, ACE inhibitors, and statins, the relationship was re-examined separately in patients hospitalized before and after 1990. Results: Diabetes, hyperuricemia, hypertension, glycaemia, and triglyceridemia increased across BMI groups. During follow-up (73?59 months) there were 1707 all-cause deaths (47% cardiac). Any relationship between BMI and mortality was lost in the ≤65 age category and in patients hospitalized before 1990, but it persisted in old patients hospitalized after 1990. Most significant independent predictors of mortality in all groups were hyperuricemia, diabetes and impaired ejection fraction. Conclusions: No independent relationship was found between BMI and mortality in subjects ≤65 years of age. This neutral relationship seems to be partly counteracted by treatment, particularly in old patients. A different effect of obesity onset in old vs. young age cannot be ruled out

Stress echocardiography for the risk stratification of patients following coronary bypass surgery

Objectives: The aim of the study was to assess the prognostic value of stress echocardiography after surgical revascularization. Methods: We evaluated 500 (100 women) patients who had undergone exercise or pharmacological SE after a median of 69 months after coronary artery by-pass grafting (CABG). Of these, 351 (70%) complained of symptoms suggestive of ischemic origin while 149 (30%) were tested for asymptomatic progression of the disease. Results: SE was positive for ischemia in 196 (39%) patients. During a median follow-up of 25 months, 61 patients died, 33 had a nonfatal myocardial infarction, and 112 underwent late (N3 months) revascularization. Multivariable Cox\u27 regression analysis indicated age (HR=1.04; 95% CI 1.01-1.06; pb0.003), and peak WMSI (HR=3.07; 95% CI 1.96-4.81; p=0.0001) as independent predictors of hard (total mortality and myocardial infarction) events. SE information provided a significant improvement in predictive power of the statistical model (chi-square increase 34%, pb0.0001 for hard and 91%, pb0.0001 for major events, respectively). Survival analysis showed ischemia at SE to be associated with significantly higher hard and major event rate in both symptomatic and asymptomatic patients. Discussion: SE represents an effective tool for the risk stratification of patients with previous CABG independently of the presence of symptoms suggestive of ischemic origin

Oxidative Stress as a predictor of cardiovascular events in coronari artery disease patients

Abstract Background: Enhanced oxidative stress has been associated with atherosclerosis and coronary artery disease (CAD). However, the predictive value of circulating oxidative stress biomarkers for cardiovascular events (CE) in patients with CAD has remained poorly understood. Aim: To assess the prognostic significance of reactive oxygen metabolites, estimated as index of oxidative stress in serum samples by means of a commercial kit (ROMs, Diacron, Italy) on the rate of mortality and major adverse CE (MACE) in CAD. Methods: A study of 93 consecutive patients with angiographically documented CAD (75 males, age: 68?10 years, mean?SD) was made during a mean follow-up of 66 months until the occurrence of one of the following CE: cardiac and all cause death, non-fatal myocardial infarction and coronary revascularization [percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG)]. Patient data were retrospectively collected from the Institute\u27s electronic databank that saves demographic, clinical, instrumental and follow-up data of all patients admitted to our department. Results: The Kaplan-Meier survival estimates showed a significantly worst outcome in patients presenting elevated ROM level (>75th percentile, corresponding to 481 AU) (log rank=11, 7.5, 5.1; p<0.001, p<0.01, p<0.05 for cardiac and all cause death and MACEs, respectively). In a multivariate Cox regression model, elevated oxidative stress remained a significant predictor of cardiac and all cause death [hazard ratio (HR) 3.9, 95% confidence interval, 95% (CI) 1.4-11.1, p=0.01; HR=2.6, 95% CI 1.1-6.2, p=0.02) and MACE (HR=1.8, 95% CI 1.1-3.1, p=0.03)]. Conclusions: The estimation of ROMs may represent an additional prognostic tool in the assessment of CE in CAD patients

Stress echocardiography for the risk stratification of patients following coronary bypass surgery

OBJECTIVES: The aim of the study was to assess the prognostic value of stress echocardiography after CABG. METHODS: We evaluated 500 (100 women) patients who had undergone exercise or pharmacological SE after a median of 69 months after CABG. Of these, 351 (70%) complained of symptoms suggestive of ischemic origin while 149 (30%) were tested for asymptomatic progression of the disease. RESULTS: SE was positive for ischemia in 196 (39%) patients. During a median follow-up of 25 months, 61 patients died, 33 had a nonfatal myocardial infarction, and 112 underwent late (>3 months) revascularization. Multivariable Cox\u27 regression analysis indicated age (HR=1.04; 95% CI 1.01-1.06; p<0.003), and peak WMSI (HR=3.07; 95% CI 1.96-4.81; p=0.0001) as independent predictors of hard (total mortality and myocardial infarction) events. SE information provided a significant improvement in predictive power of the statistical model (chi-square increase 34%, p<0.0001 for hard and 91%, p<0.0001 for major events, respectively). Survival analysis showed ischemia at SE to be associated with significantly higher hard and major event rate in both symptomatic and asymptomatic patients. DISCUSSION: SE represents an effective tool for the risk stratification of patients with previous CABG independently of the presence of symptoms suggestive of ischemic origin

Crystallization Kinetics of Alkali Feldspar in Peralkaline Rhyolitic Melts: Implications for Pantelleria Volcano

Peralkaline rhyolites, associated with extensional tectonic settings, are medium to low viscosity magmas that often produce eruptive styles ranging from effusive to highly explosive eruptions. The role of pre-eruptive conditions and crystallization kinetics in influencing the eruptive style of peralkaline rhyolitic magmas has been investigated and debated considering equilibrium conditions. However, experimental constraints on the effect of disequilibrium in crystallization in such magmas are currently lacking in the literature. Therefore, we performed isobaric cooling experiments to investigate alkali feldspar crystallization kinetics in peralkaline rhyolitic melts. Experiments were performed under water-saturated, water-undersaturated, and anhydrous conditions between 25 and 100 MPa, at 670–790°C and with experimental durations ranging from 0.5 to 420 h. Here we present the first data on crystallization kinetics of alkali feldspar, which is the main crystal phase in peralkaline rhyolitic melts, in order to improve our understanding of the evolutionary timescales of these melts and their ability to shift between effusive and explosive activity. Our experimental results indicate that the alkali feldspar nucleation delay can range from hours to several days as a function of undercooling and H2O content in the melt. Thus, a peralkaline rhyolitic magma can be stored at the pre-eruptive conditions for days without important variations of its crystal fraction. This suggests that crystallization may not necessarily play the main role in triggering fragmentation during explosive eruptions of peralkaline rhyolitic magmas

Routine laboratory tests to risk-stratify patients with chronic coronary artery disease

AbstractBackgroundSeveral biohumoral variables, taken individually, are predictors of prognosis in patients with chronic coronary artery disease (CAD). We hypothesized that taken together, laboratory tests provide prognostic information that is additive to a complete diagnostic work-up.MethodsWe prospectively examined 2370 consecutive patients with chronic CAD, as shown by a >50% coronary stenosis (in 95% of patients), previous coronary revascularization (in 31% of patients), and/or previous myocardial infarction (MI, in 54% of patients). We tested the ability of laboratory and clinical variables to predict future cardiac events (cardiac death and non-fatal MI).ResultsDuring follow-up (median, 46 months), 147 patients (6.2%) died from cardiac causes and 81 (3.4%) experienced a non-fatal MI. Using multivariate analysis, after adjustment for clinical variables (including left ventricular ejection fraction and angiographic extent of coronary stenoses), a high-density lipoprotein cholesterol (HDLc) concentration<35mg/dL (p<0.0001), a neutrophil-to-lymphocyte ratio >2.4 (p=0.0014), and an fT3 serum level<2.1pg/mL with normal thyrotropin (low-T3 syndrome) (p=0.0260) showed an independent and incremental prognostic value, and were associated with an increase in the rate of cardiac events of 86%, 57% and 41%, respectively. When these variables were added to clinical and instrumental variables, the prognostic power of the model increased significantly (global chi-square improvement: from 157.01 to 185.07, p<0.0001).ConclusionLow HDLc, high neutrophil-to-lymphocyte ratio and low-T3 syndrome, both individually and taken together, provide prognostic information that is independent of and incremental to the main clinical and instrumental findings

Low-T3 Syndrome

Background— Clinical and experimental data have suggested a potential negative impact of low-T3 state on the prognosis of cardiac diseases. The aim of the present prospective study was to assess the role of thyroid hormones in the prognosis of patient population with heart disease. Methods and Results— A total of 573 consecutive cardiac patients underwent thyroid function profile evaluation. They were divided in two subgroups: group I, 173 patients with low T3, ie, with free T3 (fT3) <3.1 pmol/L, and group II, 400 patients with normal fT3 (≥3.1 pmol/L). We considered cumulative and cardiac death events. During the 1-year follow-up, there were 25 cumulative deaths in group I and 12 in group II (14.4% versus 3%, P <0.0001); cardiac deaths were 13 in group I and 6 in group II (7.5% versus 1.5%, P =0.0006). According to the Cox model, fT3 was the most important predictor of cumulative death (hazard ratio [HR] 3.582, P <0.0001), followed by dyslipidemia (HR 2.955, P =0.023), age (HR 1.051, P <0.005), and left ventricular ejection fraction (HR 1.037, P =0.006). At the logistic multivariate analysis, fT3 was the highest independent predictor of death (HR 0.395, P =0.003). A prevalence of low fT3 levels was found in patients with NYHA class III-IV illness compared with patients with NYHA class I-II (χ 2 5.65, P =0.019). Conclusions— Low-T3 syndrome is a strong predictor of death in cardiac patients and might be directly implicated in the poor prognosis of cardiac patients

Twisting all the way: from Classical Mechanics to Quantum Fields

We discuss the effects that a noncommutative geometry induced by a Drinfeld twist has on physical theories. We systematically deform all products and symmetries of the theory. We discuss noncommutative classical mechanics, in particular its deformed Poisson bracket and hence time evolution and symmetries. The twisting is then extended to classical fields, and then to the main interest of this work: quantum fields. This leads to a geometric formulation of quantization on noncommutative spacetime, i.e. we establish a noncommutative correspondence principle from *-Poisson brackets to *-commutators. In particular commutation relations among creation and annihilation operators are deduced.Comment: 32 pages. Added references and details in the introduction and in Section

Volatiles and trace element contents in melt inclusions from the zoned Green Tuff ignimbrite (Pantelleria, Sicily): petrological inferences.

The island of Pantelleria is one of the best known localities of bimodal mafic-felsic magmatism (alkali basalt and trachyte-pantellerite). Among the felsic rocks, the coexistence in a single eruption of products of both trachyte and pantellerite compositions is limited to few occurrences, the Green Tuff (GT) ignimbrite being one of these. The GT is compositionally zoned from pantellerite (70.1 wt% SiO2, mol Na+K/Al = 1.86, 1871 ppm Zr) at the base to crystal-rich (\u3e30 vol%) comenditic trachyte (63.4 wt% SiO2, mol Na+K/Al = 1.10, 265 ppm Zr) at the top, although the pantellertic compositions dominate the erupted volume. We present here new data on melt inclusions (MIs) from the pantellerite portions of the GT eruption and, most importantly, from the trachyte member, which have not been studied in-situ by previous work focused on the GT. We document the first occurrence of trachytic melt inclusions in the late-erupted member, whose importance resides in the fact that trachytes were known mostly as crystal-rich lavas or ignimbrites, all variably affected by crystal accumulation. Besides the obvious inferences on the interplay between parental-derivative magmas, this evidence adds also some helpful elements in understanding zoning of silicic and peralkaline (i.e. low-viscosity) magma chambers. Trace elements compositions of MIs reveal that trachyte melts are of two types: (i) a low-Ba, directly descending from basaltic melts by 60-70 % of fractional crystallisation, and (ii) a high-Ba that might be affected by processes of feldspar dissolution and entrainment of the resulting small-scale melts in some MIs. MIs hosted in the deep-seated trachyte body are H2O-poor (≤ 1.2 wt %) with respect to the early erupted (and shallower) pantellerite magma (≤ 4.2 wt %), raising the possibility that either trachyte magma was H2O-undesaturated, or clinopyroxene hosted melt inclusions which suffered consistent H2O loss