The effect of iterative model reconstruction on coronary artery calcium quantification

Coronary artery calcium (CAC) scoring with computed tomography (CT) is an established tool for quantifying calcified atherosclerotic plaque burden. Despite the widespread use of novel image reconstruction techniques in CT, the effect of iterative model reconstruction on CAC score remains unclear. We sought to assess the impact of iterative model based reconstruction (IMR) on coronary artery calcium quantification as compared to the standard filtered back projection (FBP) algorithm and hybrid iterative reconstruction (HIR). In addition, we aimed to simulate the impact of iterative reconstruction techniques on calcium scoring based risk stratification of a larger asymptomatic population. We studied 63 individuals who underwent CAC scoring. Images were reconstructed with FBP, HIR and IMR and CAC scores were measured. We estimated the cardiovascular risk reclassification rate of IMR versus HIR and FBP in a larger asymptomatic population (n = 504). The median CAC scores were 147.7 (IQR 9.6-582.9), 107.0 (IQR 5.9-526.6) and 115.1 (IQR 9.3-508.3) for FBP, HIR and IMR, respectively. The HIR and IMR resulted in lower CAC scores as compared to FBP (both p < 0.001), however there was no difference between HIR and IMR (p = 0.855). The CAC score decreased by 7.2 % in HIR and 7.3 % in IMR as compared to FBP, resulting in a risk reclassification rate of 2.4 % for both HIR and IMR. The utilization of IMR for CAC scoring reduces the measured calcium quantity. However, the CAC score based risk stratification demonstrated modest reclassification in IMR and HIR versus FBP

Assessment of contractility in intact ventricular cardiomyocytes using the dimensionless ‘Frank–Starling Gain’ index

This paper briefly recapitulates the Frank–Starling law of the heart, reviews approaches to establishing diastolic and systolic force–length behaviour in intact isolated cardiomyocytes, and introduces a dimensionless index called ‘Frank–Starling Gain’, calculated as the ratio of slopes of end-systolic and end-diastolic force–length relations. The benefits and limitations of this index are illustrated on the example of regional differences in Guinea pig intact ventricular cardiomyocyte mechanics. Potential applicability of the Frank–Starling Gain for the comparison of cell contractility changes upon stretch will be discussed in the context of intra- and inter-individual variability of cardiomyocyte properties

Prognostic Value of Stress Myocardial Perfusion Imaging in Asymptomatic Diabetic Patients

Although there has been a marked decline in mortality due to coronary artery disease (CAD) in the overall population in the past three decades, reducing CAD mortality in patients with diabetes has proven exceptionally difficult. Several epidemiological studies have shown that diabetes is associated with a marked increase in the risk of CAD. The symptoms are not a reliable means of identifying patients at higher risk considering that angina is threefold less common in diabetics than in nondiabetics. The increasing prevalence of diabetes and the associated high cardiac risk raised the question as to the need to develop approaches to identify the diabetic patients at the highest risk of CAD. Stress myocardial perfusion single-photon emission computed tomography has taken a central role in the diagnosis, evaluation, and management of CAD in diabetic patients. This review focuses on the prognostic value of cardiac radionuclide imaging in asymptomatic diabetic patients. © 2014 Springer Science+Business Media New York

Calcium channel blockers and cardiovascular outcomes: a meta-analysis of 175,634 patients.

OBJECTIVE: The aim of this study was to assess the effect of calcium channel blocker (CCB) treatment, compared with other drugs or placebo/top of therapy, on all-cause mortality, cardiovascular death, major cardiovascular events, heart failure, myocardial infarction and stroke. METHODS: We performed a meta-analysis of randomized controlled trials that compared a long-acting calcium channel blocker with another drug or placebo/top of therapy and that assessed all-cause mortality and cardiovascular events. RESULTS: We included 27 trials (175,634 patients). The risk of all-cause death was reduced by dihydropyridine CCBs [odds ratio (OR) 0.96; 95% confidence interval (CI) 0.93-0.99; comparison P = 0.026; heterogeneity P = 0.87)] without influence of placebo trials. The risk of heart failure was increased by CCBs compared with active treatment (OR 1.17; 95% CI 1.11-1.24; comparison P = 0.0001; heterogeneity P = 0.0001), and it was decreased when compared with placebo (OR 0.72; 95% CI 0.59-0.87; comparison P = 0.001; heterogeneity P = 0.77), also in the subgroup of coronary artery disease patients (OR 0.76; 95% CI 0.61-0.95; comparison P = 0.01; heterogeneity P = 0.29). CCBs did not increase the risk of myocardial infarction (OR 1; 95% CI 0.95-1.04; comparison P = 0.83, heterogeneity P = 0.004), cardiovascular death (OR 0.97; 95% CI 0.93-1.02; comparison P = 0.24; heterogeneity P = 0.16), major cardiovascular events (OR 0.97; 95% CI 0.90-1.06; comparison P = 0.53; heterogeneity P = 0.0001). CCBs decreased the risk of fatal or nonfatal stroke (OR 0.86; 95% CI 0.82-0.90; comparison P = 0.0001, heterogeneity P = 0.12), also, when compared with angiotensin-converting enzyme inhibitors (OR 0.87; 95% CI 0.78-0.97; comparison P = 0.016; heterogeneity P = 0.48). CONCLUSION: Our study demonstrates that CCBs reduce the risk of all-cause mortality compared with active therapy and prevent heart failure compared with placebo. Furthermore, with the inclusion of recent trials, we confirm that they reduce the risk of stroke, also in comparison to angiotensin-converting enzyme inhibitors and do not increase the risk of cardiovascular death, myocardial infarction and major cardiovascular events

Impact of gender in primary prevention of coronary heart disease with statin therapy: a meta-analysis.

BACKGROUND: Evidence of lipid-lowering from clinical trials that included women is adequate to support their use in secondary prevention in women with known coronary disease. However the role of statin therapy in primary prevention is still controversial, in particular for female gender. The aim of our study is to perform a meta-analysis comparing by gender the cardiovascular outcomes related to statin therapy in primary prevention. METHODS: We performed a meta-analysis including 8 randomized controlled trials (19,052 and 30,194 men, mean follow-up 3.9 years) that assessed the cardiovascular outcomes related to statin therapy, including studies that provided sex-specific results. MEDLINE and the Cochrane Database, were searched for articles published in English and other languages up to March 2008. RESULTS: Statins do not appear to have a beneficial effect on total mortality for both men and women in primary prevention over the 2.8- to 5.3 year study period (men: 95% Confidence Interval (CI) 0.83-1.04; comparison p = 0.22; women: 0.96; CI 0.81-1.13; p = 0.61). Statin therapy reduced the risk of coronary heart disease (CHD) events in men (0.59; CI 0.48-0.74; p = 0.0001), however in women this risk reduction was weakly significant (0.89 CI 0.79-1.00; p = 0.05) and disappeared when in sensitivity analysis, trials not entirely of primary prevention were excluded (HPS, PROSPER) (0.95 CI 0.78-1.16; comparison p = 0.562). CONCLUSIONS: Our study showed that statin therapy reduced the risk of CHD events in men without prior cardiovascular disease, but not in women. Statins did not reduce the risk of total mortality both in men and women