Jeff M. Smit

Association Between Posterior Left Atrial Adipose Tissue Mass and Atrial Fibrillation

Background— Epicardial adipose tissue located close to the atrial wall can change the electric conduction of the left atrium, potentially leading to atrial fibrillation (AF). The aim of this study was to assess whether an increased atrial adipose tissue mass posterior to the left atrium is related to AF independent of demographical and cardiovascular risk factors. Methods and Results— Two hundred patients with AF and 200 patients without AF who underwent computed tomographic angiography were included. The posterior left atrial adipose tissue mass was quantified on computed tomographic angiography images as tissue with Hounsfield Units between −195 and −45. The adipose tissue mass was significantly larger in patients with AF compared with patients with sinus rhythm: 10.6±5.5 versus 4.7±3.5 g, P<0.001. In a multiple variable model (including age, body mass index, sex, coronary artery calcium score, diabetes mellitus, hypertension, hypercholesterolemia, family history of coronary artery disease, and known coronary artery disease), each gram increase of posterior left atrial adipose tissue was associated with 1.32 odds ratio of having AF (95% confidence interval, 1.22–1.43; P<0.001). Furthermore, the addition of the adipose tissue mass to the multiple variable analysis significantly increased the discriminatory ability to predict AF: increase in the area under the receiver operating characteristic, 0.88 (95% confidence interval, 0.84–0.91) versus 0.81 (0.76–0.85), P<0.001. Conclusions— Posterior left atrial adipose tissue mass is significantly larger in patients with AF versus without AF. An increase in adipose tissue was independently associated with AF and provided incremental value over well-known predictors of AF. These findings add to the hypothesis that the posterior left atrial adipose tissue mass contributes to structural and electric remodeling leading to AF.

Accuracy and reproducibility of fast fractional flow reserve computation from invasive coronary angiography

Fractional flow reserve (FFR) guided percutaneous coronary intervention (PCI) is associated with favourable outcome compared with revascularization based on angiographic stenosis severity alone. The feasibility of the new image-based quantitative flow ratio (QFR) assessed from 3D quantitative coronary angiography (QCA) and thrombolysis in myocardial infarction (TIMI) frame count using three different flow models has been reported recently. The aim of the current study was to assess the accuracy, and in particular, the reproducibility of these three QFR techniques when compared with invasive FFR. QFR was derived (1) from adenosine induced hyperaemic coronary angiography images (adenosine-flow QFR [aQFR]), (2) from non-hyperemic images (contrast-flow QFR [cQFR]) and (3) using a fixed empiric hyperaemic flow [fixed-flow QFR (fQFR)]. The three QFR values were calculated in 17 patients who prospectively underwent invasive FFR measurement in 20 vessels. Two independent observers performed the QFR analyses. Mean difference, standard deviation and 95% limits of agreement (LOA) between invasive FFR and aQFR, cQFR and fQFR for observer 1 were: 0.01 ± 0.04 (95% LOA: −0.07; 0.10), 0.01 ± 0.05 (95% LOA: −0.08; 0.10), 0.01 ± 0.04 (95% LOA: −0.06; 0.08) and for observer 2: 0.00 ± 0.03 (95% LOA: −0.06; 0.07), −0.01 ± 0.03 (95% LOA: −0.07; 0.05), 0.00 ± 0.03 (95% LOA: −0.06; 0.05). Values between the 2 observers were (to assess reproducibility) for aQFR: 0.01 ± 0.04 (95% LOA: −0.07; 0.09), for cQFR: 0.02 ± 0.04 (95% LOA: −0.06; 0.09) and for fQFR: 0.01 ± 0.05 (95% LOA: −0.07; 0.10). In a small number of patients we showed good accuracy of three QFR techniques (aQFR, cQFR and fQFR) to predict invasive FFR. Furthermore, good inter-observer agreement of the QFR values was observed between two independent observers.

Different manifestation of irradiation induced coronary artery disease detected with coronary computed tomography compared with matched non-irradiated controls

BACKGROUND AND PURPOSE Patients who received chest irradiation for treatment of a malignancy are at increased risk for the development of coronary artery atherosclerosis. Little is known about the anatomical coronary artery plaque characteristics of irradiation induced coronary artery disease (CAD). This study aimed to evaluate potential differences in the presence, extent, severity, composition and location of CAD in patients treated with mediastinal irradiation compared with non-irradiated controls matched on age, gender and cardiovascular risk factors. MATERIAL AND METHODS Seventy-nine asymptomatic Hodgkin and non-Hodgkin lymphoma survivors, all treated with mediastinal irradiation with or without chemotherapy, who underwent coronary computed tomography angiography (CTA) to exclude or detect CAD were included. Patients were 1:3 matched with non-irradiated controls (n=237) for age, gender, diabetes, hypertension, hypercholesterolemia, family history of CAD and currently smoking. Mean age at cancer diagnosis was 26±9years and age at the time of coronary CTA was 45±11years. RESULTS More patients had an abnormal CTA (defined as any coronary artery atherosclerosis): 59% vs. 36% (P<0.001) and significantly more patients had two vessel CAD: 10% vs. 6% and three vessel/left main CAD: 24% vs. 9% compared with controls (overall P<0.001). The maximum stenosis severity among patients was less often <30% (53% vs. 68%) and more often >70% (7% vs. 0%) (overall P=0.001). Patients had more coronary artery plaques in proximal coronary artery segments: left main (17% vs. 6%, P=0.004), proximal left anterior descending artery (30% vs. 16%, P=0.004), proximal right coronary artery (25% vs 10%, P<0.001) and proximal left circumflex artery (14% vs 6%, P=0.022), whereas the number of plaques in non-proximal segments did not differ between groups. CONCLUSIONS Hodgkin and non-Hodgkin lymphoma survivors treated with mediastinal irradiation with or without chemotherapy showed a higher presence, greater severity, larger extent and more proximally located CAD compared with age, gender and risk factor matched non-irradiated controls. These findings represent features of higher risk CAD and may explain the worse cardiovascular outcome after chest irradiation.

Relationship Between Coronary Contrast-Flow Quantitative Flow Ratio and Myocardial Ischemia Assessed by SPECT MPI

PurposeA new method has been developed to calculate fractional flow reserve (FFR) from invasive coronary angiography, the so-called “contrast-flow quantitative flow ratio (cQFR)”. Recently, cQFR was compared to invasive FFR in intermediate coronary lesions showing an overall diagnostic accuracy of 85%. The purpose of this study was to investigate the relationship between cQFR and myocardial ischemia assessed by single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI).MethodsPatients who underwent SPECT MPI and coronary angiography within 3 months were included. The cQFR computation was performed offline, using dedicated software. The cQFR computation was based on 3-dimensional quantitative coronary angiography (QCA) and computational fluid dynamics. The standard 17-segment model was used to determine the vascular territories. Myocardial ischemia was defined as a summed difference score ≥2 in a vascular territory. A cQFR of ≤0.80 was considered abnormal.ResultsTwo hundred and twenty-four coronary arteries were analysed in 85 patients. Overall accuracy of cQFR to detect ischemia on SPECT MPI was 90%. In multivariable analysis, cQFR was independently associated with ischemia on SPECT MPI (OR per 0.01 decrease of cQFR: 1.10; 95% CI 1.04-1.18, p = 0.002), whereas clinical and QCA parameters were not. Furthermore, cQFR showed incremental value for the detection of ischemia compared to clinical and QCA parameters (global chi square 48.7 to 62.6; p <0.001).ConclusionsA good relationship between cQFR and SPECT MPI was found. cQFR was independently associated with ischemia on SPECT MPI and showed incremental value to detect ischemia compared to clinical and QCA parameters.

Long-term prognostic value of single-photon emission computed tomography myocardial perfusion imaging after primary PCI for STEMI

Aims The aim of this study was to determine the long-term prognostic value of infarct size and myocardial ischaemia on single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) after primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). Methods and results In total, 1092 STEMI patients who underwent primary PCI and SPECT MPI within 1-6 months were included (median follow-up time of 6.9 years). In the entire cohort, SPECT infarct size was independently associated with the composite of cardiac death or reinfarction [hazard ratio (HR) per 10% increase in summed rest score 1.33; 95% confidence interval (95% CI) 1.12-1.58; P = 0.001], whereas myocardial ischaemia was not (HR per 5% increase in summed difference score 1.18; 95% CI 0.94-1.48; P = 0.16). Addition of SPECT infarct size to a model including the clinical variables provided significant incremental prognostic value for the prediction of cardiac death or reinfarction (global χ2 13.8 vs. 24.2; P = 0.002), whereas addition of SPECT ischaemia did not add significantly (global χ2 24.2 vs. 25.6; P = 0.24). In the subgroup of patients with left ventricular ejection fraction (LVEF) ≤ 45%, SPECT infarct size was independently associated with cardiac death or reinfarction (HR 1.59; 95% CI 1.15-2.22; P = 0.006), whereas in patients with LVEF > 45%, only SPECT ischaemia was independently associated with cardiac death or reinfarction (HR 1.28; 95% CI 1.00-1.63; P = 0.050). Conclusion In patients with first STEMI and primary PCI, SPECT infarct size was independently associated with cardiac death and/or reinfarction, whereas myocardial ischaemia was not. In patients with LVEF ≤ 45%, SPECT infarct size was independently associated with cardiac death or reinfarction, whereas myocardial ischaemia was not. Conversely, in patients with LVEF > 45%, only SPECT ischaemia was independently associated with cardiac death or reinfarction.