Multi-modality imaging in ischemic heart disease, arrhythmia and cardiac-mechanics

In this thesis, the role of multi-modality imaging in ischemic heart disease, arrhythmias and cardiac mechanics is investigated. Computed tomography (CT) is utilized to evaluate the role of sex on progression of coronary artery disease (CAD) and the relationship between anatomical and functional markers of CAD. Reference values for a novel technique, non-invasive myocardial work, are presented for different cardiac pathologies and its relation with the extent of infarct transmurality following ST-segment elevation myocardial infarction is evaluated. The prognostic value of left ventricular (LV) global longitudinal strain (GLS) on 2-dimensional speckle tracking echocardiography and heart-to-mediastinum ratio on 123I-MIBG scintigraphy on appropriate Implantable Cardioverter Defibrillator (ICD) therapy is evaluated. Furthermore, the predictive value of posterior left atrial adipose tissue attenuation on CT for atrial fibrillation recurrence following ablation is investigated.Boehringer Ingelheim bv, Canon Medical Systems Nederland, Medis Medical Imaging Systems bv and Chipsoft bvLUMC / Geneeskund

Bone Resorption Is Increased in Pheochromocytoma Patients and Normalizes following Adrenalectomy

Context: The sympathetic nervous system (SNS) controls bone turnover in rodents, but it is uncertain whether a similar role for the SNS exists in humans. Pheochromocytomas are catecholamine-producing neuroendocrine tumors. Because catecholamines are the neurotransmitters of the SNS, we hypothesized that pheochromocytoma patients have increased bone turnover. Objective: Our objective was to compare bone turnover in pheochromocytoma patients and controls. Design and Setting: This retrospective case-control study was performed at the Endocrine Department of the Academic Medical Center of the University of Amsterdam in The Netherlands from 2007 until 2011. Patients: All patients were screened for pheochromocytoma. Cases (n = 21) were identified by 24-h urinary excretion of fractionated metanephrines above the institutional reference value and confirmed by histology after adrenalectomy. All patients screened and diagnosed as not having pheochromocytoma served as controls (n = 126). Main Outcome Measure: The difference in bone turnover markers C-terminal cross-linking telopeptides of collagen type I (CTx) and procollagen type 1 N propeptide (P1NP) between cases and controls was the main outcome measure. Results: CTx concentrations were higher in cases [343 ng/liter; interquartile range (IQR), 295 ng/liter] than in controls (232 ng/liter; IQR, 168 ng/liter; P <0.001) and decreased after adrenalectomy [before, 365 ng/liter (IQR, 450 ng/liter); after, 290 ng/liter (IQR, 241 ng/liter); P = 0.044]. The effect remained after adjustment for possible confounders. P1NP concentrations did not differ. Conclusions: This study shows that pheochromocytoma patients have increased bone resorption, which normalizes after adrenalectomy. This finding supports the concept of regulation of bone remodeling by the SNS in humans. (J Clin Endocrinol Metab 97: E2093-E2097, 2012

Relationship between coronary artery calcification and myocardial ischemia on computed tomography myocardial perfusion in patients with stable chest pain

Background Coronary artery calcium (CAC) score has shown to provide incremental prognostic information when added to the Framingham risk score. Although the relation between CAC and myocardial ischemia has been evaluated, there has been little evaluation of the relationship between CAC score and inducible myocardial ischemia on computed tomography myocardial perfusion (CTP). Methods and Results Patients who were referred with stable chest pain from the outpatient clinic and who underwent non-contrast computed tomography scan, coronary computed tomography angiography, and adenosine stress CTP were included in this study. CAC score was subdivided in four groups (1 to 99; 100 to 399, 400 to 999, and >= 1000). Inducible myocardial ischemia was considered when reversible perfusion defects were observed in >= 1 segment. A total of 131 patients (age 62 +/- 9.4 years; 56% male) were included. The median CAC score was 241 (73 to 539). Forty-nine patients (37%) had evidence of inducible myocardial ischemia. The presence of inducible myocardial ischemia increased with increasing CAC score from 22% in the CAC score 1 to 99 subgroup to 35, 47, and 65% in the 100 to 399, 400 to 999, and >= 1000 CAC score subgroup, respectively. In multivariable analysis CAC score was the only determinant that significantly predicted the presence of inducible myocardial ischemia on CTP. Conclusions In a population of symptomatic patients, the majority of patients with extensive calcification had evidence of inducible myocardial ischemia on CTP. CAC score was the only independent predictor of inducible myocardial ischemia on CTP.Cardiolog

Quantification of myocardial ischemia and subtended myocardial mass at adenosine stress cardiac computed tomography: a feasibility study

Combination of coronary computed tomography angiography (CCTA) and adenosine stress CT myocardial perfusion (CTP) allows for coronary artery lesion assessment as well as myocardial ischemia. However, myocardial ischemia on CTP is nowadays assessed semi-quantitatively by visual analysis. The aim of this study was to fully quantify myocardial ischemia and the subtended myocardial mass on CTP. We included 33 patients referred for a combined CCTA and adenosine stress CTP protocol, with good or excellent imaging quality on CTP. The coronary artery tree was automatically extracted from the CCTA and the relevant coronary artery lesions with a significant stenosis (>= 50%) were manually defined using dedicated software. Secondly, epicardial and endocardial contours along with CT perfusion deficits were semi-automatically defined in short-axis reformatted images using MASS software. A Voronoi-based segmentation algorithm was used to quantify the subtended myocardial mass, distal from each relevant coronary artery lesion. Perfusion defect and subtended myocardial mass were spatially registered to the CTA. Finally, the subtended myocardial mass per lesion, total subtended myocardial mass and perfusion defect mass (per lesion) were measured. Voronoi-based segmentation was successful in all cases. We assessed a total of 64 relevant coronary artery lesions. Average values for left ventricular mass, total subtended mass and perfusion defect mass were 118, 69 and 7 g respectively. In 19/33 patients (58%) the total perfusion defect mass could be distributed over the relevant coronary artery lesion(s). Quantification of myocardial ischemia and subtended myocardial mass seem feasible at adenosine stress CTP and allows to quantitatively correlate coronary artery lesions to corresponding areas of myocardial hypoperfusion at CCTA and adenosine stress CTP.Cardiovascular Aspects of Radiolog

Prognostic value of multilayer left ventricular global longitudinal strain in patients with ST-segment elevation myocardial infarction with mildly reduced left ventricular ejection fractions

Multilayer (epi-, mid- and endocardium) left ventricular (LV) global longitudinal strain (GLS) reflects the extent of myocardial damage after ST-segment myocardial infarction (STEMI). However, the prognostic implications of multilayer LV GLS remain unclear. We studied the association between multilayer LV GLS and prognosis in patients with mildly reduced or preserved LV ejection fraction (EF) after STEMI. Patients with first STEMI and LVEF>45% were evaluated retrospectively. Baseline multilayer (endocardial, mid-myocardial and epicardial) LV GLS were measured on 2-dimensional speckle tracking echocardiography. Patients were followed up for of all-cause mortality. A total of 569 patients (77% male, 60 +/- 11 years) were included. After a median follow-up of 117 (interquartile range 106-132) months, 95 (17%) patients died. We observed no differences in baseline LVEF and peak troponin levels between survivors and non-survivors. However, non-survivors showed more impaired GLS at all layers (epicardium: -11.9 +/- 2.8% vs. -13.4 +/- 2.8%; mid-myocardium: -14.2 +/- 3.2% vs. -15.6 +/- 3.2%; endocardium: -16.5 +/- 3.7% vs. -17.7 +/- 3.6%, p<0.05, for all). On multivariable analysis, increasing age (hazard ratio 1.095; p<0.001) and impaired LV GLS of the epicardial layer (hazard ratio 1.085; p = 0.047) were independently associated with higher risk of all-cause mortality. In addition, LV GLS at the epicardium had incremental prognostic value for all-cause mortality (chi(2) = 114, p = 0.044). In conclusion, in contemporary STEMI patients with mildly reduced or preserved LVEF, ageing and reduced LV GLS of the epicardium (reflecting transmural scar formation) were independently associated with all-cause mortality after adjusting for clinical and echocardiographic variables. (C) 2021 The Authors. Published by Elsevier Inc.Cardiolog

Myocardial work, an echocardiographic measure of post myocardial infarct scar on contrast-enhanced cardiac magnetic resonance

This study investigates the relation of non-invasive myocardial work and myocardial viability following ST-segment elevation myocardial infarction (STEMI) assessed on late gadolinium contrast enhanced cardiac magnetic resonance (LGE CMR) and characterizes the remote zone using non-invasive myocardial work parameters. STEMI patients who underwent primary percutaneous coronary intervention (PCI) were included. Several non-invasive myocardial work parameters were derived from speckle tracking strain echocardiography and sphygmomanometric blood pressure, e.g.: myocardial work index (MWI), constructive work (CW), wasted work (WW) and myocardial work efficiency (MWE). LGE was quantified to determine infarct transmurality and scar burden. The core zone was defined as the segment with the largest extent of transmural LGE and the remote zone as the diametrically opposed segment without LGE. A total of 53 patients (89% male, mean age 58 +/- 9 years) and 689 segments were analyzed. The mean scar burden was 14 +/- 7% of the total LV mass, and 76 segments (11%) demonstrated transmural hyperenhancement, 280 (41%) non-transmural hyperenhancement and 333 (48%) no LGE. An inverse relation was observed between segmental MWI, CW and MWE and infarct transmurality (p < 0.05). MWI, CW and MWE were significantly lower in the core zone compared to the remote zone (p<0.05). In conclusion, non-invasive myocardial work parameters may serve as potential markers of segmental myocardial viability in post-STEMI patients who underwent primary PCI. Non-invasive myocardial work can also be utilized to characterize the remote zone, which is an emerging prognostic marker as well as a therapeutic target. (C) 2021 The Authors. Published by Elsevier Inc.Cardiovascular Aspects of Radiolog

Anatomical characteristics of the left atrium and left atrial appendage in relation to the risk of stroke in patients with versus without atrial fibrillation

Background: The left atrial appendage (LAA) has been regarded as an important source of cardiac thrombus formation and appears important in the contribution to thromboembolism in patients with atrial fibrillation (AF). Our aim was to evaluate the relationship between LAA morphology and previous stroke or transient ischemic attack in 2 large and distinct patient cohorts with and without known AF. Methods: The study population consisted of patients with and without drug-refractory AF who underwent computed tomography before transcatheter AF ablation or clinically indicated for suspected coronary artery disease. The computed tomography data were used for volumetric assessment of the left atrium and LAA and to determine LAA morphology. The LAA was classified by 3 readers in consensus as chicken wing, swan, cauliflower, or windsock, based on predefined morphology classification criteria. Results: In total, 1813 patients (mean age 59 +/- 11 years, 42% female) who underwent computed tomography were included in this analysis (908 patients with AF and 905 patients without known AF). Swan LAA morphology was independently associated with prior stroke/transient ischemic attack in the overall study population (odds ratio, 3.40, P<0.001), and in patients with (odds ratio, 2.88, P=0.012) and without known AF (odds ratio, 3.96, P=0.011). Conclusions: Swan morphology of the LAA is independently associated with prior stroke or transient ischemic attack in patients with known AF, as well as in patients not previously diagnosed with AF.Cardiolog

Changes in global left ventricular myocardial work indices and stunning detection 3 months after ST-segment elevation myocardial infarction

Global left ventricular (LV) myocardial work (MW) indices (GLVMWI) are derived from speckle tracking echocardiographic strain data in combination with non-invasive blood pressure measurements. Changes in global work index (GWI), global constructive work (GCW), global wasted work (GWW) and global work efficiency (GWE) after ST-segment elevation myocardial infarction (STEMI) have not been explored. The aim of present study was to assess the evolution of GLVMWI in STEMI patients from baseline (index infarct) to 3 months' follow-up. Three-hundred and fifty patients (265 men; mean age 61 +/- 10 years) with STEMI treated with primary percutaneous coronary intervention (PCI) and guideline-based medical therapy were retrospectively evaluated. Clinical variables, conventional echocardiographic measures and GLVMWI were recorded at baseline within 48 hours post-primary PCI and 3 months' follow-up. LV ejection fraction (from 54 +/- 10% to 57 +/- 10%, p < 0.001), GWI (from 1449 +/- 451 mm Hg% to 1953 +/- 492 mm Hg%, p < 0.001), GCW (from 1624 +/- 519 mm Hg% to 2228 +/- 563 mm Hg%, p < 0.001) and GWE (from 93% (interquartile range (IQR) 86%-95%) to 95% (IQR 91%-96%), p < 0.001) improved significantly at 3 months' follow-up with no significant difference in GWW (from 101 mm Hg% (IQR 63-155 mm Hg%) to 96 mm Hg% (IQR 64-155 mm Hg %); p = 0.535). On multivariable linear regression analysis, lower values of troponin T at baseline, increase in systolic blood pressure and improvement in LV global longitudinal strain were independently associated with higher GWI and GCW at 3 months' follow-up. In conclusion, the evolution of GWI, GCW and GWE in STEMI patients may reflect myocardial stunning, whereas the stability in GWW may reflect permanent myocardial damage and the development of non-viable scar tissue. (C) 2021 The Authors. Published by Elsevier Inc.Cardiolog

Right ventricular myocardial work: proof-of-concept for non-invasive assessment of right ventricular function

Aims Right ventricular myocardial work (RVMW) is a novel method for non-invasive assessment of right ventricular (RV) function utilizing RV pressure-strain loops. This study aimed to explore the relationship between RVMW and invasive indices of right heart catheterization (RHC) in a cohort of patients with heart failure with reduced left ventricular ejection fraction (HFrEF), and to compare values of RVMW with those of a group of patients without cardiovascular disease.Methods and results Non-invasive analysis of RVMW was performed in 22 HFrEF patients [median age 63 (59-67) years] who underwent echocardiography and invasive RHC within 48 h. Conventional RV functional measurements, RV global constructive work (RVGCW), RV global work index (RVGWI), RV global wasted work (RVGWVV), and RV global work efficiency (RVGWE) were analysed and compared with invasively measured stroke volume and stroke volume index. Non-invasive analysis of RVMW was also performed in 22 patients without cardiovascular disease to allow for comparison between groups. None of the conventional echocardiographic parameters of RV systolic function were significantly correlated with stroke volume or stroke volume index. In contrast, one of the novel indices derived non-invasively by pressure-strain Loops, RVGCW, demonstrated a moderate correlation with invasively measured stroke volume and stroke volume index (r = 0.63, P=0.002 and r = 0.59, P= 0.004, respectively). RVGWI, RVGCW, and RVGWE were significantly lower in patients with HFrEF compared to a healthy cohort, while values of RVGWVV were significantly higher.Conclusion RVGCW is a novel parameter that provides an integrative analysis of RV systolic function and correlates more closely with invasively measured stroke volume and stroke volume index than other standard echocardiographic parameters.Cardiolog

Global left ventricular myocardial work efficiency and Long-term prognosis in patients after ST-segment-elevation myocardial infarction

Background:Left ventricular (LV) global longitudinal strain has demonstrated incremental prognostic value over LV ejection fraction in patients with ST-segment-elevation myocardial infarction. However, LV global longitudinal strain does not take into consideration the effect of afterload. Novel speckle-tracking echocardiographic indices of myocardial work integrate blood pressure measurements (afterload) with LV global longitudinal strain. The present study aimed to investigate the prognostic value of global LV myocardial work efficiency (GLVMWE; reflecting LV performance) obtained from pressure-strain loops with echocardiography in patients with ST-segment-elevation myocardial infarction.Methods:A total of 507 ST-segment-elevation myocardial infarction patients (mean age, 61 +/- 11 years; 76% men) were retrospectively analyzed. LV ejection fraction and GLVMWE were measured by transthoracic echocardiography within 48 hours of admission. GLVMWE was defined as the ratio of constructive work divided by the sum of constructive and wasted work in all LV segments and expressed as a percentage. Spline curve analysis was used to define the association between reduced GLVMWE and all-cause death.Results:After a median follow-up of 80 months (interquartile range, 67-97 months), 40 (8%) patients died. Patients with reduced GLVMWE (= 86%). Reduced GLVMWE (<86%) showed an independent association with all-cause mortality (hazard ratio, 3.167 [95% CI, 1.679-5.972]; P<0.001).Conclusions:Reduced GLVMWE (<86%) measured by transthoracic echocardiography within 48 hours of admission in ST-segment-elevation myocardial infarction patients is associated with worse long-term survival.Cardiolog