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- Lav, Theodor, et al.
(författare)
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Non-invasive pressure volume loops derived by cardiovascular magnetic resonance: association between area at risk or infarct size and cardiac hemodynamics at 2-6 days after myocardial infarction
- 2023
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Konferensbidrag (refereegranskat)abstract
- BackgroundA novel non-invasive method for generation of pressure volume loops (PV-loops) using brachial blood pressure and cardiovascular magnetic resonance (CMR) imaging has recently been presented and validated (1). The non-invasive nature of this method enables calculation of PV-loops in large patient cohorts previously not feasible due to the need of invasive measurements.PurposeThe purpose of the present study was to investigate how cardiac hemodynamics assessed by PV-loop variables such as stroke work, potential energy, contractility and ventriculoarterial coupling is related to myocardium at risk and infarct size in a cohort of patients with acute myocardial infarction (MI).MethodA total of 100 patients with ST-elevation MI (STEMI) were included from the SOCCER, MITOCARE and CHILL-MI trials (2-4). The CHILL-MI cohort (n = 11) was prone to a stricter selection criterion than the SOCCER cohort, including first-time myocardial infarction and no comorbidities. All patients underwent a CMR examination at 2-6 days after MI. Non-invasive PV-loops were generated by combining volumetric CMR data and brachial sphygmomanometric pressure measurements using a recently validated method (1). Maximal elastance (Emax, translated to contractility), stroke work, potential energy and ventriculoarterial coupling (Ea/Emax) were measured from the PV-loops. Myocardium at risk and infarct size were assessed using contrast-enhanced steady state free precession and late gadolinium enhancement images, respectively.ResultsContractility, ventriculoarterial coupling, stroke work and potential energy all correlated to myocardium at risk (Emax: r²=0.25, Ea/Emax: r²=0.36, stroke work: r²=0.21, potential energy: r²=0.10) and infarct size (Emax: r²=0.29, Ea/Emax: r²=0.41, stroke work: r²=0.25, potential energy: r²=0.15) as shown in Figure 1. Furthermore, contractility showed a stronger correlation to myocardium at risk (Emax: r²=0.77) than to infarct size (Emax: r²=0.37) for the CHILL-MI patients as shown in Figure 2.ConclusionNon-invasive CMR derived PV-loop parameters can be used to assess cardiac hemodynamics early after STEMI showing that increased myocardium at risk and infarct size are both associated with an increased ventriculoarterial coupling and potential energy, and a decreased contractility and stroke work. To what extent these hemodynamic parameters provide incremental prognostic information compared to conventional parameters such as ejection fraction and left ventricular dimensions after STEMI remains to be determined.
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- Lundin, Magnus, et al.
(författare)
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Left ventricular global wall thickness is easily calculated, detects and characterizes hypertrophy, and has prognostic utility
- 2019
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- BACKGROUND: Cardiovascular magnetic resonance (CMR) can be used to measure left ventricular end-diastolic volume (LVEDV) and left ventricular mass (LVM). However, there is currently no good way to measure the normality of LVM in relation to a given LVEDV. We hypothesized that a simple measure of left ventricular global wall thickness (GWT) would be accurate, beneficial for detecting and characterizing hypertrophy, and have prognostic significance.METHODS: Subjects underwent CMR at 1.5T, including healthy volunteers (n=99) and patients assessed for heart disease (n=2828).RESULTS: GWT calculated from LVEDV and LVM had excellent agreement with measured mean end-diastolic wall thickness of the entire left ventricle (bias 0.01±0.23mm). GWT was most predictive of death or hospitalization for heart failure in patients with normal findings by CMR (n=326, log-rank 26.8, p<0.001, median [interquartile range] follow-up 5.8 [5.0–6.7] years). GWT indexed to body surface area (GWTi) was most predictive of outcomes in patients with normal LVEDV index (n=1352, log-rank 36.4, p<0.001, follow-up 5.5 [4.1–6.5] years). Patients with concentric remodeling had worse prognosis than the normal patients (p=0.02), and the patients with hypertrophy had worse prognosis than both normal patients (p<0.001) and patients with concentric remodeling (p=0.045), see Figure 1. Of patients with suspected heart disease but normal CMR findings regarding left ventricular volumes, function, mass, and scar, 22% were found to have increased mean GWTi corresponding to concentric remodeling, see Figure 2.CONCLUSIONS: Left ventricular GWT is an intuitive measure that can be easily calculated from mass and volume with high accuracy, and has prognostic utility in patients with normal CMR findings. Also, GWTi classifies hypertrophy as concentric or eccentric, and detects concentric remodeling in a substantial portion of patients with otherwise normal findings.
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- Lundin, Magnus, et al.
(författare)
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Prognostic utility and characterization of left ventricular hypertrophy using global thickness
- 2023
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Ingår i: Scientific Reports. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Cardiovascular magnetic resonance (CMR) can accurately measure left ventricular (LV) mass, and several measures related to LV wall thickness exist. We hypothesized that prognosis can be used to select an optimal measure of wall thickness for characterizing LV hypertrophy. Subjects having undergone CMR were studied (cardiac patients, n = 2543; healthy volunteers, n = 100). A new measure, global wall thickness (GT, GTI if indexed to body surface area) was accurately calculated from LV mass and end-diastolic volume. Among patients with follow-up (n = 1575, median follow-up 5.4 years), the most predictive measure of death or hospitalization for heart failure was LV mass index (LVMI) (hazard ratio (HR)[95% confidence interval] 1.16[1.12-1.20], p < 0.001), followed by GTI (HR 1.14[1.09-1.19], p < 0.001). Among patients with normal findings (n = 326, median follow-up 5.8 years), the most predictive measure was GT (HR 1.62[1.35-1.94], p < 0.001). GT and LVMI could characterize patients as having a normal LV mass and wall thickness, concentric remodeling, concentric hypertrophy, or eccentric hypertrophy, and the three abnormal groups had worse prognosis than the normal group (p < 0.05 for all). LV mass is highly prognostic when mass is elevated, but GT is easily and accurately calculated, and adds value and discrimination amongst those with normal LV mass (early disease).
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- Nordlund, David, et al.
(författare)
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Contractility, ventriculoarterial coupling, and stroke work after acute myocardial infarction using CMR-derived pressure-volume loop data
- 2024
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Ingår i: Clinical Cardiology. - 0160-9289. ; 47:1, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Noninvasive left ventricular (LV) pressure-volume (PV) loops derived by cardiac magnetic resonance (CMR) have recently been shown to enable characterization of cardiac hemodynamics. Thus, such PV loops could potentially provide additional diagnostic information such as contractility, arterial elastance (Ea) and stroke work (SW) currently not available in clinical routine. This study sought to investigate to what extent PV-loop variables derived with a novel noninvasive method can provide incremental physiological information over cardiac dimensions and blood pressure in patients with acute myocardial infarction (MI). Methods: A total of 100 patients with acute MI and 75 controls were included in the study. All patients underwent CMR 2?6 days after MI including assessment of myocardium at risk (MaR) and infarct size (IS). Noninvasive PV loops were generated from CMR derived LV volumes and brachial blood pressure measurements. The following variables were quantified: Maximal elastance (Emax) reflecting contractility, Ea, ventriculoarterial coupling (Ea/Emax), SW, potential energy, external power, energy per ejected volume, and efficiency. Results: All PV-loop variables were significantly different in MI patients compared to healthy volunteers, including contractility (Emax: 1.34?±?0.48 versus 1.50?±?0.41?mmHg/mL, p?=?.024), ventriculoarterial coupling (Ea/Emax: 1.27?±?0.61 versus 0.73?±?0.17, p?
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- Nordlund, David, et al.
(författare)
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Extent of myocardium at risk for left anterior descending artery, right coronary artery, and left circumflex artery occlusion depicted by contrast-enhanced steady state free precession and T2-weighted short tau inversion recovery magnetic resonance imaging
- 2016
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Ingår i: Circulation Cardiovascular Imaging. - 1941-9651. ; 9:7
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Tidskriftsartikel (refereegranskat)abstract
- Background - Contrast-enhanced steady state free precession (CE-SSFP) and T2-weighted short tau inversion recovery (T2-STIR) have been clinically validated to estimate myocardium at risk (MaR) by cardiovascular magnetic resonance while using myocardial perfusion single-photon emission computed tomography as reference standard. Myocardial perfusion single-photon emission computed tomography has been used to describe the coronary perfusion territories during myocardial ischemia. Compared with myocardial perfusion single-photon emission computed tomography, cardiovascular magnetic resonance offers superior image quality and practical advantages. Therefore, the aim was to describe the main coronary perfusion territories using CE-SSFP and T2-STIR cardiovascular magnetic resonance data in patients after acute ST-segment-elevation myocardial infarction. Methods and Results - CE-SSFP and T2-STIR data from 2 recent multicenter trials, CHILL-MI and MITOCARE (n=215), were used to assess MaR. Angiography was used to determine culprit vessel. Of 215 patients, 39% had left anterior descending artery occlusion, 49% had right coronary artery occlusion, and 12% had left circumflex artery occlusion. Mean extent of MaR using CE-SSFP was 44±10% for left anterior descending artery, 31±7% for right coronary artery, and 30±9% for left circumflex artery. Using T2-STIR, MaR was 44±9% for left anterior descending artery, 30±8% for right coronary artery, and 30±12% for left circumflex artery. MaR was visualized in polar plots, and expected overlap was found between right coronary artery and left circumflex artery. Detailed regional data are presented for use in software algorithms as a priori information on the extent of MaR. Conclusions - For the first time, cardiovascular magnetic resonance has been used to show the main coronary perfusion territories using CE-SSFP and T2-STIR. The good agreement between CE-SSFP and T2-STIR from this study and myocardial perfusion single-photon emission computed tomography from previous studies indicates that these 3 methods depict MaR accurately in individual patients and at a group level. Clinical Trial Registration - URL: http://www.clinicaltrials.gov. Unique identifiers: NCT01379261 and NCT01374321.
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