Accuracy of echocardiographic area-length method in chronic myocardial infarction : comparison with cardiac CT in pigs

Abstract Background We evaluated echocardiographic area-length methods to measure left ventricle (LV) volumes and ejection fraction (EF) in parasternal short axis views in comparison with cardiac computed tomography (CT) in pigs with chronic myocardial infarction (MI). Methods Male farm pigs with surgical occlusion of the left anterior descending coronary artery (n = 9) or sham operation (n = 5) had transthoracic echocardiography and cardiac-CT 3 months after surgery. We measured length of the LV in parasternal long axis view, and both systolic and diastolic LV areas in parasternal short axis views at the level of mitral valve, papillary muscles and apex. Volumes and EF of the LV were calculated using Simpson’s method of discs (tri-plane area) or Cylinder-hemiellipsoid method (single plane area). Results The pigs with coronary occlusion had anterior MI scars and reduced EF (average EF 42 ± 10%) by CT. Measurements of LV volumes and EF were reproducible by echocardiography. Compared with CT, end-diastolic volume (EDV) measured by echocardiography showed good correlation and agreement using either Simpson’s method (r = 0.90; mean difference −2, 95% CI −47 to 43 mL) or Cylinder-hemiellipsoid method (r = 0.94; mean difference 3, 95% CI −44 to 49 mL). Furthermore, End-systolic volume (ESV) measured by echocardiography showed also good correlation and agreement using either Simpson’s method (r = 0.94; mean difference 12 ml, 95% CI: −16 to 40) or Cylinder-hemiellipsoid method (r = 0.97; mean difference:13 ml, 95% CI: −8 to 33). EF was underestimated using either Simpson’s method (r = 0.78; mean difference −6, 95% CI −11 to 1%) or Cylinder-hemiellipsoid method (r = 0.74; mean difference −4, 95% CI–10 to 2%). Conclusion Our results indicate that measurement of LV volumes may be accurate, but EF is underestimated using either three or single parasternal short axis planes by echocardiography in a large animal model of chronic MI

Effect of Inhaled Xenon on Cardiac Function in Comatose Survivors of Out-of-Hospital Cardiac Arrest-A Substudy of the Xenon in Combination With Hypothermia After Cardiac Arrest Trial

Peer reviewe

Effect of Inhaled Xenon on Cardiac Function in Comatose Survivors of Out-of-Hospital Cardiac Arrest—A Substudy of the Xenon in Combination With Hypothermia After Cardiac Arrest Trial

OBJECTIVES: This explorative substudy aimed at determining the effect ofinhaled xenon on left ventricular function by echocardiography in comatose survivorsof out-of-hospital cardiac arrest.DESIGN: A randomized two-group single-blinded phase 2 clinical drug trial.SETTING: A multipurpose ICU in two university hospitals.PATIENTS: Of the 110 randomized comatose survivors after out-of-hospital cardiacarrest with a shockable rhythm in the xenon in combination with hypothermiaafter cardiac arrest trial, 38 patients (24–76 yr old) with complete echocardiographywere included in this study.INTERVENTIONS: Patients were randomized to receive either inhaled xenoncombined with hypothermia (33 C) for 24 hours or hypothermia treatment alone.Echocardiography was performed at hospital admission and 24 4 hours afterhypothermia.MEASUREMENTS AND MAIN RESULTS: Left ventricular ejection fraction,myocardial longitudinal systolic strain, and diastolic function were analyzedblinded to treatment. There were 17 xenon and 21 control patients in whom echocardiographywas completed. Clinical characteristics did not differ significantlybetween the groups. At admission, ejection fraction was similar in xenon and controlpatients (39% 10% vs 38% 11%; p = 0.711) but higher in xenon thancontrol patients after hypothermia (50% 10% vs 42% 10%; p = 0.014).Global longitudinal systolic strain was similar in xenon and control patients atadmission (–9.0% 3.8% vs –8.1% 3.6%; p = 0.555) but better in xenonthan control patients after hypothermia (–14.4.0% 4.0% vs –10.5% 4.0%;p = 0.006). In patients with coronary artery disease, longitudinal strain improved inthe nonischemic myocardial segments in xenon patients. There were no changesin diastolic function between the groups.</p

Impact of a decreasing pre-test probability on the performance of diagnostic tests for coronary artery disease

Aims To provide a pooled estimation of contemporary pre-test probabilities (PTPs) of significant coronary artery disease (CAD) across clinical patient categories, re-evaluate the utility of the application of diagnostic techniques according to such estimates, and propose a comprehensive diagnostic technique selection tool for suspected CAD.Methods and results Estimates of significant CAD prevalence across sex, age, and type of chest pain categories from three large-scale studies were pooled (n = 15 815). The updated PTPs and diagnostic performance profiles of exercise electrocardiogram, invasive coronary angiography, coronary computed tomography angiography (CCTA), positron emission tomography (PET), stress cardiac magnetic resonance (CMR), and SPECT were integrated to define the PTP ranges in which ruling-out CAD is possible with a post-test probability of <10% and <5%. These ranges were then integrated in a new colour-coded tabular diagnostic technique selection tool. The Bayesian relationship between PTP and the rate of diagnostic false positives was explored to complement the characterization of their utility. Pooled CAD prevalence was 14.9% (range = 1-52), clearly lower than that used in current clinical guidelines. Ruling-out capabilities of non-invasive imaging were good overall. The greatest ruling-out capacity (i.e. post-test probability <5%) was documented by CCTA, PET, and stress CMR. With decreasing PTP, the fraction of false positive findings rapidly increased, although a lower CAD prevalence partially cancels out such effect.Conclusion The contemporary PTP of significant CAD across symptomatic patient categories is substantially lower than currently assumed. With a low prevalence of the disease, non-invasive testing can rarely rule-in the disease and focus should shift to ruling-out obstructive CAD. The large proportion of false positive findings must be taken into account when patients with low PTP are investigated.Cardiolog

The performance of non-invasive tests to rule-in and rule-out significant coronary artery stenosis in patients with stable angina: a meta-analysis focused on post-test disease probability.

Aims: To determine the ranges of pre-test probability (PTP) of coronary artery disease (CAD) in which stress electrocardiogram (ECG), stress echocardiography, coronary computed tomography angiography (CCTA), single-photon emission computed tomography (SPECT), positron emission tomography (PET), and cardiac magnetic resonance (CMR) can reclassify patients into a post-test probability that defines (>85%) or excludes (100 patients with stable CAD that utilized either ICA or ICA with FFR measurement as reference, were included. Study-level data was pooled using a hierarchical bivariate random-effects model and likelihood ratios were obtained for each technique. The PTP ranges for each technique to rule-in or rule-out significant CAD were defined. A total of 28 664 patients from 132 studies that used ICA as reference and 4131 from 23 studies using FFR, were analysed. Stress ECG can rule-in and rule-out anatomically significant CAD only when PTP is >/=80% (76-83) and /=58% (45-70) and rule-out at a PTP /=75% (67-83) and /=71% (59-81) and /=46-59% and rule-out when PTP is </=34-57%. Conclusion: The various diagnostic modalities have different optimal performance ranges for the detection of anatomically and functionally significant CAD. Stress ECG appears to have very limited diagnostic power. The selection of a diagnostic technique for any given patient to rule-in or rule-out CAD should be based on the optimal PTP range for each test and on the assumed reference standard

Effect of Inhaled Xenon on Cardiac Function in Comatose Survivors of Out-of-Hospital Cardiac Arrest—A Substudy of the Xenon in Combination With Hypothermia After Cardiac Arrest Trial

This explorative substudy aimed at determining the effect of inhaled xenon on left ventricular function by echocardiography in comatose survivors of out-of-hospital cardiac arrest.DesignA randomized two-group single-blinded phase 2 clinical drug trial.SettingA multipurpose ICU in two university hospitals.PatientsOf the 110 randomized comatose survivors after out-of-hospital cardiac arrest with a shockable rhythm in the xenon in combination with hypothermia after cardiac arrest trial, 38 patients (24-76 yr old) with complete echocardiography were included in this study.InterventionsPatients were randomized to receive either inhaled xenon combined with hypothermia (33°C) for 24 hours or hypothermia treatment alone. Echocardiography was performed at hospital admission and 24 ± 4 hours after hypothermia.Measurements and main resultsLeft ventricular ejection fraction, myocardial longitudinal systolic strain, and diastolic function were analyzed blinded to treatment. There were 17 xenon and 21 control patients in whom echocardiography was completed. Clinical characteristics did not differ significantly between the groups. At admission, ejection fraction was similar in xenon and control patients (39% ± 10% vs 38% ± 11%; p = 0.711) but higher in xenon than control patients after hypothermia (50% ± 10% vs 42% ± 10%; p = 0.014). Global longitudinal systolic strain was similar in xenon and control patients at admission (-9.0% ± 3.8% vs -8.1% ± 3.6%; p = 0.555) but better in xenon than control patients after hypothermia (-14.4.0% ± 4.0% vs -10.5% ± 4.0%; p = 0.006). In patients with coronary artery disease, longitudinal strain improved in the nonischemic myocardial segments in xenon patients. There were no changes in diastolic function between the groups.ConclusionsAmong comatose survivors of a cardiac cause out-of-hospital cardiac arrest, inhaled xenon combined with hypothermia was associated with greater recovery of left ventricular systolic function in comparison with hypothermia alone