Echocardiographic assessment of diastolic dysfunction in elderly patients with severe aortic stenosis before and after aortic valve replacement.

BACKGROUND: The 2016 guidelines of the American Society of Echocardiography (ASE) and European Association of Cardiovascular Imaging (EACVI) for evaluation of left ventricular (LV) diastolic dysfunction by Doppler flow and tissue Doppler- echocardiography do not adjust assessment of high filling pressures for patients with aortic stenosis (AS). However, most of the studies on this patient group indicate age independent specific diastolic features in AS. The aim of this study is to identify disease-specific range and distribution of diastolic functional parameters and their ability to identify high N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels as a marker for high filling pressures. METHODS: In this study, 169 patients who underwent surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR) were prospectively enrolled. Resting echocardiography was performed including Doppler of the mitral inflow, pulmonary venous flow, tricuspid regurgitant flow and tissue Doppler in the mitral ring and indexed volume-estimates of the left atrium (LAVI). Echocardiography, and NT-proBNP levels were assessed before TAVR/SAVR and at two postoperative visits at 6 and 12 months. RESULTS: Pre- and postoperative values were septal e'; 5.1 ± 3.9, 5.2 ± 1.6 cm/s; lateral e' 6.3 ± 2.1; 7.7 ± 2.7 cm/s; E/e'19 ± 8; 16 ± 7 cm/s; E velocity 96 ± 32; 95 ± 32 cm/s; LAVI 39 ± 8; 36 ± 8 ml/m2, pulmonary artery pressure (PAP) 39 ± 8; 36 ± 8 mmHg, respectively. The scoring recommended by ASE/EACVI detected elevated NT pro-BNP with a specificity of 25%. Adjusting thresholds towards PAP ≥ 40 mmHg, E velocity ≥ 100 cm/s, E deceleration time < 220 ms, and E/septal e' ≥ 20 or septal e' < 5.0 cm/s increased prediction of NT-proBNP levels ≥500 ng/L with substantially improved specificity (> 85%). CONCLUSION: Diastolic echocardiographic parameters in AS indicate persistent impaired relaxation and NT-proBNP indicate elevated filling pressures in most of the patients, improving only modestly 6-12 months after TAVR and SAVR. Applying the 2016 ASE/EACVI recommendations for detection of elevated filling pressures to patients with AS, elevated NT pro-BNP levels could not be reliably detected. However, adjusting thresholds of the echocardiographic parameters increased specificities to useful diagnostic levels. TRIAL REGISTRATION: The study was prospectively approved by the regional ethical committee, REK North with the registration number: REK 2010/397-10 .

Assessment of myocardial ischemia by strain dobutamine stress echocardiography and cardiac magnetic resonance perfusion imaging before and after coronary artery bypass grafting.

BACKGROUND: Following coronary artery bypass grafting (CABG), testing for myocardial ischemia by noninvasive imaging is often hampered by false-positive results. The aim of this study was to find test parameters with the best potential to identify myocardial ischemia in post-CABG patients. METHODS: Fifty-two consecutive patients scheduled for CABG, underwent both dobutamine stress echocardiography (DSE) and cardiac magnetic resonance first-pass perfusion imaging (CMR-FPPI) with adenosine vasodilation, before and 8-10 months after the surgical revascularization. A pathologic biphasic stress response (PBR) expresses the presence of contractile reserve during low-dose dobutamine that decreases to hypo- or akinesia provoked by high-dose dobutamine. During DSE, potential PBR, segmental wall-motion score (WMS) as well as peak-systolic longitudinal strain (PLS) at peak-dose dobutamine were assessed. RESULTS: Post-CABG, there was still a relatively high prevalence of ischemia-positive segments evaluated by deformation imaging, but the number of such segments was significantly lower by PBR (20% and 22%) compared with peak-dose strain and WMS (62% and 77%, respectively; P<.05). The use of PBR instead of peak-dose WMS and strain could reduce the number of false-positive test results post-CABG. CONCLUSION: Among all imaging modalities tested, PBR by WMS and strain may be useful parameters for identifying patients with the need for new revascularization. We furthermore found that DSE may be interpreted as positive when revealing at least three ischemia-positive segments. The sensitivity of these test modalities for detecting coronary restenosis needs to be determined in further studies on a cohort of symptomatic post-CABG patients.

The effect of referral templates on out-patient quality of care in a hospital setting: a cluster randomized controlled trial.

BACKGROUND: The assessment of quality of care is an integral part of modern medicine. The referral represents the handing over of care from the general practitioner to the specialist. This study aimed to assess whether an improved referral could lead to improved quality of care. METHODS: A cluster randomized trial with the general practitioner surgery as the clustering unit was performed. Fourteen surgeries in the area surrounding the University Hospital of North Norway Harstad were randomized stratified by town versus countryside location. The intervention consisted of implementing referral templates for new referrals in four clinical areas: dyspepsia; suspected colorectal cancer; chest pain; and confirmed or suspected chronic obstructive pulmonary disease. The control group followed standard referral practice. Quality of treatment pathway as assessed by newly developed quality indicators was used as main outcome. Secondary outcomes included subjective quality assessment, positive predictive value of referral and adequacy of prioritization. Assessment of outcomes was done at the individual level. The patients, hospital doctors and outcome assessors were blinded to the intervention status. RESULTS: A total of 500 patients were included, with 281 in the intervention and 219 in the control arm. From the multilevel regression model the effect of the intervention on the quality indicator score was insignificant at 1.80% (95% CI, -1.46 to 5.06, p = 0.280). No significant differences between the intervention and the control groups were seen in the secondary outcomes. Active use of the referral intervention was low, estimated at approximately 50%. There was also wide variation in outcome scoring between the different assessors. CONCLUSIONS: In this study no measurable effect on quality of care or prioritization was revealed after implementation of referral templates at the general practitioner/hospital interface. The results were hindered by a limited uptake of the intervention at GP surgeries and inconsistencies in outcome assessment. TRIAL REGISTRATION: The study was registered under registration number NCT01470963 on September 5th, 2011.

Changes in Right Ventricular Shape and Deformation Following Coronary Artery Bypass Surgery-Insights from Echocardiography with Strain Rate and Magnetic Resonance Imaging.

BACKGROUND: This study was designed to assess whether altered RV geometry and deformation parameters persisted well into the recovery period after presumably uncomplicated coronary artery bypass grafting (CABG). It was our hypothesis that the altered geometry of and load in the RV following pericardial opening would change both regional and global deformation indices for an extensive period postoperatively. METHODS AND RESULTS: Fifty-seven patients scheduled for CABG underwent preoperative and 8-10 months postoperative magnetic resonance imaging (MRI) for RV volume measurements, and resting echocardiography with assessment of geometry and RV mechanical function determined by tissue Doppler imaging (TDI) based longitudinal strain. Both MRI and echocardiography revealed postoperative dilatation of the RV apex, shortened longitudinal RV length but unchanged RV ejection fraction. Echocardiography parameters associated with filling of the right atrium showed signs of constraint with a reduced systolic filling fraction and increased right atrial size. Right ventricular segmental strain (-20 ± 13% vs. -29 ± 20% preoperatively; mean ±SD, P < 0.0001) was reduced postoperatively in parallel with TAPSE (1.3 ± 0.3 cm vs. 2.2 ± 0.4 cm; P < 0.0001). CONCLUSION: Post-CABG longitudinal motion of the RV lateral wall is reduced after uneventful CABG despite preserved RV ejection fraction and stroke volume. The discrepancy in various RV systolic performance indicators results from increased sphericity of the RV following opening the pericardium during surgery. Therefore, longitudinal functional parameters may underestimate RV systolic function for at least 8-10 months post-CABG. Changes in deformation parameters should thus always be interpreted in relation to changes in geometry.

Impact of referral templates on the quality of referrals from primary to secondary care: a cluster randomised trial.

BACKGROUND: The referral letter is an important document facilitating the transfer of care from a general practitioner (GP) to secondary care. Hospital doctors have often criticised the quality and content of referral letters, and the effectiveness of improvement efforts remains uncertain. METHODS: A cluster randomised trial was conducted using referral templates for patients in four diagnostic groups: dyspepsia, suspected colorectal cancer, chest pain and chronic obstructive pulmonary disease. The GP surgery was the unit of randomisation. Of the 14 surgeries served by the University Hospital of North Norway Harstad, seven were randomised to the intervention group. Intervention GPs used referral templates soliciting core clinical information when initiating a new referral in one of the four clinical areas. Intermittent surgery visits by study personnel were also carried out. A total of 500 patients were included, with 281 in the intervention and 219 in the control arm. Referral quality scoring was performed by three blinded raters. Data were analysed using multi-level regression modelling. All analyses were conducted on intention-to-treat basis. RESULTS: In the final multilevel model, referrals in the intervention group scored 18% higher (95% CI (11%, 25%), p < 0.001) on the referral quality score than the control group. The model also showed that board certified GPs and GPs in larger surgeries produced referrals of significantly higher quality. CONCLUSION: In this study, the dissemination of referral templates coupled with intermittent surgery visits produced higher quality referrals. TRIAL REGISTRATION: This trial has been registered at ClinicalTrials.gov. The trial registration number is NCT01470963.

Automatic measurements of left ventricular volumes and ejection fraction by artificial intelligence: clinical validation in real time and large databases.

AIMS: Echocardiography is a cornerstone in cardiac imaging, and left ventricular (LV) ejection fraction (EF) is a key parameter for patient management. Recent advances in artificial intelligence (AI) have enabled fully automatic measurements of LV volumes and EF both during scanning and in stored recordings. The aim of this study was to evaluate the impact of implementing AI measurements on acquisition and processing time and test-retest reproducibility compared with standard clinical workflow, as well as to study the agreement with reference in large internal and external databases. METHODS AND RESULTS: Fully automatic measurements of LV volumes and EF by a novel AI software were compared with manual measurements in the following clinical scenarios: (i) in real time use during scanning of 50 consecutive patients, (ii) in 40 subjects with repeated echocardiographic examinations and manual measurements by 4 readers, and (iii) in large internal and external research databases of 1881 and 849 subjects, respectively. Real-time AI measurements significantly reduced the total acquisition and processing time by 77% (median 5.3 min, P < 0.001) compared with standard clinical workflow. Test-retest reproducibility of AI measurements was superior in inter-observer scenarios and non-inferior in intra-observer scenarios. AI measurements showed good agreement with reference measurements both in real time and in large research databases. CONCLUSION: The software reduced the time taken to perform and volumetrically analyse routine echocardiograms without a decrease in accuracy compared with experts.

Clinical and Echocardiographic Parameters Predicting 1- and 2-Year Mortality After Transcatheter Aortic Valve Implantation.

Background: Transcatheter aortic valve implantation (TAVI) has become a standard treatment option for patients with symptomatic aortic stenosis. Elderly high-risk patients treated with TAVI have a high residual mortality due to preexisting comorbidities. Knowledge of factors predicting futility after TAVI is sparse and clinical tools to aid the preoperative evaluation are lacking. The aim of this study was to evaluate if echocardiographic measures, including speckle-tracking analysis, in addition to clinical parameters, could aid in the prediction of mortality beyond 30 days after TAVI. Methods: This prospective observational cohort study included 227 patients treated with TAVI at the University Hospital of North Norway, Tromsø and Oslo University Hospital, Rikshospitalet from February 2010 to June 2013. All the patients underwent preoperative echocardiographic evaluation with retrospective speckle-tracking analysis. Primary endpoints were 1- and 2-year mortality beyond 30 days after TAVI. Results: All-cause 1- and 2-year mortality beyond 30 days after TAVI was 12.1 and 19.5%, respectively. Predictors of 1-year mortality beyond 30 days were body mass index [hazard ratio (HR): 0.88, 95% CI: 0.80-0.98, p = 0.018], previous myocardial infarction (HR: 2.69, 95% CI: 1.14-6.32, p = 0.023), and systolic pulmonary artery pressure ≥ 60 mm Hg (HR: 5.93, 95% CI: 1.67-21.1, p = 0.006). Moderate-to-severe mitral regurgitation (HR: 2.93, 95% CI: 1.53-5.63, p = 0.001), estimated glomerular filtration rate (HR: 0.98, 95% CI: 0.96-0.99, p = 0.002), and chronic obstructive pulmonary disease (HR: 1.9, 95% CI: 1.01-3.58, p = 0.046) were predictors of 2-year mortality. Conclusion: Both the clinical and echocardiographic parameters should be considered when evaluating high-risk patients for TAVI, as both are predictive of 1-and 2-year mortality. Our results support the importance of individual risk assessment using a multidisciplinary, multimodal, and individual approach.

Risk scores for prediction of 30-day mortality after transcatheter aortic valve implantation: Results from a two-center study in Norway.

OBJECTIVES: Transcatheter aortic valve implantation (TAVI)-specific risk scores have been developed based on large registry studies. Our aim was to evaluate how both surgical and novel TAVI risk scores performed in predicting all cause 30-day mortality. In addition, we wanted to explore the validity of our own previously developed model in a separate and more recent cohort. METHODS: The derivation cohort included patients not eligible for open surgery treated with TAVI at the University Hospital of North Norway (UNN) and Oslo University Hospital (OUS) from February 2010 through June 2013. From this cohort, a logistic prediction model (UNN/OUS) for all cause 30-day mortality was developed. The validation cohort consisted of patients not included in the derivation cohort and treated with TAVI at UNN between June 2010 and April 2017. EuroSCORE, Logistic EuroSCORE, EurosSCORE 2, STS score, German AV score, OBSERVANT score, IRRMA score, and FRANCE-2 score were calculated for both cohorts. The discriminative accuracy of each score, including our model, was evaluated by receiver operating characteristic (ROC) analysis and compared using DeLong test where P< .05 was considered statistically significant. RESULTS: The derivation cohort consisted of 218 and the validation cohort of 241 patients. Our model showed statistically significant better accuracy than all other scores in the derivation cohort. In the validation cohort, the FRANCE-2 had a significantly higher predictive accuracy compared to all scores except the IRRMA and STS score. Our model showed similar results. CONCLUSION: Existing risk scores have shown limited accuracy in predicting early mortality after TAVI. Our results indicate that TAVI-specific risk scores might be useful when evaluating patients for TAVI.

Semi-automated quantification of left ventricular volumes and ejection fraction by real-time three-dimensional echocardiography.

BACKGROUND: Recent studies have shown that real-time three-dimensional (3D) echocardiography (RT3DE) gives more accurate and reproducible left ventricular (LV) volume and ejection fraction (EF) measurements than traditional two-dimensional methods. A new semi-automated tool (4DLVQ) for volume measurements in RT3DE has been developed. We sought to evaluate the accuracy and repeatability of this method compared to a 3D echo standard. METHODS: LV end-diastolic volumes (EDV), end-systolic volumes (ESV), and EF measured using 4DLVQ were compared with a commercially available semi-automated analysis tool (TomTec 4D LV-Analysis ver. 2.2) in 35 patients. Repeated measurements were performed to investigate inter- and intra-observer variability. RESULTS: Average analysis time of the new tool was 141s, significantly shorter than 261s using TomTec (p < 0.001). Bland Altman analysis revealed high agreement of measured EDV, ESV, and EF compared to TomTec (p = NS), with bias and 95% limits of agreement of 2.1 +/- 21 ml, -0.88 +/- 17 ml, and 1.6 +/- 11% for EDV, ESV, and EF respectively. Intra-observer variability of 4DLVQ vs. TomTec was 7.5 +/- 6.2 ml vs. 7.7 +/- 7.3 ml for EDV, 5.5 +/- 5.6 ml vs. 5.0 +/- 5.9 ml for ESV, and 3.0 +/- 2.7% vs. 2.1 +/- 2.0% for EF (p = NS). The inter-observer variability of 4DLVQ vs. TomTec was 9.0 +/- 5.9 ml vs. 17 +/- 6.3 ml for EDV (p < 0.05), 5.0 +/- 3.6 ml vs. 12 +/- 7.7 ml for ESV (p < 0.05), and 2.7 +/- 2.8% vs. 3.0 +/- 2.1% for EF (p = NS). CONCLUSION: In conclusion, the new analysis tool gives rapid and reproducible measurements of LV volumes and EF, with good agreement compared to another RT3DE volume quantification tool.

Predictors of early mortality after transcatheter aortic valve implantation.

Objectives: To investigate whether preoperative echocardiographic evaluation of ventricular function, especially right ventricular systolic and diastolic parameters including speckle-tracking analysis, could aid in the prediction of 30-day mortality after transcatheter aortic valve implantation (TAVI) in patients with aortic stenosis. Methods: This is a prospective observational cohort study including 227 patients accepted for TAVI at the University Hospital of North Norway and Oslo University Hospital from February 2010 through June 2013. All patients underwent preoperative transthoracic echocardiography with retrospective speckle-tracking analysis. Primary endpoint was all-cause 30-day mortality. Results: All-cause 30-day mortality was 8.7 % (n = 19). Independent predictors of 30-day mortality were systolic pulmonary arterial pressure (SPAP) > 60 mm Hg (HR: 7.7, 95% CI: 1.90 to 31.3), heart failure (HR: 2.9, 95% CI: 1.1 to 7.78), transapical access (HR: 3.8, 95% CI: 1.3 to 11.2), peripheral artery disease (HR: 6.0, 95% CI: 2.0 to 18.0) and body mass index (HR: 0.73, 95% CI: 0.61 to 0.87). C-statistic for the model generated was 0.91 (95% CI: 0.85 to 0.98). Besides elevated SPAP, no other echocardiographic measurements were found to be an independent predictor of early mortality. Conclusion: Except for elevated systolic pulmonary artery pressure, our data suggests that clinical rather than echocardiographic parameters are useful predictors of 30-day mortality after TAVI.

Quantification of resting myocardial blood flow velocity in normal humans using real-time contrast echocardiography. A feasibility study.

BACKGROUND: Real-time myocardial contrast echocardiography (MCE) is a novel method for assessing myocardial perfusion. The aim of this study was to evaluate the feasibility of a very low-power real-time MCE for quantification of regional resting myocardial blood flow (MBF) velocity in normal human myocardium. METHODS: Twenty study subjects with normal left ventricular (LV) wall motion and normal coronary arteries, underwent low-power real-time MCE based on color-coded pulse inversion Doppler. Standard apical LV views were acquired during constant IV. infusion of SonoVue. Following transient microbubble destruction, the contrast replenishment rate (beta), reflecting MBF velocity, was derived by plotting signal intensity vs. time and fitting data to the exponential function; y (t) =A (1-e(-beta(t-t0))) + C. RESULTS: Quantification was feasible in 82%, 49% and 63% of four-chamber, two-chamber and apical long-axis view segments, respectively. The LAD (left anterior descending artery) and RCA (right coronary artery) territories could potentially be evaluated in most, but contrast detection in the LCx (left circumflex artery) bed was poor. Depending on localisation and which frames to be analysed, mean values of beta were 0.21-0.69 s(-1), with higher values in medial than lateral, and in basal compared to apical regions of scan plane (p = 0.03 and p < 0.01). Higher beta-values were obtained from end-diastole than end-systole (p < 0.001), values from all-frames analysis lying between. CONCLUSION: Low-power real-time MCE did have the potential to give contrast enhancement for quantification of resting regional MBF velocity. However, the technique is difficult and subjected to several limitations. Significant variability in beta suggests that this parameter is best suited for with-in patient changes, comparing values of stress studies to baseline.

Severe regional myocardial dysfunction by stress echocardiography does not predict the presence of transmural scarring in chronic coronary artery disease.

AIMS: Detection and correct localization of transmural lesions can be important for optimal treatment of patients with chronic coronary artery disease (CAD). The aim of the study was to investigate the ability of peak longitudinal ejection strain (PLS) to detect the presence and extent of scar-tissue in CAD patients with normal or near normal ejection fraction, in comparison to cardiac magnetic resonance (CMR). METHODS AND RESULTS: Before coronary artery bypass grafting, 57 patients underwent late gadolinium enhancement (LGE) CMR and echocardiography at rest and dobutamine stress (DS). According to the degree of LGE, segments were allocated to groups of none, subendocardial (1-50%), subtotal (51-75%), and total transmural scars (>75%). Dysfunctional segments were identified by PLS or wall motion scores (WMS). The finding of normal/near normal resting WMS and PLS, excellently identified segments without transmural LGE (AUC 94.0 CI 90.6-97.3 and AUC 85.7 CI 79.0-92.3, respectively). However, the finding of akinesia did not necessarily indicate transmural scarring. The negative predictive value was high (99%, CI 98-100%) while the positive predictive value was low. Detection-rates for subendocardial LGE were low. CONCLUSION: Normo- and slightly hypokinetic myocardium by resting WMS or strain detects the absence of transmural scars. However, the finding of severe hypo- and akinesia does not reliably predict transmural scarring, with no improvement by the addition of DS. Detection of predominant akinesia with less than two normo- or hypokinetic segments in the territory of a high-grade coronary stenosis or occlusion, warrants further examination by LGE-CMR.

Practical health co-operation - the impact of a referral template on quality of care and health care co-operation: study protocol for a cluster randomized controlled trial.

BACKGROUND: The referral letter plays a key role both in the communication between primary and secondary care, and in the quality of the health care process. Many studies have attempted to evaluate and improve the quality of these referral letters, but few have assessed the impact of their quality on the health care delivered to each patient. METHODS: A cluster randomized trial, with the general practitioner office as the unit of randomization, has been designed to evaluate the effect of a referral intervention on the quality of health care delivered. Referral templates have been developed covering four diagnostic groups: dyspepsia, suspected colonic malignancy, chest pain, and chronic obstructive pulmonary disease. Of the 14 general practitioner offices primarily served by University Hospital of North Norway Harstad, seven were randomized to the intervention group. The primary outcome is a collated quality indicator score developed for each diagnostic group. Secondary outcomes include: quality of the referral, health process outcome such as waiting times, and adequacy of prioritization. In addition, information on patient satisfaction will be collected using self-report questionnaires. Outcome data will be collected on the individual level and analyzed by random effects linear regression. DISCUSSION: Poor communication between primary and secondary care can lead to inappropriate investigations and erroneous prioritization. This study's primary hypothesis is that the use of a referral template in this communication will lead to a measurable increase in the quality of health care delivered. TRIAL REGISTRATION: This trial has been registered at ClinicalTrials.gov. The trial registration number is NCT01470963.

Persistent dysfunction of viable myocardium after revascularization in chronic ischaemic heart disease: implications for dobutamine stress echocardiography with longitudinal systolic strain and strain rate measurements.

AIMS: Studies of functional recovery after revascularization in chronic coronary artery disease are contradictory and mark a lack of knowledge of persistent dysfunction in the non-scarred myocardium. Based on tissue Doppler-derived regional longitudinal systolic strain and strain rate (SR), both at rest and during dobutamine stress (DS), we assessed to what extent ischaemia-related reduced myocardial function would recover after revascularization in hearts with predominantly viable myocardium. METHODS AND RESULTS: Reference peak systolic strain and SR values were determined from tissue Doppler imaging in 15 healthy volunteers. Fifty-seven patients scheduled for coronary artery bypass grafting (CABG), with an average ejection fraction of 49%, underwent pre-operative magnetic resonance imaging (MRI) with late enhancement, resting echocardiography, and DS echocardiography (DSE), with assessment of systolic strain and SR and post-systolic strain (PSS). Eight to 10 months after CABG, myocardial function was reassessed. Forty per cent of all segments had reduced longitudinal systolic strain pre-operatively despite only 1.4% of segments with transmural infarctions on MRI. After revascularization, 38% of prior dysfunctional segments improved their resting strain, whereas 72% were improved by DS. Positive resting systolic strain indicated the absence of significant scar tissue. Resting systolic strain and DS strain responses were good prognosticators for functional improvement with areas under the receiver operating characteristic curve of 0.753 (0.646-0.860) and 0.790 (0.685-0.895), respectively. CONCLUSION: Persistently reduced longitudinal function was observed in more than half of pre-operatively viable but dysfunctional segments after CABG. We propose that such a functional impairment marks a regional remodelling process not amendable to re-established blood flow.

Recovery of function after acute myocardial infarction evaluated by tissue Doppler strain and strain rate.

BACKGROUND: The aim of this study was to investigate the changes and time course of recovery of regional myocardial function within the first week following successful primary coronary intervention in patients with first-time ST-segment elevation myocardial infarctions using myocardial deformation analysis, which is more quantitative and thus more objective than the wall motion score. METHODS: Thirty-one consecutive patients admitted with ST-segment elevation myocardial infarctions were studied on days 1, 2, 3, and 7 using strain and strain rate tissue Doppler echocardiography. RESULTS: The mean peak troponin T level was 7.0 microg/L, and 15 patients had anterior and 16 had inferior infarct localization. Peak systolic strain rate and end-systolic strain increased significantly on day 2, both in segments with moderately reduced function (-0.6 to -1.0 s(-1) vs -8% to -15%, P < .001) and in severely reduced function (-0.2 to -1.0 s(-1) vs 1% to -12%, P < .001), but there were no further changes. Mean wall motion score in infarct related segments decreased significantly from day 1 to day 2 (2.7 to 2.4, P = .001) and from day 3 to day 7 (2.3 to 2.2, P = .001). CONCLUSIONS: Recovery of regional function after ST-segment elevation myocardial infarction occurred within 2 days and could be detected by wall motion score, strain rate, and strain. However, strain and strain rate were better discriminative parameters for the changes in function as well as being better to assess near normalization on day 2. This could have a clinical impact on early management in patients who undergo percutaneous coronary intervention.

Quantitative adenosine real-time myocardial contrast echocardiography for detection of angiographically significant coronary artery disease.

BACKGROUND: Real-time (RT) myocardial contrast echocardiography (MCE) is a novel method for assessment of regional myocardial perfusion. We sought to evaluate the feasibility and diagnostic accuracy of quantitative adenosine RT MCE in predicting significant coronary stenoses, with reference to quantitative coronary angiography. METHODS: Low-power RT MCE was performed in 43 patients scheduled for quantitative coronary angiography. Peak signal intensity (A), rate of signal intensity increase (beta), A x beta (myocardial blood flow), and their hyperemic reserves were estimated and compared with angiographic data. RESULTS: The feasibility of quantitative stress RT MCE covering all coronary territories was 77% of patients with adequate baseline image quality. At rest we found no significant difference for any of the perfusion parameters between the normal and stenosed coronary territories. During hyperemia, beta and A x beta, but not A, increased significantly in normal coronary territories. In the regions subtended by significantly stenosed arteries, there were no significant increases in beta and A x beta. Receiver operating characteristic curves indicated that beta- and A x beta-reserves, but not A-reserve, could be sensitive parameters for detecting flow-limiting coronary stenosis in selected patients, particularly if significant left anterior descending coronary artery disease was involved. CONCLUSION: Quantitative assessment of myocardial blood flow and its velocity reserve by RT MCE has the potential to detect significant coronary artery disease, but because of imaging and technical problems it is not yet robust enough for clinical use in unselected patients.

Effects of ultrasound contrast during tissue velocity imaging on regional left ventricular velocity, strain, and strain rate measurements.

BACKGROUND: Strain (epsilon) rate (SR) imaging and left ventricular (LV) opacification with intravenous (IV) contrast both potentially decrease operator dependency in interpretation of stress echocardiography. The aim of this study was to evaluate whether contrast present during tissue velocity imaging (TVI) significantly affected measurements of velocity, epsilon, and SR. Secondly, we sought to evaluate whether increased scan line density improved feasibility of simultaneous TVI and contrast echocardiography. METHODS: The 4-chamber LV view in 15 healthy volunteers and 25 patients was acquired at rest before and after IV injections of contrast using: (1) conventional TVI; (2) LV opacification with standard TVI added; and (3) modified LV opacification with doubled TVI line density. Velocity, SR, and epsilon curves, along with peak systolic velocity, peak systolic SR, and end-systolic epsilon, were assessed from midwall segments. RESULTS: IV contrast significantly reduced feasibility of TVI with standard settings, giving noisy data for SR and epsilon, particularly in the septum. Absolute values of peak systolic SR and end-systolic epsilon from adequately shaped curves were significantly higher with contrast compared with baseline. However, increased TVI line density significantly improved feasibility of velocity traces with contrast and decreased the level of noise in SR and epsilon. Furthermore, higher line density improved agreement between peak systolic velocity, peak systolic SR, and end-systolic epsilon measured with contrast, and corresponding precontrast values from the conventional TVI setting. CONCLUSIONS: SR imaging was not feasible performed with IV contrast during conventional TVI settings, and we do not recommend the clinical use of this combination. Increased TVI line density made velocity curves with contrast feasible and resulted in less noisy SR and epsilon curves, but variability in SR and epsilon measurements with contrast is still too high for clinical use.

Real-time simultaneous triplane contrast echocardiography gives rapid, accurate, and reproducible assessment of left ventricular volumes and ejection fraction: a comparison with magnetic resonance imaging.

OBJECTIVE: We sought to compare the feasibility, accuracy, and reproducibility of simultaneous triplane echocardiography for measurements of left ventricular (LV) volumes and ejection fraction (EF) with reference to magnetic resonance imaging (MRI). METHODS: Digital echocardiography recordings of apical LV views with and without intravenous contrast were collected from 53 consecutive patients with conventional 2-dimensional (2D) imaging and with simultaneous triplane imaging. MRI of multiple LV short-axis sections was performed with a 1.5-T scanner. Endocardial borders were manually traced, and LV volumes and EF from 2D biplane echocardiography and MRI were calculated by method of disks. On triplane data, a triangular mesh was constructed by 3-dimensional interpolation and volumes calculated by the divergence theorem. RESULTS: Triplane image acquisition was less time-consuming than 2D biplane. Precontrast feasibility was 72% for triplane and 82% for 2D biplane images, increasing to 98% and 100% with contrast, respectively. Bland-Altman analysis demonstrated LV volume underestimation by echocardiography versus MRI, which was significantly reduced by contrast and triplane imaging. The 95% limits of agreement for EF between echocardiography and MRI narrowed using triplane compared with 2D biplane (precontrast -12.5 to 6.7% vs -17.2 to 9.9%, and with contrast -7.1 to 5.8% vs -9.4 to 6.4%, respectively). At intraobserver and interobserver analysis of 20 patients, limits of agreement for EF narrowed with contrast triplane compared with 2D biplane. CONCLUSION: Simultaneous LV triplane imaging is feasible with simple and rapid image acquisition and volume analysis, and with contrast enhancement it gives accurate and reproducible LV EF measurements compared with MRI.

Choosing apical long-axis instead of two-chamber view gives more accurate biplane echocardiographic measurements of left ventricular ejection fraction: a comparison with magnetic resonance imaging.

BACKGROUND: We sought to evaluate whether the use of apical long-axis (APLAX) rather than two-chamber (2CH) view, in combination with four-chamber (4CH) view, improved accuracy of biplane echocardiographic measurements of left ventricular (LV) ejection fraction (EF), using magnetic resonance imaging (MRI) as a reference standard. METHODS: One hundred consecutive cardiac patients underwent cardiac MRI and 2D-echocardiography. Standard apical LV views were digitally acquired with baseline tissue harmonic imaging and low-power contrast echocardiography. Echo and MRI LV volumes were calculated by manual tracing and disc summation methods. RESULTS: Feasiblity for biplane volume measurements increased with the use of APLAX. Precontrast limits of agreement (LOA) for EF compared to MRI were -19.1 to 9.0 % (EF units) using 2CH, narrowing to -14.6 to 6.7% using the APLAX. With contrast, corresponding LOAs narrowed from -10.5 to 6.1%, to -7.3 to 3.8%, respectively. The improved accuracy with APLAX was evident regardless of image quality, previous MI and regional LV dyssynergy. Both intra- and interobserver variability improved by substituting 2CH with APLAX view. CONCLUSION: Using APLAX rather than 2CH in combination with 4CH view improved feasibility, accuracy and reproducibility of biplane echocardiographic EF measurements in cardiac patients, even with optimisation of endocardial borders by contrast.

Accurate and reproducible measurement of left ventricular volume and ejection fraction by contrast echocardiography: a comparison with magnetic resonance imaging.

OBJECTIVES: We evaluated the accuracy and reproducibility of contrast echocardiography versus tissue harmonic imaging for measurements of left ventricular (LV) volumes and ejection fraction (EF) compared to magnetic resonance imaging (MRI). METHODS: Digital echo recordings of apical LV views before and after intravenous contrast were collected from 110 consecutive patients. Magnetic resonance imaging of multiple short-axis LV sections was performed with a 1.5-T scanner. Left ventricular volumes and EF were calculated offline by method of discs. Thirty randomly selected patients were reanalyzed for intraobserver and interobserver variability. RESULTS: Compared with baseline, contrast echo increased feasibility for single-plane and biplane volume analysis from 87% to 100% and from 79% to 95%, respectively. The Bland-Altman analysis demonstrated volume underestimation by echo, but much less pronounced with contrast. Limits of agreement between echo and MRI narrowed significantly with contrast: from -18.1% to 8.3% to -7.7% to 4.1% (EF), from -98.2 to -11.7 ml to -59.0 to 10.7 ml (end-diastolic volume), and from -58.8 to 21.8 ml to -38.6 to 23.9 ml (end-systolic volume). Ejection fraction from precontrast echo and MRI differed by > or =10% (EF units) in 23 patients versus 0 after contrast (p < 0.001). At intraobserver and interobserver analysis, limits of agreement for EF narrowed significantly with contrast. CONCLUSIONS: The two-dimensional echocardiographic evaluation of LV volumes and EF in non-selected cardiac patients was found to be more accurate and reproducible when adding an intravenous contrast agent.