Diffusely Increased Myocardial Extracellular Volume With or Without Focal Late Gadolinium Enhancement: Prevalence and Associations With Left Ventricular Size and Function.

PURPOSE: Myocardial extracellular volume fraction (ECV) using cardiovascular magnetic resonance (CMR) can identify diffuse lesions not detected by late gadolinium enhancement (LGE). We aimed to determine the prevalence of increased ECV and its relation to other CMR findings. MATERIALS AND METHODS: Consecutive patients (n=609, age median [interquartile range] 53 [39 to 66] y, 62% male) underwent CMR at 1.5 T. Focal lesions on LGE images were noted. ECV in regions without focal LGE findings defined diffuse changes. Pronounced increases in left ventricular (LV) end-diastolic volume index and LV mass index, and pronounced decreases in LV ejection fraction were defined as >3 SD from the sex-specific mean in healthy volunteers. RESULTS: Of 609 patients without amyloidosis or hypertrophic cardiomyopathy, 8% had diffusely increased ECV and 5% of all patients had diffusely increased ECV without any focal LGE findings. Multivariate analysis showed that a pronounced increase in the LV end-diastolic volume index was associated with increased ECV (P=0.001), but not LGE (P=0.52). A pronounced decrease in LV ejection fraction was associated with the presence of LGE (P<0.001), but not with increased ECV (P=0.41). CONCLUSIONS: Eight percent of patients in this clinical cohort with known or suspected heart disease had diffusely increased ECV and 60% of these lacked focal LGE findings. LV size is independently associated with increased ECV, whereas systolic dysfunction is independently associated with LGE. This image-based clinical study demonstrates that ECV-CMR provides additional information negligibly related to the results of LGE imaging, and thereby increases the diagnostic yield of CMR.

Pre- and postoperative left atrial and ventricular volumetric and deformation analyses in severe aortic regurgitation.

BACKGROUND: The impact of volume overload due to aortic regurgitation (AR) on systolic and diastolic left ventricular (LV) indices and left atrial remodeling is unclear. We assessed the structural and functional effects of severe AR on LV and left atrium before and after aortic valve replacement. METHODS: Patients with severe AR scheduled for aortic valve replacement (n = 65) underwent two- and three-dimensional echocardiography, including left atrial strain imaging, before and 1 year after surgery. A control group was selected, and comprised patients undergoing surgery for thoracic aortic aneurysm without aortic valve replacement (n = 20). Logistic regression analysis was used to assess predictors of impaired left ventricular functional and structural recovery, defined as a composite variable of diastolic dysfunction grade ≥ 2, EF < 50%, or left ventricular end-diastolic volume index above the gender-specific normal range. RESULTS: Diastolic dysfunction was present in 32% of patients with AR at baseline. Diastolic LV function indices and left atrial strain improved, and both left atrial and LV volumes decreased in the AR group following aortic valve replacement. Preoperative left atrial strain during the conduit phase added to left ventricular end-systolic volume index for the prediction of impaired LV functional and structural recovery after aortic valve replacement (model p < 0.001, accuracy 70%; addition of left atrial strain during the conduit phase to end-systolic volume index p = 0.006). CONCLUSIONS: One-third of patients with severe AR had signs of diastolic dysfunction. Aortic valve surgery reduced LV and left atrial volumes and improved diastolic indices. Left atrial strain during the conduit phase added to the well-established left ventricular end-diastolic dimension for the prediction of impaired left ventricular functional and structural recovery at follow-up. However, long-term follow-up studies with hard endpoints are needed to assess the value of left atrial strain as predictor of myocardial recovery in aortic regurgitation.

Stationary tissue background correction increases the precision of clinical evaluation of intra-cardiac shunts by cardiovascular magnetic resonance.

We aimed to evaluate the clinical utility of stationary tissue background phase correction for affecting precision in the measurement of Qp/Qs by cardiovascular magnetic resonance (CMR). We enrolled consecutive patients (n = 91) referred for CMR at 1.5T without suspicion of cardiac shunt, and patients (n = 10) with verified cardiac shunts in this retrospective study. All patients underwent phase contrast flow quantification in the ascending aorta and pulmonary trunk. Flow was quantified using two semi-automatic software platforms (SyngoVia VA30, Vendor 1; Segment 2.0R4534, Vendor 2). Measurements were performed both uncorrected and corrected for linear (Vendor 1 and Vendor 2) or quadratic (Vendor 2) background phase. The proportion of patients outside the normal range of Qp/Qs was compared using the McNemar's test. Compared to uncorrected measurements, there were fewer patients with a Qp/Qs outside the normal range following linear correction using Vendor 1 (10% vs 18%, p < 0.001), and Vendor 2 (10% vs 18%, p < 0.001), and following quadratic correction using Vendor 2 (7% vs 18%, p < 0.001). No patient with known shunt was reclassified as normal following stationary background correction. Therefore, we conclude that stationary tissue background correction reduces the number of patients with a Qp/Qs ratio outside the normal range in a consecutive clinical population, while simultaneously not reclassifying any patient with known cardiac shunts as having a normal Qp/Qs. Stationary tissue background correction may be used in clinical patients to increase diagnostic precision.

Comparison of Left Ventricular Volumes Measured by 3DE, SPECT and CMR.

BACKGROUND: Information regarding left ventricular (LV) volume and left ventricular ejection fraction (LVEF) has major diagnostic and prognostic value when assessing patients after ST-elevation myocardial infarction (STEMI). We aimed to investigate the agreement between measurement of LV volumes and LVEF by three-dimensional echocardiography (3DE), single-photon emission computed tomography (SPECT) and cardiac magnetic resonance (CMR) imaging in patients in a stable phase after STEMI. METHODS: Fifteen patients underwent examinations by 3DE, SPECT and CMR three months after STEMI. RESULTS: There was a significant bias in end-diastolic volume (EDV) measured by 3DE (-64 mL, p < 0.001) and SPECT (-55 mL, p < 0.001) compared with that measured by CMR. This was also the case for end-systolic volume (ESV) measured by 3DE (-36 mL, p < 0.001) and SPECT (-28 mL, p < 0.001). No significant differences were found between 3DE and SPECT for EDV or ESV. However, LVEF did not differ between the three methods. The agreement between all three methods was moderate (intra-class correlation coefficient [ICC] = 0.44) for LV volume and good for LVEF (ICC = 0.72). CONCLUSIONS: LV volumes assessed by 3DE did not differ from SPECT, and despite larger LV volumes by CMR, measurements of LVEF showed good agreement between all three methods.

Contrast Enhancement and Image Quality Influence Two- and Three-dimensional Echocardiographic Determination of Left Ventricular Volumes: Comparison With Magnetic Resonance Imaging.

PURPOSE: To evaluate the effect of image quality and contrast enhancement (CE) on left ventricular (LV) volume determination by two- (2D) and three-dimensional (3D) echocardiography (2DE/3DE). METHODS: We studied 32 post-myocardial infarction (MI) patients without (2DE/3DE) and with CE (CE2DE/CE3DE), in comparison with cardiac magnetic resonance imaging (CMR). RESULTS: Two-dimensional echocardiography showed the largest negative bias versus CMR for diastolic and systolic volumes (-59, -28 mL, respectively) with lower biases for CE2DE (-37, -22 mL), 3DE (-31, -17 mL), and CE3DE (-17, -11 mL). Bias for ejection fraction (EF) ranged from -2.1% for 2DE to +1.4% for CE3DE. Agreement (intraclass correlation coefficient, ICC) for EF between CMR and 3DE (0.86 without and 0.85 with contrast) was better than for 2DE (0.73 without and 0.69 with contrast). The inter-/intra-observer coefficients of variation for EF varied from 16%/10% (2DE) to 6.9%/6.6% (CE2DE), and 8.3%/4.8% (3DE) to 6.7%/6.8% (CE3DE), respectively. The agreement (ICC) with CMR for EF measured by 2DE/3DE changed from 0.64/0.84 with poor image quality to 0.81/0.87 with moderate to good image quality. CONCLUSIONS: Three-dimensional echocardiography was more accurate than 2DE for estimating LV volumes, with less inter-/intra-observer variability in EF values. Contrast enhancement improved accuracy for both 2DE and 3DE and improved the inter-observer variability of EF estimates for 2DE and 3DE. Image quality had more impact on the agreement of EF values with CMR for 2DE than for 3DE. Our results emphasize the importance of using the same technique for longitudinal studies of LV EF and specially LV volumes.

Aortic valve type and calcification as assessed by transthoracic and transoesophageal echocardiography.

INTRODUCTION: Aortic valve calcification (AVC) may predict poor outcome. Bicuspid aortic valve (BAV) leads to several haemodynamic changes accelerating the progress of aortic valve (AV) disease. AIMS: To compare the diagnostic accuracy of transoesophageal echocardiography (TEE) and transthoracic echocardiography (TTE) in the assessment of aortic valve phenotype and degree of AVC, with intra-operative evaluation as a reference. METHODS: We examined 169 patients (median age 65 years, 51 women) without significant coronary artery disease undergoing AV and/or aortic root surgery. TTE was performed within a week prior to surgery and TEE at the time of surgery. RESULTS: Compared with surgical AVC assessment, visual evaluation using a 5-grade scoring system and real-time images showed a higher correlation (TTE r = 0·83 and TEE r = 0·82) than visual (TTE r = 0·64 and TEE 0·63) or grey scale mean (GSMn) (TTE r = 0·63 and TEE r = 0·52) assessment of end-diastolic still frames. AVC assessment using real-time images showed high intraclass correlation coefficients (TTE 0·94 and TEE 0·93). With regard to BAV, TEE was superior to TTE with a higher interobserver agreement, sensitivity and specificity (0·86, 92% and 94% versus 0·57, 77% and 82%, respectively). CONCLUSION: Semi-quantitative AVC assessment of real-time cine loops from both TEE and TTE correlated well with intra-operative evaluation of AVC. Applying a predefined scoring system for AVC evaluation assures a high interobserver correlation. TEE was superior to TTE for evaluation of valve phenotype and should be considered when a diagnosis of BAV is clinically important.

Elastic properties of the descending aorta in patients with a bicuspid or tricuspid aortic valve and aortic valvular disease.

BACKGROUND: The aim of this study was to explore possible differences in aortic strain, distensibility, and stiffness in the descending thoracic aorta between patients with bicuspid aortic valves (BAVs) and those with tricuspid aortic valves (TAVs) in relation to type of aortic valve disease and known cardiovascular risk factors. METHODS: Transesophageal echocardiography was used to examine 288 patients (mean age, 64 ± 13 years) in the operating room before surgery. The transesophageal echocardiographic images were analyzed offline using Velocity Vector Imaging software. One hundred forty patients had isolated severe aortic stenosis (AS) (89 of those with BAVs, 51 of those with TAVs), and 52 patients had isolated severe aortic regurgitation (AR) (24 of those with BAVs, 28 of those with TAVs). RESULTS: In patients with AS, stiffness in the descending aorta was 10 (range, 7.3-16) in those with BAVs and 13 (range, 11-18) in those with TAVs (P < .001). Distensibility was 19 kPa(-1) 10(-3) (range, 13-27 kPa(-1) 10(-3)) in patients with BAVs and 15 kPa(-1) 10(-3) (range, 11-19 kPa(-1) 10(-3)) in those with TAVs (P < .01). In patients with AR, stiffness was 6.9 (range, 5.5-7.8) in those with BAVs and 8.0 (range, 6.6-11) in those with TAVs (P < .05). After correction for age, dimension of the ascending aorta, cholesterol, and stroke volume in a multivariate regression model, BAV was associated with lower strain and distensibility of the descending aorta in the AR group and higher distensibility in the AS group, whereas stiffness was no longer related to aortic valve morphology in either of the two groups. CONCLUSIONS: The presence of BAVs in patients with severe AR is associated with lower strain and distensibility, suggesting that impairment of the elastic aortic properties may extend to the descending aorta. In patients with AS, BAVs correlate weakly with higher distensibility.