JACC. Cardiovascular imaging最新文献

Background: Coronary computed tomography (CT) angiography-derived attenuation-based plaque burden assessments can identify patients at risk of myocardial infarction.

Objectives: This study sought to assess whether more detailed plaque morphology assessment using patient-based radiomic characterization could further enhance the identification of patients at risk of myocardial infarction during long-term follow-up.

Methods: Post hoc analysis of coronary CT angiography was performed within the SCOT-HEART (Scottish Computed Tomography of the HEART) clinical trial. Coronary plaque segmentations were used to calculate plaque burdens and eigen radiomic features that described plaque morphology. Univariable and multivariable Cox proportional hazard models were used to evaluate the association between clinical and image-based features and fatal or nonfatal myocardial infarction, whereas Harrell's C-statistic and cumulative/dynamic area under the curve (AUC) values with cross-validation were used to evaluate prognostic performance.

Results: Scans from 1,750 patients (aged 58 ± 9 years; 56% male) were analyzed. Over a median of 8.6 years of follow-up, 82 patients had a fatal or nonfatal myocardial infarction. Among the eigen radiomic features, 15 were associated with myocardial infarction in univariable analysis, and 8 features retained their association following adjustment for cardiovascular risk score and plaque burden metrics. Adding plaque burden metrics to a clinical model incorporating cardiovascular risk score, Agatston score and presence of obstructive coronary artery disease had similar prediction performance (C-statistic 0.70 vs 0.70), whereas further addition of eigen radiomic features improved model performance (C-statistic 0.74). In temporal analysis, the model including eigen radiomic features had higher cumulative/dynamic AUC values following the fifth year of follow-up.

Conclusions: Radiomics-based precision phenotyping of coronary plaque morphology provided improvements to long-term prediction of myocardial infarction by CT angiography over and above clinical factors and plaque burden. (Scottish Computed Tomography of the HEART [SCOT-HEART]; NCT01149590).

Background: Guidelines for echocardiographic evaluation of aortic regurgitation (AR) have not been validated against an independent quantitative standard.

Objectives: The aim of this study was to evaluate the accuracy of the ASE (American Society of Echocardiography) AR guidelines against cardiac magnetic resonance (CMR) and to develop simplified approaches for detection of significant AR.

Methods: Patients with AR underwent echocardiography and CMR <4 hours apart. AR severity was graded according to ASE guidelines. Quantitation of regurgitant volume (RegV) was performed with pulsed Doppler at the mitral annulus and right ventricular outflow compared with left ventricular (LV) outflow, and with proximal isovelocity surface area.

Results: The authors studied 81 patients; median age was 52 years, and 58% had a bicuspid aortic valve. According to echo, 35 (43%) patients had mild AR, 18 (22%) moderate, 12 (15%) moderate to severe, and 16 (20%) had severe AR. The area under the curve (AUC) for detection of severe AR by CMR using ASE grading was 0.9 (82.4% sensitivity and 96.9% specificity). Feasibility of RegV quantitation was >88% using either echo volumetric method, and it was low for proximal isovelocity surface area (37%). The highest accuracy for echo parameters against CMR was seen with vena contracta width, jet width, and LV end-diastolic volume index (AUC: 0.86-0.89); pressure half-time had the lowest accuracy. Without RegV quantitation, a vena contracta width ≥0.5 cm and indexed LV end-diastolic volume ≥82 mL/m² had 95.5% positive predictive value and 87.5% negative predictive value for identifying ≥moderate to severe AR by CMR (AUC: 0.89).

Conclusions: The ASE guidelines display very good performance in identifying significant AR. A simplified approach using vena contracta width and LV volumes can be used to reliably identify significant AR. Further validation of the findings in larger cohorts and against clinical outcomes is needed.

Background: The ideal timing for surgery in asymptomatic chronic aortic regurgitation (AR) remains unclear. New thresholds for left ventricular ejection fraction (LVEF), left ventricular (LV) indexed end-systolic volume (iESV), and global longitudinal strain (GLS) have been associated with mortality in these patients. These represent markers of early LV dysfunction.

Objectives: The authors sought to assess the relationship between these markers (LVEF <60%, iESV ≥45 mL/m², and GLS worse than -15%) and mortality, comparing them to Class I/IIa American College of Cardiology/American Heart Association guideline recommendations and absence of any of these.

Methods: A total of 673 asymptomatic patients with chronic clinically significant (≥ moderate-severe) AR between 2004 and 2019 at a single referral center were retrospectively analyzed. The primary study outcome was all-cause mortality.

Results: Mean age was 57 ± 17 years, 97 (14%) were female, 293 (45%) had hypertension, and 273 (41%) had an abnormal number of valve cusps. Aortic valve replacement was performed in 281 (48%) patients, and 69 (10%) died while under surveillance (without aortic valve replacement). LVEF <60% was present in 296 (44%) patients, 122 (25%) of 482 had GLS worse than -15%, and 261 (39%) had iESV ≥45 mL/m². Mortality under surveillance was highest when Class I/IIa recommendations were present (HR: 4.22; 95% CI: 2.15-8.29), followed by the presence of 1 or more markers of early LV dysfunction (HR: 2.18; 95% CI: 1.21-3.92); no markers was used as the reference (all, P < 0.05). LVEF showed the strongest association with mortality, statistically slightly better than GLS and iESV. In the absence of Class I/IIa recommendations, 1 marker of early LV dysfunction was associated with higher, although not statistically significant, mortality compared with no markers (P = 0.063), followed by 2 markers; highest mortality was when all 3 markers were present (HR: 5.46; 95% CI: 2.51-11.90; P < 0.001).

Conclusions: Patients with asymptomatic clinically significant chronic AR incur a survival penalty when Class I/IIa guideline recommendations are attained. In patients without these recommendations, at least 2 markers of early LV dysfunction identify those with higher mortality risk who may benefit from early surgery.