JACC. Cardiovascular imaging最新文献

Background: Patients with moderate or asymptomatic severe aortic stenosis (AS) are at risk of cardiovascular events.

Objectives: The authors investigated the utility of cardiac magnetic resonance (CMR) to identify drivers of outcome in patients with moderate or asymptomatic severe AS.

Methods: A prospective, international, multicenter cohort (n = 457) of patients with moderate (aortic valve area [AVA]: 1.0-1.5 cm²) or asymptomatic severe AS (AVA ≤1.0 cm² and NYHA functional class I-II) patients underwent CMR. Diffuse interstitial fibrosis and scar in the myocardium were analyzed with extracellular volume fraction (ECV%) and late gadolinium enhancement (LGE). The outcome was a composite of mortality and heart failure admission.

Results: Median ECV% was 26.6% (IQR: 24.4%-29.9%), and LGE was present in 31.5% (median 0.8%; IQR: 0.1%-1.7%). Greater AS severity was associated with greater left ventricular mass and diastolic dysfunction, but not with ECV% or LGE. During a median 5.7 years of follow-up, 83 events occurred. Patients with events had higher ECV% (median ECV% 26.3% vs 28.2%; P = 0.003). Patients in the highest ECV% tertiles (ECV% >28.6%) had worse outcomes both in the entire cohort and in those with NYHA functional class I moderate or severe AS, and ECV% was independently associated with outcome (adjusted HR: 1.05; P = 0.039). The ECV% had significant incremental prognostic value when added to parameters of AS severity and cardiac function, comorbidities, aortic valve replacement, and LGE (P < 0.05).

Conclusions: Increased diffuse interstitial fibrosis of the myocardium is associated with poor outcomes in patients with moderate and asymptomatic severe AS and can help identify those who require closer surveillance for adverse outcomes.

Background: Myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) using stress cardiovascular magnetic resonance (CMR) have been shown to identify epicardial coronary artery disease. However, comparative analysis between quantitative perfusion and conventional qualitative assessment (QA) remains limited.

Objectives: The aim of this multicenter study was to test the hypothesis that quantitative stress MBF (sMBF) and MPR analysis can identify obstructive coronary artery disease (obCAD) with comparable performance as QA of stress CMR performed by experienced physicians in interpretation.

Methods: The analysis included 127 individuals (mean age 62 ± 16 years, 84 men [67%]) who underwent stress CMR. obCAD was defined as the presence of stenosis ≥50% in the left main coronary artery or ≥70% in a major vessel. Each patient, coronary territory, and myocardial segment was categorized as having either obCAD or no obCAD (noCAD). Global, per coronary territory, and segmental MBF and MPR values were calculated. QA was performed by 4 CMR experts.

Results: At the patient level, global sMBF and MPR were significantly lower in subjects with obCAD than in those with noCAD, with median values of sMBF of 1.5 mL/g/min (Q1-Q3: 1.2-1.8 mL/g/min) vs 2.4 mL/g/min (Q1-Q3: 2.1-2.7 mL/g/min) (P < 0.001) and median values of MPR of 1.3 (Q1-Q3: 1.0-1.6) vs 2.1 (Q1-Q3: 1.6-2.7) (P < 0.001). At the coronary artery level, sMBF and MPR were also significantly lower in vessels with obCAD compared with those with noCAD. Global sMBF and MPR had areas under the curve (AUCs) of 0.90 (95% CI: 0.84-0.96) and 0.86 (95% CI: 0.80-0.93). The AUCs for QA by 4 physicians ranged between 0.69 and 0.88. The AUC for global sMBF and MPR was significantly better than the average AUC for QA.

Conclusions: This study demonstrates that sMBF and MPR using dual-sequence stress CMR can identify obCAD more accurately than qualitative analysis by experienced CMR readers.

Background: The development and progression of aortic stenosis (AS) from aortic valve (AV) sclerosis is highly variable and difficult to predict.

Objectives: The authors investigated whether a previously validated echocardiography-based deep learning (DL) model assessing diastolic dysfunction (DD) could identify the latent risk associated with the development and progression of AS.

Methods: The authors evaluated 898 participants with AV sclerosis from the ARIC (Atherosclerosis Risk In Communities) cohort study and associated the DL-predicted probability of DD with 2 endpoints: 1) the new diagnosis of AS; and 2) the composite of subsequent mortality or AV interventions. Validation was performed in 2 additional cohorts: 1) in 50 patients with mild-to-moderate AS undergoing cardiac magnetic resonance (CMR) imaging and serial echocardiographic assessments; and 2) in 18 patients with AV sclerosis undergoing ¹⁸F-sodium fluoride (NaF) and ¹⁸F-fluorodeoxyglucose positron emission tomography (PET) combined with computed tomography (CT) to assess valvular inflammation and calcification.

Results: In the ARIC cohort, a higher DL-predicted probability of DD was associated with the development of AS (adjusted HR: 3.482 [95% CI: 2.061-5.884]; P < 0.001) and subsequent mortality or AV interventions (adjusted HR: 7.033 [95% CI: 3.036-16.290]; P < 0.001). The multivariable Cox model (incorporating the DL-predicted probability of DD) derived from the ARIC cohort efficiently predicted the progression of AS (C-index: 0.798 [95% CI: 0.648-0.948]) in the CMR cohort. Moreover, the predictions of this multivariable Cox model correlated positively with valvular ¹⁸F-NaF mean standardized uptake values in the PET/CT cohort (r = 0.62; P = 0.008).

Conclusions: Assessment of DD using DL can stratify the latent risk associated with the progression of early-stage AS.

Background: Clinical features and outcomes in severe aortic stenosis (AS) have been described according to the hemodynamic phenotypes.

Objectives: The aim of this study was to investigate the clinical features and prognosis of patients with high-gradient (HG) AS with aortic valve area (AVA) >1.0 cm².

Methods: A total of 3,209 patients were identified according to AVA (cm²), peak velocity (m/s), systolic mean pressure gradient (MG) (mm Hg): HG-AVA >1 = >1.0, ≥4, and ≥40, HG-AVA ≤1 = ≤1.0, ≥4, and ≥40; LG-AVA ≤1 (low-gradient) = ≤1.0, <4, and <40; moderate AS = 1.0 

Results: HG-AVA >1 accounted for 230 individuals (7.2%). Compared with others, patients with HG-AVA >1 were younger (70.2 ± 12.0 years), more frequently male (85.7%), had fewer comorbidities, larger body surface area and stroke volume (115 ± 19.3 mL), and had higher prevalence of bicuspid valve (39.6%). After a follow-up of 944 days (Q1-Q3: 27-2,212 days), 1,523 deaths occurred. Compared with the HG-AVA >1 group, all-cause mortality was higher in HG-AVA ≤1 (HR: 1.4; 95% CI: 1.1-1.7), LG-AVA ≤1 (HR: 2.8; 95% CI: 2.2-3.6), and moderate AS (HR: 1.4; 95% CI: 1.1-1.7). These differences were no longer significant after adjustment for age, comorbidities, bicuspid valve, and cardiac function. In the HG-AVA >1 group, patients with aortic valve replacement had better survival outcomes than those without aortic valve replacement (P < 0.001) after balancing the 2 groups.

Conclusions: The underlying relative high-flow status is responsible for HG in patients with HG-AVA >1. This profile has better prognosis than others, being related to underlying younger age and better general and cardiac conditions, but aortic valve replacement may still benefit these patients.