Omar K. Khalique

Aortic regurgitation (AR) is a complex and often misdiagnosed valvular heart disease. It is often asymptomatic for years, making early detection critical. Once symptoms develop, left ventricular dysfunction may already be irreversible. Timely and accurate grading of AR severity can guide clinical decision-making and improve survival rates. Delayed diagnosis increases the risk of heart failure, arrhythmias, and sudden cardiac death. Transthoracic echocardiography (TTE) is the first-line imaging modality, providing assessment of valve morphology, AR severity, left ventricular size and function, and aortic dimensions. When TTE is inconclusive or additional anatomical information is required, complementary imaging modalities provide incremental value. Transesophageal echocardiography often helps to define AR mechanism and is particularly relevant for valve repair assessment and procedural guidance. Cardiovascular magnetic resonance enables accurate quantification of regurgitant volume and fraction, detailed evaluation of ventricular remodeling, and detection of myocardial fibrosis. Cardiac computed tomography offers high-resolution characterization of the aorta and is increasingly important for surgical and transcatheter planning. In selected patients, multimodality imaging also helps evaluate prosthetic valve dysfunction and suspected infective endocarditis. This paper reviews the currently used imaging modalities and their clinical applicability, and proposes an integrated multimodality imaging approach to guide patient management in chronic AR.

Right ventricular (RV) remodeling is an important determinant of prognosis in conditions marked by chronic RV volume or pressure overload, including functional tricuspid regurgitation (TR) and pulmonary hypertension (PH). Conventional volumetric and functional measures, including RV ejection fraction (RVEF), often fail to detect adverse remodeling until it is advanced, particularly in significant TR, where regurgitant flow inflates total stroke volume and can mask a reduction in effective forward output. Cardiac magnetic resonance (CMR) is well suited to address this gap, combining highly reproducible chamber quantification with novel measures of myocardial deformation, tissue characterization, RV–pulmonary artery (PA) interaction, and flow hemodynamics. This narrative review examines emerging CMR-derived indices of adverse right heart remodeling, including effective RVEF, the RV/left ventricular volume ratio, the right atrioventricular coupling index, nonischemic septal fibrosis, and hepatic extracellular volume (ECV). We further review functional CMR markers, including surrogates of RV-PA coupling, RV and right atrial strain, myocardial T1 and ECV mapping, markers of treatment response and reverse remodeling, and 4D-flow assessment of PA hemodynamics. For each, we discuss underlying physiology, supporting data, proposed clinical thresholds, and current barriers to clinical adoption, and we compare the maturity of the supporting evidence across indices. Collectively, these indices represent a shift toward physiologically based, mechanism-specific risk stratification in right heart disease and may help identify patients at risk for adverse outcomes before conventional volumetric or functional parameters decline. However, their supporting evidence varies considerably in maturity, proposed thresholds are population- and methodology-dependent, and whether their use improves the timing of intervention or patient outcomes remains to be established in prospective studies.

BACKGROUND: Large left atrial volume (LAV) is a strong predictor of advanced left atrial substrate and is associated with less successful outcomes following pulmonary vein isolation (PVI) alone. Prespecified variables of the aMAZE trial (Left Atrial Appendage Ligation Adjunctive to PVI for Persistent or Longstanding Persistent Atrial Fibrillation) were evaluated to access for the impact of LAV and left atrial appendage ligation on atrial fibrillation (AF) outcomes. METHODS: The aMAZE trial was a multicenter, randomized-controlled study evaluating the effects of LAV on freedom from atrial arrhythmias (AA) following PVI-only compared with LARIAT and PVI (LARIAT+PVI). In total, 610 drug-refractory patients with nonparoxysmal AF were randomized 2:1 to LARIAT versus PVI alone. Freedom from AA was assessed 12 months postprocedure. LAV was independently assessed by a core laboratory from cardiac computed tomography performed before ablation. (REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02513797) RESULTS: There were 404 patients in the LARIAT+PVI group and 206 in the PVI-only group. Logistic regression performed within each subgroup for primary effectiveness with LAV demonstrated that the recurrence of AA after PVI was directly related to increasing LAV. Freedom from recurrence of AA in the LARIAT+PVI arm was independent and preserved irrespective of LAV. Similar results were seen with LAV index. A tercile analysis of early persistent AF (perAF) patients (AF >7 days and 148 cm ³ ) LAV tercile showed statistically significant freedom from AA compared with PVI-only (69% versus 49%; P =0.02). Significant differences ( P 3 and an LAV index of 65 cm ³ /m ² . CONCLUSIONS: The correlation of LAV with PVI effectiveness in this study demonstrates that AA recurrence after PVI alone is directly related to increasing LAV. Freedom from AA after left atrial appendage ligation in addition to PVI is independent of increasing LAV, and left atrial appendage ligation may therefore provide an adjunctive benefit in patients with nonparoxysmal AF and enlarged LAV.