Aortic Regurgitation: Review of the Diagnostic Criteria and the Management Guidelines.

PURPOSE OF REVIEW: The evaluation of aortic regurgitation (AR) has advanced from physical examination and angiography towards evidence based non-invasive quantitative methods, primarily with echocardiography and more recently with cardiac magnetic resonance (CMR). This review highlights the guidelines and recent evidence in the diagnosis and management of AR; and outlines future areas of research. RECENT FINDINGS: Contemporary large cohorts of AR patients studied with echocardiography and CMR suggest that the left ventricular remodeling and systolic function triggers for intervention may be lower than previously recommended in the guidelines and emphasize the importance of LV volumes in risk stratification. Important gaps of knowledge in the quantitation of AR severity and patient risk stratification were fulfilled recently. Potential thresholds for intervention using ventricular volumes and CMR quantitative findings were recently described. The criteria for what constitutes hemodynamically significant AR and the optimal timing of intervention AR deserve further study.

Sex differences in myocardial remodeling and extracellular volume in aortic regurgitation.

Whether sex differences exist in the cardiac remodeling related to aortic regurgitation (AR) is unclear. Cardiac magnetic resonance (CMR) is the current non-invasive reference standard for cardiac remodeling assessment and can evaluate tissue characteristics. This prospective cohort included patients with AR undergoing CMR between 2011 and 2020. We excluded patients with confounding causes of remodeling. We quantified left ventricular (LV) volume, mass, AR severity, replacement fibrosis by late Gadolinium enhancement (LGE), and extracellular expansion by extracellular volume fraction (ECV). We studied 280 patients (109 women), median age 59.5 (47.2, 68.6) years (P for age = 0.25 between sexes). Women had smaller absolute LV volume and mass than men across the spectrum of regurgitation volume (RVol) (P ≤ 0.01). In patients with ≥ moderate AR and with adjustment for body surface area, indexed LV end-diastolic volume and mass were not significantly different between sexes (all P > 0.5) but men had larger indexed LV end systolic volume and lower LV ejection fraction (P ≥ 0.01). Women were more likely to have NYHA class II or greater symptoms than men but underwent surgery at a similar rate. Prevalence and extent of LGE was not significantly different between sexes or across RVol. Increasing RVol was independently associated with increasing ECV in women, but not in men (adjusted P for interaction = 0.03). In conclusion, women had lower LV volumes and mass than men across AR severity  but their ECV increased with higher regurgitant volume, while ECV did not change in men. Indexing to body surface area did not fully correct for the cardiac remodeling differences between men and women. Women were more likely to have symptoms but underwent surgery at a similar rate to men. Further research is needed to determine if differences in ECV would translate to differences in the course of AR and outcomes.

Influence of Cardiac Remodeling on Clinical Outcomes in Patients With Aortic Regurgitation.

BACKGROUND: Quantitative cardiac magnetic resonance (CMR) outcome studies in aortic regurgitation (AR) are few. It is unclear if volume measurements are beneficial over diameters. OBJECTIVES: This study sought to evaluate the association of CMR quantitative thresholds and outcomes in AR patients. METHODS: In a multicenter study, asymptomatic patients with moderate or severe AR on CMR with preserved left ventricular ejection fraction (LVEF) were evaluated. Primary outcome was development of symptoms or decrease in LVEF to <50%, development of guideline indications for surgery based on LV dimensions, or death under medical management. Secondary outcome was the same as the primary outcome, excluding surgery for remodeling indications. We excluded patients who underwent surgery within 30 days of CMR. Receiver-operating characteristic analyses for the association with outcomes were performed. RESULTS: We studied 458 patients (median age: 60 years; IQR: 46-70 years). During a median follow-up of 2.4 years (IQR: 0.9-5.3 years), 133 events occurred. Optimal thresholds were regurgitant volume of 47 mL and regurgitant fraction of 43%, indexed LV end-systolic (iLVES) volume of 43 mL/m2, indexed LV end-diastolic volume of 109 mL/m2, and iLVES diameter of 2 cm/m2. In multivariable regression analysis, iLVES volume of ≥43 mL/m2 (HR: 2.53; 95% CI: 1.75-3.66; P < 0.001) and indexed LV end-diastolic volume of ≥109 mL/m2 were independently associated with the outcomes and provided additional discrimination improvement over iLVES diameter, whereas iLVES diameter was independently associated with the primary outcome but not the secondary outcome. CONCLUSIONS: In asymptomatic AR patients with preserved LVEF, CMR findings can be used to guide management. CMR-based LVES volume assessment performed favorably compared to LV diameters.

Medical Management of Aortic Disease: If They Don't Need Surgery, What Do They Need?

Management of aortic disease has evolved significantly over the past few decades. A preemptive diagnostic approach with a multidisciplinary team and shared decision-making has led to improved clinical outcomes. Surgery is the cornerstone of management for most aortic conditions; however, medical therapy is now an important adjunctive therapy in most if not all patients. Herein, we review the role and evidence behind medical management of patients with aortic disease.