Staging of Cardiac Adverse Remodeling in Moderate or Severe Aortic Regurgitation

BACKGROUND: A recently proposed staging system for cardiac structural and functional abnormalities demonstrated incremental prognostic value in aortic stenosis. OBJECTIVES: The authors investigate a staging system incorporating cardiac magnetic resonance (CMR) in moderate or severe aortic regurgitation (AR). METHODS: Patients prospectively enrolled in DEBAKEY-CMR (DeBakey Cardiovascular Magnetic Resonance Study; NCT04281823) between 2009 and 2020 who had moderate or severe AR by CMR were studied. We excluded patients with a primary cardiomyopathy (eg, hypertrophic cardiomyopathy, amyloidosis, sarcoidosis) or prior valve intervention. The stages were defined as stage 0: no cardiac remodeling; stage 1: left ventricular (LV) remodeling; stage 2: mitral valve or left atrial abnormalities; and stage 3: right heart remodeling. The outcome was all-cause mortality. RESULTS: The authors studied 395 patients, median age 62 years (Q1-Q3: 51-72 years); 79.2% were male, and 25.8% had bicuspid aortic valve. Thirty-two patients (8.10%) were classified as stage 0, 146 (37.0%) as stage 1, 77 (19.5%) as stage 2, and 140 (35.4%) as stage 3. Over a mean follow-up period of 3.9 ± 2.9 years, the annualized mortality rate was 0.68% per year in stage 0, 2.25% per year in stage 1, 3.76% per year in stage 2, and 7.25% per year in stage 3 (P for trend of mortality <0.001). The extent of cardiac remodeling was independently associated with increased hazard for mortality (adjusted HR: 1.69 per increment of stage 95% CI: 1.28-2.23; P < 0.001) after adjusting for regurgitation severity, aortic valve replacement (AVR), and EuroSCORE II (European System for Cardiac Operative Risk Evaluation). Patients with right heart remodeling had the highest hazard for events. CONCLUSIONS: A cardiac remodeling staging system incorporating CMR findings provides incremental prognostication in AR after adjusting for surgical risk, AVR, and regurgitation severity. Right heart remodeling in AR was associated with the highest mortality. Further research can determine whether the staging system could aid in guiding patient management and the timing of intervention.