Impact of Aortic Valve Replacement on Outcome of Symptomatic Patients With Severe Aortic Stenosis With Low Gradient and Preserved Left Ventricular Ejection Fraction

• Published in: Circulation (New York, N.Y.) Vol. 128; no. 6; pp. 622 - 631
• Main Authors: Ozkan, Alper, Hachamovitch, Rory, Kapadia, Samir R, Tuzcu, E Murat, Marwick, Thomas H
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD by the American College of Cardiology Foundation and the American Heart Association, Inc 06.08.2013; Lippincott Williams & Wilkins
• Subjects: Aged; Aged, 80 and over; Aortic Valve Stenosis - diagnostic imaging; Aortic Valve Stenosis - mortality; Aortic Valve Stenosis - physiopathology; Aortic Valve Stenosis - surgery; Balloon Valvuloplasty; Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Cardiovascular system; Diabetes Mellitus - mortality; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Echocardiography; Female; Follow-Up Studies; Heart Valve Prosthesis Implantation - mortality; Hemodynamics - physiology; Humans; Investigative techniques of hemodynamics; Investigative techniques, diagnostic techniques (general aspects); Kaplan-Meier Estimate; Logistic Models; Male; Medical sciences; Prevalence; Prospective Studies; Risk Factors; Severity of Illness Index; Stroke Volume - physiology; Treatment Outcome; Ventricular Function, Left - physiology; Human; Aortic stenosis; Gradient; Prognosis; Patient; Cardiovascular disease; Heart valve; treatment outcome; Left ventricle; Symptomatology; Treatment; Low; Surgery; Evolution; Ventricular ejection; Circulatory system; Hemodynamics; Cardiology; Severe; Aortic valve; Ejection fraction; aortic valve; aortic stenosis
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/CIRCULATIONAHA.112.001094

BACKGROUND—The optimal management of low-gradient “severe” aortic stenosis (mean gradient <40 mm Hg, indexed aortic valve area ≤0.6 cm/m) with preserved left ventricular ejection fraction remains controversial because gradients may be similar after aortic valve replacement (AVR). We compared outcomes of low-gradient severe aortic stenosis with AVR or medical therapy. METHODS AND RESULTS—Comprehensive echocardiographic measurements including hemodynamic calculations were completed in 260 prospectively identified patients with symptomatic low-gradient severe aortic stenosis. Patients were followed up for mortality over 28±24 months. AVR was performed in 123 patients (47%). Compared with AVR patients, medically treated patients had a higher prevalence of diabetes mellitus (25% versus 41%, P=0.009), lower stroke volume index (36.4±8.4 versus 34.4±8.7 mL/m, P=0.02), higher pulmonary artery pressure (38±11 versus 48±21 mm Hg, P=0.001), and higher creatinine level (1.1±0.4 versus 1.22±0.5 mg/dL, P=0.02). These and other clinically relevant variables were entered into a propensity model that reflected likelihood of referral to AVR. This score and other variables were entered into a Cox model to explore the independent effect of AVR on outcome. During follow-up, 105 patients died (40%)32 (30%) in the AVR group and 73 (70%) in the medical treatment group. AVR (hazard ratio, 0.54; 95% confidence interval, 0.32–0.94; P<0.001) was independently associated with outcome and remained a strong predictor of survival after adjustment for propensity score. Medical therapy was associated with 2-fold greater all-cause mortality than AVR. The protective effect of AVR was similar in 125 patients with normal flow (stroke volume index >35 mL/m; P=0.22). CONCLUSIONS—AVR is associated with better survival than medical therapy in patients with symptomatic low-gradient severe AS and preserved left ventricular ejection fraction.