Slides courtesy of Dr. Randall Harada Aortic Stenosis Slides courtesy of Dr. Randall Harada 2008 Zoll Firm Lecture Series

Zoll Firm Lecture Series Etiology Age < 70 Age ≥ 70 2008 Zoll Firm Lecture Series

Zoll Firm Lecture Series Pathophysiology Aortic stenosis Increased afterload Atrial contraction LVH Increased preload Preserved wall stress Normal systolic function 2008 Zoll Firm Lecture Series

Zoll Firm Lecture Series Pathophysiology Aortic stenosis Increased afterload LVH LVH inadequate (afterload mismatch) ↑ O2 demand ↓ coronary perfusion pressure Compression of intramyocardial arteries ↓ CBF per unit of mass Reduced myocardial contractility Myocardial ischemia 2008 Zoll Firm Lecture Series

Zoll Firm Lecture Series Natural history Mortality is low during the latent period; similar to age-matched controls. The risk of surgery outweigh the benefit in this population. Progression to symptomatic or severe aortic stenosis has marked individual variability Average rate of progression 0.10 – 0.12 cm2 per year. 2008 Zoll Firm Lecture Series

Natural history Severe stenosis with symptoms: Avg life expectancy (y) Angina 5 Syncope 3 Heart failure <2 Ross J, Circ 36(supp IV) 1968 2008 Zoll Firm Lecture Series

Zoll Firm Lecture Series Clinical care of AS Assessment of symptoms; patient education Careful exercise testing for asymptomatic patients with unclear medical histories: Echocardiography: eval AS severity, LV function ACC/AHA, Circ 114, 2006 2008 Zoll Firm Lecture Series

Zoll Firm Lecture Series AS severity Maximum aortic velocity Mild: 2.6 – 3.0 m/s Moderate: 3 – 4 m/s Severe: >4 m/s Mean transvalvular gradient Mild <25mmHg Moderate 25-40mmHg Severe >40mmHg Aortic valve area by continuity equation Mild: > 1.2 cm2 Moderate: 0.8 – 1.2 cm2 Severe: < 0.8 cm2 2008 Zoll Firm Lecture Series

Zoll Firm Lecture Series Medical therapy No medical therapies proven to prevent or delay AS In severe AS, atrial fibrillation is often poorly tolerated 2008 Zoll Firm Lecture Series

Timing of valve replacement 2008 Zoll Firm Lecture Series Otto CM, JACC 47, 2006

Timing of valve replacement Otto CM, JACC 47, 2006 2008 Zoll Firm Lecture Series

Problematic situations LV dysfunction Primary cardiomyopathy vs. secondary due to true AS Low stroke volume may reduce leaflet motion in a non-stenotic valve Dobutamine stress echo to differentiate Flexible leaflets: increase in EF, leaflet excursion, and AVA Severe AS: increase in EF, no change in AVA “Lack of contractile reserve”: no increase in EF 2008 Zoll Firm Lecture Series

Zoll Firm Lecture Series Aortic valvuloplasty Not an effective long-term therapy for most adult patients. Nearly 50% of the patients have re-stenosis in 6 months. Mainly used for “palliation” and as a bridge to AVR and sometimes for patients who requires urgent non-cardiac surgery. Serious complications (stroke, severe aortic regurgitation, myocardial infarction) occur in approximately 10 to 20 percent of patients 2008 Zoll Firm Lecture Series