inpatient / cardiology
Aortic Stenosis
# Aortic Stenosis
Severe: peak velocity >4m/s, mean pressure grad >40mmHg, area <1cm^2
Checklist
-- ABCs: patients with low BP 2/2 hypovolemia or distributive shock can get phenylephrine (will not increase afterload the heart sees)
-- Chart Check: prior echos, prior valve surgery
-- HPI Intake: angina, DOE, syncope
-- Can't Miss: cardiogenic shock or syncope 2/2 AS
-- Admission Orders: TTE
-- Initial Treatment to Consider: optimize volume and afterload reduction; discuss with CT surgery if feel patient may need eval while inpatient
Assessment:
-- History: *** symptoms, h/o syncope, prior echos, surgeries, performance status
-- Clinical: *** angina, syncope, dyspnea, HFpEF, vWF def - bleeding
-- Exam: *** systolic crescendo-decrescendo mumur (severe AS is late peaking with soft S2); radiate to carotid (LR 7.5), slow carotid upstroke (LR 9.2)
-- Data: *** echo, peak velocity, mean pressure gradient, area of valve
-- Etiology/DDx: *** senile/calcific, bicuspid valve, rhematic
The patient's HPI is notable for ***. Exam showed ***. Labwork and data were notable for ***. Taken together, the patient's presentation is most concerning for ***, with a differential including ***.
Plan:
Workup
-- f/u TTE if any change in symptoms (usually q6 months for severe AS)
-- Exercise stress testing if asx with severe AS on TTE
-- TAVR clearance: TTE, CTA chest protocol, dental clearance
Treatment
-- Preload: *** diuretics if c/f HF; narrow range - prone to under and overfill
-- Afterload: *** ACE/ARB to reduce HTN (low and slow); avoid vasodilators (hydral, nifedipine, nitro)
-- Aortic valve replacement if: severe and symptomatic OR severe and asx with EF<50% or already undergoing another cardiac surgery
PDF coming soon!
If You Remember Nothing Else
Aortic stenosis (AS) is a surgically treated disease - medical management only addresses a patient's symptoms. When those symptoms begin in severe AS, the prognosis is poor. Severe AS is based on TTE findings, including: peak velocity >4m/s, mean pressure grad >40mmHg, area <1cm^2. In general, trans-catheter aortic valve replacement (TAVR) is non-inferior to surgical-aortic valve replacement (SAVR). Patients with mechanical valves requires warfarin, those who have TAVR procedure are okay with just ASA or clopidogrel.
Clinical Pearls
- ~3% of patients >75yo have AS; 1-2% of population born with bicuspid valve
- Dismal prognosis once symptoms begin - 50% mortality at 5y angina, 3y syncope, 2y HF/dyspnea
- Severe AS on TTE: peak velocity >4m/s, mean pressure grad >40mmHg, area <1cm squared
- Decision for valve replacement based on symptoms, severity of AS, and LVEF
- Mechanical valves have higher bleed risk, but bioprosthetic wear out quicker requiring more frequent re-operation
- TAVR - no AC needed, just indefinite antiplatelet - either ASA 81mg or clopidogrel 75mg
- Perioperative MI, early major bleeding, acute kidney injury, and new-onset atrial fibrillation were less common with TAVR than surgical aortic valve replacement, whereas early vascular complications, need for pacemaker implantation, and perivalvular leaks were more common with TAVR
- Balloon valvotomy less common - palliative but high complication rate, temporary relief
- Treating with phenylephrine (though it sounds crazy) is okay as it should not increase the afterload the LV sees since it is already working to push through the narrow valve - it doesn't matter what comes after it; as such phenylephrine will increase BP through systemic contraction without adding further strain on the LV
- Heyde’s Syndrome - acquired vWF deficiency from shear seen in severe AS - exposes bleeding from GI AVMs
Trials and Literature
- Asymptomatic, very severe AS (area <0.75) may benefit from TAVR vs conservative care (NEJM, 2020)
- PARTNER Trial - TAVR > medical management (or balloon valvuloplasty)for those who are not surgical candidates (NEJM, 2010)
- PARTNER Trial (follow up) - TAVR non-inferior to surgery (SAVR) in high, intermediate, and low surgical risk patients (NEJM, 2011)
- Aspirin is non-inferior to DAPT after TAVR (NEJM, 2020)
Other Resources
