Aortic regurgitation resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Alejandro Lemor, M.D. [2]

Aortic Regurgitation Resident Survival Guide Microchapters
Overview
Causes
FIRE
Diagnosis Acute Chronic
Treatment Acute Chronic Type of Valve and Anticoagulation
Do's
Don'ts

Overview

Aortic regurgitation (AR) refers to the retrograde or backward flow of blood from the aorta into the left ventricle during diastole. The presentation depends on the response and adaptability of the left ventricle to the increased left ventricular diastolic volume. In chronic AR, the left ventricle has adapted by dilatation of its walls; however, in acute AR a rapid increase in the diastolic volume is not tolerated by a normal-size ventricle which could lead to cardiogenic shock. Acute AR can be caused by aortic dissection and infective endocarditis which require immediate surgical intervention. The most common causes of chronic AR are bicuspid aortic valve and calcific valve disease. The treatment of chronic AR depends on the stage of the disease. Acute AR is a life-threatening condition and must be recognized and treated promptly.

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

• Aortic dissection
• Infective endocarditis

Common Causes

• Bicuspid aortic valve
• Senile or degenerative calcific aortic valve disease
• Dilatation of the aorta due to primary diseases
• Rheumatic fever (developing countries)

Click here for the complete list of causes.

FIRE: Focused Initial Rapid Evaluation

A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention. The algorithm below is based on the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease.

Boxes in red signify that an urgent management is needed.

Abbreviations: ECG: Electrocardiogram; ICU: Intensive care unit; MAP: Mean arterial pressure ; P2: Second heart sound, pulmonary component; S1: First heart sound; S3: Third heart sound; TTE: Transthoracic echocardiography; TEE: Transesophageal echocardiography

Identify cardinal findings that increase the pretest probability of aortic regurgitation Acute aortic regurgitation ❑ Low pitched early diastolic murmur ❑ Best heard at the right 2nd intercostal space ❑ Decreased or absent S1 ❑ Increased P2 ❑ Sudden onset of dyspnea Chronic aortic regurgitation ❑ High pitched holodiastolic decrescendo murmur ❑ Best heard at the upper left sternal border ❑ Increases with sitting forward, expiration and handgrip ❑ Wide pulse pressure (≥ 60 mmHg) ❑ Presence of S3 ❑ Corrigan's pulse: a rapid upstroke and collapse of the carotid artery pulse

Does the patient have any findings of cardiogenic shock that require urgent management? ❑ Tachycardia ❑ Hypotension ❑ Altered mental status ❑ Tachypnea ❑ Oliguria ❑ Cold extremities

YES

NO

Proceed to the complete diagnostic approach below

Initiate resuscitation measures: ❑ Secure airway ❑ Administer oxygen ❑ Secure wide bore IV access ❑ Perform ECG monitor ❑ Monitor vitals continuously ❑ Admit to ICU Initiate medical therapy to treat cardiogenic shock: ❑ Administer nitroprusside 0.3-0.5 υg/kg/min IV (max 10 υg/kg/min), AND ❑ Administer dobutamine 0.5 υg/kg/min IV (max 20 υg/kg/min) ❑ Titrate to maintain MAP > 60 mmHg ❑ Administer beta blockers in high suspicion of aortic dissection Do not use beta blockers for other causes as they will block the compensatory tachycardia Order urgent TTE: ❑ Confirm aortic regurgitation ❑ Look for additional findings according to etiology: ❑ Vegetations on the leaflets ❑ Aortic root dissection ❑ In high suspicion of aortic dissection or when TTE is nondiagnostic, perform a TEE Do not perform percutaneous aortic balloon counterpulsation (it will increase the diastolic pressure and the regurgitant volume)

Click here for cardiogenic shock resident survival guide

What is the etiology of aortic regurgitation based on clinical findings and echocardiography?

Type A aortic dissection Diagnostic clues: ❑ Chest pain of the following characteristics: ❑ Sudden onset ❑ Intense ❑ Tearing and sharp ❑ Worsened by deep breathing or cough ❑ Relieved by sitting upright ❑ Unexplained syncope ❑ Low pitched early diastolic murmur ❑ Best heard at the right 2nd intercostal space ❑ Aortic root dissection found on TTE ❑ Previous history of: ❑ Marfan syndrome ❑ Connective tissue disorder

Infective endocarditis Diagnostic clues: ❑ Persistent fever ❑ New valvular regurgitation murmur ❑ Previous blood culture positive ❑ Vegetations found on TTE ❑ High risk factors: ❑ Pre-existing cardiac abnormality ❑ Prosthetic valve ❑ Recent surgical or medical procedures ❑ Intravenous drug use ❑ Recent bacterial infection ❑ History of previous endocarditis ❑ Order blood cultures (if they have not been previously ordered) ❑ Evaluate the modified Duke criteria (click here to see)

Symptomatic severe chronic AR Diagnostic clues: ❑ No TTE findings of aortic dissection or leaflet vegetations ❑ Previous history of aortic valve disease ❑ High pitched holodiastolic decrescendo murmur ❑ Best heard at the upper left sternal border ❑ Increases with sitting forward, expiration and handgrip ❑ Wide pulse pressure (≥ 60 mmHg) ❑ S3 ❑ Corrigan's pulse: a rapid upstroke and collapse of the carotid artery pulse

❑ Immediate surgical intervention

❑ Immediate surgical intervention

Proceed to the complete diagnostic approach below

Click here for aortic dissection resident survival guide

Click here for infective endocarditis resident survival guide

Complete Diagnostic Approach

A complete diagnostic approach should be carried out after a focused initial rapid evaluation is conducted and following initiation of any urgent intervention.

Abbreviations: AVR: Aortic valve replacement; BP: Blood pressure; CBC: Complete blood count; CXR: Chest X-ray; ECG: Electrocardiogram; ESR: Erythrocyte sedimentation rate; HF: Heart failure; LV: Left ventricle; LVEF: Left ventricle ejection fraction; MI: Myocardial infarction; S1: First heart sound; S2: Second heart sound; S3: Third heart sound; S4: Fourth heart sound; TTE: Transthoracic echocardiography; TEE: Transesophageal echocardiography; TAVR: Transcatheter aortic valve replacement

Acute Aortic Regurgitation

Shown below is a complete diagnostic approach for acute aortic regurgitation based on the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease.

Characterize the symptoms: ❑ Sudden and severe dyspnea ❑ Palpitations ❑ Altered mental status ❑ Cold extremities ❑ Oliguria Symptoms suggestive of aortic dissection ❑ Chest pain ❑ Sudden onset ❑ Intense ❑ Tearing and sharp ❑ Interscapular ❑ Worsened by deep breathing or cough ❑ Relieved by sitting upright ❑ Unexplained syncope Symptoms suggestive of infective endocarditis ❑ Fever ❑ Sweats ❑ Fatigue ❑ Pleuritic chest pain ❑ Back pain ❑ Weakness ❑ Myalgias

Inquire about past medical history: Suggestive of infective endocarditis ❑ Bicuspid aortic valve ❑ Rheumatic fever ❑ Prosthetic valves ❑ Intravenous drug use ❑ Substances used in the mixture ❑ Sharing the equipment ❑ The process of cleaning the equipment ❑ Previous infective endocarditis Suggestive of aortic dissection ❑ Hypertension ❑ Marfan syndrome ❑ Connective tissue disorder

Examine the patient: Vitals ❑ Temperature ❑ Fever (suggestive of infective endocarditis) ❑ Heart rate ❑ Tachycardia ❑ Blood pressure ❑ Asymmetric blood pressure in the upper extremities ❑ Hypertension (suggestive of aortic dissection) ❑ Hypotension (suggestive of severe regurgitation or aortic dissection) ❑ Respiratory rate ❑ Tachypnea Cardiovascular examination ❑ Weak pulses ❑ Jugular venous distension ❑ Cardiac auscultation ❑ Murmur ❑ Low pitched early diastolic murmur (may be absent) ❑ Best heard at the right 2nd intercostal space in aortic dissection ❑ Heart sounds ❑ Decreased or absent S1 ❑ Increased P2 (suggestive of pulmonary hypertension) ❑ S3 and S4 may be present ❑ Apical diastolic rumble Respiratory examination ❑ Rales (suggestive of pulmonary congestion) ❑ Wheeze

Order labs and tests: ❑ TTE (most important test) (Class I; Level of Evidence: B) ❑ In high suspicion of aortic dissection, perform a TEE ❑ Chest X-ray ❑ Increased cardiac silhouette (suggestive of aortic dissection) ❑ Widened mediastinum (suggestive of aortic root dilation) ❑ Pulmonary congestion (suggestive of pulmonary edema or pulmonary hypertension) ❑ ECG ❑ Nonspecific changes of ST and T wave (due to LV enlargement) ❑ Right coronary artery ischemic changes (suggestive of aortic dissection) ❑ ST elevation in II, III, aVF (inferior MI) ❑ ST elevation in V3R and V4R (right ventricle MI) ❑ ST depression in V1-V3 (posterior MI) ❑ Blood culture (if suspected infective endocarditis) ❑ CBC ❑ ESR ❑ Cardiac enzymes (Troponin, CK-MB)

Determine the etiology of the acute aortic regurgitation

Aortic dissection Diagnostic clues: ❑ Chest pain of the following characteristics: ❑ Sudden onset ❑ Intense ❑ Tearing and sharp ❑ Worsened by deep breathing or cough ❑ Relieved by sitting upright ❑ Syncope ❑ Low pitched early diastolic murmur ❑ Best heard at the right 2nd intercostal space ❑ Previous history of: ❑ Marfan syndrome ❑ Connective tissue disorder Click here for aortic dissection resident survival guide

Infective endocarditis Diagnostic clues: ❑ Persistent fever ❑ New valvular regurgitation murmur ❑ Positive blood culture ❑ Vegetations found on TTE ❑ High risk factors: ❑ Pre-existing cardiac abnormality ❑ Prosthetic valve ❑ Recent surgical or medical procedures ❑ Intravenous drug use ❑ Recent bacterial infection ❑ History of previous endocarditis ❑ Evaluate the modified Duke criteria (click here to see) Click here for infective endocarditis resident survival guide

Other causes ❑ Complication of: ❑ TAVR ❑ Percutaneous aortic balloon dilation ❑ Prosthetic valve dysfunction ❑ Blunt chest trauma

Chronic Aortic Regurgitation

Shown below is a complete diagnostic approach for chronic aortic regurgitation based on the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease.

Characterize the symptoms: ❑ Asymptomatic ❑ Dyspnea on exertion ❑ Orthopnea ❑ Paroxysmal nocturnal dyspnea ❑ Palpitations ❑ Chest pain ❑ Shortness of breath ❑ Cough ❑ Altered mental status ❑ Syncope ❑ Fatigue

Inquire about past medical history: ❑ Cardiac disease: ❑ Hypertension ❑ Bicuspid aortic valve ❑ Rheumatic fever ❑ Pulmonary disease ❑ Trauma ❑ Syphilis ❑ Ankylosing spondylitis ❑ Acromegaly ❑ Marfan syndrome ❑ Ehlers-Danlos syndrome ❑ Giant cell arteritis ❑ Takayasu's arteritis ❑ Previous cardiac surgery

Examine the patient: Vitals ❑ Heart rate: ❑ Tachycardia (suggestive of reduced stroke volume) ❑ Blood pressure: ❑ Wide pulse pressure (≥ 60 mmHg) Cardiovascular examination ❑ Pulses ❑ Corrigan's pulse: a rapid upstroke and collapse of the carotid artery pulse ❑ Cardiac auscultation ❑ Murmur ❑ High pitched holodiastolic decrescendo murmur ❑ Best heard at the upper left sternal border ❑ Murmur increases with sitting forward, expiration and handgrip ❑ Austin Flint murmur: a soft mid-diastolic rumble, best heard at the cardiac apex (suggestive of severe regurgitation) ❑ Heart sounds ❑ S2: decreased or absent A2; normal P2 ❑ S3 may be present (suggestive of left ventricular dysfunction) ❑ S4 may also be present ❑ Search for other characteristic signs suggestive of aortic regurgitation ❑ Traube's sign: 'pistol shot' pulse heard over the femoral artery ❑ Müller's sign: systolic pulsations of uvula ❑ de Musset's sign: head bobbing with each heart beat ❑ Hill's sign: ≥ 20 mmHg difference in popliteal and brachial systolic cuff pressures (suggestive of chronic severe AR) ❑ Quincke's sign: pulsation of the capillary bed in the nail Respiratory examination ❑ Rales (seen when congestive heart failure has developed)

Order imaging studies: ❑ TTE (most important evaluation test) (Class I; Level of Evidence: B) ❑ CMR in cases of moderate or severe AR and suboptimal echocardiographic images for the evaluation of the severity of AR (Class I; Level of Evidence: B) ❑ Chest X-ray ❑ Increased cardiac silhouette (suggestive of LV dilatation) ❑ Widened mediastinum (suggestive of aortic root dilation) ❑ Pulmonary congestion (suggestive of HF) ❑ ECG ❑ Nonspecific changes of ST and T wave (due to LV dilatation)

Classify aortic regurgitation based on the following findings on TTE: ❑ Vena contracta ❑ Jet/LVOT ❑ Regurgitant volume ❑ Regurgitant fraction ❑ Effective regurgitant orifice

Risk of aortic regurgitation (Stage A) ❑ No regurgitation

Mild (Stage B) ❑ Vena contracta <0.3 cm ❑ Jet/LVOT <25% ❑ Regurgitant volume <30 mL/beat ❑ Regurgitant fraction <30% ❑ Effective regurgitant orifice <0.10 cm²

Moderate (Stage B) ❑ Vena contracta 0.3-0.6 cm ❑ Jet/LVOT 25-64% ❑ Regurgitant volume 30-59 mL/beat ❑ Regurgitant fraction 30-49% ❑ Effective regurgitant orifice 0.10-0.29 cm²

Severe ❑ Vena contracta >0.6 cm ❑ Jet/LVOT ≥ 65% ❑ Regurgitant volume ≥60 mL/beat ❑ Regurgitant fraction ≥50% ❑ Effective regurgitant orifice ≥ 0.30 cm² ❑ Holodiastolic flow reversal in the proximal abdominal aorta

Is the patient symptomatic?

No

Yes

Asses the LV and LVEF

Stage C1 ❑ Normal LVEF ❑ Mild to moderate dilatation of LV

Stage C2 ❑ LV systolic dysfunction ❑ Decreased LVEF or severe LV dilatation

Stage D ❑ Normal or decreased LV systolic function ❑ Moderate to severe LV dilatation

Treatment

Abbreviations: AVR: Aortic valve replacement; ACE: Angiotensin converting enzyme; ARB: Angiotensin receptor blocker; CCB: Calcium channel blocker; LVEF: Left ventricle ejection fraction; TTE: Transthoracic echocardiography

Treatment of Acute Aortic Regurgitation

Shown below is an algorithm for the treatment of acute aortic regurgitation.

What is the cause of acute AR?

Infective endocarditis

Aortic dissection

Does the patient have AR related heart failure symptoms?

❑ Schedule for an emergent surgery ❑ Administer beta blockers with caution (beta blockers inhibit compensatory tachycardia)

Yes

No

❑ Schedule for early aortic valve replacement (Class I, level of evidence B) Click here for more details

❑ Administer antibiotics ❑ Follow up the patient Click here for more details

Treatment of Chronic Aortic Regurgitation

Shown below is an algorithm depicting the indications for aortic valve replacement (AVR) in chronic aortic regurgitation. Patients that fulfill the indications for AVR but have existing comorbidities that do not permit AVR should be treated for hypertension if the blood pressure is more than 140 mmHg. Patients with stage A AR do not require any treatment.

Abbreviations: LVEF: left ventricular ejection fraction; LVEDD: left ventricular end diastolic diameter; LVESV: left ventricular end systolic diameter

What is the severity of the aortic regurgitation?

Severe regurgitation ❑ Vena contracta >0.6 cm ❑ Doppler jet width ≥ 65% of LVOT ❑ Regurgitant volume ≥60 mL/beat ❑ Regurgitant fraction ≥50% ❑ Effective regurgitant orifice ≥ 0.30 cm² ❑ Holodiastolic flow reversal in the proximal abdominal aorta ❑ Left ventricle dilatation

Progressive regurgitation (Stage B) ❑ Vena contracta <0.6 cm ❑ Regurgitant volume <60 mL/beat ❑ Regurgitant fraction <50% ❑ Effective regurgitant orifice <0.30 cm²

Is the patient symptomatic?

Is the patient undergoing another surgery?

Yes (Stage D)

No (Stage C)

No

Yes

❑ LVEF<50% (Stage C2)

❑ The patient is undergoing another surgery

❑ LVEF ≥ 50% AND ❑ LVESD > 50mm (Stage C2)

❑ LVEF ≥ 50% AND ❑ LVEDD > 65mm AND ❑ Low surgical risk

❑ LVEF ≥ 50% AND ❑ LVESD ≤ 50mm AND ❑ LVEDD ≤ 65mm

❑ Perform a periodic echocardiogram (Class I; Level of Evidence:B) ❑ Every 3 -5 years for mild regurgitation ❑ Every 1 - 2 years for moderate regurgitation ❑ Control hypertension preferably with ❑ Dihydropyridine CCB, or ❑ ACE inhibitors or ARBs (Class I; Level of Evidence: B)

AVR (Class I)

AVR (Class I)

AVR (Class I)

AVR (Class IIa)

AVR (Class IIb)

❑ Perform a periodic echocardiogram every 6 - 12 months (Class I, Level of Evidence C) ❑ Control hypertension preferably with ❑ Dihydropyridine CCB, or ❑ ACE inhibitors or ARBs (Class I; Level of Evidence: B)

AVR (Class IIa)

Type of Valve and Discharge Anticoagulation Therapy

Abbreviations: AVR: Aortic valve replacement; INR: International normalized ratio; TAVR Tansthoracic aortic valve replacement

Determine: ❑ Age ❑ Contraindications for anticoagulation ❑ Major bleeding diathesis or coagulopathy ❑ Uncontrolled severe hypertension (systolic blood pressure >200 mmHg) ❑ Recent head trauma ❑ Platelet count < 100 000 ❑ Pregnancy ❑ Hypersensitivity to warfarin ❑ Hemorrhagic stroke

❑ Patients ≤ 60 years old AND ❑ No contraindication for anticoagulation (Class IIa; Level of Evidence: B)

❑ Patients 60 - 70 years old AND ❑ No contraindication for anticoagulation

❑ Patients ≥ 70 years old (Class IIa; Level of Evidence: B) OR ❑ Patients at any age AND contraindications for anticoagulation therapy (Class I; Level of Evidence: C)

Bioprosthesic OR Mechanical prosthesis (Class IIa; Level of Evidence: B)

Mechanical prosthesis Avoid the use of direct thrombin inhibitors or anti-Xa agents in patients with mechanical prosthesis (Class III; Level of Evidence: B)

Bioprosthesis

Does the patient have risk factors for thromboembolism†?

Surgical AVR OR TAVR

Yes

No

Surgical AVR

TAVR

Administer for long term: ❑ Warfarin to achieve INR of 3.0 (Class I; Level of Evidence: B) AND ❑ Aspirin 75-100 mg/d (Class I; Level of Evidence: A)

Administer for long term: ❑ Warfarin to achieve INR of 2.5 (Class I; Level of Evidence: B) AND ❑ Aspirin 75-100 mg/d (Class I; Level of Evidence: A)

Administer ❑ Warfarin to achieve INR of 2.5 for 3 months (Class IIb; Level of Evidence: B) AND ❑ Aspirin 75-100 mg/d long term (Class IIa; Level of Evidence: B)

Administer: ❑ Warfarin to achieve INR of 2.5 for 3 months (Class IIb; Level of Evidence: B), OR ❑ Clopidogrel 75 mg/d (first 6 months) (Class IIb; Level of Evidence: C) AND ❑ Aspirin 75-100 mg/d (for life) (Class IIa; Level of Evidence: B)

†Risk factors for thromboembolism include atrial fibrillation, hypercoagulable conditions, left ventricle dysfunction, and previous thromboembolism.

Do's

• Order a cardiac MRI in patients with moderate or severe AR with an inconclusive TTE to assess the left ventricular systolic function and the systolic and diastolic volumes, as well as to evaluate the severity of AR (Class I; Level of Evidence: B).

• Schedule for a transthoracic echocardiography (TTE) after aortic valve replacement to evaluate the valve hemodynamics (Class I; Level of Evidence: B).

• Order a TTE when clinical symptoms or signs suggest prosthetic valve dysfunction (Class I; Level of Evidence: C).

Don'ts

• Avoid beta blockers in aortic regurgitation that is not caused by aortic dissection as it will block the compensatory tachycardia.

• Do not use intra-aortic balloon counterpulsation in severe acute aortic regurgitation as it will increase the aortic diastolic pressure and the regurgitant volume.

• Do not administer antibiotics to patients with known aortic regurgitation before blood cultures are obtained for unexplained fever (Class III; Level of Evidence: C).

• Do not prescribe ACE inhibitors to pregnant patients with aortic regurgitation (Class III; Level of Evidence: B).

References

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