CHAPTER 11

History

An 85-year-old man presented with dyspnea on exertion, ankle swelling, and NYHA class II heart failure. He reported no orthopnea or paroxysmal nocturnal dyspnea. Patient had a bioprosthetic aortic valve (AV) implanted 15 years ago and was referred for “diastolic heart failure.”

Physical examination

There was a 3/6 crescendo-decrescendo systolic murmur at the right second intercostal space and a 3/6 holosystolic murmur at the cardiac apex. No diastolic murmur was audible. There was 1+ bilateral lower extremity pitting edema to just above ankles.

Electrocardiography

ECG showed sinus rhythm with voltage criteria of LV hypertrophy in the precordial leads.

Chest radiography

Chest x-ray (CXR) showed a normal cardiac silhouette, blunting of the right costophrenic angle, sternotomy wires, and a bioprosthetic aortic valve.

Handheld echocardiography findings during consultation

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  Normal-to-hyperkinetic left ventricle with an ejection fraction estimated at 65% ( Fig. 11.1 , Video 11.1 ) and left ventricular hypertrophy.

  

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  Mild-to-moderate right ventricular enlargement with interventricular septal (IVS) flattening ( Fig. 11.1 , Video 11.1 ).

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  Marked mitral annular calcification extending to mitral leaflets ( Fig. 11.1 , Video 11.1 ) with markedly turbulent color Doppler flow across the mitral valve, moderate central mitral regurgitation, and left atrial enlargement ( Fig. 11.2 , Video 11.2 ).

  

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  Moderate tricuspid regurgitation and marked right atrial enlargement.

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  Bioprosthetic aortic valve with marked leaflet thickening and limited excursion, focal nodular calcification with possible mobile density on aortic cusp ( Fig. 11.3 , Video 11.3 ).

  

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  There was an increase in right atrial (RA) pressure based on inferior vena cava (IVC) size estimated at 8 mm Hg.

Standard echocardiogram

Standard echocardiogram confirmed bioprosthetic aortic valve (AV) stenosis ( Fig. 11.4 ) with a mean AV gradient of 32 mm Hg ( Fig. 11.5 ). Peak pulmonary artery (PA) pressure was 75 mm Hg, consistent with severe pulmonary hypertension. An outside echocardiogram 1 year ago had shown a mean AV gradient of 20 mm Hg.

Transesophageal echocardiography

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  A transesophageal echocardiogram (TEE) confirmed bioprosthetic aortic valve stenosis with cusp motion of the noncoronary cusp and fixed right coronary cusp of the aortic valve ( Fig. 11.6 ). There was mild intravalvular regurgitation. Thrombus on AV could not be ruled out. Three-dimensional (3D) imaging of the mitral valve showed heavy mitral leaflet calcification ( Fig. 11.7 ). Mean mitral valve gradient was 8 mm Hg ( Fig. 11.8 ).

  
  
  

Subsequent clinical course

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  A nodular thickening was found adjacent to valve leaflet calcification of the bioprosthetic AV, and an increase in AV gradient compared with a year ago was concerning for a possible valve thrombus. However, as a result of an increased serum creatinine of 2.5 mg/dL a contrast enhanced CT was not performed to rule out valve thrombosis.

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  The patient was started on a trial of coumadin with an international normalized ratio (INR) goal of 2 to 3 with a plan for follow-up assessment of AV gradient and nodular thickening.

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  Metoprolol dose was increased from 50 to 62.5 mg a day to allow for a slower heart rate and reduced mitral gradient. Renal insufficiency and mixed mitral stenosis and regurgitation were considered to be the etiology of pulmonary hypertension. Furosemide was increased.

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  Patient presented with a gastrointestinal bleed 3.5 weeks later and coumadin was stopped. No change in AV gradient occurred when the patient was on coumadin.

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  Subsequent capsule endoscopy and CT enterography identified a small bowel mass that was found to be diffusely metastatic on subsequent positron emission tomography CT scan, and the patient died 5 months later.

Utility of handheld echocardiography in clinical management

HHE assisted with the initial evaluation of LV function, bioprosthetic aortic valve and function, presence of calcific mixed mitral valve disease, and dilated right ventricle with pressure overload.

Final diagnosis

The diagnosis was severe bioprosthetic aortic valve stenosis from structural valve degeneration (SVD) with severe calcific mitral valve stenosis and pulmonary hypertension.

Teaching point

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  There has been an increased use of aortic bioprosthesis compared with mechanical prosthesis. The 2017 focused update of the American College of Cardiology (ACC)/American Heart Association (AHA) guidelines, suggests that it is reasonable (class IIa) to implant bioprostheses in patients >70 years old.

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  The goal at the time of valve implant in the aortic position is for the valve to outlive the patient; however, biological valves are prone to structural valve deterioration (SVD) over time.

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  There is no consensus on the definition of SVD. The 2016 European Association of Cardiovascular Imaging guidelines suggest defining SVD as: (1) an increase in mean gradient ≥10 mm Hg (possible SVD) or ≥20 mm Hg (significant SVD) during follow up, with a concomitant decrease in effective orifice area (EOA) and abnormal valve leaflet morphology and mobility; and/or (2) new onset or worsening of prosthetic regurgitation.

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  The Valve Academic Research Consortium-2 recommendations suggest consideration of valve dysfunction at follow up if there is an increase in the mean gradient >10 mm Hg, a decrease in the EOA of >0.3 to 0.4 cm ² , or a reduction in the dimensionless velocity index of >0.1 to 0.13 from the echocardiography performed within 30 days after transcatheter aortic valve replacement (TAVR).

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  Morphologic changes of leaflet thickening, calcification, flail, pannus and/or reduced or increased mobility from avulsion compared with the baseline echocardiography performed at 1 to 3 months after the procedure suggest SVD.

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  Causes of SVD manifests as calcification and leaflet degradation leading to valve stenosis or leaflet tear with ensuing valve regurgitation. Bovine pericardial valves have a greater propensity to develop stenosis, whereas porcine valves have a tendency to develop leaflet tear with regurgitation.

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  Valve degeneration appears more rapidly on the left-sided cardiac valves than on the low-pressure right-sided cardiac valves and in the mitral valve more rapidly than in the aortic position. In older adults the longevity of bioprosthetic valves in the aortic position is between 10 to 20 years; and in the mitral position, 8 to 15 years. Younger age and increased BMI are associated with a more rapid SVD.

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  The treatment for SVD has conventionally been surgical valve replacement; however, because of age and comorbidities in this cohort, redo surgery is associated with increased morbidity and mortality. Valve-in-valve replacement by TAVR has become a feasible option in such patients.

Video 11.1 HHE parasternal long-axis view showing thickening and restricted motion of bioprosthetic aortic valve, heavy mitral annular calcification, and restricted mitral leaflet motion. A dilated right ventricle (RV) with interventricular septal flattening from RV pressure overload is also shown. LA, Left atrium; LV, left ventricle.

Video 11.2 HHE color Doppler parasternal long-axis view showing turbulent diastolic flow across the mitral valve and moderate mitral regurgitation. LA, Left atrium; LV, left ventricle; RV, right ventricle.

Video 11.3 HHE subcostal sweep showed tricuspid (TV), bioprosthetic, and pulmonic (PV) valves. There is calcification and a nodular density on the aortic valve (AV) cusp. Dilated right ventricle (RV) inflow and outflow and dilated right atrium (RA) are also shown.