other major morbidity and good LV function. This page intentionally left blank 156 CHAPTER 3 Valvular heart disease Mitral stenosis guidelines Mitral stenosis History, Physical exam CXR, ECG, 2D echo/Doppler Symptoms? Symptomatic Asymptomatic Moderate or severe stenosis* MVA \211 1.5 cm2 Mild stenosis MVA >1.5 cm2 Yearly follow-up History, Physical exam, CXR, ECG Valve morphology favorable for PMBV? No \200 Yes PASP > 50 mm Hg? Yes \200 No Class I Exercise Consider PMBV Poor exercise tolerance or PASP >60 mm Hg or PAWP \211 25 mm Hg Class I Exclude LA clot, 3+ to 4+ MR Yes No No Class IIb Yes New-onset AF? Fig. 3.2 Management strategy for patients with mitral stenosis. *The writing committee reco gnizes that there may be variability in the measurement of mitral valve area (MVA) and that the mean transmitral gradients, pulmonary artery wedge pressure (PAWP), and pulmonary arte ry systolic pressure (PASP) should also be taken into consideration. \200 There is controv ersy as to whether patients with severe mitral stenosis (MVA less than 1.0 cm 2 ) and sever e pulmonary hypertension (pulmonary artery pressure greater than 60 mm Hg) should undergo p ercutaneous mitral balloon valvotomy (PMBV) or mitral valve replacement to prevent right ve ntricular failure. \200 Assuming no other cause for pulmonary hypertension is present. AF indicates atrial \201 brillation; CXR, chest X-ray; ECG, electrocardiogram; echo, echoca rdiography; LA, left atrial; MR, mitral regurgitation; and 2D, 2-dimensional. Reproduced wi th permission from Journal of the American College of Cardiology , Vol 48 , No.3, 2006. Aug ust 1, 2006:e1 \200\223148. Bonow et al, AHA/ACC Best Practice Guidelines. MITRAL STENOSIS GUIDELINES 157 Symptomatic mitral stenosis NYHA functional class II History, Physical exam CXR, ECG, 2D echo/Doppler Mild stenosis MVA >1.5 cm2* Moderate or severe stenosis MVA \211 1.5 cm2* Exercise PASP >60 mm Hg PAWP \211 25 mm Hg MVG >15 mm Hg Valve morphology favorable for PMBV? Yes No Valve morphology favorable for PMBV? Yes No Yearly follow-up Severe PH PAP >60 \200\22380 mm Hg No Yes Class IIb Class I No Yes Consider PMBV Class IIa 6-month follow-up 6-month follow-up \200 Consider commissurotomy or MVR Exclude LA clot, 3+ to 4+ MR Fig. 3.3 Management strategy for patients with mitral stenosis and mild symptoms. *The comm ittee recognizes that there may be variability in the measurement of mitral valve area (MVA ) and that the mean transmitral gradient, pulmonary artery wedge pressure (PAWP), and pulmo nary artery systolic pressure (PASP) should also be taken into consideration. \200 There is controversy as to whether patients with severe mitral stenosis (MVA less than 1.0 cm 2 ) and severe pulmonary hyperten- sion (PH; PASP greater than 60 to 80 mm Hg) should undergo percutaneous mitral balloon valvotomy (PMBV) or mitral valve replacement (MVR) to prevent r ight ventricular failure. CXR indicates chest X-ray; ECG, electrocardiogram; echo, echocard iography; LA, left atrial; MR, mitral regurgitation; MVG, mean mitral valve pressure gradie nt; NYHA, New York Heart Association; PAP, pulmonary artery pressure; and 2D, 2-dimensional . Reproduced with permission from Journal of the American College of Cardiology , Vol 48 , No.3, 2006. August 1, 2006:e1 \200\223148. Bonow et al , AHA/ACC Best Practice Guidelines. 158 CHAPTER 3 Valvular heart disease Mitral regurgitation Causes Acute: Infective endocarditis, acute myocardial infarction (MI) , trauma. Chronic: Most common \200\224 myxomatous degeneration (mitral valve prolapse), chronic rhe umatic heart disease, left ventricular or annular dilatation of any cause (e.g. chronic isc haemia, cardiomyopathy, annular calci \201 cation), degeneration of valve cusps, collagen vascular disease, hypertrophic cardiomyopathy. Nomenclature \200 Essentially there is a spectrum of myxomatous degenerative disease from single-segment prolapse in small valves ( \201 broelastic de \201 ciency) to multise gment prolapse in large valves (Barlow \200\231s disease). Mitral regurgitation (MR) can be classi \201 ed by mechanism according to Carpentier \200\231s classi \201 cation: \200 type I \200\224 normal lea \202 et motio n, e.g. dilated annulus from dilated cardiomyopathy, lea \202 et perforation due to endocarditis \200 type II \200\224 lea \202 et prolapse, e.g. myxomatous degeneration \200 type IIIa \200\224 restricted lea \202 et opening, e.g. rheumatic disease \200 type IIIb \200\224 restricted lea \202 et closing, e.g. ischaemic dilated cardiomyopathy (functional). Pathophysiology \200 Damage to lea \202 ets, chordae, papillary muscles, or LV can cause MR. \200 The LV ejects into the LA during systole, as well as antegrade into the aorta. In acute MR: there is little enlargement of the LA due to normal compliance. This results in raised LA p ressure and can result in pulmonary oedema \200 there is no compensatory LV enlargement, so the forward ejection fraction (EF) is reduced, leading to low CO. In longstanding severe MR, there is enlargement of the LA, which accommodates the volume overload with minimal rise in LA pressure. The LV dilates, and larg e stroke volume compensates for regurgitation, maintaining the forward EF. LV failure resul ts from longstanding volume overload. The low-pressure regurgitant pathway masks LV failure : EF is often normal even when LV is very impaired. Clinical features In acute severe MR \200\224 pulmonary oedema is common, hypotension, car dio- genic shock. This is a medical emergency. See b p. 728. History \200 Chronic MR \200\224 initially asymptomatic. Fatigue (due to d forward CO), exertional dyspnoea, orthopnoea, systemic embolization (less common than MS). Palpitations ( i stroke volume/associated AF). Right heart failure in later stages Symptoms and risk factors of endocarditis, ischaemic heart disease. MITRAL REGURGITATION 159 Physical examination Rapid upstroke in arterial pulse. Irregularly irregular pulse in AF. P rominent \200\230a \200\231 waves in JVP in patients in sinus rhythm. Large \200\230v \200\231 waves if there is asso- ciated tricuspid regurgitation (TR). Forceful apex displac ed laterally (LV dilatation). Systolic thrill at apex. Auscultation: Pansystolic murmur loudest at the apex and radiating into the axilla. Soft \201 rst heart sound. Loud mitral valve closure sound helpful in excluding severe MR. Wide splitting of S 2 due to premature aortic valve closure. Prominent low-pitched S 3 . A mid-d iastolic \202 ow murmur may follow S 3 even in the absence of MS. Investigations \200 ECG: LA enlargement, left ventricular hypertrophy (LVH), RA enlargement in pulmonary hypertension. AF common in chronic MR. \200 CXR: Cardiomegaly, L A and LV enlargement, and pulmonary venous congestion. Calci \201 ed mitral annulus may be seen. TTE: Demonstrates MV anatomy (lesion and type of MR). Color Doppler to detect and quantify the MR (Table 3.3 ). Assessment of LV function from EF, end- systolic dimension and end-diastolic dimension ( Note: In compensated MR, EF is always over estimated because of the low-resistance retrograde pathway). TOE: Shows the anatomy in greater detail and allows accurate assessment of the feasibility of valve repair. Should be performed pre- or intra-operativel y. Cardiac catheterization: Not always required. Ventriculogram can quantify MR severity and EF. Detection of co-existing valve lesions and coronary artery dis ease. Classi \201 cation of organic mitral regurgitation See Table 3.3 . Table 3.3 Classi \201 cation of mitral regurgitation Severity Angiographic grade Jet area ( % of LA area) Jet width (cm) Regurgitant fraction ( % ) ERO (cm 2 ) Mild MR Contrast seen entering LA <20 <0.3 <30 <0.2 20 \200\22340 0.3 \200\2230.69 30 \200\22349 0.2 \200\2230.39 Moderate MR Contrast in LA same intensity as LV within 3 \200\2234 beats > 40 (cid:116) 0.7 (cid:116) 50 (cid:116) 0.4 Severe MR Contrast in LA same intensity as LV within 3 \200\2234 beats ERO = effective regurgitant ori \201 ce. 160 CHAPTER 3 Valvular heart disease Prognosis Prognosis depends upon the atiology of MR (e.g. ischaemic MR confers signi \201 cantly worse prognosis). Outcome is poor in symptomatic severe MR; 33 % survival at 8 years without surgical intervention. Death occurs mostly from heart failure but there is a subst antial incidence of sudden death, which may be arrhythmia related. MITRAL REGURGITATION GUIDELINES 161 Mitral regurgitation guidelines Management Medical management \200 Although at increased risk for endocarditis, in the 2008 update to the American College of Cardiology (ACC)/Ameri can Heart Association (AHA) guidelines, routine prophylaxis is no longer recommended. \200 Asymptomatic patients with mild MR are managed conservatively with serial echocardiograms. Vasodilators in symptomatic patients to increase forward CO and reduce regurgitant volume. In AF: rate control and anticoagulation (goal international normalized ratio (INR) 2 \200 \2233). Note: new-onset AF is a class IIa indication for surgery in chronic, severe MR. Surgical treatment \200 Indicated for patients with severe MR who are symptomatic despite optimum medical management. Asymptomatic patients with severe MR may need surgery if there is: worsening of LV function (EF 30 \200\22360 % or LV end-systolic dimension (cid:116) 40 mm) new AF \200 pulmonary hypertension. Mitral valve repair is strongly preferred to valve replacement: it is the only intervention that restores life expectancy to normal, and offers event-free survival that is superior t o medical management or replacement. \200 Likelihood of repair is highly dependent on sur geon expertise. \200 Repair minimizes risk of hemorrhage and thromboembolism, reoperation, LV dysfunction, and endocarditis. Multisegment prolapse, and heavily calci \201 ed valves, are more dif \201 cult to repair than single-segment prolapse, and non-calci \201 ed valves. \200 Percutaneous MV repair methods (edge-to-edge mitral clip and coronary sinus annuloplasty band) are currently being tested, but are not yet approved. Risk of surgery : 1 \200\2232 % mortality and stroke in 65-year-old patient with no other m ajor morbidity and good LV function. Ischaemic MR and endocarditis risk rises to around 2 \200\2235 % . Further reading European Society of Cardiology (ESC) ( 2007 ). Guidelines on the Management of Valvular Heart Disease: The Task Force on the Management of Valvular Heart Disease of t he European Society of Cardiology . Eur Heart J 28 : 230 \200\223 68 . Y http://www.escard io.org/guidelines-surveys/ esc-guidelines/GuidelinesDocuments/guidelines-VHD-FT.pdf 162 CHAPTER 3 Valvular heart disease Mitral valve prolapse \200 De \201 nition: Systolic billowing of one or both MV lea \202 ets above the plane of the MV annulus into the LA Nomenclature is confused: MV prolapse may result in MR, and is almost always due to degener ative disease (also known as \200\230 \202 oppy valve \200\231 or myxomatous degeneration ), and occasionally connective tissue disorders. There is a spectrum of degenerative diseas e which includes Barlow \200\231s disease (multisegment prolapse in giant valves) and \201 broelastic de \201 ciency (single segment prolapse in small valves). These terms are often used interchangeably. Prevalence: 0.6 \200\2232.4 % . 4 > 5 Causes Most cases are idiopathic. Connective tissue disorders including Marfan \200\231s sy ndrome, Ehlers \200\223Danos syndrome, pseudoe xanthoma elasticum, osteo- genesis imperfect a. Present in 20 % of ostium secundum ASD. Pathophysiology Myxomatous degeneration and excess mucopolysaccharides lead to thickened, e nlarged valve lea \202 ets, in one or more segments. Prolapse results from elongated or ru ptured chordae tendinae and excess lea \202 et tissue. MV lea \202 et (usually posterior \200\224 P2 segment) prolapses into the LA during ventricular systole. Clinical features Mostly asymptomatic. Atypical chest pain, Palpitations resulting from ven tricular and supraventricular arrhythmias. Symptoms of MR if signi \201 cant. Mid or late systolic click due to tensing of the chordae tendinae and prolapse of the lea \202 et. Late systolic murmur due to associated MR. Investigations ECG is usually normal. Some non-speci \201 c changes may be seen. CXR is no rmal if there is no signi \201 cant MR on TTE. Systolic displacement of one or both MV lea \202 ets by > 2 mm into the LA beyond the high points of mitral annulus. Assessment of MR . Management Infective endocarditis prophylaxis no longer recommended. 1 Beta-blocker for che st pain and palpitations. Anticoagulation if in AF or prior throm- boembolic event. MV repa ir (rarely replacement) for severe MR (surgical indications same as for MR). 1 Wilson W, Taubert KA, Gewitz M, et al (2007). Prevention of infective endocarditis: guide lines from the American Heart Association: a guideline from the American Heart Association Rheuma tic Fever, Endocarditis, and Kawasaki Disease Committee, Council on Cardiovascular Disease in the Young, and the Council on Clinical Cardiology, Council on Cardiovascular Surgery and Anesthesia, and the Quality of Care and Outcomes Research Interdisciplinary Working Group. Circulation 116 (15): 1736 \200\22354. This page intentionally left blank 164 CHAPTER 3 Valvular heart disease Aortic stenosis Incidence Commonest valve lesion in UK. 4 > 5. i with age. 2 % of people > 65 years have ECHO features of aortic stenosis (AS). Congenital bicuspid AS presents 20 ye ars earlier. Becoming more common (population aging, improved diagnosis). Causes Acquired: Degenerative calci \201 c AS (commonest); rheumatic fever, Paget disease of bone, end-stage renal failure, ochronosis. Congenital: Bicuspid aortic valve 1 \200\2232 % live births. Bicuspid AV results in chronic turbulent \202 ow, which results in calci \201 cation and \201 brosis of lea \202 et s with reduced valve area. Pathogenesis AS can occur at the level of the valve or above (supravalvular stenosis) or be low (subvalvular) the aortic valve. Degenerative calci \201 c AS results from years of nor mal stress on the valve. Similar risk factors as ischaemic heart disease (IHD) ( i blood pr essure (BP), i lipids, diabetes mellitus (DM)). In \202 ammatory change occurs within the valve, with calcium deposited along \202 exion lines causing immobility, reduced excursio n, and reduced opening area. Rheumatic AS is due to adhesion and fusion of commisures, with \201 brosis and retraction. Pathophysiology Progressive narrowing of the valve ori \201 ce results in compensatory LVH to maintain stroke volume. LVH results in a stiff, non-compliant ventricle with elevated e nd-diastolic pressure (diminished coronary perfusion pressure). Atrial component of LV \201 lling then becomes more signi \201 cant. Pressure overload eventually results in LV f ailure (pulmonary oedema, low cardiac output) and fall in transvalvular gradient because of reduced EF through valve. Clinical features History \200 Classical triad: angina, syncope, dyspnoea \200 Angina p ectoris: from i O 2 demand due to LVH and increased wall tension ( d subendocardial perfusion). Occurs in 2 / 3 \200\224 only 1 / 2 of these have o bstructive coronary lesions) Syncope: on exertion cannot increase CO in setting of peripheral vasodilation leading to d cerebral perfusion Dyspnoea: pulmonary oedema causing dyspnoea (exacerbated by AF). sudden death from ventricular arrhythmias \200 acquired von Willebrand disease and plaele t dysfunction in patients with severe AS due to shearing of von Willebrand factor (VWF) mul timers and platelets. Physical examination Slow-rising, small-volume pulse (pulsus parvus et tardus) \200\224 be st felt at carotid. BP \200\224 narrow pulse pressure, in advanced AS systolic BP is d. AORTIC STENOSIS 165 Prominent \200\230a \200\231 wave on JVP. Sustained, heaving apical impulse. If conges- ti ve cardiac failure (CCF) develops, the apex beat is displaced inferolater- ally. Systolic t hrill is felt in the aortic area (2nd intercostal space on right) during full expiration. A uscultation: S 1 normal or soft. In mild AS, S 2 normal (i.e. A 2 precedes P 2 ). In modera te AS, S 2 becomes single (closure of AV delayed until it coincides with closure of PV). In severe AS, there is paradoxical splitting with A 2 after P 2 . S 4 is often heard (atrial contraction into stiff ventricle) and systolic ejection click (if valve pliable). Mid-systo lic crescendo \200\223decrescendo ejection murmur is heard throughout precordium but best h eard at right upper sternal border in full expiration. Radiates to carotids. As AS severity worsens, the murmur peaks later, extends later through systole, and may obscure S 2 . Investigations \200 ECG : LVH with strain; left bundle branch block (LBBB), left atrial enlargement (LAE). CXR : calci \201 cation in valve or aortic root, post-stenotic dilatation in ascending aorta. TTE : calci \201 ed valve with restricted opening (M-mode). Color Doppler to detect concomitant aortic regurgitation (AR). CW Doppler to assess velocity (and hence g radient) across valve (see b Transthoracic Doppler imaging, p. 14). Determine AV area and E F. Cardiac catheterization : mainly to assess for concomitant coronary artery disease prior to aortic valve surgery (present in 50 % with calci \201 c AS). No ne ed to assess pullback gradient across valve nowadays (signi \201 cant risk of embolic even ts with this, CW Doppler accurately assesses gradient and LV function). Dobutamine stress : in patients with severe AS and low EF/low gradient to detect myocardial reserve and differentiate true stenosis with secondary LV dysfunction from pseudostenosis (low gradient from moderate AS and low CO from myocardial disease unrel ated to valve lesion). In pseudostenosis, measured AV area will i with dobutamine). Classi \201 cation See Table 3.4 . Table 3.4 Classi \201 cation of aortic stenosis AV area (cm 2 ) Severity Jet velocity (m/s) Gradient (mmHg) Mild AS <3 <25 > 1.5 Moderate AS 3 \200\2234 25 \200\22340 1 \200\2231.5 Severe AS > 4 > 40 <1 166 CHAPTER 3 Valvular heart disease Prognosis Rate of progression is highly variable, although AV area is estimated to decrease approximately 0.1cm 2 per year. Symptoms are often not present until AS is severe (gradien t across valve often > 100 mmHg). Once symp- toms occur, prognosis signi \201 cantly worse ns without surgical intervention. \200 Patients who present with angina have a 5-year mea n survival. \200 Patients who present with syncope have a 3-year mean survival. \200 Pa tients who present with dyspnoea due to CHF have a 2-year mean survival. This page intentionally left blank 168 CHAPTER 3 Valvular heart disease Management of aortic stenosis Medical management \200 No medical treatments are proven to prevent or delay the disease process in the AV lea \202 ets. There is no effective medical treatment to improve prognosis: \200 B -blockers reduce myo cardial O 2 demand and may improve coronary blood \202 ow cautious use of loop diuretics may relieve preload and help with dyspnoea (avoid hypovolaemia) in CHF or dilated LV, digoxin may help with dyspnoea (particularly if patient is in AF/ \202 utter) in severe AS, avoid negative inotropes and drugs that reduce afterload (e.g. glyceryl trinitrate (GTN,) angiotensin-converting enzyme inhibitors (ACE-Is )), as these may worsen the gradient and cause syncope. Surgical treatment \200 Surgery is the treatment of choice for symptomatic AS. \200 Acu te decompensation of severe AS is a medical emergency. \200 In asymptomatic severe AS, EF <50 % (see algorithm opposite). \200 Aortic valve replacement (AVR) is reasonable for asy mptomatic moderate or severe AS when undergoing concomitant coronary artery bypass graft (CABG), aort ic, or valve surgery. AVR is a safe effective procedure (surgical mortality 1 % , complication rate thereafter 1 % /year cumulative in large-volume centers, but national registries repor t mortality around 3 % . Bioprosthetic valves are preferred in older patients as they have excellent freedom from structural valve degeneration, and may be used in younger patients w ho want to avoid the 2 \200\2234 % linearized annual risk of thromboembolic or haemorrhagic stroke. Balloon aortic valvuloplasty \200 Introduced as non-surgical alternative treatment for AS . \200 Prognosis same as for medical management because of procedural complications (73 % mortality and 76 % MI/severe AR/myocardial perforation) and restenosis rates (50 % resteno sis within 3 \200\2236 months): \200 children/adolescents with non-calci \201 ed AS. \200 patients deemed un \201 t for AVR or who refuse surgery. \200 bridge to transcathe ter aortic valve replacement (TAVI)/AVR (treat acute decompensation so patient can be optim ized before surgery). Transcatheter aortic valve replacement \200 TAVI is approved in Europe and is currently u ndergoing phase III clinical trials in the United States. Pericardial valves mounted on expandable stents may be placed in the aortic position via the transfemoral or transapical routes, after a balloon is expanded inside the stenotic valve. MANAGEMENT OF AORTIC STENOSIS 169 Increased experience and technological improvements have led to low procedural morbidity an d mortality, with good early results suggesting surivival superior to that of medical manag ement or balloon valvuloplasty. Further reading European Society of Cardiology (ESC) ( 2007 ). Guidelines on the Management of Valvular Heart Disease: The Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology . Eur Heart J 28 : 230 \200\223 68 . Y http://www.escardio.org/guidelines-s urveys/ esc-guidelines/GuidelinesDocuments/guidelines-VHD-FT.pdf 170 CHAPTER 3 Valvular heart disease Aortic regurgitation Causes Valvular: Rheumatic heart disease (often combined with AS as we ll as MS/MR), infective endocarditis, degenerative calci \201 c (with AS), bicuspid aortic valve, trauma. Aortic root disease: Hypertension, aortic dissection, Marfan \200\231s synd rome. Other causes are rare: osteogenesis imperfecta, syph- ilitic aortitis, spondyloarthri tides (ankylosing spondylitis, Reiter \200\231s, etc.), arteritis (Takayasu \200\231s, gian t cell). Incidence Less common than AS. Valvular causes are becoming less frequent and aortic root c auses now account for > 50 % of cases. Pathogenesis Valvular disease: Valvular \201 brosis and fusion of cusps results in retrac tion of cusps such that they cannot coapt properly. Subacute bacterial endocarditis (SBE): Direct destruction of valve cusps/ vegetations. Aortic root disease: Progressive dilatation of aortic root causes failure of coaptation of cusps and regurgitation. Pathophysiology As the valve fails, more of the LV stroke volume regurgitates into the LV. CO is maintained by compensatory LV dilatation and hypertrophy increasing stroke volume but at the expense of increasing end-diastolic volume. Volume overload leads to eccentric hype rtrophy, myocyte function deteriorates, and further LV dilatation occurs, leading to LV dec ompensation. Clinical features In acute AR, dyspnoea is common ( i forward CO in a setting of non- compl iant LV ( d left ventricular end-diastolic pressure (LVEDP)) leads to pulmonary oedema), hy potension, and cardiogenic shock. Acute AR is a medical emergency. History \200 In chronic AR, initially asymptomatic. LVEDP is low due to LV dilatation. Chronic volume overload leads to LV failure and CHF. \200 Angina, symptoms of aortic dissection (e.g. chest pain radiating to back). Ask about symptoms of endocarditis. Physical examination Wide pulse pressure: collapsing (w ater-hammer) pulse, Corrigan \200\231s sign (visible carotid pulsation), De Musset \200\231 s sign (head nodding with each pulse), M ller \200\231s sign (visible pulsation of uvula), Traube sign ( \200\230pistol shot femorals \200\231 \200\224 loud bruit heard with stetho scope over femoral artery), Quincke sign (visible capillary pulsation in nailbed), Duroziez sign (systolic and diastolic bruits heard over femoral artery when artery is digitally com pressed). AORTIC REGURGITATION 171 Apex beat displaced inferolaterally and diffuse/hyperdynamic. May feel apical systolic thri ll. Auscultation: A 2 may be normal (or louder) if AR is due to aortic root pathology, and may be soft or absent if AR is due to aortic valve pathology. S 3 may be heard with dilated LV or with incipient failure. An ejection systolic murmur (ESM) similar to AS may be audib le (either due to mixed AR/AS or due to turbulent \202 ow due to i stroke volume (SV)). M urmur of AR is a high-pitched, early-diastolic decrescendo murmur immediately following A 2 . Best heard with patient sitting up and leaning forward in expiration. Heard most clearly along the left upper sternal border (occasionally along right sternal border if aortic roo t dilated). Duration of murmur in diastole correlates with severity of AR. Austin Flint mur mur is a mid-diastolic murmur heard at apex due to antegrade \202 ow across a mitral valv e ori \201 ce which has been narrowed by a combination of rising LV pressure and jet of AR directed at the anterior MV lea \202 et. Investigations \200 ECG : LVH with strain, left axis deviation. \200 CXR : in chronic A R there is enlarged cardiac shadow. Dilated ascending aorta with aortic root pathology. TTE : color Doppler and CW Doppler con \201 rm diagnosis and assess severity. M-mode measu res aortic root and LV dimensions, EF. \200 Cardiac catheterization : to assess for conco mitant coronary artery disease prior to aortic valve/root surgery. Aortogram in left anterior oblique (LAO) projec tion shows aortic root and severity of AR. Classi \201 cation See Table 3.5 . Table 3.5 Classi \201 cation of aortic regurgitation Severity Angiographic grade Jet width ( % of LVOT) Regurgitant fraction ( % ) ROA (cm 2 ) Mild AR Contrast enters LV, clears with systole <25 <30 <0.1 Moderate AR Opaci \201 cation entire LV 25 \200\22365 30 \200\22349 0.1 \200\2230.29 Severe AR Opaci \201 cation LV > aorta > 65 (cid:2) 50 (cid:2) 0.3 Additional essential criteria: left ventricular size increased. LVOT = left ventricular out \202 ow tract; ROA = regurgitant ori \201 ce area. Prognosis Chronic AR can be well tolerated for many years and is associated with a good pro gnosis. 5-year survival 75 % , 10-year survival 50 % . Prognosis worsens as symptoms inte rvene (see box, b p.172). Acute severe AR however is associated with a high mortality from LVF, and early interven- tion is indicated. 172 CHAPTER 3 Valvular heart disease Natural history of AR Asymptomatic patients with normal LV function Progression to symptoms/signs CCF <6 % /year Progression to asymptomatic LV dysfunction <3.5 % /year Sudden death <0.2 % /year Asymptomatic patients with LV systolic dysfunction Progression to cardiac symptoms > 25 % /year Symptomatic patients Mortality rate > 10 % /year This page intentionally left blank 174 CHAPTER 3 Valvular heart disease Aortic regurgitation guidelines Management (see also Fig. 3.4) Medical management \200 As ymptomatic mild/moderate AR with normal LV \200\224 routine follow-up (every 1 \200\2232 years) with ECHO. Asymptomatic severe AR with normal LV \200\224 frequent (6-monthly) follow-up \200\224 or sooner if symptoms intervene. Bene \201 t of vasodilators is debata ble. Severe AR with LV dysfunction or symptoms (and patient not operative candidate) \200\224 symptoms of CCF respond to loop diuretics and digoxin while arrangements are made for surgery. Vasodilators (ACE-Is, calcium-channel blockers) offer go od symptomatic relief and may improve haemodynamic pro \201 le. Anginal chest pain can be treated with nitrates but use B -blockers with caution. Concomitant hypertension can worsen AR, therefore treat in the usual manner. Acute severe AR \200\224 urgent surgical intervention recommended. Nitroprusside and inotr opic agents (dopamine, dobutamine) augment forward CO and reduce LVEDP and are useful to ma nage the patient temporarily before surgery. Intra-aortic balloon pump (IABP) contraindicat ed. Use B -blockers cautiously because they block compensatory tachycardia. Surgical treatment \200 Because of the relatively benign nature of asymptomatic AR with normal LV function, these patients should be kept under observation. Once symptoms interven e or evidence of signi \201 cant LV dysfunction appears, referral for AVR/root replacement should be considered. In borderline cases frequent (2 \200\2234-monthly) follow-up is indi cated. AVR is indicated for patients with symptomatic severe AR, or asymptomatic severe AR and EF (cid:3) 50 % , severe LV dilatation (LV end-diastolic dimensi on > 75 mm or LV end-systolic dimension > 55 mm), or concomitant CABG, valvular, or aortic surgery. AVR is a safe effective procedure (surgical mortality 1 % , complication rate thereafter 1 % /year cumulative in large-volume centers, but national registries repor t mortality around 3 % . Root replacement, performed if aortic root is dilated, is a more c omplex procedure, with mortality 3 \200\2235 % . Bioprosthetic valves are preferred in older patients as they have excellent freedom from structural valve degeneration, and may be used in younger patients w ho want to avoid the 2 \200\2234 % linearized annual risk of thromboembolic or haemorrhagic stroke. Valve-sparing procedures may be useful in young patients with normal lea \202 ets where ao rtic AI is due to aortic root dilatation: durability may be better than bioprosthetic valve s in young patients. AORTIC REGURGITATION GUIDELINES 175 Chronic severe aortic regurgitation Clinical evaluation + Echo Reevaluation Symptoms? No Yes Equivocal Class I Exercise test Class I AVR Symptoms No symptoms LV function? Class I Normal EF EF of 50% or less EF borderline or uncertain RVG or MRI Class IIa SD >55 mm or DD >75 mm LV dimensions? Class IIb SD 45 \200\22350 mm or DD 60 \200\22370 mm SD 50 \200\22355 mm or DD 70 \200\22375 mm SD <45 mm or DD <60 mm Abnormal Consider hemodynamic response to exercise Stable? Stable? Stable? No, or initial study No, or initial study Yes Yes Yes Normal Clinical eval every 6 \200\22312 mo Echo every 12 mo Clinical eval every 6 mo Echo every 6 mo Clinical eval every 6 mo Echo every 12 mo Reevaluate and Echo 3 mo Reevalute and Echo 3 mo Fig. 3.4 Management strategy for patients with chronic severe aortic regurgitation. Preoper ative coronary angiography should be performed routinely as determined by age, symptoms, an d coronary risk factors. Cardiac catheterization and angiog- raphy may also be helpful when there is discordance between clinical \201 ndings and echocardiography. \200\230Stable \200\231 refers to stable echocardiographic measurements. In some centers, serial follow-up may be performed with radionuclide ventriculog- raphy (RVG) or magnetic resonance imaging (MRI) rather than echocardiography (Echo) to assess left ventricular (LV) volume and systol ic function. AVR indicates aortic valve replacement; DD, end-diastolic dimension; EF, eject ion fraction; eval, evaluation; and SD, end-systolic dimension. Reproduced with permission from Journal of the American College of Cardiology , Vol 48 , No.3, 2006. August 1, 2006: e 1 \200\223148. Bonow et al , AHA/ACC Best Practice Guidelines . 176 CHAPTER 3 Valvular heart disease Tricuspid and pulmonary disease Tricuspid regurgitation Causes: Functional or secondary TR (normal lea \202 ets, RV annular dilatation due to MV disease, congenital heart disease) i s common. Organic tricuspid lesions: endocarditis most common (particularly intravenous (IV ) drug abuse), transvalvular pacing wires, Marfan \200\231s syndrome, Ebstein anomaly, rheu matic heart disease, carcinoid. Clinical features: Usually minimal. Peripheral oedema, ascites, nausea, anorexia, abdominal pain (tender, congested liver) are late signs. Physical examination: Cachexia/wasting, jaundice, oedema, AF common, elevated JVP with syst olic CV waves, tender pulsatile hepatomegaly. Auscultation \200\224 RV S 3 often heard ( i in inspiration), presystolic murmur (PSM) audible at left sternal edge (LSE) ( i in inspir ation). Murmur loudest in TR secondary to pulmonary hypertension. Investigations: ECG \200\224 non-speci \201 c, may show evidence of underlying condition. CXR \200\224 cardiomegaly in patients with functional TR, occasionally distended azygos v ein, pleural effusion. TTE \200\224 color Doppler con \201 rms diagnosis. CW Doppler of T R jet can assess PA systolic pressure. Two- dimensional (2D) images can give idea of cause of TR (RV infarction, ventricular septal defect (VSD), Ebstein, etc.) Severe TR \200\224 j et width > 0.7 cm and systolic \202 ow reversal in hepatic veins. Treatment \200 In the absence of pulmonary hypertension, TR is well tolerated and may not require speci \201 c treatment (indeed in SBE of TV, valve excision is sometimes p erformed with good recovery). Symptoms of RV failure respond to diuretics and \202 uid/salt restriction. \200 If co-e xistent MV disease is being operated on and TR is mild (with normal PA pressure), TR may improve postoperatively as PA pressure falls. TV annuloplasty is indicated in patients undergoing MVR with severe or moderate TR and annular dilatation or pulmonary hypertension. TR secondary to valve pathology (Ebstein, carcinoid) may require valve replacement, prefera bly with a large bioprosthesis to minimize the risk of thrombosis (but high operative morta lity 15 % ). Tricuspid stenosis Causes: Rheumatic heart disease (almost always associated with MS), cong enital, carcinoid, pacemaker lead. Extremely rare. Clinical features: Fatigue, anorexia, peripheral oedema. Physical examination: Wasting, oed ema, hepatomegaly, i JVP, prominent \200\230a \200\231 waves, rumbling mid-diastolic murmu r at LLSE in inspiration. Investigations: ECG \200\224 sinus rhythm with signs RA enlargem ent ( i \200\230P \200\231 waves in II, V 1 \200\224 often coincides with signs of LA enl argement because of MS) but no RVH. CXR \200\224 enlarged RA but normal PA size. TTE \200 \224 2D image can show thickened restricted lea \202 ets. CW Doppler is diagnostic. Severe TS \200\224 valve area <1.0 cm 2 . Look for co-existent MS. TRICUSPID AND PULMONARY DISEASE 177 Management: Salt restriction and diuretics. If co-existent MS is being operated on then sur gical valvuloplasty may help. TV replacement is occasionally performed. Bioprosthetic valve s give better results than mechanical valves. There is recent evidence of usefulness of TV balloon valvuloplasty but use remains controversial. Pulmonic stenosis Causes: Congenital (virtually all), carcinoid, rheumatic, compression. Clinical features: Usually none. If longstanding severe stenosis \200\224 exertional dyspn oea, light-headedness/syncope (inability to i CO). Ultimately may develop TR symptoms of RV failure (see previous). Physical examination: Prominent \200\230a \200\231 wave in JVP, RV heave, occasionally thr ill in 2nd left intercostal space. Auscultation \200\224 widely split S 2 (as pulmonary va lve (PV) closure becomes later), P 2 becomes softer (unless stenosis is supravalvular), eje ction systolic murmur (ESM) at left edge of upper sternum, heard best in inspiration. Investigations: ECG \200\224 RVH and RA enlargement. CXR \200\224 dilated pulmonary arter ies, occasionally with calci \201 cation of valve, if severe then oligaemic lung \201 el ds. TTE \200\224 con \201 rms diagnosis and can show level of stenosis (valvular, suprava lvular or RV out \202 ow tract) and severity. Severe pulmonic stenosis (PS): jet velocity > 4 m/s or max gradient > 60 mmHg. Will also show associated conditions (ASD, patent ductus arteriosus (PDA), Fallot \200\231s, etc). Cardiac catheterization \200\224 to assess seve rity of obstruction and haemodynamic effects. Management: In general, invasive intervention is recommended when gradient across valve is > 40 mmHg at rest or when symptoms occur. Medical \200\224 supportive/symptomatic treatmen t of RV failure, diuretics, \202 uid restriction (cautious). Balloon valvuloplasty \200 \224 treatment of choice for stenosis at valvular level. Highly effective, safe with good l ong-term results. Pulmonary regurgitation (PR) is common following valvuloplasty, but is ra rely clinically important. Surgical \200\224 valvotomy is very effective with minimal recu rrence. Pulmonic valve replacement \200\224 indicated if not suitable for above treatments or for severe PR following these treatments. Pulmonary regurgitation Causes: Any cause of pulmonary hypertension (causes dilatation of v alve ring), infective endocarditis, connective tissue disease (e.g. Marfan \200\231s), iatr ogenic (following valvotomy or PA catheter placement), carcinoid. Clinical features: Often asymptomatic. Symptoms occur when pulmonary hypertension or RV fai lure exist. Then patients get dyspnoea on exertion, lethargy, peripheral oedema, abdominal pain. Physical examination: RV heave, occasionally a thrill in pulmonary area. Auscultation \200 \224 P 2 may be delayed (large SV), loud (if pulmonary i BP), or soft (if PV stenosis). Mur mur of PR heard best in 3rd/4th intercostal space on left adjacent to sternum, I during ins piration. 178 CHAPTER 3 Valvular heart disease Investigations: ECG \200\224 RVH (if pulmonary i BP), right bundle branch block (RBBB)/rsR pattern in V 1 . CXR \200\224 enlarged PA and RV. TTE \200\224 2D images may show RV dil atation/hypertrophy. Abnormal septal motion if RV volume overload. PR seen on color Doppler and quanti \201 ed with pulsed Doppler. Severe PR \200\224 color jet \201 lls out \202 ow tract. Management: Usually supportive treatment suf \201 ces. Treat RV failure in usual way (diur etics, etc). If PR is due to PV ring dilatation secondary to pulmonary hypertension, treati ng the underlying cause of pulmonary i BP can decrease the severity of PR (e.g. mitral valv e surgery). If there is symptomatic right heart failure with severe PR, then PV replacement should be considered. Indications for PVR in asymptomatic individuals remain unclear. This page intentionally left blank 180 CHAPTER 3 Valvular heart disease Prosthetic heart valves Types See Fig. 3.5 . Mechanical: Bilea \202 et (St Jude Medical , Carbomedics ) most common today. Ball and cage (Starr \200\223Edwards ) or tilting disc (Medtronic Hall ) Bioprosthetic: Porcine (stented or stentless) or bovine pericardium (Carpentier \200\223Edw ards) Non prosthetic valves: Homograft (preserved cadaveric human valve), autograft (pulmonary va lve \200\224 Ross procedure) Mechanical valves Minimal risk of structural failure. Lifetime risk of reoperation for non- structural valve dysfunction around 5 % . Thrombogenic, therefore requiring lifelong warfa rin therapy ( aspirin if high risk). Even with optimal INR, there is 2 \200\2234 % linea rized annual lifetime risk of major thromboembolic or haemorrhagic events, including stroke .