Natural history and management of chronic aortic regurgitation in adults

INTRODUCTION — In most patients with chronic aortic regurgitation (AR), the disease evolves in a slow and insidious manner with a very low morbidity during a long asymptomatic phase. While some patients with mild AR do not progress for decades, others exhibit progression of the regurgitant lesion with the gradual development of severe AR with subsequent left ventricular dilation, systolic dysfunction, and eventually heart failure (table 1). (See 'Natural history' below.)

The volume load that burdens the left ventricle in patients with chronic AR leads to a series of compensatory myocardial and circulatory adjustments that can be affected by pharmacologic therapy and reversed by valve replacement. Thus, the management of patients with this disorder requires an understanding of the natural history of the disease, the limited role of medical therapy, and the timing of surgery [1].

This topic will review the management and prognosis of chronic AR. The pathophysiology and major clinical features of chronic AR and issues related to acute AR in adults are discussed separately. (See "Clinical manifestations and diagnosis of chronic aortic regurgitation in adults" and "Acute aortic regurgitation in adults".)

NATURAL HISTORY — Chronic AR generally evolves slowly with a long asymptomatic compensated phase with some patients developing worsening regurgitation that may progress to severe AR with left ventricular (LV) dilation, LV systolic dysfunction, and heart failure (table 1).

Data from case series of patients with chronic AR have been used to develop criteria to define compensated and decompensated phases of chronic severe AR (table 2A-B):

●Asymptomatic patients with severe AR with LV ejection fraction (LVEF) >50 percent and LV end-systolic dimension (LVESD) ≤45 to 50 mm [2] are in a compensated phase associated with low risk of early progression to development of heart failure symptoms or LV dysfunction. This phase corresponds to stages B and C (asymptomatic AR with borderline or only mildly increased LVESD) chronic AR as defined in the 2020 American Heart Association/American College of Cardiology valve guidelines [3].

•For patients with an LVESD between 41 and 49 mm, the risk of developing symptoms, LV dysfunction, or death ranges from 1 to 2 percent per year [4] to as high as 6 percent per year (table 1) [5].

•Patients with an LVESD below 40 mm have only minimal risk of these complications until the LVESD increases to a higher level [5].

●Asymptomatic patients with severe AR with LV systolic dysfunction (an LVEF <50 percent or LVESD >50 mm [or indexed LVESD >25 mm/m²]) are entering a decompensated phase with high risk of progression to development of heart failure symptoms requiring aortic valve surgery. This corresponds to stage C2 (asymptomatic with LV systolic dysfunction or increase in LVESD, usually with moderate to severe LV dilation) [3].

•The yearly rate of becoming symptomatic is more than 25 percent in asymptomatic patients with LVEF <50 percent.

•The yearly rate of developing LV systolic dysfunction or becoming symptomatic and requiring surgery is approximately 19 percent when the LVESD exceeds 50 mm [4] and over 25 percent when the LVESD is greater than 55 mm [6].

The mortality rate for patients with severe AR with New York Heart Association (NYHA) Class II symptoms (table 3) is approximately 6 percent per year and nearly 25 percent per year for patients with NYHA Class III or IV symptoms [7].

The nature of the transition from a compensated to a decompensated phase is poorly understood, and the definition of such a transition has not been validated in a prospective fashion. The transitional phase appears to develop during the latter portion of stage C (C2) [3]. Thus, these phases should only be used as general guidelines in making clinical decisions that include all other clinical data and patient preferences. Intercurrent illness, such as infective endocarditis, may alter the clinical course of a patient with mild AR, worsening the degree of regurgitation, and precipitating the need for surgery. Nevertheless, this information has been useful in defining limits that are predictive of the future need for aortic valve replacement [4,5].

MONITORING

General approach — Patients with chronic AR should be monitored for changes in symptoms, severity of AR, and LV systolic dysfunction to reassess the stage of AR. The clinical stages of chronic AR are defined by symptoms, valve anatomy, severity of regurgitation, and LV systolic function (generally quantified as LVEF and LV end-systolic dimension [LVESD]) (table 2B) [3]. Serial monitoring of the severity of AR is generally performed by transthoracic echocardiogram since physical findings are not reliable. If the echocardiogram is inconclusive, cardiovascular magnetic resonance (CMR) imaging is suggested. Cardiac catheterization is recommended if noninvasive tests are inconclusive or if there is a need to assess coronary anatomy prior to aortic valve surgery. (See "Clinical manifestations and diagnosis of chronic aortic regurgitation in adults", section on 'Diagnosis and evaluation'.)

Clinical follow-up — Patients with chronic AR should undergo at least yearly clinical evaluation including history and physical examination [3]. The key symptoms for staging of AR are symptoms of heart failure (and occasionally angina), which generally develop as late manifestations in patients with severe AR. Symptoms may include exertional dyspnea or more severe symptoms of heart failure such as orthopnea or paroxysmal nocturnal dyspnea. Some patients with chronic AR develop exertional or nocturnal angina in the absence of coexistent coronary artery disease due to reduction in coronary flow reserve [8,9] Patients should be educated on the possible symptoms that may develop and be encouraged to report any that develop prior to the next scheduled routine visit. The physical examination may reveal signs of progressive valvular and ventricular changes but confirmation by imaging is required for staging.

Imaging — Echocardiography is the mainstay for serial monitoring and evaluation of patients with chronic AR. For patients with suspected moderate or severe AR with inconclusive echocardiography findings, CMR provides accurate quantitation of AR regurgitant volume and fraction and precise measurement of LV volumes and function. CMR is particularly helpful when the degree of LV dilation seems greater than expected for AR severity on echocardiography. CMR may also be useful in patients thought to have severe AR without LV enlargement; the diagnosis of severe AR should be questioned if the LV end-diastolic volume or dimension is not increased. In patients undergoing cardiac catheterization, aortic angiography provides a semiquantitative assessment of AR severity.

Evaluation of LV size and function is important because these parameters predict outcome and do not correlate well with symptoms. As an example, in one report of 450 patients, 28 percent of patients with an LVEF <35 percent were asymptomatic, a value not significantly different from the 37 percent of patients with an LVEF ≥50 percent who were asymptomatic [10].

Using imaging techniques, LV systolic function is generally quantified as LVEF. Increases in LVESD also reflect worsening LV systolic function. Increased LV end-diastolic dimension (>60 to 65 mm) is also associated with risk of development of symptoms or LV systolic dysfunction, but less so than LVESD [3]. (See "Clinical manifestations and diagnosis of chronic aortic regurgitation in adults", section on 'Symptoms' and "Clinical manifestations and diagnosis of chronic aortic regurgitation in adults", section on 'Staging'.)

Echocardiography — We agree with the following approach to monitoring asymptomatic patients with chronic AR and normal LV systolic function, as recommended in the 2014 American Heart Association/American College of Cardiology valve guideline [3]:

●For mild AR, echocardiograms every three to five years.

●For moderate AR, echocardiograms every one to two years.

●For severe AR, echocardiograms every 6 to 12 months; more frequently if there appears to be progressive LV dilatation.

With periodic echocardiographic monitoring, some studies can be limited to evaluate only the severity of AR, LV size, and systolic function with a more complete study at longer intervals. In addition to this schedule for routine monitoring, echocardiography should be performed more frequently if the patient becomes symptomatic or has equivocal symptoms or a decline in exercise tolerance.

Cardiovascular magnetic resonance — In patients with moderate or severe AR with suboptimal or inconclusive echocardiographic assessment, CMR imaging is indicated to quantify AR severity, measure LV diastolic and systolic volumes, and assess LV systolic function [3]. Aortic regurgitant volume can be quantified by CMR [11-13]. No ionizing radiation or exogenous contrast is required for this assessment.

Cardiac catheterization — Cardiac catheterization is recommended in patients with chronic AR when noninvasive tests are inconclusive or provide discrepant results from clinical findings.

Angiography (left ventriculography and aortography) enables assessment of LV size and EF, aortic root size and associated disorders (eg, sinus of Valsalva aneurysm, dissection), aortic valve movement and leaflet number, and semiquantitative assessment of the severity of AR.

Bicuspid aortic valve and aortic disease — When AR is due to a bicuspid aortic valve, there is the additional concern about dilation of the aortic root and/or ascending aorta, which eventually develops in many if not most patients and can lead to aneurysm formation or dissection. Monitoring of the aorta in patients with bicuspid aortic valve is discussed separately. (See "Bicuspid aortic valve: General management in adults", section on 'Surveillance'.)

TREATMENT

Approach to treatment — Aortic valve surgery (predominantly aortic valve replacement) is the mainstay of treatment of symptomatic severe AR or asymptomatic severe AR with LV systolic dysfunction. The role of pharmacologic therapy in treatment of severe chronic AR is limited to symptomatic patients (or asymptomatic patients with LV systolic dysfunction) who are not candidates for aortic valve surgery. In addition, pharmacologic therapy is used to treat symptomatic patients with severe AR in preparation for aortic valve surgery.

General management

Pharmacologic therapy — The role of pharmacologic therapy in the treatment of chronic AR is limited since efficacy of such therapy has not been established. Routine vasodilator therapy is not recommended in patients with chronic asymptomatic AR and normal LV function as there is no evidence that vasodilator therapy alters the disease course in this setting [3,14]. The following recommendations are consistent with the 2020 American College of Cardiology/American Heart Association (ACC/AHA) guidelines [3]:

●For symptomatic patients with severe AR who are candidates for valve surgery, valve replacement is recommended after a period of intense medical treatment for heart failure with reduced ejection fraction (HFrEF) including diuretics and angiotensin converting enzyme (ACE) inhibitor, single-agent angiotensin II receptor blocker (ARB), or angiotensin receptor-neprilysin inhibitor (ARNI) [3]. (See "Overview of the management of heart failure with reduced ejection fraction in adults".)

●For symptomatic patients with severe AR who are not candidates for surgery, therapy is similar to that for other causes of heart failure with reduced ejection fraction (HFrEF). (See "Overview of the management of heart failure with reduced ejection fraction in adults".)

●Patients with chronic AR should receive treatment for hypertension (systolic blood pressure >140 mmHg). Vasodilators such as ACE inhibitors, ARBs, or dihydropyridine calcium channel blockers (eg, amlodipine) may be favored since they may reduce systolic blood pressure in this setting. Beta blocker therapy may be less effective in this setting since reduction in heart rate and associated increase in stroke volume may contribute to elevated systolic pressure. The reduction in heart rate also leads to an increase in the duration of diastole, which can contribute to an increase in the regurgitant volume.

Endocarditis prophylaxis — Antibiotic prophylaxis is not recommended when patients with native valve disease, including chronic AR, undergo dental or other invasive procedures that produce significant bacteremia with organisms associated with endocarditis. Antibiotic prophylaxis is recommended in certain high-risk settings, including presence of a prosthetic heart valve or prior history of infective endocarditis. (See "Prevention of endocarditis: Antibiotic prophylaxis and other measures".)

Recommendations for physical activity and exercise — The following recommendations are similar to those in the 2015 AHA/ACC scientific statement for athletes with AR [15]:

●Athletes with greater-than-mild AR should be evaluated yearly to determine whether they should continue their participation in sports.

●Exercise testing to at least the level of activity achieved in competition and training is helpful to confirm asymptomatic status and assess blood pressure responses.

●Athletes with mild to moderate degrees of AR (stage B) with normal LVEF and normal or mildly increased LV end-systolic dimension (LVESD) with normal exercise tolerance on exercise testing can participate in all competitive sports.

●Athletes with mild to moderate degrees of AR with normal LVEF and moderately increased LVESD (<50 mm [men], <40 mm [women], or <25 mm/m² [either sex]) with normal exercise tolerance on exercise testing can participate in all competitive sports.

●Athletes with severe AR, LVEF ≥50 percent, and LVESD <50 mm (men), <40 mm (women), or <25 mm/m² (either sex) with normal exercise and no progression of AR severity or degree of increase in LVESD on serial Doppler echocardiography may continue to participate in all competitive sports.

●It is reasonable for athletes with AR (without bicuspid aortic valve or Marfan) and aortic dimensions of 41 to 44 mm to participate in sports with low risk of bodily contact.

Recommendations for athletes with bicuspid aortic valve and for athletes with Marfan syndrome are discussed separately. (See "Bicuspid aortic valve: General management in adults", section on 'Physical activity and exercise' and "Management of Marfan syndrome and related disorders", section on 'Restriction of strenuous activity'.)

●Athletes with severe AR and symptoms (stage D), or LV systolic dysfunction with ejection fraction <50 percent (stage C2), or LVESD >50 mm or >25 mm/m² (stage C2), or severe increase in LV end-diastolic dimension (LVEDD >70 mm or ‡35.3 mm/m² [men], >65 mm or ‡40.8 mm/m² [women]) should not participate in competitive sports.

As noted in the 2015 AHA/ACC scientific statement for athletes with valvular heart disease, when AR is present in an athlete, it is difficult to differentiate the LV dilatation produced by exercise training from the dilatation produced by chronic severe AR [15]. There is overlap between the LV volumes that occur in normal athletes and those in patients with AR, although progressive AR can result in LV volumes that exceed those seen in normal athletes. Among elite athletes, the upper limit of normal for LVEDD is 66 to 70 mm in men and approximately 66 mm in women [16,17].

Recommendations for exercise in patients with bicuspid aortic valves who have aortic root dilatation are presented separately. (See "Bicuspid aortic valve: General management in adults", section on 'Physical activity and exercise'.)

Aortic valve surgery — Aortic valve surgery (predominantly aortic valve replacement) is the mainstay of treatment of symptomatic severe AR and select patients with asymptomatic AR as described in the indications below. Patients with moderate or severe AR should be monitored for development of an indication for aortic valve surgery.

Indications for aortic valve surgery — The following recommendations for aortic valve surgery (largely aortic valve replacement) in patients with chronic AR are adopted from the 2020 ACC/AHA valve guidelines:

●Aortic valve surgery is recommended for symptomatic patients with severe AR (stage D) (table 2B), regardless of LV systolic function.

●Aortic valve surgery is recommended for asymptomatic patients with chronic severe AR and evidence of LV systolic dysfunction with an LVEF ≤55 percent (stage C2) if no other cause for systolic dysfunction is identified.

●Aortic valve surgery is suggested for asymptomatic patients with chronic severe AR with a normal LVEF >55 percent) but with a severely enlarged LV (an LV end-systolic dimension >50 mm or indexed LVESD >25 mm/m²) (stage C2).

●Aortic valve surgery is suggested for asymptomatic patients with severe AR and normal LVEF (>55 percent, stage C) but with progressive severe LV dilation (LVEDD >65 mm) or progressive decline in LVEF on at least three serial studies to the low normal range (LVEF 55 to 60 percent), if surgical risk is low.

●Aortic valve surgery is recommended for patients with severe AR (stage C or D) while undergoing cardiac surgery for other indications.

●Aortic valve surgery is suggested in patients with moderate AR (stage B) who are undergoing other cardiac surgery.

Aortic valve surgery is not indicated in a truly asymptomatic patient with severe AR with stable normal LV function (LVEF >55 percent and LVESD ≤50 mm) unless there is another indication for cardiac surgery. Early surgery exposes the patient to perioperative mortality (that averages 2 to 4 percent compared with <0.2 percent per year without surgery) as well as morbidity and the long-term complications of a prosthetic heart valve [18]. (See "Mechanical prosthetic valve thrombosis or obstruction: Clinical manifestations and diagnosis".)

Aortic valve surgery also is not recommended for mild to moderate AR. Symptoms, LV dilation or a reduced EF in the setting of less than severe AR should not be assumed to be related to the AR.

Preoperative evaluation — Estimating the risk of mortality and morbidity with valve surgery is discussed separately. Models have been developed to estimate the risk of in-hospital mortality and complications associated with valve surgery with or without coronary artery bypass graft surgery. (See "Estimating the risk of valvular procedures".)

Coronary angiography is indicated when there is a need to assess coronary anatomy before aortic valve surgery because of risk for coronary heart disease, including symptoms of angina, objective evidence of ischemia, decreased LV systolic function, history of coronary artery disease, or coronary risk factors (eg, men age >40 years and postmenopausal women) [3].

A possible alternative to invasive coronary angiography is noninvasive coronary angiography, which may be accomplished using coronary computed tomography angiography (CCTA) or cardiac magnetic resonance imaging. Data are limited in patients with AR [19,20]. CCTA is a reasonable alternative in selected patients with low pretest probability of coronary artery disease, with invasive coronary angiography performed if CCTA shows any epicardial coronary artery disease [3]. The utility of these tests as an alternative to conventional selective coronary angiography is discussed separately. (See "Cardiac imaging with computed tomography and magnetic resonance in the adult".)

Choice of procedure — Nearly all patients with an indication for aortic valve surgery for chronic AR require aortic valve replacement.

Most patients requiring aortic valve surgery for chronic severe AR will require aortic valve replacement. For selected patients with AR caused by aortic dilation with no aortic valve thickening, calcification, or deformity, valve-sparing replacement of the aortic sinuses and ascending aorta is a possible option [3]. For selected patients (particularly young patients with bicuspid aortic valve) receiving care at centers with established expertise in primary aortic valve repair, valve repair may be considered as a potential alternative to valve replacement. (See "Bicuspid aortic valve: General management in adults".)

Aortic valve repair is an option only at centers with established expertise and experience and for patients with suitable anatomy (aortic dilation without a thickened, deformed, or calcified valve) [3].

For patients undergoing aortic valve replacement, choice of prosthetic valve type is discussed separately. (See "Choice of prosthetic heart valve for surgical aortic or mitral valve replacement".)

Investigational transcatheter alternative — Surgical aortic valve replacement (SAVR) remains the treatment of choice for patients with severe native valve AR. Transcatheter aortic valve implantation (TAVI) is under investigation to treat native AR as a potential alternative when SAVR is absolutely contraindicated and with appropriate annular size and valvular calcification for a transcatheter approach [3]. (See 'For investigational transcatheter aortic valve implantation' below.)

Evidence

For aortic valve surgery — The indications for aortic valve surgery in patients with chronic severe AR are based upon limited observational data [3].

Recommendations for aortic valve surgery in patients with chronic AR are based upon the following types of data:

●Natural history studies demonstrating the risk of mortality in patients with symptomatic severe AR, and risk of progression to symptoms requiring surgery or death in patients with asymptomatic severe AR with depressed LVEF and/or increased LV systolic dimension (table 1). (See 'Natural history' above.)

●Studies of patients undergoing aortic valve surgery for chronic AR indicating an association between surgery and improved cardiovascular mortality [7] or reduced symptoms [21-23]. As an example, in a report from the Mayo Clinic of 246 patients with severe or moderately severe AR followed for a mean of seven years, aortic valve surgery was independently associated with reduced cardiovascular mortality [7].

●Studies of patients undergoing aortic valve surgery for chronic AR showing worse postoperative survival in patients with pre-operative LV systolic dysfunction [6,10,24-27] or preoperative class III or IV symptoms [28]. Waiting for the patient to develop exercise intolerance or dyspnea may result in some degree of irreversible LV dysfunction. Furthermore, the combination of LV dysfunction and symptoms of heart failure generally precludes an optimal surgical result (figure 1A-B) [28,29].

●Studies showing that the preoperative LVESD is negatively correlated with postoperative LVEF [22,27,30] and patients with increased LVESD have higher postoperative mortality rates [6,30,31].

Borderline or even definite LV systolic dysfunction (LVEF <50 percent) of short duration may not carry the same ominous prognosis as a prolonged period of LV dysfunction. If LV dysfunction is present for less than 14 months, corrective surgery is more likely to reverse the volume-overload state and to allow recovery of the ventricle [32]. In contrast, more prolonged LV dysfunction, particularly in association with congestive symptoms, is usually predictive of a poor LV response to corrective surgery. However, aortic valve surgery is still beneficial in patients with prolonged LV dysfunction; while the LV response may be suboptimal (persistent LV enlargement and low LVEF), the reduction in regurgitant volume is followed by a reduction in LV filling pressures and a reduction in congestive symptoms.

Some consideration of body size should be included in any estimation of LV dimension, since smaller women are less likely to reach the above criteria that were established in men [27,33]. However, simply indexing to body surface area can lead to misleading conclusions, especially in obese patients. In general, somewhat lower values should be used in very small patients and somewhat higher values in very large patients.

The importance of timely aortic valve surgery for chronic AR was suggested by a prospective study of 170 patients [34]. Sixty patients underwent early surgery according to standard guideline recommendations (for New York Heart Association [NYHA] functional class II symptoms, an LVEF between 45 and 50 percent, and/or an LVESD between 50 and 55 mm) and 110 patients underwent "too late" surgery, defined as occurring in the presence of severe symptoms (NYHA class III or IV), an LVEF <45 percent, or an LVESD >55 mm.

●At a mean follow-up of 10 years, mortality was significantly higher in the patients who underwent "too late" surgery compared with those undergoing early surgery (37 versus 12 percent). The increase in mortality was largely due to more deaths from heart failure or sudden death in the "too late" surgery group (20 versus 1).

●Surgery after the onset of severe symptoms was associated with worse outcomes. Patients with NYHA functional class III or IV symptoms compared with those with no or only mild (NYHA class II) symptoms, had significant increases in both operative mortality (14 versus 3 percent) and long-term cardiac mortality (35 versus 10 percent).

Aortic valve repair — As noted above, most patients with AR require aortic valve replacement but aortic valve repair is an option for some patients with chronic AR [19,35-38]. Aortic valve repair has the major advantages compared to aortic valve replacement of low thromboembolic risk, which avoids the need for chronic anticoagulation, preservation of a near normal aortic valve orifice, and the potential for a less complicated reoperation. The main disadvantages are a higher rate of reoperation (about 15 percent at ten years) and less widespread surgical experience [39]. Valve repair has more often been performed in young patients (figure 2).

Use of aortic valve repair is primarily limited to AR due to aortic root dilatation and/or excess cusp motion since repair of retracted or heavily calcified valves (such as rheumatic valves) has not provided long-term success [35,40]. Aortic valve repair may consist of an isolated aortic valve sparing operation, an isolated aortic cusp repair, or a combination of these procedures.

The predictive value of aortic valve anatomy for valve repairability was evaluated in a study of 163 patients undergoing surgery for AR [35]. The mechanism of aortic regurgitation was classified as due to aortic root dilatation (type 1), excess cusp motion, including cusp prolapse and cusp fenestrations, with good cusp tissue quality (type 2), or poor cusp tissue quality including cusp retraction, extensive cusp calcifications and/or endocarditis (type 3). Type 1 and 2 lesions were considered repairable unless cusp body calcification was present, while type 3 lesions were considered nonrepairable. Transesophageal echocardiography classification of lesion type agreed strongly with surgical inspection (93 percent) and was strongly predictive of valve repairability and postoperative outcome.

The outcomes after aortic valve repair were evaluated in a 2004 report from the Mayo Clinic of 160 patients who underwent repair procedures, there was one early death, a need for repeat repair during the initial hospitalization, and 16 late deaths at a mean follow-up of 4.2 years, only two of which might have been related to AR [36]. The survival rate was similar to that of an age- and sex-matched control population. Reoperation, primarily aortic valve replacement for severe AR, was required in 9, 11, and 15 percent of patients at three, five, and seven years, respectively.

Another study compared the short-term outcomes in 44 patients with a bicuspid aortic valve and chronic AR who underwent valve repair to 44 patients matched for age and left ventricular function who underwent valve replacement [37]. The following findings were noted:

●There were no early or late deaths in either groups.

●Mild AR in the early postoperative period was present in nine patients who underwent repair and five who underwent valve replacement.

●Freedom from repeat valve surgery at five years for progressive AR or endocarditis was similar in the two groups: 91 versus 94 percent. However, freedom from moderate to severe AR at five years was significantly lower with valve repair (79 versus 94 percent).

For investigational transcatheter aortic valve implantation — Off-label first generation self-expanding transcatheter heart valve (CoreValve) use for chronic aortic regurgitation has been tried but limited by insufficient anchoring of the transcatheter heart valve within the noncalcified aortic annulus and the risk of residual AR with resulting high rate (18.8 percent) of acute valve-in-valve implantations [41]. Limited off-label balloon expandable (SAPIEN 3) valve use in this setting has also been reported [42]. In Europe, a transfemoral TAVI system (JenaValve) is under investigation to treat severe native aortic valve regurgitation in patients with high or greater risk for open surgical valve implantation or repair.

Transcatheter aortic valve-in-valve implantation to treat bioprosthetic aortic valve dysfunction (regurgitation and/or stenosis) is discussed separately. (See "Management and prognosis of surgical aortic and mitral prosthetic valve regurgitation", section on 'Intervention'.)

POSTOPERATIVE MONITORING — An echocardiogram should be performed approximately six weeks to three months after valve implantation to provide an assessment of the effects of surgery and to serve as a baseline for future comparison [3]. A good predictor of the eventual improvement in LV function is the reduction in left ventricular end-diastolic dimension, approximately 80 percent of which occurs in the first 10 to 14 days after surgery [39,43,44].

The frequency of follow-up depends upon the patient’s clinical condition. After the first postoperative evaluation, asymptomatic patients with an uncomplicated course are generally seen yearly. Routine serial echocardiography is not usually indicated if the first postoperative echocardiogram shows a substantial reduction in left ventricular end-diastolic dimension, the LVEF is normal, and the patient is asymptomatic. Echocardiography is warranted if the patient develops new symptoms or signs, such as a new murmur.

Patients with persistent left ventricular dilatation are treated as other patients with asymptomatic or symptomatic left ventricular dysfunction. (See "Management and prognosis of asymptomatic left ventricular systolic dysfunction" and "Overview of the management of heart failure with reduced ejection fraction in adults".)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Cardiac valve disease".)

SUMMARY AND RECOMMENDATIONS

●Natural history – Chronic aortic regurgitation (AR) generally evolves slowly with a long asymptomatic compensated phase with some patients developing worsening regurgitation that may progress to severe AR with left ventricular (LV) dilation, LV systolic dysfunction, and heart failure (table 1). (See 'Natural history' above.)

●Monitoring – Patients with chronic AR should be monitored for changes in symptoms, severity of AR, and LV systolic dysfunction to reassess the stage of AR. The clinical stages of chronic AR are defined by symptoms, valve anatomy, severity of regurgitation, and LV systolic function (generally quantified as LV ejection fraction [LVEF] and LV dilation) (table 2B). (See 'Monitoring' above.)

●Indications for aortic valve surgery – Aortic valve surgery (predominantly aortic valve replacement) is the mainstay of treatment of symptomatic severe AR and select patients with asymptomatic AR as follows (see 'Approach to treatment' above and 'Aortic valve surgery' above):

•Symptomatic patients – Aortic valve surgery is recommended for symptomatic patients with severe AR (stage D) (table 2B), regardless of LV systolic function.

•Asymptomatic patients

-LV systolic dysfunction – Aortic valve surgery is recommended for asymptomatic patients with chronic severe AR and evidence of LV systolic dysfunction with an LVEF ≤55 percent (stage C2) if no other cause for systolic dysfunction is identified.

-Severely enlarged LV – Aortic valve surgery is suggested for asymptomatic patients with chronic severe AR with a normal LVEF >55 percent) but with a severely enlarged LV (an LV end-systolic dimension [LVESD] >50 mm or indexed LVESD >25 mm/m²) (stage C2).

-Progressive LV changes – Aortic valve surgery is suggested for asymptomatic patients with severe AR and normal LVEF (>55 percent, stage C) but with progressive severe LV dilation (LV end-diastolic dimension [LVEDD] >65 mm) or progressive decline in LVEF on at least three serial studies to the low normal range (LVEF 55 to 60 percent), if surgical risk is low.

•Undergoing cardiac surgery for other indications – Aortic valve surgery is recommended for patients with severe AR (stage C or D) while undergoing cardiac surgery for other indications. Aortic valve surgery is suggested in patients with moderate AR (stage B) who are undergoing other cardiac surgery.

●Pharmacologic therapy – The role of pharmacologic therapy in treatment of severe chronic AR is largely limited to symptomatic patients (or asymptomatic patients with LV systolic dysfunction) who are not candidates for aortic valve surgery or who are symptomatic and preparing for aortic valve surgery. (See 'Approach to treatment' above and 'General management' above.)

ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges William H Gaasch, MD (deceased), who contributed to earlier versions of this topic review.