Noncardiac surgery in patients with mitral or aortic regurgitation

INTRODUCTION — Significant valvular heart disease is a clinical predictor for increased cardiac risk for patients undergoing noncardiac surgery [1,2]. Moderate-to-severe or severe mitral regurgitation (MR) or aortic regurgitation (AR) convey increased cardiac risk during noncardiac surgery, though these lesions are generally better tolerated than stenotic valvular disease such as aortic stenosis and mitral stenosis [3].

The perioperative considerations in patients with chronic MR or AR who are undergoing noncardiac surgery will be reviewed here. The perioperative management of patients with mitral or aortic stenosis or prosthetic heart valves is discussed elsewhere. (See "Noncardiac surgery in adults with aortic stenosis" and "Overview of the management of patients with prosthetic heart valves" and "Antithrombotic therapy for mechanical heart valves" and "Rheumatic mitral stenosis: Overview of management", section on 'Management of noncardiac surgery'.)

IDENTIFICATION OF VALVE DISEASE — The diagnosis of valve disease may have been previously established or a cardiac murmur may be auscultated during the preoperative examination. The quality, intensity, timing, and location of the murmur help distinguish a pathologic from a functional murmur but are of limited utility for evaluation of the severity or functional consequences of valve regurgitation. If valvular heart disease is suspected due to symptoms, a murmur auscultated on physical exam, or incidental findings on chest imaging or non-invasive imaging, then an echocardiogram is appropriate and findings should be correlated clinically with symptoms and evaluation [1,2] . (See "Auscultation of cardiac murmurs in adults" and "Physiologic and pharmacologic maneuvers in the differential diagnosis of heart murmurs and sounds".)

CHRONIC MITRAL REGURGITATION

Features of mitral regurgitation — MR arises from abnormalities of one or more parts of the mitral valve apparatus, including the valve leaflets, annulus, chordae tendineae, and papillary muscles. The nature and severity of symptoms associated with chronic MR are related to the severity of the regurgitation, its rate of progression, the pulmonary artery pressure, and associated cardiac disease. In most cases, the patient remains relatively asymptomatic until the left ventricle (LV) begins to fail. (See "Pathophysiology and natural history of chronic mitral regurgitation", section on 'Pathophysiology'.)

The most common symptoms, when present, reflect a decreased forward or effective cardiac output and include weakness, fatigue, and exercise intolerance. Patients with more severe disease and LV enlargement eventually progress to symptomatic heart failure with pulmonary congestion and edema. (See "Clinical manifestations and diagnosis of chronic mitral regurgitation".)

The murmur of MR is systolic, but its timing, duration, quality, intensity, location, and radiation are variable and depend upon the etiology and component of the mitral apparatus that is diseased. In most cases, the murmur is holosystolic, commencing with S1 and continuing up to and sometimes beyond and obscuring A2, a result of the persistent pressure gradient between the LV and atrium (movie 1). The murmur is heard best over the apex, radiating to the axilla and when very loud may often radiate to the back. It is most often blowing and high pitched in quality. (See "Auscultation of cardiac murmurs in adults".)

There is a variable correlation between murmur grade and regurgitant severity with primary mitral valve disease. A loud murmur associated with a thrill (Grade 4 or greater) has a specificity of 91 percent for severe regurgitation, but a sensitivity of only 24 percent [4]. Conversely, severe regurgitation is rarely present with a Grade 1 to 2 murmur. However, there is a wide range of regurgitant severity with a Grade 3 murmur (which is common) [4]. In contrast, the loudness of the murmur does not necessarily correlate with severity in secondary (functional) MR. (See "Clinical manifestations and diagnosis of chronic mitral regurgitation".)

Evaluation of MR severity — In addition to history and physical examination, echocardiography is essential for establishing the etiology, severity, and hemodynamic consequences of MR. Echocardiography and other tests are discussed separately (see "Echocardiographic evaluation of the mitral valve" and "Transesophageal echocardiography in the evaluation of mitral valve disease" and "Clinical manifestations and diagnosis of chronic mitral regurgitation", section on 'Diagnosis and evaluation'). Stages of primary MR (table 1) and secondary MR (table 2) are described in the 2020 American College of Cardiology/American Heart Association (ACC/AHA) guideline [1], and a similar system is described in the 2021 European Society of Cardiology valve guideline [2]. In staging and managing MR it is important to differentiate between chronic primary or degenerative MR versus chronic secondary or functional MR, with primary MR involving pathology of the mitral valve apparatus (leaflets, chordae tendineae, papillary muscles, and annulus) and secondary MR involving pathology of the ventricle [1].

Perioperative risk of mitral regurgitation — The risk of noncardiac surgery in patients with chronic MR depends upon the etiology and severity of regurgitation and the level of hemodynamic and clinical compensation as well as the risk level of the procedure. Predictors of increased cardiovascular risk in patients with moderate-to-severe or severe MR undergoing noncardiac surgery include depressed LV systolic function, atrial fibrillation, ischemic MR, and comorbidities (ie, diabetes mellitus, history of carotid endarterectomy) [5,6]. Patients with good functional status and preserved LV systolic function are generally tolerant of general anesthesia [1,7,8]. (See "Clinical manifestations and diagnosis of chronic mitral regurgitation".)

Limited data are available on the risk of noncardiac surgery in patients with advanced MR. Perioperative outcomes and predictors of risk were illustrated by the following two observational studies of patients with moderate-to-severe (3+) or severe (4+) MR undergoing noncardiac surgery. Neither study described how many patients were symptomatic at baseline:

●A study of 84 patients (mean age 66 years) with moderate-to-severe or severe MR who underwent noncardiac surgery (28 percent low risk; 56 percent intermediate risk; 12 percent emergency) reported high rates of postoperative morbidity and mortality [5]:

•Intraoperative adverse events occurred frequently (in 31 percent) and consisted largely of treatable hypotension (23 percent) with few cases complicated by bradycardia (4 percent).

•High rates of major postoperative morbidity (27 percent, mostly pulmonary edema with prolonged tracheal intubation) and mortality (12 percent) were observed. The procedural risk level (intermediate versus low), depressed LV ejection fraction (LVEF), and atrial fibrillation were independent predictors of morbidity. Atrial fibrillation was a predictor of in-hospital death. No comparison group was included.

●A later study from a tertiary care center of 298 patients with moderate-severe or severe MR and 1172 controls without MR undergoing planned noncardiac surgery (78 percent intermediate risk) found low rates of postoperative mortality but high rates of postoperative morbidity [6]:

•The incidence of the primary outcome (a composite of 30-day mortality, myocardial infarction, heart failure, and stroke) was higher in the MR group compared with the controls (22.2 percent versus 16.4 percent) due to higher rates of myocardial infarction and stroke. Mortality rates were similar in the two groups (1.7 and 1.1 percent).

•Independent predictors of the primary outcome included LVEF <35 percent, ischemic MR, diabetes mellitus, and history of carotid endarterectomy.

-Of the patients with MR, 34 percent had ischemic MR and 66 percent had nonischemic MR as identified by echocardiograms. Patients with ischemic MR had a higher incidence of the primary outcome compared with patients with nonischemic MR (39.2 versus 13.3 percent).

Management of patients with MR — Since patients with moderate-to-severe or severe MR are at risk for adverse perioperative outcomes, these patients should be identified, treated, and undergo individualized risk assessment prior to proceeding with noncardiac surgery. In patients with MR, cardiac risk of noncardiac surgery is also impacted by other cardiac conditions that may be present, such as coronary artery disease. LV systolic dysfunction and dilatation may cause as well as result from severe MR and heart failure should be appropriately treated. (See "Evaluation of cardiac risk prior to noncardiac surgery" and "Chronic primary mitral regurgitation: General management" and "Overview of the management of heart failure with reduced ejection fraction in adults".)

Although evidence is limited, most asymptomatic patients with severe MR and normal LV systolic function can undergo urgent or elective noncardiac surgery at an acceptable risk with careful intraoperative and postoperative management, including careful attention to afterload control and fluid balance, which can affect the severity of MR (particularly if functional). Thus, elective noncardiac surgery is generally reasonable to perform in adults with asymptomatic severe MR and normal LV systolic function with less than severe pulmonary hypertension (pulmonary artery systolic pressure <50 mmHg), as noted in major society guidelines [1,2,9,10]. The risks and benefits of various treatment options should be carefully weighted if urgent noncardiac surgery is contemplated in a patient with symptomatic moderate to severe MR. Standard indications for intervention for chronic MR apply to patients who are planning to undergo noncardiac surgery; if delaying the noncardiac procedure is clinically feasible, then the intervention should be performed before elective noncardiac surgery to optimize perioperative risk [1]. (See "Chronic primary mitral regurgitation: General management" and "Chronic secondary mitral regurgitation: General management and prognosis".)

Intraoperative hemodynamic and anesthetic management of patients with MR are discussed separately. Summarized briefly, for patients with primary MR, preload should be maintained or reduced, to maintain intravascular volume while avoiding fluid overload, taking into consideration increased LV volumes and compliance; and excessive systemic afterload should be avoided, as noted in the 2014 ACC/AHA perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery guideline [9]. In patients with MR, marked increases in blood pressure should be avoided since they can increase MR and diminish forward flow [7,8]. Patients with MR and heart failure require careful titration of diuretics and afterload reduction to optimize perioperative hemodynamic status. (See "Anesthesia for noncardiac surgery in patients with aortic or mitral valve disease", section on 'Hemodynamic management' and "Chronic primary mitral regurgitation: General management" and "Overview of the management of heart failure with reduced ejection fraction in adults", section on 'Pharmacologic therapy'.)

Patients with symptomatic moderate-to-severe MR undergoing higher-risk noncardiac surgery might be managed with intraoperative invasive hemodynamic and/or transesophageal echocardiography monitoring and postoperative intensive care unit monitoring [1,9]. Though data on hemodynamic monitoring in this setting are limited, invasive hemodynamic monitoring enables monitoring intracardiac filling pressures and vascular resistance, thus facilitating intravenous fluid management and appropriate use of vasodilators. (See "Pulmonary artery catheterization: Indications, contraindications, and complications in adults".)

Management of MR during pregnancy is discussed separately. (See "Pregnancy and valve disease", section on 'Mitral regurgitation'.)

CHRONIC AORTIC REGURGITATION

Features of aortic regurgitation — AR is caused by inadequate closure of the aortic valve leaflets induced by disease of the aortic valve leaflets and/or distortion or dilatation of the aortic root. The inability of the aortic valve leaflets to remain closed or coapted during diastole results in a portion of the LV stroke volume leaking back from the aorta into the LV. The added volume of regurgitant blood produces an increase in LV end-diastolic volume; as described by Laplace's law, the increase in LV end-diastolic volume causes an elevation in wall stress. The heart responds with compensatory myocardial hypertrophy, which returns wall stress toward normal. (See "Clinical manifestations and diagnosis of chronic aortic regurgitation in adults".)

The combination of hypertrophy and chamber enlargement raises the total stroke volume. The net effect is that forward stroke volume and therefore the cardiac output are initially maintained despite the regurgitant lesion. Although LV volume is increased, end-diastolic pressure is normal due to an increase in ventricular compliance. Thus, the heart initially adapts well to chronic AR, functioning as a very efficient and compliant high output pump.

As a result of these hemodynamic changes, patients with AR remain asymptomatic for decades, even if there is progressive ventricular dilatation. In contrast, dramatic signs may be detected on physical examination when severe AR is present (see "Clinical manifestations and diagnosis of chronic aortic regurgitation in adults"):

●There is a wide pulse pressure, which is manifested on examination as a water hammer or Corrigan's pulse. (See "Examination of the arterial pulse", section on 'Water hammer pulse'.)

●The apical impulse is displaced laterally and inferiorly, and is diffuse and hyperdynamic.

●The diastolic murmur of AR begins immediately after A2 (movie 2A-C). It is high pitched, often blowing in quality, and may be sustained in intensity or decrescendo.

The intensity of the murmur does not correlate well with the severity of AR. In some patients, the murmur is soft and barely audible, often appreciated only when the patient is sitting up, leaning forward, and holding his or her breath in expiration. However, the timing and duration of the murmur may be helpful. In mild AR, the murmur occurs only in early diastole; as the regurgitation becomes more severe, the murmur extends through more of diastole. (See "Clinical manifestations and diagnosis of chronic aortic regurgitation in adults", section on 'Cardiac auscultation'.)

A number of other findings may be evident in association with hyperdynamic pulses. (See "Clinical manifestations and diagnosis of chronic aortic regurgitation in adults".)

Evaluation of AR severity — In addition to history and physical examination, echocardiography is essential for establishing the etiology, severity, and hemodynamic consequences of AR. Echocardiography and other tests are discussed separately (see "Echocardiographic evaluation of the aortic valve" and "Clinical manifestations and diagnosis of chronic aortic regurgitation in adults", section on 'Staging'). Stages of AR are described in the 2020 American College of Cardiology/American Heart Association guideline (table 3) [1], and a similar system is described in the 2021 European Society of Cardiology valve guideline [2].

Perioperative risk of aortic regurgitation — The risk of noncardiac surgery in patients with chronic AR depends upon the severity and etiology of regurgitation and the degree of hemodynamic and clinical compensation as well as the risk level of the procedure. Predictors of increased risk of noncardiac surgery in patients with AR include depressed LVEF, serum creatinine >2 mg/dL (>177 micromol/L), and lack of perioperative medical management [11]. Patients with good functional status and preserved LV systolic function are generally tolerant of general anesthesia [7,8]. (See "Clinical manifestations and diagnosis of chronic aortic regurgitation in adults" and "Natural history and management of chronic aortic regurgitation in adults".)

Limited data are available on the risk of noncardiac surgery in patients with advanced chronic AR. Substantial perioperative risk was identified by a report of 167 patients with chronic moderate-to-severe (3+) or severe (4+) AR who were case-matched with 167 patients without significant AR [11]. The two groups had similar mean baseline LVEF (52 percent) and baseline serum creatinine (1.9 and 1.6 mg/dL [168 and 141 micromol/L]).

●Patients with AR had greater postoperative morbidity (16.2 versus 5.4 percent). The most common postoperative adverse events were prolonged intubation (13.8 versus 3.0 percent) and pulmonary edema (4.8 versus 0.6 percent).

●In-hospital deaths were also more common in patients with AR (9.0 versus 1.8 percent). The most common cause for in-hospital deaths was pneumonia/respiratory failure (5.4 versus 0 percent).

●Predictors of postoperative in-hospital deaths in patients with AR included LVEF <55 percent, serum creatinine >2 mg/dL (>177 micromol/L), high- or intermediate-risk surgery, and absence of cardiovascular medications.

Management of patients with AR — Given the significant risk of noncardiac surgery in patients with moderate-to-severe or severe (3+ or 4+) AR, these patients should identified, treated, and undergo individualized risk assessment prior to proceeding with noncardiac surgery. In patients with AR, cardiac risk of noncardiac surgery is also impacted by other cardiac conditions that may be present, such as coronary artery disease. (See "Evaluation of cardiac risk prior to noncardiac surgery".)

Aortic valve replacement or repair is indicated, preferably prior to elective intermediate- or high-risk noncardiac surgery, for symptomatic severe chronic AR or asymptomatic chronic AR with LVEF <50 percent. In addition, patients with bicuspid aortic valve should be evaluated for aortic root and ascending aorta dilation that may require aortic surgery (see "Bicuspid aortic valve: General management in adults"). However, aortic valve surgery prior to noncardiac surgery is not always feasible, as some patients require an urgent noncardiac procedure, in some the risk of aortic valve surgery may not be deemed acceptable, and some may decline aortic valve surgery. (See "Natural history and management of chronic aortic regurgitation in adults", section on 'Aortic valve surgery'.)

Although evidence is limited, most asymptomatic patients with severe AR can undergo urgent noncardiac surgery at an acceptable risk with careful intraoperative and postoperative management, including careful attention to afterload control and fluid balance. Thus, elective noncardiac surgery is generally reasonable to perform in adults with asymptomatic moderate or greater degrees of AR with normal LV systolic function, as noted in major society guidelines [1,2,9,10]. The risks and benefits of various treatment options should be carefully weighted if urgent noncardiac surgery is contemplated in a patient with symptomatic severe AR. (See "Natural history and management of chronic aortic regurgitation in adults", section on 'General management' and "Overview of the management of heart failure with reduced ejection fraction in adults".)

Intraoperative hemodynamic and anesthetic management of patients with AR are discussed separately. Summarized briefly, heart rate should be maintained since bradycardia-associated increases in total diastolic time may acutely increase AR, which may precipitate decompensated heart failure; afterload should be controlled; and preload should be maintained or reduced as needed to maintain adequate intravascular volume without precipitating fluid overload, taking into consideration increased LV volumes and compliance [7,8]. In patients with advanced AR, marked increases in systemic blood pressure should be avoided since they can diminish forward flow [7,8]. Patients with heart failure and AR require diuretics and afterload reduction to optimize volume status prior to noncardiac surgery. (See "Anesthesia for noncardiac surgery in patients with aortic or mitral valve disease", section on 'Aortic regurgitation' and "Natural history and management of chronic aortic regurgitation in adults".)

Patients with moderate-to-severe or severe AR undergoing moderate- or higher-risk noncardiac surgery should receive intraoperative invasive hemodynamic and/or transesophageal echocardiography monitoring and postoperative intensive care unit monitoring [1,9]. Though data on hemodynamic monitoring in this setting are limited, invasive hemodynamic monitoring enables monitoring intracardiac filling pressures and vascular resistance, thus facilitating intravenous fluid management and appropriate use of vasodilators. (See "Pulmonary artery catheterization: Indications, contraindications, and complications in adults".)

Management of AR during pregnancy is discussed separately. (See "Pregnancy and valve disease", section on 'Aortic regurgitation'.)

ADDITIONAL PERIOPERATIVE ISSUES — The following perioperative issues are of particular concern in certain subgroups of patients:

●For patients at highest risk of endocarditis – For patients at the highest risk of endocarditis (including those with a prosthetic valve or prior history of endocarditis) the type of the noncardiac procedure to be performed (eg, dental) will determine whether antimicrobial prophylaxis is indicated for bacterial endocarditis. (See "Prevention of endocarditis: Antibiotic prophylaxis and other measures".)

●For patients receiving anticoagulant therapy – In patients receiving anticoagulant therapy (eg, those anticoagulated for atrial fibrillation or a mechanical prosthetic valve), interruption of anticoagulation prior to noncardiac surgery may be required. Management is discussed separately. (See "Perioperative management of patients receiving anticoagulants" and "Anticoagulation for prosthetic heart valves: Management of bleeding and invasive procedures", section on 'Planning for invasive procedures'.)

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" and "Society guideline links: Perioperative cardiovascular evaluation and management".)

SUMMARY AND RECOMMENDATIONS

●For patients with moderate-to-severe or severe mitral regurgitation (MR) undergoing noncardiac surgery, risk factors for adverse perioperative events include depressed left ventricular ejection fraction (LVEF), ischemic MR, atrial fibrillation, and comorbidities (ie, diabetes mellitus, and history of carotid endarterectomy), as well as the level of surgical procedural risk. (See 'Perioperative risk of mitral regurgitation' above.)

●For patients with moderate-to-severe or severe aortic regurgitation (AR) undergoing noncardiac surgery, risk factors for in-hospital mortality include depressed LVEF, lack of perioperative medical management, and serum creatinine >2 mg/dL (>177 micromol/L), as well as the level of surgical procedural risk. (See 'Perioperative risk of aortic regurgitation' above.)

●Patients with severe MR or AR with indications for valve surgery should generally undergo valve surgery prior to elective intermediate or higher risk noncardiac surgery. (See 'Management of patients with MR' above and 'Management of patients with AR' above.)

●The risks and benefits of various treatment options should be carefully weighted if urgent, noncardiac surgery is contemplated in a patient with symptomatic severe MR or AR. Patients with heart failure require diuretics and afterload reduction to optimize volume status prior to noncardiac surgery. (See 'Management of patients with MR' above and 'Management of patients with AR' above.)

●Although evidence is limited, most asymptomatic patients with severe MR and normal LV systolic function can undergo urgent or elective noncardiac surgery at an acceptable risk with careful intraoperative and postoperative management, including careful attention to afterload control and fluid balance, which can affect the severity of MR (particularly if functional). (See 'Management of patients with MR' above and "Anesthesia for noncardiac surgery in patients with aortic or mitral valve disease", section on 'Hemodynamic management'.)

●Although evidence is limited, most asymptomatic patients with severe AR and normal LV systolic function can undergo urgent or elective noncardiac surgery at an acceptable risk with careful intraoperative and postoperative management, including careful attention to afterload control, fluid balance, and heart rate. (See 'Management of patients with AR' above and "Anesthesia for noncardiac surgery in patients with aortic or mitral valve disease", section on 'Hemodynamic management'.)

●Bradycardia should be avoided in patients with AR since increases in total diastolic time may acutely increase AR, which may precipitate decompensated heart failure. (See 'Management of patients with AR' above.)

ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Joe M Moody, Jr, MD, who contributed to earlier versions of this topic review.