Anesthetizing patients with cardiovascular disease is one of the greatest challenges facing the anesthesiologist. The constellation of anesthetic drug effects, the physiologic stresses of surgery, and underlying cardiovascular diseases complicate and limit the choice of anesthetic techniques for any particular procedure. The anesthesiologist’s approach to the patient with cardiovascular disease is to select agents and techniques that will optimize the patient’s cardiopulmonary function. The perioperative management of a patient with cardiovascular disease requires close cooperation between the cardiologist/internist, surgeon, and anesthesiologist. Each specialist has a unique knowledge base that complements the others. The approach should emphasize a continuum of care from the preoperative evaluation through the extended postoperative period.

The assessment of cardiac risk and preoperative optimization of the patient’s cardiovascular status are the traditional goals of the preoperative evaluation of patients with cardiovascular disease. In 1977, Goldman et al1 introduced the Cardiac Risk Index Score (CRIS) to guide more quantitatively the assignment of cardiac risk in patients undergoing noncardiac surgery. This study had a major impact because clinicians concluded that improvements in factors such as congestive heart failure symptoms and general medical condition would decrease cardiac risk. Although the predictive value of the CRIS remains controversial,2 the emphasis on preoperative optimization continues and is reviewed in Chap. 87. The American College of Cardiology (ACC)/American Heart Association (AHA) Task Force on Practice Guidelines published “Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery” that were last updated in 2009.3 The algorithmic approach to preoperative evaluation described in these guidelines is valuable in that more consistent clinical approaches have emerged. The information derived from the clinical cardiac evaluation should provide answers to the following questions:

1. 
   

   Is there a need for emergency noncardiac surgery?

   
   
2. 
   

   Are there “active cardiac conditions” (previously known as “major risk factors”)?

   
   
3. 
   

   What is the cardiac risk of the planned surgery?

   
   
4. 
   

   What is the functional capacity of the patient?

   
   
5. 
   

   Does the patient have “clinical risk factors” (formerly known as “intermediate risk factors”)?

The preoperative assessment that is of particular value to the anesthesiologist regarding choice of anesthesia technique and administration of anesthetic agents can be summarized as follows:

1. 
   

   What is (are) the clinically significant pathologic condition(s) affecting the cardiovascular system?

   
   
2. 
   

   Are further diagnostic studies required prior to elective surgery?

   
   
3. 
   

   Will the patient derive benefit from delaying surgery to optimize preoperative medical therapy?

   
   
4. 
   

   Should there be perioperative antithrombotic therapy?

   
   
5. 
   

   What is the regimen of preoperative cardiovascular medications that should be continued through the perioperative period? Should β-blockers or statins be started?

   
   
6. 
   

   What is the specific device information regarding the patient’s pacemaker or automatic implantable cardioverter-defibrillator (AICD), and what are the recommendations regarding pacemaker/AICD programming in the perioperative setting?

A cogent and legible summary of the pertinent clinical, laboratory, radiologic, echocardiographic, radionuclide, and cardiac catheterization data comprises the ideal cardiac consultation for the anesthesiologist. With the benefit of this information, the two specialties can make intelligent decisions regarding the patient’s preoperative therapy and the optimal timing of surgery.4

As cardiovascular disease management increasingly includes anticoagulants, antiplatelet agents, and percutaneous coronary interventions, new challenges have arisen in the perioperative management of these patients. Elective surgery and neuraxial anesthesia may require the withdrawal of anticoagulant and antiplatelet therapy during the immediate perioperative period.

Recent percutaneous myocardial revascularization is strongly associated with perioperative cardiac events.5-8 These observations are likely related to the perioperative hypercoagulability associated with surgical stress in the setting of nonendothelialized stent surfaces where anticoagulant/ antiplatelet medications have been discontinued to facilitate surgical hemostasis. A retrospective study by Posner et al9 found that adverse cardiac outcomes after noncardiac surgery among 686 patients with prior percutaneous transluminal coronary angioplasty (PTCA) were increased. Patients with prior PTCA had twice the rate of adverse cardiac outcomes as normal subjects, seven times the rate of angina, almost four times the rate of myocardial infarction, and twice the rate of congestive heart failure. Patients who underwent PTCA within 90 days of noncardiac surgery had twice the rate of perioperative myocardial infarction compared with patients with uncorrected coronary artery disease.

Early recommendations regarding anticoagulant/antiplatelet medications in the perioperative setting in patients with prior coronary stent placement were mainly based on experience with bare metal stents. However, the period of risk for acute stent thrombosis may extend even more than 1 year following drug-eluting stent placement.10 The answer to when and if anticoagulant/antiplatelet medications can be safely discontinued for surgery at any point after drug-eluting stent implantation has yet to be determined.11,12 Ideally, elective noncardiac surgery is delayed until full completion of antiplatelet therapy.13 The ACC and the AHA recently updated their recommendations on elective procedures following coronary stent placement.14 The 2007 ACC/AHA guidelines do not recommend elective noncardiac surgery within 4 to 6 weeks after bare metal stent placement and 12 months after drug-eluting stent placement. Based on these guidelines, the American Society of Anesthesiologists (ASA) recently issued a Practice Alert for the perioperative management of patients with coronary artery stents.15 In addition to the time intervals noted earlier, if surgery cannot be deferred and thienopyridine therapy must be interrupted in patients with recently placed coronary stents, aspirin should be continued if possible, and thienopyridine therapy should be restarted as soon as possible after the surgical procedure. In emergency procedures, patients on long-acting antiplatelet drugs have increased risk of hemorrhage, and platelet transfusions may be necessary to achieve hemostasis.

In addition to the implications for perioperative cardiovascular events and surgical hemostasis, anticoagulant therapy and antiplatelet therapy are associated with neurologic complications after neuraxial anesthesia that are described later in this chapter in the Regional Anesthesia section.

Perioperative monitoring guidelines are almost entirely based on observational cohort analyses and expert opinion. Large-scale monitoring trials are unlikely to be conducted due to the low incidence rates of major perioperative complications, the cost of the research, and ethical concerns. The ASA established standards for basic intraoperative monitoring in 1986.16 The intraoperative monitoring that is required based on these guidelines includes the following: (1) heart rate, (2) electrocardiogram (ECG), (3) blood pressure, (4) pulse oximetry, (5) capnometry, and (6) body temperature. The indications for the use of more invasive monitors, such as intra-arterial and central venous monitoring, vary by institution and practitioner (Tables 88–1 and 88–2).17

The indications for pulmonary arterial catheter (PAC) monitoring are especially controversial. Data from the intensive care setting suggest that the PAC is harmful,18 whereas other data indicate that PAC may provide prognostic information in the perioperative period.19 Large randomized prospective studies of PAC use in various clinical settings have failed to demonstrate improved patient outcomes.20-23 Therefore, current evidence does not support specific indications for perioperative PAC monitoring. As with all monitoring devices, the caregiver’s competency in interpreting PAC-derived data and instituting appropriate treatment is essential to derive maximal benefit and avoid complications.24-26 The ASA published practice parameters to guide practitioners in the appropriate use of the PAC.27 The decision to use perioperative PAC monitoring should be based on a combination of patient risk factors, surgical risk, and the experience of the practitioner. Many clinicians believe that certain patient groups benefit from PAC monitoring, such as selected patients undergoing cardiac surgery or liver transplantation and patients with clinically significant pulmonary hypertension and other severe cardiac conditions.

Transesophageal echocardiography (TEE) is less invasive and has acquired a much larger role in perioperative management in recent years. The more widespread availability of these devices in the operating room and intensive care unit setting and the development of newer modalities such as three-dimensional echocardiography and tissue Doppler have enhanced the ability of anesthesiologists, cardiologists, and surgeons to make intraoperative diagnoses, evaluate hemodynamic aberrations, and assess the quality of cardiac surgical interventions. Standardized intraoperative examination guidelines for multiplane TEE28 and training guidelines29 have been published. The National Board of Echocardiography administers a certification process. The ASA and ACC have published practice guidelines that address perioperative TEE.30,31 These are guidelines only, and the practitioner should decide on intraoperative TEE monitoring based on his or her level of experience, as well as patient- and surgery-related factors.

Less invasive and noninvasive methods of cardiovascular monitoring are continually being developed. Cardiac output can be estimated using arterial pressure waveform analysis (pulse contour analysis), indicator dilution technique, electrical bioimpedance, and esophageal Doppler ultrasound. Parameters such as intrathoracic blood volume and extravascular lung water can also be estimated by some of these devices. The limitations that remain with many newer cardiovascular monitoring technologies include the need for calibration against more invasive measurements, mechanical ventilation, stable hemodynamics, and regular rhythm. The lack of outcomes evidence in support of invasive monitoring and the established problems (eg, central line–associated bloodstream infections) give further impetus for improvements and innovations in less invasive and noninvasive monitoring.

Various “brain function” monitors using proprietary electroencephalographic analysis have been developed for the purpose of monitoring depth of sedation and level of consciousness.32 Incomplete amnesia leading to intraoperative awareness is rare with current anesthetic techniques, with a reported incidence of 0.1% to 0.2%.33,34 In a recently published practice advisory, the ASA did not recommend routine brain function monitoring in patients undergoing general anesthesia.35 Elevated risk of intraoperative awareness is associated with a prior history of intraoperative awareness, morbid obesity, substance abuse, chronic pain patients with opioid tolerance, and certain procedures (eg, trauma surgery). Brain function monitoring should thus be used on a case-by-case basis.

The choice of anesthetic technique is inherently a difficult one because multiple factors must be considered. These include the desires of the patient, the requirements of the surgical procedure, and the patient’s underlying medical condition. Although a specific anesthetic technique is occasionally desirable for a particular procedure (eg, spinal anesthesia for transurethral resection of prostate), there is little scientific evidence that any particular anesthetic approach is superior to reasonable alternatives or that anesthetic technique per se influences patient outcome.

There is long-standing controversy regarding the effects of regional anesthesia (with postoperative epidural analgesia) on cardiovascular morbidity/mortality in high-risk patients. Although some studies suggest that regional anesthesia and epidural analgesia have salutary effects in vascular surgical patients,36 the issue is unresolved due to the limited and conflicting clinical evidence.37-40 In certain defined sets of endovascular, orthopedic, and genitourinary procedures, there is evidence that local and regional anesthesia techniques are associated with better outcomes compared with general anesthesia.41,42 These data are not applicable in all circumstances, however, and clinical judgment must be exercised to make the best choices in individual circumstances.

Regional anesthetics and monitored anesthesia care are not infrequently converted to general anesthetics intraoperatively due to unexpectedly long surgery, patient discomfort, or changes in the surgical plan. No practitioner can be certain that a particular technique will be adequate for the surgical procedure, given the unpredictability of the situation, and the anesthesiologist must have flexibility to alter the technique as needed. Therefore, it is essential that the cardiologist/internist does not recommend excluding specific anesthetic technique(s) during a preoperative consultation.

Regional Anesthesia

Cushing coined the term regional anesthesia for operations where local anesthetics were used to operate on localized areas of the body without loss of consciousness. The advantages of regional anesthesia include simplicity, low cost, and minimal equipment requirements. Many of the adverse effects of general anesthesia are avoided, such as myocardial and respiratory depression. The potential disadvantages include patients’ reluctance to be awake in the operating room, the preference of some surgeons not to operate on the awake patient, local anesthetic agents of insufficient or excessive duration, local anesthetic toxicity, and the risk of neuraxial hematoma in anticoagulated patients.

The cardiovascular adverse effects of regional anesthesia vary depending on the technique chosen. Regional anesthesia may also be combined with general anesthesia in adults and children to decrease the requirements for the general anesthetic agents and for postoperative analgesia. The institution of analgesia prior to surgical stimulation (preemptive analgesia) may have salutary effects on postoperative pain control.

Local Anesthetic Agents

Local anesthetics are classified based on their chemical structure as esters or amides. The esters are hydrolyzed by esterases in the plasma, and the amides are metabolized in the liver. The duration of action of local anesthetic agents is affected by the protein-binding characteristics of the molecule and the addition of vasoconstrictors to the local anesthetic solution. Toxic reactions to local anesthetics are generally characterized by central nervous system excitation (seizures), which may be followed by central nervous system depression and cardiovascular collapse. Table 88–3 provides an overview of commonly used local anesthetics in current practice.

Epinephrine and phenylephrine may be added in small doses to local anesthetic solutions to prolong their duration of action by local vasoconstriction. The systemic absorption of epinephrine occurs very slowly, and the β-adrenergic effects predominate. This results in slight tachycardia and diastolic hypotension, which is undesirable in patients with certain cardiovascular diseases.

Spinal Anesthesia