Heart Failure (Cardiac Anesthesia)

Impact of CHF on Anesthetic Risk

Known CHF is associated with an increased risk of surgical mortality [Stoelting p. 382, 2006]. In fact, in the Revised Cardiac Index validation set (1422 patients), CHF (diagnosed by chest X-ray in combination with clinical suspicion) had the highest OR for major cardiac complications (OR 4.3) [Hernandez et al. AIM 164: 1729, 2004] – other significant factors in the validation cohort included ischemic heart disease, cerebrovascular disease, and high risk surgery [Lee TH et al. Circulation 100: 1043, 1999]

Patients with decompensated heart failure should have all non-emergent operations postponed – the cause of decompensation should be determined, and the patient should not return to the operating room until two weeks after symptoms have resolved [Reginelli JP et al. Heart 85: 505, 2001]

Perioperative Assessment

Clinical Assessment

New York Heart Association Functional Class Class I: Patient has no limitation of regular physical activities Class II: Mild limitation of physical activities; comfortable at rest; normal physical activity results in dyspnoea, fatigue or angina Class III: Major limitation of physical activities; comfortable at rest; minimal physical activity results in dyspnoea, fatigue, or angina Class IV: Inability to perform any physical activity without symptoms; symptoms are present at rest, and are worsened with any activity

Ejection Fraction and TEE Assessment

While several studies have shown a relationship between low EF (usually < 35%) and MACE, patients with compensated heart failure generally need no further workup as preoperative determination of LVEF has not been supported by any data [Reginelli JP et al. Heart 85: 505, 2001]. Interestingly, it may be the CHF patients with normal EF that are most problematic, as they tend to have diastolic dysfunction and are highly intolerant of both tachycardia and volume shifts [Reginelli JP et al. Heart 85: 505, 2001]

There is no evidence that echocardiography (for calculation of EF) adds any appreciable information to clinical and EKG evaluations [Mangano et. al. NEJM 333: 1750, 1995; Hernandez et al. AIM 164: 1729, 2004] – the VA study of 339 men found the sensitivity of EF < 40% to be between 0.28 and 0.31 for predicting any/all adverse outcomes (whereas the specificity was 0.87-0.89) [Halm EA et al. AIM 125: 433, 1996]. Rohde’s study, which examined 570 patients via TTE before major noncardiac surgery and found a significant relationship between preoperative systolic dysfunction and postoperative myocardial infarction (OR 2.8), cardiogenic pulmonary edema (OR 3.2), and major cardiac complications (OR 2.4), may contradict Halm’s [Rohde LE et al. Am J Cardiol 87: 505, 2001]. Rodhe’s findings should be viewed with caution, however, as they relaxed their criteria for an abnormal echocardiogram in order to boost sensitivity (which was 80%), thus reducing specificity to 52% and positive predictive value to 12% (negative predictive value, as expected, was 97%). Furthermore, on Rodhe’s study severe LV dysfunction had a weaker correlation than mild or moderate dysfunction, a counterintuitive finding which casts doubt on their results [Hernandez et al. AIM 164: 1729, 2004]

Other Testing in the CHF Patient

A metaanalysis of thallium imaging, which combined 5 studies (1168 patients) showed that a reversible defect was the most significant predictor for cardiac events, followed by heart failure (OR 3.6, p < 0.001) [Shaw LJ et al. J Am Coll Cardiol 27: 787, 1996]. Dobutamine stress echocardiography only adds meaningful prognostic information to patients with a revised clinical risk index of 3 or more [Boersma et a. JAMA 285: 1865, 2001]. Right-heart catheterization appears to be of even less use – an observational study of 4059 patients undergoing major non-cardiac surgery showed absolutely no reduction in complication rates associated with the use of preoperative right heart catheterization (which was conducted in 221 of the 4059 patients) – keep in mind, however, that this study was observational, and most likely the patients who received RHC were sicker to begin with, although a case-control analysis of 215 matched pairs of patients (adjusted for type of procedure etc.) showed an increased risk of CHF and major non-cardiac events in the RHC group [Polanczyk CA et al. JAMA 286: 309, 2001]

Perioperative Medication Regimen

Preoperative administration of beta-blockers, vasodilators, and ACE inhibitors may reduce this risk [Stoelting RK. Basics of Anesthesia, 5th ed. Elsevier (China) p. 382, 2006], however the randomized, controlled trials supporting beta-blockade contained very few patients with heart failure (~ 30) [Hernandez et al. AIM 164: 1729, 2004]. Regional anesthesia should be considered in this patient population, however if general anesthesia is administered, the goal should be to maximize cardiac output. Volatile anesthetics can be problematic as they are cardiac depressants, thus while there is no evidence to suggest that an opiate-based anesthetic regimen results in better outcomes, there is similarly no evidence to the contrary and therefore it should at least be considered. Positive pressure ventilation can be helpful for a) reducing pulmonary edema and b) preventing excessive diastolic filling, on the other hand extubation can be difficult because as diastolic filling returns, the possibility of a CHF exacerbation arises. It is thought that beta-agonists may decrease survival in CHF patients, thus their use should be minimized [Stoelting RK. Basics of Anesthesia, 5th ed. Elsevier (China) p. 382, 2006]

Most CHF patients will be on beta-blockers and ACE inhibitors at the time of surgery, as these medications are supported by a large body of data. This does not mean, however, that a patient in acute decompensation or with new-onset heart failure or in whom beta-blockers have not previously been started should be placed on beta-blockade specifically for surgery [Reginelli JP et al. Heart 85: 505, 2001]

Reginelli et al. recommend delaying surgery in NYHA class IV patients undergoing moderate or high risk surgery, and NYHA class III patients undergoing high risk surgery. They also recommend use of caution (which includes PA catheter placement) in all CHF patients undergoing high risk surgery, as well as NYHA III undergoing moderate risk surgery and NYHA IV undergoing low risk surgery, although none of these recommendations are evidence-based [Reginelli JP et al. Heart 85: 505, 2001]