Preoperative cardiac risk assessment
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Mohammed A. Sbeih, M.D. [2]; Kashish Goel,M.D.
Stepwise approach to preoperative cardiac assessment
Adapted from Fleisher et al. Circulation. 2009 Nov 24;120(21):e169-276[1]
§,∧ Noninvasive testing is not useful for patients with no clinical risk factors undergoing intermediate-risk or low-risk noncardiac surgery (AHA guidelines Class III, Level of Evidence: C).
¶ Clinical risk factors: Ischemic heart disease, compensated or prior heart failure, diabetes mellitus, renal insufficiency, and cerebrovascular disease
Active Cardiac conditions*
1. Unstable coronary syndromes
- Unstable or severe angina (Canadian Cardiovascular Society class III or IV): May include “stable” angina in patients who are unusually sedentary.
- Recent MI: Greater than 7 days, but less than or equal to 1 month (within 30 days)
2. Decompensated HF
- NYHA functional class IV
- Worsening or new-onset heart failure
3. Significant arrhythmias
- High-grade atrioventricular block
- Mobitz II atrioventricular block
- Third-degree atrioventricular heart block
- Symptomatic ventricular arrhythmias
- Supraventricular arrhythmias (including atrial fibrillation) with uncontrolled ventricular rate (HR greater than 100 bpm at rest)
- Symptomatic bradycardia
- Newly recognized ventricular tachycardia
4. Severe valvular disease
- Severe aortic stenosis (mean pressure gradient >40 mm Hg, aortic valve area <1.0 cm2, or symptomatic)
- Symptomatic mitral stenosis (progressive dyspnea on exertion, exertional presyncope, or heart failure)
Estimated energy requirements for various activities#
The metabolic equivalent of task (MET), or simply metabolic equivalent, is a physiological concept expressing the energy cost of physical activities[2] as multiples of resting metabolic rate (RMR) and is defined as the ratio of metabolic rate (and therefore the rate of energy consumption) during a specific physical activity to a reference rate of metabolic rate at rest, set by convention to 3.5 ml O2·kg-1·min-1 or equivalently 1 kcal·kg-1· h-1 or 4.184 kJ·kg-1· h-1. By convention 1 MET is considered as the resting metabolic rate obtained during quiet sitting[3][4] . MET values of physical activities range from 0.9 (sleeping) to 18 (running at 17.5 km/h or a 5:31 mile pace).
Calculating the weekly energy expended in recreational-time physical activity using METs (Metabolic equivalent task) [5].
| Physical Activity | MET |
|---|---|
| Light Intensity Activities | < 3 |
| sleeping | 0.9 |
| watching television | 1.0 |
| writing, desk work, typing | 1.8 |
| walking, 1.7 mph (2.7 km/h), level ground, strolling, very slow | 2.3 |
| walking, 2.5 mph (4 km/h) | 2.9 |
| Moderate Intensity Activities | 3 to 6 |
| bicycling, stationary, 50 watts, very light effort | 3.0 |
| walking 3.0 mph (4.8 km/h) | 3.3 |
| calisthenics, home exercise, light or moderate effort, general | 3.5 |
| walking 3.4 mph (5.5 km/h) | 3.6 |
| bicycling, <10 mph (16 km/h), leisure, to work or for pleasure | 4.0 |
| bicycling, stationary, 100 watts, light effort | 5.5 |
| Vigorous Intensity Activities | > 6 |
| jogging, general | 7.0 |
| calisthenics (e.g. pushups, situps, pullups,jumping jacks), heavy, vigorous effort | 8.0 |
| running jogging, in place | 8.0 |
| rope jumping | 10.0 |
Cardiac risk stratification for noncardiac surgical procedures
High (Reported cardiac risk often greater than 5%)
- Emergent major operations, particularly in the elderly.
- Aortic and other major vascular surgery.
- Peripheral vascular surgery.
- Anticipated prolonged surgical procedures associated with large fluid shifts and/or blood loss.
Intermediate (Reported cardiac risk generally less than 5%)
- Carotid endarterectomy.
- Head and neck surgery.
- Intraperitoneal and intrathoracic surgery.
- Orthopedic surgery.
- Prostate surgery.
Low (Reported cardiac risk generally less than 1%)
- Endoscopic procedures.
- Superficial procedure.
- Cataract surgery.
- Breast surgery.
References
- ↑ Fleisher LA, Beckman JA, Brown KA; et al. (2009). "2009 ACCF/AHA focused update on perioperative beta blockade incorporated into the ACC/AHA 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery: a report of the American college of cardiology foundation/American heart association task force on practice guidelines". Circulation. 120 (21): e169–276. doi:10.1161/CIRCULATIONAHA.109.192690. PMID 19884473. Unknown parameter
|month=ignored (help) - ↑ Physical activity can be defined as “bodily movement produced by the contraction of skeletal muscle that increases energy expenditure above the basal level”
- ↑ Ainsworth et al., 1993
- ↑ Ainsworth et al., 2000.
- ↑ Adapted from Compendium of Physical Activities. Ainsworth, BE et al. Medicine and Science in Sports and Exercise. Vol 25, Pg 713 (1993) and Vol 32, S498 (2000).