Preoperative Cardiac Risk Assessment for Non‑Cardiac Surgery in CAD and Dilated Cardiomyopathy Patients

Primary Risk Assessment Tools

The American College of Cardiology/American Heart Association (ACC/AHA) recommends using the Revised Cardiac Risk Index (RCRI) together with the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) risk calculator as the initial stratification strategy for patients undergoing non‑cardiac surgery [1][2].
The RCRI assigns one point for each of the following validated risk factors: (1) history of ischemic heart disease, (2) history of congestive heart failure, (3) history of cerebrovascular disease, (4) insulin‑treated diabetes, (5) pre‑operative serum creatinine > 177 µmol/L, and (6) high‑risk surgery (intraperitoneal, intrathoracic, or supra‑inguinal vascular procedures) [3][4].
The American College of Surgeons NSQIP calculator provides procedure‑specific peri‑operative risk estimates and may be used as an alternative or adjunct to the RCRI [1][2]5.

Emergency surgery – Proceed immediately with appropriate monitoring; formal cardiac risk assessment is not performed because delay would increase mortality [1][2][3][4] (ACC/AHA, Class I).
Urgent or semi‑urgent surgery – Delay cardiac assessment only if the patient has an unstable cardiovascular condition, a severe obstructive intracardiac lesion, or severe pulmonary hypertension [3][4] (ACC/AHA, Class IIa).
Elective surgery – Perform a full stepwise cardiac evaluation before proceeding [1][2] (ACC/AHA, Class I).

If acute coronary syndrome (ACS) is identified, the patient must be referred immediately to cardiology and managed according to contemporary STEMI/NSTEMI guidelines before any non‑cardiac operation [1][2] (ACC/AHA, Class I).

Low‑risk category (< 1 % MACE) – RCRI = 0 with low‑risk surgery, or any RCRI score with a very low‑risk procedure (e.g., ophthalmologic surgery) [1][2] (ACC/AHA, Class IIa).
Elevated‑risk category (≥ 1 % MACE) – RCRI ≥ 1 with intermediate/high‑risk surgery, or RCRI ≥ 2 with any surgery [1][2] (ACC/AHA, Class IIa).

Assess functional capacity using the Duke Activity Status Index (DASI) or the ability to climb ≥ 2 flights of stairs (≈ 4 METs) [1][2] (ACC/AHA, Class IIa).
Good functional capacity (≥ 4 METs) – Proceed to surgery without additional cardiac testing [1][2] (ACC/AHA, Class IIa).
Poor functional capacity (< 4 METs) – Advance to the “Further Testing” pathway [1][2] (ACC/AHA, Class IIa).

Perform pharmacologic stress testing (preferred) or exercise stress testing if true functional capacity is unknown, provided that the results are expected to change peri‑operative management [1][2] (ACC/AHA, Class IIa).
Abnormal stress test – Consider coronary angiography and revascularization based on the extent of ischemia, followed by guideline‑directed medical therapy (GDMT) before surgery [1][2] (ACC/AHA, Class IIa).
Normal stress test – Proceed to surgery with GDMT [1][2] (ACC/AHA, Class IIa).
If testing would not alter management, skip testing and proceed directly to surgery with GDMT or explore non‑surgical alternatives [1][2] (ACC/AHA, Class IIa).

Class I – Evaluate left‑ventricular (LV) function in patients with current or prior heart failure who have worsening dyspnea or a change in clinical status, if LV assessment has not been performed within the past 12 months [6][7] (American College of Cardiology, Class I).
Class IIa – It is reasonable to assess LV function in patients presenting with dyspnea of unknown origin [6][7] (ACC, Class IIa).
Pre‑operative ECG – Reasonable (Class IIa) for patients with known coronary disease, significant arrhythmia, peripheral arterial disease, cerebrovascular disease, or other structural heart disease (including dilated cardiomyopathy), except when the planned surgery is low‑risk [1][2] (ACC/AHA, Class IIa).

Routine prophylactic coronary revascularization in stable CAD patients does not improve peri‑operative outcomes and should not be performed solely to lower surgical risk [8][9]10 (ACC, Class III).
Stress testing in patients with good functional capacity (≥ 4 METs) rarely changes management and should be avoided regardless of the RCRI score [1][2] (ACC/AHA, Class III).
Delaying emergency surgery for cardiac testing increases mortality and should be avoided [3][4] (ACC/AHA, Class III).
Initiating high‑dose beta‑blockers on the day of surgery increases stroke and mortality risk; such dosing should be avoided 11 (ACC/AHA, Class III).

The 2024 ACC/AHA peri‑operative cardiovascular guidelines (Class IIa) emphasize that validated risk‑prediction tools—such as the RCRI and NSQIP calculators—should be employed to estimate peri‑operative MACE risk; no single tool has demonstrated superiority 5.
The RCRI remains the most widely validated and practical bedside tool, while the NSQIP calculator offers more granular, procedure‑specific estimates 5 (ACC/AHA, Class IIa).
For patients with dilated cardiomyopathy, the same stepwise algorithm applies, but clinicians must pay particular attention to the current heart‑failure status and recent changes in functional capacity, as these patients are prone to rapid peri‑operative decompensation [6][7] (ACC, Class IIa).