Cardiovascular

Preoperative cardiac risk assessment for non-cardiac surgery

Clinical Overview and When to Suspect Elevated Perioperative Cardiac Risk

— Low risk (<1% MACE): cataract, endoscopy, superficial, breast, ambulatory — generally proceed without further cardiac testing

— Elevated risk (≥1%): intraperitoneal, intrathoracic, vascular (especially aortic, suprainguinal), major orthopedic, head/neck cancer

— High-risk surgery, ischemic heart disease, history of CHF, history of CVA/TIA, insulin-dependent diabetes, creatinine >2.0 mg/dL

— 0 factors ≈ 0.4%, 1 ≈ 0.9%, 2 ≈ 6.6%, ≥3 ≈ ~11% MACE

— Active cardiac conditions: unstable angina, decompensated HF, severe valve disease (severe AS, symptomatic MR), significant arrhythmia

— Poor or unknown functional capacity (<4 METs: can't climb a flight of stairs, walk up a hill, do heavy housework)

— Recent MI (<60 days), recent PCI with DAPT timing issues, decompensated valvular disease

Board pearl: Step 3 loves the phrase "would the test change management?" — if you wouldn't revascularize or cancel surgery based on the stress test result, don't order it. Routine preop stress testing before low-risk or even intermediate-risk surgery in a stable patient is a high-yield wrong answer.

Definition: Preoperative cardiac risk assessment estimates the probability of major adverse cardiac events (MACE) — perioperative MI, cardiac arrest, or cardiac death — within 30 days of non-cardiac surgery, guiding whether to proceed, optimize, or pursue further testing.

Why it matters for Step 3: This is a quintessential ambulatory/perioperative decision — the question is rarely "what's the diagnosis" but "do you operate now, delay, or get a stress test?"

Two surgical risk tiers (RCRI/ACS-NSQIP framework):

Patient-level risk factors (Revised Cardiac Risk Index — RCRI):

When to suspect a patient needs deeper workup:

The fundamental algorithm (ACC/AHA 2014, updated 2024): Emergency? → proceed. Active condition? → delay & treat. Low-risk surgery? → proceed. Adequate METs (≥4)? → proceed. Otherwise → consider pharmacologic stress testing only if results would change management.

Presentation Patterns and Key History

— Functional capacity in METs: Can the patient climb 2 flights of stairs without stopping? Walk up a hill? Do yard work? ≥4 METs without symptoms = adequate and obviates further testing in most cases

— Anginal pattern: Stable vs unstable; CCS class; nocturnal/rest pain

— HF symptoms: orthopnea, PND, weight gain, lower extremity edema, recent diuretic escalation

— Syncope/presyncope/palpitations — suggests arrhythmia or severe AS

— Prior interventions: PCI (bare-metal vs DES, date), CABG, valve repair/replacement (mechanical vs bioprosthetic — affects anticoagulation bridging)

— Medication reconciliation: beta-blocker, statin, antiplatelet, anticoagulant, ACEi/ARB, SGLT2, insulin/oral hypoglycemics

— Urgency: emergency (<6h), urgent (6–24h), time-sensitive (1–6 wks, e.g., cancer), elective

— Type and risk tier

— Anticipated blood loss, fluid shifts, duration

— Pulmonary hypertension, severe COPD, OSA (STOP-BANG ≥3), cirrhosis (MELD), frailty

— Recent COVID-19 — delay elective surgery 4–7 weeks per ASA guidance

— MI: defer elective surgery ≥60 days if no revascularization

— Balloon angioplasty: wait ≥14 days

— BMS: ≥30 days on DAPT before elective surgery

— DES: ≥6 months ideally (3 months acceptable if surgery can't be delayed and risk of delay > stent thrombosis)

— CABG: typically ≥6 weeks

Step 3 management: When asked about timing after a coronary stent, the answer is almost always "delay elective surgery until DAPT duration is complete" — do not stop DAPT early for elective procedures.

Typical stem: A 68-year-old man with HTN, DM on insulin, prior CABG 5 years ago, and CKD (Cr 2.3) is scheduled for elective open AAA repair next week. He walks 2 blocks on flat ground before stopping for knee pain. What is the next best step?

Critical history elements to extract:

Surgery-specific history:

Comorbidities that re-stratify risk upward:

Time-from-event rules to memorize:

Physical Exam Findings and Hemodynamic Assessment

— Vitals: uncontrolled HTN (>180/110 — delay elective surgery), resting tachycardia (occult HF, anemia, hyperthyroidism, infection), hypoxia

— JVP elevation, S3, bibasilar crackles, hepatojugular reflux, peripheral edema → decompensated HF — STOP and treat before elective surgery

— Carotid exam: delayed upstroke (parvus et tardus) = severe AS; bruits suggest CVD

— Cardiac auscultation:

– Late-peaking systolic murmur at RUSB radiating to carotids with soft/absent S2 → severe AS → echo before non-cardiac surgery

– Holosystolic murmur at apex → MR

– Diastolic murmur → AR, MS — always abnormal, always evaluate

— Lower extremity: diminished pulses (PAD = CAD equivalent), unilateral edema (DVT risk), ulcers

— Severe symptomatic AS (mean gradient >40, valve area <1.0, V_max >4) — high perioperative mortality; consider AVR/TAVR first

— Severe MS with PHTN

— Decompensated HF (any class IV symptoms or recent hospitalization)

— Uncontrolled arrhythmia: AF with RVR (HR >110), symptomatic bradycardia, high-grade AV block

— Can rise from chair without using arms

— Can walk down a hallway at conversational pace

— Tandem gait, grip strength — frailty surrogates increasingly used in geriatric preop

— Critical in CKD, HF, cirrhosis — preop hypervolemia → postop pulmonary edema; hypovolemia → postop AKI and hypotension on induction

Key distinction: A flow murmur (soft, early systolic, no radiation, normal S2, no symptoms) in a young patient with normal functional capacity needs no further workup. A late-peaking systolic murmur with diminished S2 in a 75-year-old getting hip replacement needs an echocardiogram before the OR.

Targeted exam — what the question stem is hinting at:

Hemodynamic red flags that mandate delay:

Functional capacity exam-table proxies:

Volume status assessment:

Diagnostic Workup — Initial Labs, ECG, and Biomarkers

— CBC: if anticipated significant blood loss, known anemia, hematologic disease, symptoms

— BMP: patients on diuretics, ACEi/ARB, with renal disease, DM, or undergoing major surgery with fluid shifts

— Coags (PT/INR, aPTT): only if on anticoagulants, known bleeding diathesis, or hepatic disease — not as routine screen

— Type & screen/crossmatch: procedure-dependent

— Pregnancy test: all women of reproductive age before elective surgery

— HbA1c: if DM and not recent; ideally <8% before elective surgery (no hard cutoff, but >8.5% → optimize)

— TSH: only if symptoms or known thyroid disease

— Reasonable in patients with known CAD, significant arrhythmia, PAD, CVD, or other structural heart disease undergoing elevated-risk surgery

— NOT recommended for asymptomatic patients undergoing low-risk surgery regardless of age

— Look for: pathologic Q waves, LBBB, LVH with strain, AF, prolonged QT, ischemic ST-T changes

— BNP/NT-proBNP: Class IIa per 2024 ACC/AHA — consider in patients ≥65, or ≥45 with cardiac disease, undergoing elevated-risk surgery. Elevated levels (BNP ≥92, NT-proBNP ≥300) predict MACE

— Troponin: baseline if BNP elevated or high-risk; surveillance hs-troponin at 24h and 48h postop in selected high-risk patients can detect MINS (myocardial injury after non-cardiac surgery)

Board pearl: Asymptomatic patient + low-risk surgery + no comorbid red flags = NO preop testing (no ECG, no labs, no CXR). The answer choice "obtain baseline ECG and BMP" in a healthy 55-year-old getting an inguinal hernia repair is a classic distractor — the right answer is proceed to surgery.

Routine "preop labs" are NOT routine — order based on patient and procedure:

ECG indications (12-lead, resting):

Cardiac biomarkers:

CXR: only if new/unexplained cardiopulmonary symptoms or known disease with potential change; not routine for age alone

Diagnostic Workup — Advanced and Confirmatory Studies

— New or worsening dyspnea of unknown cause

— Known HF with clinical change in the last 12 months

— Suspected significant valvular disease (new murmur, symptoms)

— Not for routine LV function assessment in stable patients

— Indicated only if ALL three are true: (1) elevated-risk surgery, (2) poor or unknown functional capacity (<4 METs), AND (3) the results would change management (i.e., you'd cancel surgery or revascularize)

— Exercise stress preferred if patient can exercise and has interpretable ECG

— Pharmacologic stress (dobutamine echo or vasodilator nuclear) if can't exercise

– Avoid dobutamine in severe HTN, recent VT, severe AS

– Avoid vasodilators (regadenoson, adenosine) in severe bronchospasm, high-grade AV block

Key distinction: A stress test that finds disease but won't lead to revascularization is clinically useless and increases delay/cost — Step 3 rewards the candidate who says "proceed to surgery with medical optimization" over "obtain dobutamine echo." The 2024 ACC/AHA guidelines specifically warn against testing that won't alter management.

Echocardiography (TTE) — when indicated preoperatively:

Stress testing — the most over-tested area on Step 3:

Coronary CTA: emerging role; not yet routine preop

Coronary angiography: reserved for the same indications as in the non-operative setting — ACS, high-risk stress test findings, refractory angina. Do not "cath before surgery just to be safe" — CARP trial showed no benefit of routine revascularization before elective vascular surgery in stable CAD

Pulmonary function testing & ABG: for lung resection or severe COPD, not for cardiac assessment

Carotid Doppler: only if bruit + symptoms or planned vascular surgery with neurologic history

Sleep study: if STOP-BANG ≥3 and elective surgery — OSA increases perioperative cardiopulmonary risk; CPAP optimization helpful but should not delay urgent surgery

Risk Stratification and Decision Algorithm

— Step 1: Is the surgery emergent? → Proceed to OR; manage cardiac issues perioperatively

— Step 2: Does the patient have an acute coronary syndrome or decompensated condition? → Delay elective surgery; treat first (cath if STEMI/NSTEMI, diurese if HF, rate-control if AF with RVR)

— Step 3: Calculate MACE risk using RCRI or ACS-NSQIP/MICA calculator

– <1% = low risk → proceed

– ≥1% = elevated risk → continue algorithm

— Step 4: Assess functional capacity — ≥4 METs without symptoms → proceed

— Step 5: If poor/unknown METs AND elevated risk → consider pharmacologic stress testing only if results would change management

— Step 6: Abnormal stress test → consider revascularization vs canceling surgery vs proceeding with optimized medical therapy

— High-risk surgery, ischemic heart disease, HF history, CVA/TIA, insulin-treated DM, Cr >2.0

— Recent MI <60 days → defer elective surgery

— DES <6 months (or BMS <30 days) → defer if possible; if not, continue aspirin perioperatively, hold P2Y12 5–7 days only if surgical bleeding risk demands

— Document MACE estimate, functional capacity, shared decision-making, and rationale for/against testing in the chart

Step 3 management: The answer to "what is the next best step?" is almost always either "proceed to surgery with continued medical therapy" or "delay surgery and optimize [specific condition]" — rarely a stress test, rarer still a cath.

Step-by-step algorithm (memorize this — it's the spine of the topic):

RCRI quick recall — 6 factors, 1 point each:

ACS-NSQIP / Gupta MICA — online calculators, more granular, often preferred; incorporate age, functional status, ASA class

Special timing rules to integrate:

Documentation requirements (Step 3 patient-safety flavor):

Pharmacotherapy — Perioperative Medication Management

— Continue if already on chronic therapy — abrupt discontinuation causes rebound ischemia and arrhythmia

— Do NOT start beta-blocker on the day of surgery (POISE trial: increased stroke and death with high-dose metoprolol XL started preop)

— May initiate ≥1 week preop with cautious titration if RCRI ≥3 or known significant CAD — start low, go slow, target HR 60–70 without hypotension

— Continue in chronic users

— Initiate preoperatively in patients undergoing vascular surgery regardless of LDL — Class I; reduces MACE

— Reasonable to initiate in elevated-risk non-vascular surgery with other indication

— Continue in patients with coronary stents (especially recent DES) — stent thrombosis risk > bleeding risk in most surgeries

— Hold ~7 days preop in primary prevention or low CV risk patients undergoing surgery with significant bleeding risk

— Continue through CEA and most vascular surgery

— Ideally delay elective surgery until DAPT duration is complete

— If must proceed: hold clopidogrel/ticagrelor 5 days, prasugrel 7 days; continue aspirin

— Hold morning of surgery — reduces intraoperative hypotension; resume postop once euvolemic

— Warfarin: stop 5 days preop, bridge with LMWH only if very high thrombotic risk (mechanical mitral valve, recent VTE <3 months, CHA₂DS₂-VASc ≥7)

— DOACs: stop 24–48h preop based on bleeding risk and CrCl; no bridging needed

Board pearl: Continue beta-blockers, continue statins (and start them before vascular surgery), hold ACEi/ARB and SGLT2 the morning of surgery, and don't start a beta-blocker the day of surgery.

Beta-blockers:

Statins:

Aspirin:

P2Y12 inhibitors (clopidogrel, ticagrelor, prasugrel):

ACEi/ARB:

Diuretics: hold morning of surgery

SGLT2 inhibitors: hold 3–4 days preop — risk of euglycemic DKA

Anticoagulants:

Insulin: half of basal long-acting dose morning of surgery; hold short-acting; check glucose q1–2h

GLP-1 agonists: emerging guidance — consider holding day-of or week-of for delayed gastric emptying/aspiration risk

Procedures, Revascularization, and Bridging Strategy

— CARP trial: No mortality or MI benefit from preop revascularization in stable CAD before major vascular surgery

— Revascularize only if the patient meets standard indications independent of surgery (ACS, left main, three-vessel disease with reduced EF, refractory angina)

— Balloon angioplasty alone: delay non-cardiac surgery ≥14 days

— Bare-metal stent: delay ≥30 days (DAPT required minimum)

— Drug-eluting stent: delay ≥6 months ideally; 3 months if surgery is time-sensitive (e.g., cancer) and risk of delay outweighs stent thrombosis

— If urgent/emergent surgery within these windows: continue aspirin, hold P2Y12, perform surgery in a center with cath lab capability, resume P2Y12 ASAP postop

— Symptomatic severe AS → AVR or TAVR before elective non-cardiac surgery

— Asymptomatic severe AS undergoing elevated-risk surgery → cardiology referral; TAVR increasingly used as a "bridge"

— Emergent surgery in severe AS → proceed with invasive monitoring, careful hemodynamics, avoid hypotension and tachycardia

— Rate-controlled, stable AF → proceed

— New or RVR → rate control before surgery; consider TEE/cardioversion only if hemodynamically compromised

— Interrogate device within 6–12 months preop

— Magnet over ICD intraop to suspend tachy-therapy if electrocautery used; reprogram pacemaker to asynchronous mode if pacemaker-dependent

CCS pearl: In a CCS case of severe symptomatic AS scheduled for elective hip replacement, the correct sequence is delay surgery → cardiology consult → TAVR or AVR → recover → then proceed with orthopedic surgery. Proceeding directly to the OR is wrong.

Prophylactic coronary revascularization before non-cardiac surgery — generally NOT indicated:

PCI considerations:

CABG before non-cardiac surgery: wait ≥6 weeks after CABG before elective non-cardiac surgery in stable patients

Severe aortic stenosis prior to non-cardiac surgery:

Atrial fibrillation:

Pacemaker/ICD:

Special Populations — Elderly and Renal/Hepatic Impairment

— Frailty assessment independently predicts MACE, delirium, and 1-year mortality — use Clinical Frailty Scale, gait speed (<0.8 m/s = frail), grip strength, or FRAIL scale

— Polypharmacy review — deprescribe anticholinergics, benzodiazepines (Beers criteria); risk of postop delirium

— Cognitive screening (Mini-Cog) — baseline for postop delirium detection

— Higher incidence of silent ischemia → consider postop troponin surveillance

— Lower physiologic reserve → conservative fluid management, multimodal analgesia to minimize opioids

— Cr >2.0 = 1 RCRI point; eGFR <30 substantially increases MACE

— Hold nephrotoxins preop: NSAIDs, ACEi/ARB (morning of), contrast where possible

— Optimize volume status — neither hypovolemic nor hypervolemic

— Dialysis patients: dialyze within 24h preop, but not immediately before (avoid hypovolemia and electrolyte shifts); check K+ morning of surgery (<5.5 ideal)

— Avoid morphine (active metabolites accumulate), gadolinium in eGFR <30

— MELD score predicts perioperative mortality: MELD <10 generally tolerable for elective surgery, 10–15 caution, >15 high mortality, >20 prohibitive for elective procedures

— Child-Pugh: A (5–6) low risk, B (7–9) intermediate, C (≥10) high risk

— Correct coagulopathy thoughtfully — INR doesn't reflect bleeding risk in cirrhosis; consider thromboelastography

— Watch for hepatorenal physiology, hypoalbuminemia, esophageal varices in NG tube placement

— Independent risk factor for MACE; optimize with iron (oral or IV) 4–6 weeks preop if elective and time permits

Step 3 management: In an 82-year-old with CKD stage 4, frail, scheduled for elective knee replacement — the right answer often includes "shared decision-making about goals and risks" and non-surgical alternatives, not just optimization.

Elderly (≥65, especially ≥80):

Chronic kidney disease:

Hepatic impairment:

Anemia (Hgb <13 men, <12 women):

Special Populations — Pregnancy, Pediatrics, and Other Subgroups

— Elective non-cardiac surgery should be deferred until postpartum

— Urgent surgery: second trimester is safest window (organogenesis complete, preterm labor risk lower than third trimester)

— Cardiovascular changes: ↑ plasma volume, ↑ CO 30–50%, ↓ SVR, supine hypotension after 20 weeks → left lateral tilt to relieve IVC compression

— Maternal cardiac disease (peripartum cardiomyopathy, congenital heart disease, mechanical valves) — multidisciplinary cardio-obstetric team

— Avoid teratogens: warfarin (first trimester), ACEi/ARB throughout, statins

— Continue beta-blockers (labetalol preferred); consider LMWH for anticoagulation

— Congenital heart disease patients need careful anesthesia planning; endocarditis prophylaxis per AHA for high-risk lesions (prosthetic valve, unrepaired cyanotic CHD, repaired CHD with residual defects, prior IE)

— Healthy children — no routine cardiac testing

— Murmur evaluation should distinguish HCM (worsens with Valsalva) from benign flow murmurs

— Avoid unnecessary preop echo in asymptomatic young patients

— One of the highest-risk perioperative conditions — mortality up to 18% for major surgery

— Continue PH-specific therapy (sildenafil, bosentan, prostacyclins), avoid hypoxia/hypercarbia/acidosis (all increase PVR), maintain preload, multidisciplinary planning

— Continue immunosuppression; stress-dose steroids if chronic steroid use; infection prophylaxis; nephrotoxin avoidance

— Device interrogation, magnet plan, perfusion specialist for LVAD

Board pearl: A pregnant patient at 32 weeks needing emergent appendectomy → proceed with surgery, left lateral tilt, fetal monitoring, OB available. Do not delay for elective cardiac workup.

Pregnancy:

Pediatric considerations (Step 3 less commonly tested, but be aware):

Athletes and young adults:

Pulmonary hypertension:

Organ transplant recipients:

Patients with implanted devices (LVAD, ICD, pacemaker):

Complications and Adverse Outcomes

— Peaks 24–72 hours postop; often silent (>50% asymptomatic) due to analgesia, sedation, sympatholysis

— Two mechanisms: Type 1 (plaque rupture, classic ACS — minority) and Type 2 (supply-demand mismatch from tachycardia, anemia, hypotension — majority postop)

— Surveillance hs-troponin in high-risk patients at 24h and 48h

— Troponin elevation without symptoms or ECG changes meeting MI criteria

— Independently associated with 30-day mortality 8–10%

— Management: aspirin, statin, BP/HR control, cardiology consult; consider DOAC (dabigatran) per MANAGE trial in selected patients

— Fluid overload from intraoperative resuscitation, withholding diuretics

— Manage with cautious diuresis, restart HF regimen

— Postop AF (especially after thoracic surgery) — rate control, anticoagulation if persists >48h or unstable

— Bradyarrhythmias from beta-blocker overdose, vagal stimulation

Key distinction: MINS ≠ MI. MINS is troponin elevation alone postop; it still carries substantial mortality and should not be dismissed as "demand ischemia." Step 3 may test recognition and initiation of secondary prevention even without classic MI criteria.

Perioperative myocardial infarction (PMI):

Myocardial injury after non-cardiac surgery (MINS):

Heart failure decompensation:

Arrhythmias:

Stroke: 0.1–1% non-cardiac surgery; higher in vascular, prior CVA; avoid intraop hypotension

VTE: PE remains leading preventable cause of postop death — mechanical and pharmacologic prophylaxis (Caprini score)

Acute kidney injury: 1–7%; multifactorial — hypotension, nephrotoxins, contrast

Delirium: especially elderly; multifactorial — minimize benzodiazepines, anticholinergics, opioids; reorient, early mobilization

Hemorrhage: anticoagulant timing errors; have reversal agents ready (PCC for warfarin/factor Xa, idarucizumab for dabigatran, vitamin K)

When to Escalate Care — ICU, Consult, and Triage Decisions

— Active cardiac condition (unstable angina, decompensated HF, severe arrhythmia, severe valve disease)

— Abnormal stress test in patient where revascularization is being considered

— Recent MI, recent stent (DES <6 months, BMS <30 days)

— Complex congenital heart disease, pulmonary hypertension

— Mechanical valve requiring bridging strategy

— Unclear functional capacity in high-risk surgery patient

— All elevated-risk surgery patients

— Difficult airway history, OSA, neuromuscular disease, malignant hyperthermia history

— Major vascular, prolonged/large fluid-shift surgery with significant cardiac disease

— Severe pulmonary hypertension

— LVAD, recent MI within 60 days

— Anticipated need for invasive monitoring (arterial line, PA catheter rare now)

— Postop respiratory failure risk (severe COPD, OSA on nighttime BiPAP)

— Known CAD, prior arrhythmia, intermediate-risk surgery in elevated-risk patients

— Acute MI <60 days without revascularization

— Decompensated HF

— Severe symptomatic AS without intervention plan

— Uncontrolled HTN (>180/110) — postpone elective

— Active infection

— New atrial fibrillation with RVR or hemodynamic instability

— Order: vitals, IV access, telemetry, ECG, troponin, BNP, CBC, BMP, T&S

— Consults: cardiology, anesthesia

— Hold/continue medications as appropriate

— Update patient and family; document discussion

CCS pearl: On CCS cases, don't forget to order the consults (cardiology preop, anesthesia preop) when patient has elevated cardiac risk — the simulation often grades on these process steps, not just final outcome.

Cardiology consultation indications preoperatively:

Anesthesia consultation:

ICU admission criteria postoperatively (preop planning):

Floor with telemetry:

When to cancel or delay surgery (not just consult):

CCS-style sequencing:

Key Differentials — Same-Category Cardiac Causes of Perioperative Risk

— Stable: predictable angina with exertion, relieved by rest/nitrates, unchanged pattern → optimize medically, proceed if functional capacity adequate

— Unstable angina/NSTEMI/STEMI: rest pain, crescendo pattern, new ECG changes, troponin elevation → delay elective surgery, ACS pathway

— Compensated: stable weight, no orthopnea, baseline exercise tolerance, stable diuretic regimen → proceed cautiously

— Decompensated: weight gain, orthopnea, recent hospitalization, escalating diuretics → delay and treat

— Severe symptomatic AS, MS, MR, AR all carry high perioperative risk → intervene or modify surgical plan

— Moderate asymptomatic disease — proceed with hemodynamic awareness

— Rate-controlled chronic AF on anticoagulation → proceed; manage anticoagulation

— Paroxysmal AF — assess rhythm at time of surgery

— New AF with RVR — control rate, then proceed

— Stage 1–2 HTN — proceed

— Severe (>180/110) — defer elective; risk of intraop lability, MI, stroke

— HCM: avoid hypovolemia and vasodilators (worsens outflow obstruction)

— Dilated CM with low EF — manage as HF

— Restrictive — careful fluid management

Key distinction: A patient with compensated chronic systolic HF (EF 30%, no recent decompensation, NYHA II) on guideline-directed therapy can usually proceed with elevated-risk surgery with careful intraop management. A patient with decompensated HF (recent admission, escalating diuretics) must have elective surgery delayed.

When evaluating a patient with cardiopulmonary symptoms preoperatively, the differential of "what's driving the risk" must be narrowed:

Stable ischemic heart disease vs ACS:

Decompensated vs compensated heart failure:

Severe vs moderate valvular disease:

Atrial fibrillation patterns:

Hypertension severity:

Cardiomyopathies:

Pulmonary hypertension: WHO Group 1 (PAH) carries highest risk; avoid hypoxia, acidosis

Key Differentials — Non-Cardiac Causes Mimicking Cardiac Risk

— COPD: dyspnea, reduced functional capacity, may have cor pulmonale; optimize bronchodilators, pulmonary rehab, smoking cessation ≥4–8 weeks preop (acute cessation <4 weeks may transiently increase secretions)

— OSA: STOP-BANG screen; CPAP optimization; perioperative cardiac and pulmonary risk increased

— Pulmonary embolism: acute or recent — major contraindication to elective surgery; treat first

— ILD/pulmonary fibrosis: PFTs, oxygen needs; high postoperative pulmonary complication risk

— Severe anemia causes exertional dyspnea, tachycardia, "low METs" — optimize Hgb with iron, EPO if appropriate, transfusion if symptomatic and surgery imminent

— Anticoagulant management — separate decision from cardiac risk

— Uncontrolled hyperthyroidism → tachycardia, arrhythmia, thyroid storm risk — treat with methimazole, beta-blocker before elective surgery

— Uncontrolled DM (HbA1c >8.5%) → wound infection, MI, mortality risk

— Adrenal insufficiency → stress-dose steroids if chronic steroid use (prednisone ≥5 mg/d for ≥3 weeks within last year)

— Pheochromocytoma — alpha-blockade (phenoxybenzamine) before beta-blockade preop

Step 3 management: A patient with poor functional capacity isn't always cardiac — anemia, COPD, deconditioning, and depression can all produce the "<4 METs" history. Address modifiable non-cardiac contributors before defaulting to cardiac stress testing.

Pulmonary disease masquerading as cardiac symptoms:

Hematologic mimics:

Endocrine:

Renal: AKI vs CKD distinction affects timing

Hepatic: cirrhosis with portal HTN → bleeding, encephalopathy, ascites — risk often underestimated

Neuromuscular: myasthenia gravis (succinylcholine sensitivity), Duchenne (cardiomyopathy, malignant hyperthermia–like response)

Psychiatric/social: uncontrolled substance use, severe depression — affect adherence, recovery

Infection: active untreated infection → delay elective surgery

Secondary Prevention and Long-Term Management Post-Procedure

— Aspirin 81 mg daily — indefinite

— High-intensity statin (atorvastatin 40–80 or rosuvastatin 20–40) — LDL goal <70 (or <55 if very high risk)

— Beta-blocker — continue/initiate (carvedilol, metoprolol succinate if HF; atenolol/metoprolol otherwise)

— ACEi/ARB if reduced EF, HTN, DM, or CKD

— Outpatient cardiology follow-up within 1–2 weeks of discharge

— Cardiac rehab referral if eligible — Class I recommendation post-MI

— Initiate guideline-directed medical therapy (GDMT): aspirin, statin, beta-blocker if indicated, ACEi if appropriate

— Address risk factors: BP <130/80 (per ACC/AHA), HbA1c <7% individualized, LDL <70, smoking cessation, weight, exercise

— Optimize quadruple therapy for HFrEF: ARNI (or ACEi/ARB), beta-blocker, MRA, SGLT2 inhibitor

— Continue diuretic at lowest effective dose

— Monitor weights daily; resume baseline activity per cardiac rehab

— CHA₂DS₂-VASc–based anticoagulation decision: DOAC preferred over warfarin in non-valvular AF; warfarin still required for mechanical valves and moderate-severe mitral stenosis

— Rate vs rhythm control individualized

— Outpatient cardiology follow-up, serial echo, endocarditis education, dental prophylaxis only for highest-risk lesions

Board pearl: Perioperative MI is an MI — patients need full secondary prevention (aspirin, statin, beta-blocker, ACEi if indicated, cardiac rehab). Failing to initiate GDMT after a perioperative event is a frequently tested error.

Patients who experienced perioperative MI or MINS:

Patients with newly identified CAD on preop workup:

HF patients:

AF patients identified perioperatively:

Valvular disease identified:

Smoking cessation: every encounter — 5 A's; nicotine replacement, varenicline, bupropion; surgical pause is a teachable moment

Lifestyle counseling: Mediterranean/DASH diet, 150 min/week moderate exercise, weight reduction if BMI ≥30

Follow-Up, Monitoring, and Rehabilitation

— Uncomplicated elevated-risk surgery in stable cardiac patient: outpatient PCP visit within 2 weeks, cardiology follow-up if pre-existing CAD/HF within 2–4 weeks

— Postop MI or MINS: cardiology within 1–2 weeks, repeat echo if indicated, troponin trend documentation

— Anticoagulation restart: typically 24–72h postop depending on bleeding risk; bridge with prophylactic-dose LMWH if needed

— Vital signs (HR, BP, O₂ sat) — patients with HF should resume daily weights

— Symptoms: chest pain, dyspnea, palpitations, edema, lightheadedness — patient education to call or return for these

— Wound healing — DM patients especially

— Renal function at 1 week for patients with CKD or who received contrast/nephrotoxins

— Medication reconciliation at every visit — common errors include resuming SGLT2 too early, forgetting to restart ACEi, missing DAPT

— Class I indication after MI, PCI, CABG, stable angina, HF (HFrEF), valve surgery, heart transplant

— Typically 36 sessions over 12 weeks; covered by Medicare; underutilized — refer at discharge

— Reduces all-cause mortality 20–25%, cardiovascular mortality 25%, rehospitalization

— Smoking cessation reinforcement

— Diet (DASH/Mediterranean)

— Exercise: gradual return; cardiac rehab is the structured pathway

— Weight management

— Influenza annually, pneumococcal per age/risk, COVID-19 boosters — all reduce cardiac mortality

Step 3 management: Always refer eligible patients to cardiac rehab at discharge. It's a Class I recommendation, frequently tested as the "next best step" alongside secondary prevention medications.

Routine post-op cardiac follow-up cadence:

Monitoring parameters in the first 30 days:

Cardiac rehabilitation:

Pulmonary rehab: if COPD contributed to perioperative course

Lifestyle counseling at follow-up:

Vaccinations:

Ethical, Legal, and Patient Safety Considerations

— Must disclose quantitative MACE estimate (e.g., RCRI-based percentage), alternatives (non-surgical management, less invasive procedure), and possibility of perioperative MI/stroke/death

— Special case — patient with severe AS refusing AVR/TAVR: must document understanding of high perioperative mortality; respect autonomy if decision-making capacity intact; offer second opinion and palliative options

— Pregnant patient: consent must address fetal risks; involve OB; document shared decision-making

— Required when patient declines recommended workup or surgery, or accepts very high-risk surgery; capacity is decision-specific

— Cognitive impairment alone ≠ incapacity; assess understanding, appreciation, reasoning, expression of choice

— DNR is not automatically suspended in the OR — required discussion with patient/surrogate before surgery

— Three options: full suspension during OR/PACU, partial (specific interventions only), goal-directed

— Document explicitly; failure to discuss is a sentinel-event-level safety lapse

— Medication errors at admission, transfer, and discharge cause ~50% of preventable harm

— Use structured handoffs (I-PASS, SBAR), explicit anticoagulation restart plans, scheduled follow-up before discharge

— Reconcile every medication with the outpatient list at discharge

— Suspected impairment of surgeon/anesthesiologist

— Driving restrictions after syncope, ICD shock, recent MI (state-specific, often 1 week to 6 months)

— Avoid low-value preop testing (Choosing Wisely) — routine ECG/CXR/labs in low-risk patients = wasted resource and false positives leading to delay

Board pearl: DNR status must be addressed explicitly preoperatively — it is neither automatically rescinded nor automatically honored. Documentation of the discussion is required and tested.

Informed consent in preop cardiac risk discussions:

Capacity assessment:

DNR/DNI orders intraoperatively:

Transitions of care — highest-risk window for cardiac events:

Mandatory reporting:

Health systems and value:

Disclosure of complications: transparent, timely disclosure to patient/family after adverse events is both ethical and reduces litigation

High-Yield Associations and Rapid-Fire Clinical Facts

Key distinction: The exam loves to contrast "would you order a stress test?" scenarios. Default to no unless the patient has elevated risk and poor METs and the result would change management.

RCRI factors (6): high-risk surgery, IHD, HF history, CVA/TIA, insulin-treated DM, Cr >2.0

METs threshold: ≥4 METs without symptoms = adequate functional capacity → proceed without stress testing

DAPT delays for elective non-cardiac surgery: balloon 14 d, BMS 30 d, DES 6 mo (3 mo if necessary)

Beta-blockers: continue chronic, don't start day-of (POISE)

Statins: start before vascular surgery — Class I

ACEi/ARB and SGLT2: hold morning of surgery (SGLT2 — 3–4 days)

Severe AS: symptomatic → AVR/TAVR before elective non-cardiac surgery

MI: delay elective surgery ≥60 days

CABG: delay elective non-cardiac surgery ≥6 weeks

Pulmonary HTN: one of highest perioperative mortality risks

MINS: troponin elevation alone postop = real, prognostic, and treatable with aspirin/statin

CARP trial: no benefit of routine revascularization before vascular surgery in stable CAD

POISE trial: routine perioperative metoprolol increased stroke and death

Smoking cessation: ≥4–8 weeks preop ideal

MELD >15: high perioperative mortality for elective surgery in cirrhotics

Pregnancy: second trimester safest for non-cardiac surgery if unavoidable

Asymptomatic patient + low-risk surgery: no ECG, no labs, no testing — proceed

Always continue aspirin in patients with recent coronary stents through most surgeries

Pacemaker/ICD: interrogate within 12 months preop, magnet plan for cautery

Cardiac rehab post-MI/PCI/CABG/HF: Class I, always refer

DNR in OR: explicit discussion required preop

Endocarditis prophylaxis: only highest-risk (prosthetic valve, prior IE, unrepaired cyanotic CHD, repaired CHD with residual defects, cardiac transplant with valvulopathy) for dental and selected procedures

Board Question Stem Patterns

— Answer: None — proceed to surgery.

— Answer: Proceed with surgery on current medical therapy; continue aspirin, ensure statin, continue beta-blocker.

— Answer: Delay surgery until DAPT duration completed (≥6 months ideally). If truly time-sensitive, continue aspirin, hold P2Y12 minimally, multidisciplinary discussion.

— Answer: Echocardiogram; if severe AS, cardiology referral for AVR/TAVR before elective surgery.

— Answer: No — initiating beta-blocker day-of/day-before increases stroke and mortality.

— Answer: MINS — start aspirin and statin, cardiology consult, BP/HR control, telemetry.

— Answer: Stop warfarin 5 days preop; no bridging (CHA₂DS₂-VASc 4 alone doesn't mandate bridging — BRIDGE trial).

— Answer: Proceed with surgery; arterial line, careful hemodynamics, avoid hypotension/tachycardia, cardiac anesthesia.

— Answer: Address DNR preoperatively; document patient's wishes for intraop resuscitation.

— Answer: Consider pharmacologic stress testing only if result would change management (elevated-risk surgery + plausible revascularization).

Step 3 management: The exam rewards restraint — fewer tests, more shared decision-making, more "proceed with optimized medical therapy."

Stem 1 — "Routine preop in healthy patient": 55-year-old healthy male for inguinal hernia repair. Best preop testing?

Stem 2 — "Stable CAD before vascular surgery": 70-year-old with stable CAD, prior PCI 3 years ago, walks 4 blocks, climbs stairs, scheduled for elective AAA repair. Next step?

Stem 3 — "Recent DES": 65-year-old with DES placed 2 months ago for stable angina, on DAPT, needs elective cholecystectomy.

Stem 4 — "New murmur": 78-year-old with new harsh systolic crescendo-decrescendo murmur, diminished S2, syncope, scheduled for elective hip replacement.

Stem 5 — "POISE trap": RCRI 3 patient, not on beta-blocker, scheduled for major surgery tomorrow. Should you start metoprolol?

Stem 6 — "Postop troponin": Asymptomatic patient post hip surgery; routine troponin elevated to 0.15.

Stem 7 — "Anticoagulation timing": AF on warfarin with CHA₂DS₂-VASc 4 needs elective surgery.

Stem 8 — "Emergency surgery, severe AS": Acute abdomen, known severe AS.

Stem 9 — "DNR in OR": Patient with DNR scheduled for surgery — never discussed.

Stem 10 — "Functional capacity ambiguous": Cannot climb stairs due to severe knee OA.

One-Line Recap

Preoperative cardiac risk assessment is a structured algorithm that combines surgery-specific risk, patient-specific risk (RCRI), and functional capacity — and recommends additional testing or intervention only when the results would change management.

Board pearl: When in doubt on a Step 3 perioperative question, the best answer is usually "proceed to surgery with continued guideline-directed medical therapy" or "delay surgery and treat the specific decompensated condition" — almost never "obtain a stress test" and almost never "perform prophylactic revascularization."

The algorithm in one breath: Emergency → proceed. Active cardiac condition → delay and treat. Low-risk surgery → proceed. ≥4 METs → proceed. Otherwise consider stress testing only if it would change management.

Medication day-of rules: Continue beta-blockers and statins; start statin before vascular surgery; hold ACEi/ARB and diuretics morning-of; hold SGLT2 3–4 days; never start a beta-blocker the day of surgery (POISE).

Stent timing rules: balloon 14 days, BMS 30 days, DES 6 months (3 months if necessary); continue aspirin through most surgeries in stent patients.

High-mortality red flags: decompensated HF, severe symptomatic AS, MI <60 days, recent DES on DAPT, pulmonary hypertension — delay elective surgery and intervene first.

Don't forget: address DNR status preoperatively, refer post-event patients to cardiac rehab, recognize MINS as a real entity requiring secondary prevention, and avoid low-value routine testing in asymptomatic low-risk patients.