Cardiovascular

Cardiac rehabilitation: referral criteria and counseling

Clinical Overview and When to Suspect Cardiac Rehab Need

— Acute MI (STEMI or NSTEMI)

— Status post PCI or CABG

— Stable angina (chronic coronary disease)

— Heart valve repair or replacement (surgical or TAVR)

— Heart or heart-lung transplantation

— HFrEF with EF ≤35% on guideline-directed medical therapy, NYHA II–III, stable ≥6 weeks (CMS expanded coverage)

— Symptomatic PAD (supervised exercise therapy, SET, now CMS-covered for intermittent claudication)

Cardiac rehabilitation (CR) is a structured, multidisciplinary secondary-prevention program combining supervised exercise training, risk-factor modification, nutrition counseling, psychosocial support, and medication optimization

Class I indication (AHA/ACC, AACVPR, CMS-covered) for patients with any of the following within the prior 12 months:

Despite Class I recommendation, only ~25–30% of eligible patients are referred, and <5% complete a full 36-session program — this gap is a major board and quality-metric target

Underreferral disproportionately affects women, older adults, racial/ethnic minorities, rural patients, and lower-income patients — a recurring Step 3 health-equity theme

Automatic/opt-out referral at discharge is the single most effective system-level intervention to raise enrollment — favored over clinician-dependent referral

Step 3 management: When a 58-year-old man is being discharged post-PCI for NSTEMI, the correct order is "Refer to outpatient cardiac rehabilitation" before discharge — not at the 2-week follow-up. Document the referral as part of the discharge bundle alongside dual antiplatelet therapy, statin, beta-blocker, and ACEi/ARB.

Board pearl: CR reduces cardiovascular mortality by ~20–25% and all-cause mortality by ~15–20% after MI; it also reduces hospital readmissions and improves quality of life, depression scores, and functional capacity.

Presentation Patterns and Key History

— Post-MI patient at 2-week post-discharge visit, deconditioned, anxious about exertion, asking when they can return to work, drive, have sex, or exercise

— Post-CABG patient at 4–6 weeks, sternal precautions lifting, fatigued

— HFrEF patient with EF 28% on sacubitril/valsartan, carvedilol, spironolactone, dapagliflozin, NYHA II — eligible for HFrEF CR track

— PAD patient with claudication at 1 block, asking about exercise vs. revascularization

— Index event date and procedure details (DES type, residual disease, EF, valve type)

— Functional status pre-event (METs achievable, occupation demands)

— Symptoms with exertion: chest pain, dyspnea, presyncope, claudication distance

— Adherence barriers: transportation, insurance, work schedule, caregiving duties, depression

— Tobacco, alcohol, substance use; dietary patterns; sleep (screen for OSA)

— Mood: PHQ-9 — post-MI depression prevalence ~20% and independently raises mortality

— Sexual activity concerns — patients frequently won't volunteer; ask directly

— Unstable angina, decompensated HF, uncontrolled arrhythmia, severe symptomatic AS, resting SBP >180 or DBP >110, resting tachycardia >120, active myocarditis/pericarditis, recent PE/DVT untreated

On Step 3, the "presentation" is usually the transition-of-care moment — a patient recovering from an index cardiac event for whom you must identify CR eligibility and barriers

Typical vignettes:

Key history elements to capture before referral:

Red flags that delay or modify CR start rather than exclude it:

Key distinction: CR is not contraindicated in elderly, frail, or low-EF patients — these are precisely the patients who benefit most. "Too sick for rehab" is almost always wrong on the boards; the answer is "tailored, supervised CR."

Board pearl: Sexual activity is generally safe when a patient can climb 2 flights of stairs (4–5 METs) without symptoms — a classic counseling point.

Physical Exam Findings and Pre-Rehab Functional Assessment

— Resting HR, BP (both arms at intake), orthostatics if symptomatic, SpO2

— Identify resting SBP >180/110 (defer), HR >100 (investigate cause), SpO2 <90% (needs workup or supplemental O2 during exercise)

— Symptom-limited exercise stress test (treadmill or bike) ideally within 4 weeks of event entry — yields peak HR, peak METs, ischemic threshold, BP response, arrhythmia

— 6-minute walk test for HFrEF, elderly, or those unable to do treadmill — <300 m predicts poor outcomes

— Cardiopulmonary exercise testing (CPET) with peak VO2 for advanced HF/transplant evaluation (peak VO2 <14 mL/kg/min is a transplant trigger)

Pre-CR evaluation is less about a single diagnostic exam finding and more about baseline functional and hemodynamic profiling to write a safe exercise prescription

Vital signs and resting hemodynamics:

Cardiac exam: assess for new murmurs (post-valve patients — paravalvular leak), S3 (decompensation), JVD, peripheral edema, sternal stability post-CABG (rocking, click, drainage = halt upper-body resistance)

Pulmonary: rales suggest volume overload — optimize diuretics before progressing intensity

Vascular: femoral/radial access site exam post-PCI (hematoma, bruit, pseudoaneurysm); ABI for PAD patients

Musculoskeletal/neurologic: gait, balance (fall risk in elderly), arthritis limiting modality choice, prior stroke deficits

Functional capacity testing drives the exercise prescription:

CCS pearl: Before ordering "Cardiac rehabilitation," sequence the workup — order Exercise stress test (or 6-MWT) and Echocardiogram (if not done post-event) to define safe target HR and rule out unaddressed mechanical issues. Then place the rehab referral.

Board pearl: Target training HR is typically 60–80% of HR reserve using Karvonen formula, OR 10 bpm below the ischemic threshold identified on stress test — whichever is lower.

Diagnostic Workup — Initial Labs, ECG, and Baseline Studies

— Lipid panel within 4–12 weeks post-event to confirm LDL <70 mg/dL (or ≥50% reduction) on high-intensity statin

— HbA1c in all patients (diabetes screening + monitoring); target individualized, generally <7%

— BMP — potassium and creatinine before titrating ACEi/ARB/MRA; eGFR for medication dosing

— CBC — anemia limits exercise capacity and may unmask underlying GI bleed on DAPT

— TSH — untreated hypo/hyperthyroidism affects HR response and lipids

— BNP/NT-proBNP in HFrEF for trend; rising values signal decompensation

— Resting 12-lead ECG at intake — establish baseline rhythm, QTc, conduction, ischemic changes; repeat if symptoms develop

— TTE to document EF, wall motion, valve function, RV size, pulmonary pressures — informs prognosis and arrhythmia/ICD candidacy reassessment at 40–90 days post-MI

Pre-enrollment standard labs and studies (most should already exist from index hospitalization — reorder only if outdated or clinically changed):

Imaging baseline:

Tobacco assessment: cotinine if needed; document quit-date plan, offer varenicline or combination NRT + behavioral counseling (most effective combo)

Depression screening: PHQ-9 at intake and periodically; PHQ-9 ≥10 warrants treatment (SSRI — sertraline preferred post-MI for cardiac safety profile — plus referral to behavioral health)

Sleep: STOP-BANG; refer for polysomnography if positive — untreated OSA worsens HF, AF, HTN, and exercise tolerance

Step 3 management: A 62-year-old 6 weeks post-CABG enrolls in CR with new fatigue. Order BMP (diuretic-induced hypokalemia?), BNP (occult HF?), CBC (post-op anemia?), and TSH before assuming deconditioning. Don't just push intensity.

Board pearl: Lipid panel 4–12 weeks post-MI is the right interval — earlier samples reflect acute-phase suppression of LDL.

Diagnostic Workup — Advanced and Confirmatory Studies

— Identifies ischemic threshold HR, exercise-induced arrhythmia, abnormal BP response (drop >10 mmHg with exertion = high risk), chronotropic incompetence

— In post-revascularization patients, a submaximal ETT before discharge (4–7 days) or symptom-limited ETT at 3–6 weeks is standard

— Peak VO2 <14 mL/kg/min (or <50% predicted) → consider advanced HF therapies/transplant

— VE/VCO2 slope >35 → poor prognosis

— Distinguishes cardiac vs. pulmonary vs. deconditioning limitation

— Low risk: EF >50%, no complex ectopy, asymptomatic, normal hemodynamic response, >7 METs achieved → can progress more rapidly, less intensive monitoring

— Moderate risk: EF 40–49%, 5–7 METs, mild angina with exertion

— High risk: EF <40%, complex ventricular ectopy at low workloads, exercise-induced ischemia, abnormal BP response, survived cardiac arrest, recent PCI for STEMI with complications → continuous ECG monitoring, slower progression, lower target HR

Symptom-limited exercise tolerance test (ETT) is the cornerstone confirmatory study for safe CR prescription:

Cardiopulmonary exercise testing (CPET) — gold standard for HFrEF, transplant candidates, unexplained dyspnea:

Stress imaging (stress echo or nuclear MPI) when resting ECG is uninterpretable (LBBB, paced, LVH with strain, WPW, digoxin) or when localizing residual ischemia matters

Holter or event monitor if palpitations, syncope, or unexplained low exercise tolerance during early CR sessions

Coronary angiography is not routinely required before CR — only if symptoms, ischemia on testing, or incomplete revascularization is suspected

Risk stratification stratifies CR supervision intensity:

Key distinction: Submaximal pre-discharge ETT (stop at ~70% predicted max HR or 5 METs) vs. symptom-limited ETT at 3–6 weeks — different purposes; the latter writes the actual exercise prescription.

Board pearl: Failure of SBP to rise ≥20 mmHg or a drop during exercise signals severe LV dysfunction or multivessel disease — pause CR and re-evaluate.

Risk Stratification and Program Structure

— EF >50%, uncomplicated MI/CABG/PCI course, no resting or exercise-induced ischemia, no complex arrhythmias, normal hemodynamics, functional capacity >7 METs, asymptomatic with absent or mild depression

— EF <40%, survived sudden cardiac arrest, complex ventricular arrhythmia at rest or with exercise <6 METs, MI/cardiac procedure complicated by cardiogenic shock or HF, signs/symptoms of ischemia at low workloads, clinically significant depression

— Phase I: inpatient mobilization, education, discharge planning

— Phase II: outpatient supervised CR — up to 36 one-hour sessions over 12–36 weeks (typically 3×/week × 12 weeks); CMS-covered; this is the box you check

— Intensive cardiac rehab (ICR): up to 72 sessions over 18 weeks, evidence-based programs (Ornish, Pritikin, Benson-Henry) — also CMS-covered for same indications

— Phase III/IV: maintenance, often community gym–based, lifelong

AACVPR risk stratification dictates monitoring intensity and progression speed, not eligibility — nearly all eligible patients should still attend CR

Low-risk criteria (all must be present):

High-risk criteria (any one):

Standard CR program structure (Medicare-covered):

Each session contains: warm-up, 20–60 minutes aerobic training at prescribed HR/RPE (Borg 11–14, "light to somewhat hard"), resistance training 2–3×/week (after 3–5 weeks post-MI or 5–8 weeks post-sternotomy), cool-down, education module, individual counseling

Home-based CR is non-inferior for low-to-moderate risk patients — expanded after COVID-19; combine with telehealth coaching and wearables

Step 3 management: For a rural patient declining in-center CR due to a 90-minute drive, the right answer is home-based or hybrid CR with remote monitoring, not "no CR." Refusing access is the wrong answer on equity-flavored stems.

Board pearl: Medicare covers 36 sessions standard, up to 72 with documented medical necessity — know these numbers.

Pharmacotherapy — Secondary Prevention Regimen Reinforced in CR

— Antiplatelet: aspirin 81 mg indefinitely + P2Y12 inhibitor (ticagrelor or prasugrel preferred over clopidogrel post-ACS) for 12 months standard; shorten to 1–6 months if high bleeding risk, extend with rivaroxaban 2.5 mg BID in select high ischemic-risk patients

— Beta-blocker: metoprolol succinate, carvedilol, or bisoprolol; titrate to resting HR 55–70; continue ≥1 year post-MI, indefinitely if EF <40%

— ACEi or ARB: all post-MI with EF <40%, HTN, DM, or CKD; titrate to max tolerated; switch to sacubitril/valsartan in HFrEF

— Statin — high-intensity (atorvastatin 40–80 or rosuvastatin 20–40): target LDL <70 mg/dL (newer guidance <55 in very high risk); add ezetimibe, then PCSK9 inhibitor or bempedoic acid if not at goal

— MRA (spironolactone/eplerenone) if EF ≤40% with HF symptoms or DM post-MI

— SGLT2 inhibitor (empagliflozin, dapagliflozin) for HFrEF, HFpEF, DM with ASCVD, or CKD — now a pillar regardless of diabetes status in HF

— Icosapent ethyl 2 g BID if TG 150–499 on statin with ASCVD or DM + risk factor

CR is the structured environment where guideline-directed medical therapy (GDMT) is titrated to target — the rehab team rechecks BP, HR, symptoms, and labs each visit

Post-ACS / post-revascularization core regimen ("ABCDE+"):

Anti-anginal add-ons: long-acting nitrates, ranolazine, amlodipine if residual angina

Smoking cessation pharmacotherapy: varenicline is first-line (safe post-MI per EAGLES trial), bupropion, or combination NRT (patch + lozenge/gum)

CCS pearl: On CCS, after placing the rehab referral, advance the clock 2 weeks and recheck BMP and lipids, then uptitrate beta-blocker and ACEi toward target doses — partial-credit programs reward titration, not just initiation.

Board pearl: DAPT duration is 12 months default post-ACS; deviations require explicit bleeding/ischemic rationale.

Exercise Prescription — The FITT-VP Framework

— Frequency: 3–5 days/week (supervised + home days)

— Intensity: 40–80% of HR reserve (Karvonen) or RPE 11–14 on Borg 6–20 scale; for high-risk patients start at 40–50% HRR and progress; stay ≥10 bpm below ischemic threshold

— Time: build from 5–10 min intervals to 20–60 min continuous

— Type: treadmill, stationary cycle, arm ergometry, rowing, elliptical; avoid Valsalva-heavy activities early

— Progression: increase duration first, then intensity; reassess every 4–6 weeks

— 1–3 sets, 10–15 reps, 8–10 major muscle groups, 2–3 days/week

— Start at 30–40% 1-RM upper body, 50–60% lower body

— Avoid breath-holding; exhale on exertion

CR delivers a personalized exercise prescription using the FITT-VP structure: Frequency, Intensity, Time, Type, Volume, Progression

Aerobic training:

Resistance training (begin 3 weeks post-MI/PCI, 5 weeks post-CABG/sternotomy with sternal precautions, 6 weeks post-valve):

Flexibility and balance: daily stretching; balance training especially in elderly to reduce falls

High-intensity interval training (HIIT) is safe and effective in selected stable patients and may improve peak VO2 more than moderate continuous training — increasingly adopted

HFrEF-specific: lower starting intensity, longer warm-up/cool-down, daily weights at home, fluid restriction reinforcement

PAD/claudication SET: walk to moderate-to-severe claudication pain (3–4/4), rest, repeat, for 30–60 min, 3×/week × 12 weeks — improves walking distance more than revascularization for many

Stop-exercise red flags drilled into patients: chest pain, severe dyspnea, lightheadedness, palpitations, SBP drop >10 mmHg, SBP >250 or DBP >115, new arrhythmia, claudication 4/4 not resolving

Board pearl: Sternal precautions = no lifting >5–10 lb, no pushing/pulling, no overhead reaching for ~6–8 weeks post-sternotomy.

Special Populations — Elderly and Renal/Hepatic Impairment

— Comprehensive geriatric assessment: cognition (Mini-Cog), gait speed, grip strength, frailty (Fried criteria, FRAIL scale)

— Start at lower intensity, longer warm-up, more balance and resistance work to address sarcopenia and fall risk

— Polypharmacy review at each visit — deprescribe anticholinergics, sedatives; reconcile after every hospitalization

— Address hearing/vision, transportation, caregiver involvement

— Orthostatic BP each visit; titrate antihypertensives cautiously; SBP goal individualized (often <130 if tolerated, looser if frailty/falls)

— Dose-adjust: enoxaparin, DOACs, atenolol, sotalol, digoxin, many antibiotics

— Avoid: NSAIDs, IV contrast when possible, metformin if eGFR <30

— Continue/expand: ACEi/ARB if eGFR >30 and stable (accept K up to 5.5 with monitoring); SGLT2i down to eGFR 20; finerenone for DKD with albuminuria

— Statin: atorvastatin preferred (no renal adjustment); rosuvastatin cap at 10 mg if eGFR <30

— Exercise: aerobic + resistance reduces uremic sarcopenia; safe on dialysis days (often intradialytic cycling programs)

— Avoid/dose-reduce: amiodarone, statins (use pravastatin or low-dose rosuvastatin in mild-moderate; avoid in decompensated cirrhosis), ticagrelor (avoid in severe), warfarin titration is difficult

— Clopidogrel preferred over ticagrelor/prasugrel in advanced liver disease

— Watch for varices before initiating non-selective beta-blocker decisions

Elderly patients (≥75) derive the largest absolute benefit from CR — mortality, function, independence, fall reduction — yet are referred least often. "Too old for rehab" is always wrong on Step 3.

Tailoring for older adults:

CKD (eGFR <60):

Hepatic impairment:

Step 3 management: A frail 82-year-old post-NSTEMI with eGFR 38 — still refer to CR, choose home-based or low-intensity in-center, continue atorvastatin 40, hold metformin if eGFR drops <30, continue aspirin + clopidogrel (less bleeding than ticagrelor), and assess falls.

Board pearl: Frailty is an indication for, not a contraindication to, supervised CR.

Special Populations — Women, Pregnancy, and Other Subgroups

— Barriers: caregiving responsibilities, less physician encouragement, atypical symptom dismissal, body-image and group-setting concerns, transportation

— Solutions: women-only sessions, flexible scheduling, home-based options, explicit referral language, addressing depression (post-MI depression more prevalent in women)

— Post SCAD (spontaneous coronary artery dissection) — predominantly young women — CR is recommended but with lower-intensity isometric work, avoidance of Valsalva, and BP control as priorities; emotional stress management is central

— Peripartum cardiomyopathy (PPCM): CR after stabilization improves recovery; avoid ACEi/ARB/ARNI/MRA during pregnancy and breastfeeding (use hydralazine + nitrates, beta-blocker — metoprolol or labetalol); bromocriptine considered in select cases

— Pregnancy after MI or with congenital heart disease — managed in cardio-obstetrics programs; exercise prescription modified (avoid supine after 20 weeks, avoid Valsalva, monitor for fetal bradycardia signals)

— Denervated heart → blunted HR response; use RPE (Borg) rather than HR targets; longer warm-up and cool-down; HR rises and falls more slowly

— Watch for rejection (fatigue, low-grade fever, drop in exercise tolerance), CMV, immunosuppression side effects (HTN, DM, dyslipidemia, CKD from CNIs)

Women are referred to CR ~30% less than men, enroll less, and drop out more — a high-yield equity stem

Pregnancy and peripartum:

Heart transplant recipients:

Adult congenital heart disease (ACHD), HCM, LVAD patients: all CR-eligible with tailored programs in specialized centers

Cancer survivors with cardiotoxicity (anthracycline, trastuzumab, chest XRT): cardio-oncology rehab is an emerging Class IIa indication

Key distinction: In transplant patients, target Borg 11–13, not a percentage of HRmax — denervation invalidates HR-based prescriptions for the first 1–2 years.

Board pearl: SCAD patients need lifelong BP control and stress management; competitive/isometric sport is generally restricted.

Complications and Adverse Outcomes

— Exercise-induced ischemia — anginal recurrence, ST depression on tele; pause, reassess, consider stress imaging and angiography

— Arrhythmias — NSVT, sustained VT (high-risk in low EF), AF with RVR; ensure AED on-site and ACLS-trained staff

— Hemodynamic: hypotension (overdiuresis, excessive beta-blockade), hypertensive response (>250/115), orthostasis

— Musculoskeletal: tendinopathy, joint flares, sternal nonunion or dehiscence post-CABG (rocking, click, drainage, fever → urgent CT surgery referral)

— Hypoglycemia in insulin/sulfonylurea-treated diabetics — check pre/post glucose, snack protocol, avoid exercising at peak insulin action

— Bleeding on DAPT/anticoagulation — bruising, GI bleed; review PPI use, falls

— Psychological: anxiety, panic, post-traumatic symptoms after cardiac arrest survival — screen and refer

— Under-titration of GDMT because rehab team and PCP each assumed the other was doing it — closed-loop communication essential

— Premature discontinuation — track attendance; rehab teams should re-engage patients missing >2 sessions

— Failure to address depression — independently doubles cardiac mortality post-MI

Cardiac event rate during supervised CR is extremely low: roughly 1 cardiac arrest per 117,000 patient-hours, 1 MI per 220,000 patient-hours, mortality ~1 per 750,000 patient-hours — the safety profile is a frequent exam point

Potential adverse events to monitor and counsel:

Program-level adverse outcomes to avoid:

Emergency preparedness: every CR site must have AED, emergency drugs, oxygen, suction, BLS/ACLS-trained staff, and a written response plan with hospital transfer agreements

CCS pearl: A CR patient with new NSVT at low workload — order Holter, echo (recheck EF), electrolytes, and consider EP consult/ICD reassessment; don't just lower the treadmill speed.

Board pearl: CR safety statistics are board favorites — events are rare and benefits are large.

When to Escalate Care — Pausing or Modifying CR

— Unstable angina, decompensated HF, uncontrolled symptomatic arrhythmia, severe symptomatic AS, hypertrophic obstructive cardiomyopathy with severe outflow gradient and syncope, active myocarditis or pericarditis, acute systemic illness/fever, acute PE or DVT untreated, resting BP >200/110, intracardiac thrombus with risk of embolization

— Chest pain unresolved with rest or NTG, ST elevation, sustained VT, syncope, SBP drop >10 mmHg with worsening symptoms, SpO2 <88% despite supplemental O2

— Cardiology: recurrent ischemia, declining functional capacity, new arrhythmia, EF reassessment for ICD/CRT timing (re-evaluate EF at 40 days post-MI medically managed or 90 days post-revascularization for primary prevention ICD)

— EP: syncope, sustained VT, new AF, ICD shocks

— HF/Transplant: peak VO2 <14 mL/kg/min, recurrent HF admissions, rising NT-proBNP despite optimized GDMT

— CT surgery: sternal instability, mediastinitis concerns, paravalvular leak

— Vascular surgery: PAD progression to rest pain or tissue loss despite SET

— Psychiatry/behavioral health: PHQ-9 ≥15, suicidal ideation, severe PTSD post-arrest

— Endocrine/diabetes educator: recurrent hypo/hyperglycemia during sessions

Absolute contraindications (defer CR until resolved):

Same-session "stop and reassess" triggers — patient leaves the floor for urgent evaluation:

Consultation triggers from the CR setting:

Inpatient triage if patient presents during/after a session with ACS-like symptoms — call EMS, give aspirin 325 mg chewed, NTG if SBP >100 and not on PDE5, supplemental O2 if hypoxic, 12-lead ECG, prepare for transport

Step 3 management: A CR patient develops new exertional angina at session 8 after being asymptomatic. Pause CR, schedule stress imaging within the week, and continue meds. Don't simply lower workload and continue.

Board pearl: ICD re-evaluation timing — 40 days post-MI (medical) and 90 days post-revascularization — is a recurring item.

Key Differentials — Other Cardiac Causes of Exercise Intolerance

— Incomplete PCI of multivessel disease, in-stent restenosis (peak 3–6 months for DES), graft failure (saphenous vein graft attrition)

— Workup: stress imaging, repeat angiography if high pretest probability

— EF decline, new HFpEF, diastolic dysfunction post-MI

— Workup: repeat echo, BNP/NT-proBNP, optimize GDMT (all four pillars in HFrEF)

— Progressive AS, ischemic MR, post-surgical paravalvular leak, prosthetic valve dysfunction (thrombosis, pannus, endocarditis)

— Workup: TTE, TEE if prosthetic concern, blood cultures if fever

— New AF (rate vs. rhythm control + anticoagulation per CHA2DS2-VASc), chronotropic incompetence (consider pacemaker if symptomatic), sinus node dysfunction, NSVT/VT

— Workup: Holter/event monitor, EP referral

— Post-MI pericarditis (early) vs. Dressler syndrome (2–10 weeks post-MI), constrictive pericarditis post-CABG

When a CR patient is not progressing or is regressing, the differential within the cardiovascular system is broad — don't anchor on "deconditioning"

Inadequate revascularization / residual ischemia:

Left ventricular dysfunction progression:

Valvular disease:

Arrhythmia:

Pericardial disease:

Pulmonary hypertension secondary to left heart disease or chronic PE — RV failure presentation

Aortic disease: post-MI LV thrombus → embolic event; aortic dissection in HTN — rare but catastrophic during exertion

Key distinction: Stent thrombosis (acute, dramatic STEMI-like, often from DAPT nonadherence) vs. in-stent restenosis (subacute, exertional angina returning at 3–9 months) — different mechanisms and management.

Board pearl: A patient missing clopidogrel for 3 days post-DES who develops crushing chest pain — acute stent thrombosis until proven otherwise — emergent cath.

Key Differentials — Non-Cardiac Causes of Poor CR Progress

— Undiagnosed/under-treated COPD or asthma — spirometry, optimize inhalers (LAMA/LABA ± ICS), pulmonary rehab co-enrollment

— OSA — STOP-BANG, PSG, CPAP; untreated OSA undermines BP, AF, HF control

— Pulmonary embolism — post-op patients, immobilized — D-dimer, CTPA

— Interstitial lung disease in older patients — DLCO, HRCT

— Anemia — iron deficiency (GI bleed on DAPT/anticoagulation), anemia of CKD; treat to Hb >10 minimum; IV iron improves outcomes in HFrEF with iron deficiency (ferritin <100 or 100–300 with TSAT <20%)

— Hypothyroidism — TSH; treat to normal

— Diabetes — both hyper- and hypoglycemia impair exercise tolerance

— Adrenal insufficiency — rare but consider in chronic steroid users

— Osteoarthritis, lumbar stenosis, post-sternotomy pain, plantar fasciitis — change exercise modality (recumbent bike, pool therapy)

— Prior stroke deficits, peripheral neuropathy, autonomic dysfunction

— Depression (PHQ-9), anxiety (GAD-7), PTSD post-arrest, panic disorder mimicking angina — treat appropriately; CBT and SSRI (sertraline preferred)

— Beta-blocker–induced fatigue (consider switching agent or dose), statin myalgia (rule out CK elevation, try alternative statin, ezetimibe + PCSK9), amiodarone pulmonary toxicity, diuretic-induced electrolyte issues

Cardiovascular tunnel vision misses common non-cardiac explanations for fatigue, dyspnea, or inability to advance in CR

Pulmonary:

Hematologic:

Endocrine/metabolic:

Musculoskeletal:

Neurologic:

Psychiatric:

Medication side effects:

Step 3 management: A 70-year-old in CR with fatigue, Hb 9.2, ferritin 40, on aspirin + clopidogrel — order FOBT/colonoscopy, treat iron deficiency, and review PPI co-prescription. Don't blame "deconditioning."

Board pearl: Statin myalgia without CK rise → trial of rosuvastatin every other day or pitavastatin, then add ezetimibe; rarely is statin discontinuation correct.

Secondary Prevention, Discharge Medications, and Long-Term Plan

— High-intensity statin indefinitely; LDL goal <70 mg/dL (consider <55 in very high-risk: recurrent ACS, multivessel disease, DM, PAD, CKD)

— Add ezetimibe, then PCSK9i (alirocumab, evolocumab) or inclisiran if not at goal

— Bempedoic acid for statin-intolerant

— Icosapent ethyl if TG 150–499 on statin with ASCVD/DM

— Target <130/80 for ASCVD, DM, CKD per ACC/AHA

— Preferred agents post-MI/HFrEF: ACEi/ARB/ARNI, beta-blocker, MRA; add thiazide or amlodipine as needed

— A1c individualized (~7%, looser in frail elderly)

— Preferred agents with ASCVD: SGLT2i (empagliflozin, dapagliflozin, canagliflozin) and GLP-1 RA (semaglutide, liraglutide, dulaglutide, tirzepatide) — both have CV mortality benefit

— Metformin foundational unless contraindicated

— Mediterranean or DASH diet; sodium <2,300 mg/day, <1,500 mg if HF/HTN

— 150 min/week moderate aerobic + 2 days resistance lifelong

— Weight: BMI 18.5–24.9; waist <40 men, <35 women; consider GLP-1 RA for obesity

— Tobacco: complete cessation; assess at every visit

— Alcohol: ≤1 drink/day women, ≤2 men; abstain in HF/AF

— Vaccines: annual influenza (Class I post-MI), COVID-19 boosters, pneumococcal, RSV ≥60, Tdap

— Sleep: 7–9 hours, treat OSA

CR is the delivery vehicle for comprehensive secondary prevention — the long-term plan extends well beyond the 36 sessions

Lipid management:

Blood pressure:

Diabetes:

Antithrombotic: aspirin 81 mg indefinitely; P2Y12 for prescribed DAPT duration; reassess bleeding risk yearly

Lifestyle (the core CR curriculum):

Cardiac psychology: ongoing depression/anxiety screening and treatment

Board pearl: Annual influenza vaccination has a Class I AHA recommendation post-MI — reduces cardiovascular events.

Key distinction: Lifestyle change is not optional adjunct — it is GDMT.

Follow-Up, Monitoring Parameters, and Counseling Anchors

— PCP visit within 7–14 days post-discharge for ACS/HF — medication reconciliation, symptom check, labs

— Cardiology follow-up at 2–6 weeks, then 3–6 months, then yearly if stable

— CR initiation within 2–4 weeks of discharge — earlier enrollment = better adherence

— Lipid panel at 4–12 weeks after statin initiation/intensification, then yearly

— BMP, eGFR 1–2 weeks after starting/uptitrating ACEi/ARB/MRA/diuretic/SGLT2i

— A1c every 3–6 months until at goal, then every 6–12 months

— Echo at 40 days post-MI (medical management) or 90 days post-revascularization to reassess EF for ICD indication

— Depression rescreen at 3 and 12 months

— Driving: usually 1 week post-uncomplicated PCI, 4 weeks post-CABG (commercial 3 months); post-ICD shock or sustained VT: 6 months no driving (private), commercial often permanent disqualification

— Air travel: uncomplicated PCI/MI — typically after 2 weeks if stable; CABG after 2–3 weeks

— Return to work: sedentary 1–2 weeks post-PCI; heavy labor 6–12 weeks post-CABG

— Sexual activity: safe when 3–5 METs tolerated (2 flights of stairs); avoid PDE5 inhibitors within 24 h (sildenafil/vardenafil) or 48 h (tadalafil) of nitrates

— Exercise alone vs. supervised: low-risk patients can transition to home/community after Phase II

Post-discharge follow-up cadence (Step 3 favorite):

Return-to-activity counseling (high-yield):

Self-monitoring: daily weights in HF (alert if >2 lb/day or >5 lb/week), BP log, symptom diary, pedometer/wearable step goals (~7,000–10,000/day)

CCS pearl: On discharge, schedule the PCP visit at 7 days, cardiology at 3 weeks, and CR intake at 2 weeks. Advance the clock and recheck symptoms, BP, HR, BMP, lipids — titrate as you go.

Board pearl: Nitrate + PDE5 inhibitor = absolute contraindication — life-threatening hypotension.

Ethical, Legal, and Patient Safety Considerations

— Underreferral of women, minorities, elderly, rural, Medicaid, and non-English-speaking patients is a quality-of-care failure, not a patient preference issue — use automatic referral, interpreters, hybrid/home-based programs, and transportation assistance

— Refusing referral because "the patient won't go" without offering alternatives is ethically inadequate

— Medication reconciliation at discharge, at PCP visit, and at CR intake — discrepancies are common and dangerous

— Closed-loop communication: who is titrating which drug? Document explicitly to avoid the rehab team and PCP both deferring to each other

— Teach-back method for new meds, sternal precautions, warning signs

— Commercial drivers (DOT), pilots (FAA), and law enforcement have mandatory cardiac event reporting and disqualification periods — counsel and document

— ICD recipients: 6-month private driving restriction after secondary-prevention ICD or shock; some states have physician reporting laws (know your state)

Informed consent for CR: discuss benefits (mortality, function, QoL), risks (rare cardiac events, MSK injury), alternatives (home-based, declining), and the right to discontinue. Document in the chart.

Health equity and access — a Step 3 ethics flavor:

Transitions of care — the highest-risk window:

Driving and occupation reporting:

Advance care planning: post-MI and HF visits are appropriate moments for goals-of-care discussion, ICD deactivation conversations (especially in advanced HF, hospice), and DNR/DNI clarification. Avoid first raising deactivation only at end of life.

Patient safety in the rehab facility: AED availability, ACLS staff, emergency plan, fall prevention, infection control (shared equipment), correct patient identification at each session

Confidentiality: group sessions create incidental disclosure — discuss expectations

Billing integrity: CMS requires physician-supervised CR with specific staffing and documentation; fraudulent billing is a legal exposure

Step 3 management: A post-ICD patient asks when he can drive his delivery truck. Counsel: 6 months no private driving after secondary-prevention ICD and commercial driving permanently disqualified per most guidelines — document the discussion and notify employer per state law.

High-Yield Associations and Rapid-Fire Clinical Facts

Mortality benefit of CR: ~20–25% reduction in CV mortality, ~15–20% in all-cause mortality post-MI

Class I CR indications: MI, PCI, CABG, stable angina, valve repair/replacement (including TAVR), heart transplant, HFrEF with EF ≤35%, symptomatic PAD (SET)

CMS coverage: up to 36 sessions standard Phase II CR, up to 72 sessions ICR (Ornish, Pritikin, Benson-Henry), SET for PAD up to 36 sessions over 12 weeks

Karvonen formula: Target HR = [(HRmax – HRrest) × intensity %] + HRrest; CR target 40–80% HRR

Borg RPE 6–20 scale: target 11–14 ("light to somewhat hard")

MET equivalents: 1 MET = rest; 3–4 = walking; 4–5 = sexual activity, light gardening; 5–7 = brisk walking, golf; 7–10 = jogging, singles tennis

Sternal precautions: ~6–8 weeks; no lifting >5–10 lb, no pushing/pulling, no overhead

Resistance training start: 3 weeks post-MI/PCI, 5 weeks post-CABG, 6 weeks post-valve

Driving: 1 week PCI, 4 weeks CABG, 6 months post-ICD secondary prevention

Sexual activity: safe at 3–5 METs; no PDE5 with nitrates (24–48 h washout)

EF reassessment for ICD: 40 days post-MI (medical), 90 days post-revasc

Post-MI flu vaccine: Class I, annually

Depression post-MI: ~20%; doubles mortality; sertraline preferred SSRI

HFrEF four pillars: ARNI/ACEi/ARB, beta-blocker, MRA, SGLT2i

PAD SET: walk to claudication 3–4/4, rest, repeat, 30–60 min, 3×/week × 12 weeks

Peak VO2 <14: advanced HF / transplant trigger

VE/VCO2 >35: poor prognosis

Automatic referral: most effective intervention to raise CR enrollment

DAPT default post-ACS: 12 months

LDL goal post-ACS: <70 (consider <55 very high risk)

BP goal: <130/80 in ASCVD

Board pearl: When the stem mentions a recent MI/PCI/CABG/valve/HFrEF/PAD/transplant and asks for "best next step in prevention," the answer is almost always refer to cardiac rehabilitation.

Board Question Stem Patterns

— Answer: Refer to outpatient cardiac rehabilitation. Distractors: "lifestyle counseling alone," "follow-up in 3 months," "repeat angiography in 6 months."

— Answer: Offer home-based or hybrid CR with telehealth supervision — not "respect her decision" and not "insist on in-center."

— Answer: No private driving for 6 months; commercial driving permanently restricted.

— Answer: When 3–5 METs (2 flights of stairs) tolerated without symptoms; avoid PDE5i with nitrates.

— Answer: Refer to cardiac rehabilitation (CMS-covered for HFrEF since 2014).

— Answer: Supervised exercise therapy (SET), not immediate revascularization.

— Answer: Initiate sertraline and refer for CBT; continue CR.

— Answer: Pause upper-body resistance, urgent CT surgery evaluation for dehiscence/mediastinitis.

— Answer: Switch to alternate-day rosuvastatin or pitavastatin; add ezetimibe; consider PCSK9i if LDL still high.

— Answer: Initiate referral now with interpreter services and transportation assistance — never too late within the eligibility window.

Pattern 1 — The discharge planning vignette: 58-year-old man status post PCI for NSTEMI being discharged on aspirin, ticagrelor, atorvastatin 80, metoprolol succinate, lisinopril. What is the most appropriate next step?

Pattern 2 — The underreferred subgroup: 72-year-old woman 4 weeks post-CABG, declines CR because "I'm too old and it's far." Best response?

Pattern 3 — Driving/return-to-activity: Patient post-secondary-prevention ICD asks when he can drive.

Pattern 4 — Sexual activity counseling: Post-MI patient asks when resumption is safe.

Pattern 5 — HFrEF expansion: Patient with EF 30%, NYHA II, on optimized GDMT × 8 weeks.

Pattern 6 — PAD claudication: Patient with 1-block claudication, ABI 0.65, no rest pain.

Pattern 7 — Depression post-MI: PHQ-9 of 14 at 6-week follow-up.

Pattern 8 — Sternal complications: Post-CABG patient with sternal click, drainage at week 4.

Pattern 9 — Statin intolerance: Myalgia without CK rise on atorvastatin 80.

Pattern 10 — Equity: Spanish-speaking Medicaid patient never offered CR after MI.

Board pearl: When two answers seem equally reasonable, pick the one that expands access and operationalizes a system fix rather than placing the burden on the patient.

One-Line Recap

Cardiac rehabilitation is a Class I, CMS-covered, mortality-reducing secondary-prevention program that should be referred — preferably via automatic discharge order — for every eligible patient after MI, PCI, CABG, valve surgery/TAVR, heart transplant, HFrEF (EF ≤35%), stable angina, or symptomatic PAD, with home-based and hybrid options offered when in-center attendance is a barrier.

Eligibility checklist (memorize): MI, PCI, CABG, stable angina, valve repair/replacement (including TAVR), heart transplant, HFrEF ≤35% on GDMT, symptomatic PAD — all Class I, all CMS-covered, up to 36 sessions (72 for ICR)

The big numbers: ~20–25% CV mortality reduction; only ~25% of eligible patients referred; women, elderly, minorities, rural patients underreferred — automatic opt-out referral is the system fix

Exercise prescription: 40–80% HRR or Borg 11–14, ≥10 bpm below ischemic threshold, 3–5×/week, 20–60 min aerobic + resistance 2–3×/week starting 3 weeks post-MI/PCI or 5 weeks post-sternotomy; sexual activity safe at 3–5 METs; no PDE5 with nitrates

Counseling anchors: GDMT titration (statin to LDL <70, BP <130/80, A1c ~7%, four-pillar HFrEF therapy), tobacco cessation with varenicline, Mediterranean/DASH diet, annual influenza vaccine (Class I), depression screening with sertraline as preferred SSRI, ICD/driving rules (6 months post-secondary-prevention ICD), and EF reassessment at 40 days post-MI or 90 days post-revascularization for ICD eligibility

Final Board pearl: If the Step 3 stem describes any recent qualifying cardiac event and asks what to do next for prevention, "refer to cardiac rehabilitation" is almost certainly the right answer — and on CCS, place that order before discharge, not at follow-up.