Patient Assessment and Risk Stratification
Purpose
Risk stratification matches patient acuity to the level of monitoring and supervision a program can safely deliver. The assessment includes history, physical examination, resting 12-lead ECG, functional capacity, ventricular function, evidence of ischemia or arrhythmia, hemodynamic response to exercise, comorbidities, and medications.
Risk categories
Broadly, low-risk patients have preserved ventricular function, functional capacity at higher levels (roughly 7 METs or more), no exercise-induced ischemia, no complex arrhythmias, and normal hemodynamics. Higher-risk patients have reduced functional capacity (roughly below 5 METs), ejection fraction below 40%, exercise-induced ischemia or complex arrhythmias, heart failure, or abnormal blood pressure and heart rate responses. Stratification is dynamic and should be repeated as clinical status changes.
Contraindications
Absolute contraindications to exercise training include unstable angina, uncompensated heart failure, uncontrolled or symptomatic arrhythmias, severe symptomatic aortic stenosis, acute pulmonary embolism, acute myocarditis or pericarditis, acute systemic illness, and severe uncontrolled hypertension. Relative contraindications include moderate valvular disease, electrolyte abnormalities, uncontrolled diabetes, and high-grade atrioventricular block. Traps often hinge on absolute versus relative status, or on a stem describing a decompensated patient who should simply be deferred.
Worked example
A patient referred after an uncomplicated myocardial infarction arrives with resting dyspnea, rales, and a heart rate of 120 in atrial fibrillation. Rule of thumb: instability today overrides any referral urgency, so defer exercise, notify the referring clinician, and reassess when stable.
Exam traps
Remember that an uncomplicated, stable post-event patient can generally begin early; the discriminating feature in questions is stability, not the historical event itself.