ADD-RS calculation
Advanced USMLE-Style MCQs — ADD-RS & D-dimer
Q1 A 58-year-old man presents with sudden severe chest pain radiating to his back. Blood pressure: 170/95 mmHg in the right arm and 120/70 mmHg in the left arm. A new diastolic murmur is noted. How many ADD-RS categories are positive?
Answer: C. High-risk pain features (abrupt, severe) and high-risk exam features (pulse/BP differential, new aortic regurgitation murmur) → 2 categories.
Q2 A 45-year-old woman with Marfan syndrome complains of sudden chest pain. ADD-RS category count?
Answer: B. Marfan syndrome is a high-risk condition → 1 category. Additional pain/exam features would increase the count.
Q3 A patient presents with sudden tearing chest pain. ADD-RS = 0 and D-dimer = 400 ng/mL. Most appropriate next step?
Answer: A. Low-risk ADD-RS (0) with negative D-dimer allows many protocols to safely rule out AAS without immediate imaging.
Q4 A 62-year-old presents with syncope, focal right arm weakness, and severe back pain. Which ADD-RS category is triggered by the neurological deficit?
Answer: B. Focal neurologic deficit with pain is a high-risk exam feature, reflecting possible branch vessel involvement from dissection.
Q5 A 70-year-old woman with hypotension and pulseless lower extremities has abrupt chest pain. ADD-RS category count?
Answer: C. Multiple exam features (shock, pulse deficits) and high-risk pain suggest ≥2–3 categories → high pretest probability.
Q6 A 50-year-old with chest pain 36 hours ago has D-dimer = 200 ng/mL. How should this be interpreted?
Answer: B. Sensitivity of D-dimer drops >24h from onset; negative result is less reassuring → imaging may still be warranted.
Q7 Which imaging modality is first-line for hemodynamically stable suspected AAS?
Answer: B. CTA is fast, widely available, and accurate for AAS evaluation in stable patients.
Q8 A 66-year-old with ADD-RS = 1, D-dimer = 480 ng/mL. Best next step?
Answer: B. Low-intermediate risk with negative D-dimer may permit safe exclusion, but always integrate clinical judgment and institutional protocol.
Q9 Which ADD-RS component does a history of recent aortic surgery fall under?
Answer: B. Recent aortic manipulation (surgery or catheterization) is a high-risk condition.
Q10 A patient has abrupt chest pain, ADD-RS = 0, D-dimer = 520 ng/mL. Which is correct?
Answer: B. D-dimer above cutoff (>500 ng/mL) in any patient, even ADD-RS 0, warrants imaging to exclude AAS.
Q11 Which high-risk exam feature is classically included in ADD-RS?
Answer: B. Pulse deficit or systolic BP difference is a hallmark exam finding indicating possible dissection affecting branch vessels.
Q12 D-dimer sensitivity for AAS approaches which of the following within 24 hours?
Answer: B. D-dimer is highly sensitive (>95%) within the first 24 hours of symptom onset.
Q13 A 59-year-old with ADD-RS = 2 has negative D-dimer. Most appropriate action?
Answer: B. High pretest probability (ADD-RS ≥2) → imaging required regardless of D-dimer to avoid missing a life-threatening dissection.
Q14 Which ADD-RS pain feature is considered high-risk?
Answer: B. Abrupt onset, severe intensity, tearing/ripping character → high-risk pain features in ADD-RS.
Q15 A 54-year-old with chest pain and ADD-RS = 1. D-dimer = 700 ng/mL. What is the best next step?
Answer: B. Positive D-dimer in low-intermediate risk patient warrants imaging to rule out AAS.
Q16 Which statement is TRUE regarding ADD-RS + D-dimer strategy?
Answer: B. The strategy safely decreases imaging in low-risk patients, but clinical judgment remains essential.
Q17 A patient presents with back pain and ADD-RS = 0, D-dimer <500 ng/mL. According to ADvISED protocol, what is next?
Answer: A. Low-risk patient with negative D-dimer can often be observed safely with close clinical follow-up.
Q18 Which high-risk condition is included in ADD-RS?
Answer: B. Known connective tissue disorder → high-risk condition in ADD-RS.
Q19 Which scenario would most likely require imaging despite negative D-dimer?
Answer: B. High ADD-RS (≥2) patients require imaging even if D-dimer is negative.
Q20 Key limitation of D-dimer in ruling out AAS?
Answer: A. D-dimer is most sensitive early; delayed presentation reduces its reliability.
ADD-RS Calculation — Overview
ADD-RS assigns 1 point per category if any high-risk feature is present. Total score ranges from 0 to 3.
| Category | High-Risk Feature | Point |
|---|---|---|
| High-risk conditions | Known aortic disease (Marfan, Ehlers-Danlos, bicuspid aortic valve), family history of aortic dissection, recent aortic manipulation (surgery or catheterization) | 1 if any present |
| High-risk pain features | Abrupt onset, severe intensity, tearing/ripping, chest/back/abdominal pain | 1 if any present |
| High-risk exam features | Pulse deficit or systolic BP difference, focal neurologic deficit, new aortic murmur, hypotension/shock | 1 if any present |
Step 1: Assess each category:
- If any feature present → assign 1 point for that category.
- If none present → 0 for that category.
Step 2: Add points from all three categories:
- ADD-RS = sum of points (0–3)
ADD-RS Score Interpretation
| Score | Risk | Clinical Use |
|---|---|---|
| 0 | Low | Can combine with negative D-dimer to safely rule out AAS |
| 1 | Intermediate | Consider D-dimer and clinical judgment; may rule out if D-dimer negative |
| 2–3 | High | Imaging strongly indicated regardless of D-dimer |
Example Case 1 — Stepwise ADD-RS Calculation
Patient: 58-year-old man with:
- Sudden severe chest pain radiating to back
- BP: 170/95 mmHg (right) vs 120/70 mmHg (left)
- New diastolic murmur
Step 1: High-risk conditions
- No history of Marfan, prior aortic surgery → 0 points
Step 2: High-risk pain
- Abrupt, severe, back-radiating chest pain → 1 point
Step 3: High-risk exam
- BP differential and new diastolic murmur → 1 point
ADD-RS Total = 0 + 1 + 1 = 2 → High pretest probability
Next step: Immediate imaging (CTA) recommended, even if D-dimer is normal.
Example Case 2 — Low-Risk Patient
Patient: 45-year-old woman with:
- Marfan syndrome
- Mild chest discomfort, gradual onset
- Normal vitals, no pulse deficit
Step 1: High-risk conditions
- Marfan syndrome → 1 point
Step 2: High-risk pain
- Gradual, mild pain → 0 points
Step 3: High-risk exam
- Normal BP, no pulse deficit → 0 points
ADD-RS Total = 1 → Low-intermediate risk
Next step: D-dimer can be used to rule out AAS if negative; otherwise imaging as clinically indicated.
