# Duke treadmill score Duke treadmill score Status: LIVE Price: $0.005 USDC `GET /api/calc/duke_treadmill` HTML: https://magentlab.com/docs/duke-treadmill Markdown: https://magentlab.com/docs/duke-treadmill.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Compute the Mark 1991 Duke treadmill score from Bruce-protocol exercise duration in minutes, maximal net ST-segment deviation in millimetres, and angina index (0 none, 1 nonlimiting, 2 exercise-limiting), with the paper’s illustrative three-group cutoffs. ## When to use When an agent needs the published Mark 1991 Duke treadmill score and must not invent a catheterization order, diagnose coronary artery disease, prescribe a Bruce protocol, or read the ECG. ## When not to use - Not a medical device. magent does not diagnose coronary artery disease. - Not a catheterization order and not a Bruce-protocol prescription. - magent does not read the ECG. Maximal net ST-segment deviation is supplied by the caller in millimetres. - Bands are the Mark 1991 illustrative groups only: high if score < -10, moderate if -10 ≤ score ≤ 4, low if score ≥ 5. ## Formula ``` duke_treadmill_score = exercise_min - (5 * st_deviation_mm) - (4 * angina_index) ``` ## Citation [Prognostic value of a treadmill exercise score in outpatients with suspected coronary artery disease](https://doi.org/10.1056/NEJM199109193251204) Mark DB, Shaw L, Harrell FE Jr, Hlatky MA, Lee KL, Bengtson JR, McCants CB, Califf RM, Pryor DB N Engl J Med. 1991;325(12):849-853 DOI: [10.1056/NEJM199109193251204](https://doi.org/10.1056/NEJM199109193251204) ## Worked example ### 10 min, 1 mm ST, no angina Given: `angina_index=0, exercise_min=10, st_deviation_mm=1` 1. duke_treadmill_score = 10 − (5 × 1) − (4 × 0) = 5.0 2. score ≥ 5 → low ### 5 min, 2 mm ST, nonlimiting angina Given: `angina_index=1, exercise_min=5, st_deviation_mm=2` 1. duke_treadmill_score = 5 − (5 × 2) − (4 × 1) = −9.0 2. −10 ≤ −9.0 ≤ 4 → moderate ### 3 min, 2 mm ST, exercise-limiting angina Given: `angina_index=2, exercise_min=3, st_deviation_mm=2` 1. duke_treadmill_score = 3 − (5 × 2) − (4 × 2) = −15.0 2. −15.0 < −10 → high ## Also searched as - Duke treadmill score - DTS - Mark treadmill score - Bruce protocol treadmill score - exercise treadmill score - Duke exercise score - ST deviation treadmill score ## Parameters - `exercise_min` (number, required): Bruce-protocol exercise duration in minutes (number 0-21). Mark 1991. Not a Bruce-protocol prescription. - `st_deviation_mm` (number, required): Maximal net ST-segment deviation during or after exercise in millimetres (number 0-10). Mark 1991. magent does not read the ECG. - `angina_index` (integer, required): Mark 1991 angina index: 0 no angina during exercise, 1 nonlimiting angina, 2 exercise-limiting angina. Integer 0, 1, or 2. ## Bulk (POST) POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement. Method: `POST /api/calc/duke_treadmill` Max items: 25 Price: unit_amount + extra_item_amount * (n - 1) (unit 5000 atomic, extra 2000 atomic) Status: PREVIEW - 1 to 25 items. Each item uses the same keys as the GET query parameters. - POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows. - The first invalid item fails the whole request (index in the 400 JSON). You are not charged. - HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row. - Catalog misses (empty matches, found=false) stay paid 200s inside that slot. - x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items. Example request: ```json { "items": [ { "angina_index": "0", "exercise_min": "10", "st_deviation_mm": "1" }, { "angina_index": "0", "exercise_min": "10", "st_deviation_mm": "1" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/duke-treadmill Example 200: ```json { "count": 2, "path": "/api/calc/duke_treadmill", "items": [ { "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.", "citation": { "authors": "Mark DB, Shaw L, Harrell FE Jr, Hlatky MA, Lee KL, Bengtson JR, McCants CB, Califf RM, Pryor DB", "doi": "10.1056/NEJM199109193251204", "id": "mark-1991", "pmid": "1875969", "source": "N Engl J Med. 1991;325(12):849-853", "title": "Prognostic value of a treadmill exercise score in outpatients with suspected coronary artery disease" }, "formula": "duke_treadmill", "formula_expression": "duke_treadmill_score = exercise_min - (5 * st_deviation_mm) - (4 * angina_index)", "angina_index": 0, "duke_band": "low", "duke_treadmill_score": 5.0, "exercise_min": 10.0, "st_deviation_mm": 1.0 }, { "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.", "citation": { "authors": "Mark DB, Shaw L, Harrell FE Jr, Hlatky MA, Lee KL, Bengtson JR, McCants CB, Califf RM, Pryor DB", "doi": "10.1056/NEJM199109193251204", "id": "mark-1991", "pmid": "1875969", "source": "N Engl J Med. 1991;325(12):849-853", "title": "Prognostic value of a treadmill exercise score in outpatients with suspected coronary artery disease" }, "formula": "duke_treadmill", "formula_expression": "duke_treadmill_score = exercise_min - (5 * st_deviation_mm) - (4 * angina_index)", "angina_index": 0, "duke_band": "low", "duke_treadmill_score": 5.0, "exercise_min": 10.0, "st_deviation_mm": 1.0 } ] } ``` ## Response fields - `formula` (string): duke_treadmill - `formula_expression` (string): Exact expression used - `exercise_min` (number): Bruce-protocol exercise duration used, minutes - `st_deviation_mm` (number): Maximal net ST-segment deviation used, millimetres - `angina_index` (integer): Angina index used: 0 none, 1 nonlimiting, 2 exercise-limiting - `duke_treadmill_score` (number): Mark 1991 Duke treadmill score, 1 decimal - `duke_band` (string): Mark 1991 illustrative groups: high (score < -10), moderate (-10 ≤ score ≤ 4), low (score ≥ 5). Not a catheterization order and not a CAD diagnosis. - `citation` (object): Mark 1991 NEJM citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.", "citation": { "authors": "Mark DB, Shaw L, Harrell FE Jr, Hlatky MA, Lee KL, Bengtson JR, McCants CB, Califf RM, Pryor DB", "doi": "10.1056/NEJM199109193251204", "id": "mark-1991", "pmid": "1875969", "source": "N Engl J Med. 1991;325(12):849-853", "title": "Prognostic value of a treadmill exercise score in outpatients with suspected coronary artery disease" }, "formula": "duke_treadmill", "formula_expression": "duke_treadmill_score = exercise_min - (5 * st_deviation_mm) - (4 * angina_index)", "angina_index": 0, "duke_band": "low", "duke_treadmill_score": 5.0, "exercise_min": 10.0, "st_deviation_mm": 1.0 } ``` ## Errors - HTTP 400 `invalid_exercise_min`: exercise_min must be a number from 0 to 21 (Mark 1991 Bruce protocol minutes). Returned before settlement; you are not charged. - HTTP 400 `invalid_st_deviation_mm`: st_deviation_mm must be a number from 0 to 10 (Mark 1991 maximal ST deviation in millimetres). Returned before settlement; you are not charged. - HTTP 400 `invalid_angina_index`: angina_index must be 0 (none), 1 (nonlimiting), or 2 (exercise-limiting) (Mark 1991). Returned before settlement; you are not charged. - HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged. - HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged. - HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged. Shared HTTP 402 and 503: https://magentlab.com/docs/payments ## Related tools - [HEART score](https://magentlab.com/docs/heart) — Compute the HEART score as age points plus caller-assigned history, ECG, risk factors, and troponin (each 0-2). - [TIMI risk score for STEMI](https://magentlab.com/docs/timi-stemi) — Compute the TIMI risk score for ST-elevation myocardial infarction from published bedside factors at presentation. - [EDACS](https://magentlab.com/docs/edacs) — Compute the Than 2014 Emergency Department Assessment of Chest pain Score from age, sex, and caller-assigned flags. ## Payment Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. - GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall). - HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote. - Sign accepts[0] (exact, EIP-3009) with validBefore = now + maxTimeoutSeconds (600 seconds), or accepts[1] (batch-settlement deposit/voucher) on product GET. Ping and POST {items} stay exact. Magent retries transient facilitator 429/5xx before answering. - Retry the same URL with PAYMENT-SIGNATURE (base64 JSON of accepted and payload). Magent attaches canonical extensions.bazaar on CDP verify/settle; echoing 402 bazaar is optional. - Success is HTTP 200 JSON plus PAYMENT-RESPONSE. exact settles before the tool. batch-settlement verifies (and deposit-settles) before the tool and commits the charge after HTTP 2xx. HTTP 503: retry the same PAYMENT-SIGNATURE. Mint a new exact nonce only after a new HTTP 402. - offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront. - offered `batch-settlement` on eip155:8453: Payment-channel vouchers claimed later in batches. Exact stays accepts[0]. Same-path POST {items} is still exact. extra.assetTransferMethod=eip3009 extra.paymentFlow=authorization. - not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search. Same-path POST {items} is still scheme exact: one EIP-3009 authorization for GET unit plus $0.002 per extra item. That is not x402 batch-settlement (payment channels / vouchers). Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments Stdio MCP (one process per host): https://magentlab.com/docs/mcp ## Guarantees - HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. - exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE. - HTTP 402 is unpaid only. Do not sign a second authorization because of a 503. - Execution is timeout-bounded and concurrency-capped. - Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.