# CAR-OLT 1-year CVD risk after liver transplant CAR-OLT Status: LIVE Price: $0.005 USDC `GET /api/calc/car_olt` HTML: https://magentlab.com/docs/car-olt Markdown: https://magentlab.com/docs/car-olt.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Sum VanWagner 2017 Table 3 CAR-OLT integer points and return the Table 4 1-year predicted CVD complication percent. ## When to use When an agent has caller-assigned age, sex, race as used in VanWagner 2017, work, education, and comorbidity flags and needs the published CAR-OLT total and Table 4 predicted percent, not a listing decision or RCRI. ## When not to use - Not a medical device. Not a transplant listing, operative clearance, or cardiac-testing order. - race_group is caller-assigned as used in VanWagner 2017 Table 3 (white, black, other). magent does not assign race. Hispanic and Asian map to other (referent) in that model. - Table 4 color/risk labels are arbitrary; magent reports the integer score and the table 1-year predicted percent only. - Table 4 has no row for total score 9; that score uses the <9 predicted <5% row. - Scores >40 map to Table 4 45% (the paper prints 45+). Unclamped except as Table 3. - magent does not examine the patient, assign work or education, or observe a ventilator. Flags are caller-assigned. ## Formula ``` CAR-OLT = age (<45 0, 45-49 -6, 50-54 -4, 55-59 2, 60-64 5, >=65 8) + sex (male 0, female 1) + race_group (white 7, black 10, other 0) + not working 10 + education (high_school_or_unknown 5, college 0) + atrial_fibrillation 25 + ventilator_respiratory_failure 13 + pulmonary_hypertension 9 + no HCC 6 + hypertension 4 + diabetes 4 + heart_failure 7; VanWagner 2017 Table 3; Table 4 1-year predicted CVD %; unclamped; score 9 uses the <9 row ``` ## Citation [A point-based prediction model for cardiovascular risk in orthotopic liver transplantation: The CAR-OLT score](https://doi.org/10.1002/hep.29329) VanWagner LB, Ning H, Whitsett M, Levitsky J, Uttal S, Wilkins JT, Abecassis MM, Ladner DP, Skaro AI, Lloyd-Jones DM Hepatology. 2017;66(6):1968-1979 DOI: [10.1002/hep.29329](https://doi.org/10.1002/hep.29329) ## Worked example ### Referent first-OLT candidate (score 0) Given: `age=40, atrial_fibrillation=false, diabetes=false, education=college, hcc=true, heart_failure=false, hypertension=false, pulmonary_hypertension=false, race_group=other, sex=male, ventilator_respiratory_failure=false, working_for_income=true` 1. Age 40 <45 → 0; male → 0; race_group other → 0; working_for_income true → 0; education college → 0 2. No AF, ventilator, pulmonary hypertension, hypertension, diabetes, or heart failure; HCC true → 0 3. Score = 0; Table 4 predicted 1-year CVD complication <5% ## Also searched as - CAR-OLT score - CAR OLT - VanWagner 2017 CAR-OLT - cardiovascular risk orthotopic liver transplantation - liver transplant CVD score - 1-year CVD after OLT - OLT cardiovascular complication score - VanWagner liver transplant cardiac risk ## Parameters - `age` (integer, required): Age in years (integer 18-120). VanWagner 2017 Table 3: <45 scores 0; 45-49 scores -6; 50-54 scores -4; 55-59 scores 2; 60-64 scores 5; ≥65 scores 8. Derivation was first OLT ages 18-75; ≥65 is the top Table 3 band. - `sex` (string, required): Caller-assigned sex (VanWagner 2017 Table 3). male scores 0 (referent); female scores 1. magent does not assign sex. - `race_group` (string, required): Caller-assigned race as used in VanWagner 2017 Table 3. white scores 7; black scores 10; other scores 0 (referent). Hispanic and Asian map to other in this model. magent does not assign race. - `working_for_income` (boolean, required): Working for income at transplant (VanWagner 2017 Table 3). true scores 0 (referent); false scores 10. magent does not assign employment. - `education` (string, required): Caller-assigned education (VanWagner 2017 Table 3). college scores 0 (College+ referent); high_school_or_unknown scores 5. magent does not assign education. - `atrial_fibrillation` (boolean, required): History of atrial fibrillation prior to transplant (VanWagner 2017 Table 3). true scores 25. magent does not read an ECG. - `ventilator_respiratory_failure` (boolean, required): Respiratory failure on a ventilator at transplant (VanWagner 2017 Table 3). true scores 13. magent does not observe ventilation. - `pulmonary_hypertension` (boolean, required): History of pulmonary hypertension prior to transplant (VanWagner 2017 Table 3). true scores 9. magent does not perform right-heart catheterization. - `hcc` (boolean, required): History of hepatocellular carcinoma (VanWagner 2017 Table 3). true scores 0 (referent); false scores 6. No HCC is the higher-risk term. magent does not diagnose HCC. - `hypertension` (boolean, required): History of systemic hypertension prior to transplant (VanWagner 2017 Table 3). true scores 4. magent does not measure blood pressure. - `diabetes` (boolean, required): History of diabetes prior to transplant (VanWagner 2017 Table 3). true scores 4. magent does not assay glucose. - `heart_failure` (boolean, required): History of heart failure prior to transplant (VanWagner 2017 Table 3). true scores 7. magent does not diagnose heart failure. ## 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/car_olt` 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": [ { "age": "40", "atrial_fibrillation": "false", "diabetes": "false", "education": "college", "hcc": "true", "heart_failure": "false", "hypertension": "false", "pulmonary_hypertension": "false", "race_group": "other", "sex": "male", "ventilator_respiratory_failure": "false", "working_for_income": "true" }, { "age": "40", "atrial_fibrillation": "false", "diabetes": "false", "education": "college", "hcc": "true", "heart_failure": "false", "hypertension": "false", "pulmonary_hypertension": "false", "race_group": "other", "sex": "male", "ventilator_respiratory_failure": "false", "working_for_income": "true" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/car-olt Example 200: ```json { "count": 2, "path": "/api/calc/car_olt", "items": [ { "components": [ { "value": 40, "factor": "age", "points": 0, "present": false }, { "value": "male", "factor": "sex", "points": 0, "present": false }, { "value": "other", "factor": "race_group", "points": 0, "present": false }, { "value": true, "factor": "working_for_income", "points": 0, "present": false }, { "value": "college", "factor": "education", "points": 0, "present": false }, { "factor": "atrial_fibrillation", "points": 0, "present": false }, { "factor": "ventilator_respiratory_failure", "points": 0, "present": false }, { "factor": "pulmonary_hypertension", "points": 0, "present": false }, { "value": true, "factor": "hcc", "points": 0, "present": false }, { "factor": "hypertension", "points": 0, "present": false }, { "factor": "diabetes", "points": 0, "present": false }, { "factor": "heart_failure", "points": 0, "present": false } ], "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": "VanWagner LB, Ning H, Whitsett M, Levitsky J, Uttal S, Wilkins JT, Abecassis MM, Ladner DP, Skaro AI, Lloyd-Jones DM", "doi": "10.1002/hep.29329", "id": "vanwagner-2017-car-olt", "pmid": "28703417", "source": "Hepatology. 2017;66(6):1968-1979", "title": "A point-based prediction model for cardiovascular risk in orthotopic liver transplantation: The CAR-OLT score" }, "formula": "car_olt", "formula_expression": "CAR-OLT = age (<45 0, 45-49 -6, 50-54 -4, 55-59 2, 60-64 5, >=65 8) + sex (male 0, female 1) + race_group (white 7, black 10, other 0) + not working 10 + education (high_school_or_unknown 5, college 0) + atrial_fibrillation 25 + ventilator_respiratory_failure 13 + pulmonary_hypertension 9 + no HCC 6 + hypertension 4 + diabetes 4 + heart_failure 7; VanWagner 2017 Table 3; Table 4 1-year predicted CVD %; unclamped; score 9 uses the <9 row", "max_score": 102, "score": 0, "age_years": 40, "sex": "male", "education": "college", "predicted_1yr_cvd_percent": "<5%", "race_group": "other", "working_for_income": true }, { "components": [ { "value": 40, "factor": "age", "points": 0, "present": false }, { "value": "male", "factor": "sex", "points": 0, "present": false }, { "value": "other", "factor": "race_group", "points": 0, "present": false }, { "value": true, "factor": "working_for_income", "points": 0, "present": false }, { "value": "college", "factor": "education", "points": 0, "present": false }, { "factor": "atrial_fibrillation", "points": 0, "present": false }, { "factor": "ventilator_respiratory_failure", "points": 0, "present": false }, { "factor": "pulmonary_hypertension", "points": 0, "present": false }, { "value": true, "factor": "hcc", "points": 0, "present": false }, { "factor": "hypertension", "points": 0, "present": false }, { "factor": "diabetes", "points": 0, "present": false }, { "factor": "heart_failure", "points": 0, "present": false } ], "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": "VanWagner LB, Ning H, Whitsett M, Levitsky J, Uttal S, Wilkins JT, Abecassis MM, Ladner DP, Skaro AI, Lloyd-Jones DM", "doi": "10.1002/hep.29329", "id": "vanwagner-2017-car-olt", "pmid": "28703417", "source": "Hepatology. 2017;66(6):1968-1979", "title": "A point-based prediction model for cardiovascular risk in orthotopic liver transplantation: The CAR-OLT score" }, "formula": "car_olt", "formula_expression": "CAR-OLT = age (<45 0, 45-49 -6, 50-54 -4, 55-59 2, 60-64 5, >=65 8) + sex (male 0, female 1) + race_group (white 7, black 10, other 0) + not working 10 + education (high_school_or_unknown 5, college 0) + atrial_fibrillation 25 + ventilator_respiratory_failure 13 + pulmonary_hypertension 9 + no HCC 6 + hypertension 4 + diabetes 4 + heart_failure 7; VanWagner 2017 Table 3; Table 4 1-year predicted CVD %; unclamped; score 9 uses the <9 row", "max_score": 102, "score": 0, "age_years": 40, "sex": "male", "education": "college", "predicted_1yr_cvd_percent": "<5%", "race_group": "other", "working_for_income": true } ] } ``` ## Response fields - `formula` (string): car_olt - `formula_expression` (string): VanWagner 2017 Table 3 expression - `score` (integer): Unclamped Table 3 integer sum. May be negative (age 45-49 is -6). Theoretical max 102. - `max_score` (integer): 102 (sum of Table 3 maxima) - `predicted_1yr_cvd_percent` (string): VanWagner 2017 Table 4 1-year predicted CVD complication percent: <5%, 6%, 8%, 10%, 12%, 14%, 17%, 20%, 22%, 26%, 30%, 34%, 38%, 40%, 43%, or 45%. Score 9 uses the <9 row. Not a named low/moderate/high band. - `age_years` (integer): Age in years used for the age band - `sex` (string): female or male used - `race_group` (string): Caller-assigned white, black, or other used - `education` (string): Caller-assigned high_school_or_unknown or college used - `working_for_income` (boolean): Working-for-income flag used - `components` (array): Per-factor Table 3 points - `citation` (object): VanWagner 2017 Hepatology citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "components": [ { "value": 40, "factor": "age", "points": 0, "present": false }, { "value": "male", "factor": "sex", "points": 0, "present": false }, { "value": "other", "factor": "race_group", "points": 0, "present": false }, { "value": true, "factor": "working_for_income", "points": 0, "present": false }, { "value": "college", "factor": "education", "points": 0, "present": false }, { "factor": "atrial_fibrillation", "points": 0, "present": false }, { "factor": "ventilator_respiratory_failure", "points": 0, "present": false }, { "factor": "pulmonary_hypertension", "points": 0, "present": false }, { "value": true, "factor": "hcc", "points": 0, "present": false }, { "factor": "hypertension", "points": 0, "present": false }, { "factor": "diabetes", "points": 0, "present": false }, { "factor": "heart_failure", "points": 0, "present": false } ], "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": "VanWagner LB, Ning H, Whitsett M, Levitsky J, Uttal S, Wilkins JT, Abecassis MM, Ladner DP, Skaro AI, Lloyd-Jones DM", "doi": "10.1002/hep.29329", "id": "vanwagner-2017-car-olt", "pmid": "28703417", "source": "Hepatology. 2017;66(6):1968-1979", "title": "A point-based prediction model for cardiovascular risk in orthotopic liver transplantation: The CAR-OLT score" }, "formula": "car_olt", "formula_expression": "CAR-OLT = age (<45 0, 45-49 -6, 50-54 -4, 55-59 2, 60-64 5, >=65 8) + sex (male 0, female 1) + race_group (white 7, black 10, other 0) + not working 10 + education (high_school_or_unknown 5, college 0) + atrial_fibrillation 25 + ventilator_respiratory_failure 13 + pulmonary_hypertension 9 + no HCC 6 + hypertension 4 + diabetes 4 + heart_failure 7; VanWagner 2017 Table 3; Table 4 1-year predicted CVD %; unclamped; score 9 uses the <9 row", "max_score": 102, "score": 0, "age_years": 40, "sex": "male", "education": "college", "predicted_1yr_cvd_percent": "<5%", "race_group": "other", "working_for_income": true } ``` ## Errors - HTTP 400 `invalid_age`: age must be an integer from 18 to 120 Returned before settlement; you are not charged. - HTTP 400 `invalid_sex`: sex must be female or male Returned before settlement; you are not charged. - HTTP 400 `invalid_flag`: boolean clinical flags must be true or false Returned before settlement; you are not charged. - HTTP 400 `invalid_car_olt`: CAR-OLT inputs must match VanWagner 2017 Table 3 age group, sex, race, work, education, and comorbidity flags. 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 - [MELD](https://magentlab.com/docs/meld) — Compute the Kamath 2001 model for end-stage liver disease (MELD) integer from creatinine, bilirubin, INR, and cholestatic or alcoholic etiology. - [Child–Pugh](https://magentlab.com/docs/child-pugh) — Compute the Child–Turcotte–Pugh cirrhosis severity score from bilirubin, albumin, INR, encephalopathy, and ascites. - [UKELD](https://magentlab.com/docs/ukeld) — Compute the Barber 2011 United Kingdom end-stage liver disease (UKELD) integer from INR, creatinine, bilirubin, and sodium, with the UK elective-list 9% 1-year mortality threshold of 49. ## 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. HTTP 402 never includes the tool JSON. - 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.