# CHA2DS2-VASc

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/cha2ds2_vasc`
HTML: https://magentlab.com/docs/cha2ds2-vasc
Markdown: https://magentlab.com/docs/cha2ds2-vasc.md

Not a medical device. Not a diagnosis, dose, or listing recommendation.

## What it computes

Compute the CHA2DS2-VASc stroke-risk score from discrete clinical flags.

## When to use

When an agent needs AF stroke-risk arithmetic and must not invent the point total from prose.

## When not to use

- Not a diagnosis and not a treatment or anticoagulation recommendation.
- Flags are caller-supplied booleans. magent does not infer CHF or vascular disease from text.

## Formula

```
CHA2DS2-VASc = CHF 1 + HTN 1 + Age≥75 2 (or 65-74 1) + diabetes 1 + stroke/TIA 2 + vascular 1 + female 1; max 9
```

## Citation

Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the euro heart survey on atrial fibrillation
Lip GYH, Nieuwlaat R, Pisters R, Lane DA, Crijns HJ
Chest. 2010;137(2):263-272
DOI: [10.1378/chest.09-1584](https://doi.org/10.1378/chest.09-1584)

## Worked example

### Age 78 female, HTN + diabetes

Given: `age=78, chf=false, diabetes=true, hypertension=true, sex=female, stroke_tia=false, vascular_disease=false`

1. Age ≥75 → 2; female → 1; hypertension → 1; diabetes → 1
2. Score = 5


## Parameters

- `age` (integer, required): Age in years (18-120). ≥75 scores 2; 65-74 scores 1.
- `sex` (string, required): female scores 1 (Sc); male scores 0.
- `chf` (boolean, required): Congestive heart failure or LV dysfunction. true or false.
- `hypertension` (boolean, required): Hypertension history. true or false.
- `diabetes` (boolean, required): Diabetes mellitus. true or false.
- `stroke_tia` (boolean, required): Prior stroke, TIA, or thromboembolism. true or false (2 points).
- `vascular_disease` (boolean, required): Prior MI, peripheral artery disease, or aortic plaque. true or false.

## Bulk (POST)

POST the same path with a JSON items array. Price is n times the GET unit. Invalid items return HTTP 400 before settlement.

Method: `POST /api/calc/cha2ds2_vasc`
Max items: 25
Price: unit_amount * n (unit 5000 atomic)
Status: PREVIEW

- 1 to 25 items. Each item uses the same keys as the GET query parameters.
- 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": "78",
      "chf": "false",
      "diabetes": "true",
      "hypertension": "true",
      "sex": "female",
      "stroke_tia": "false",
      "vascular_disease": "false"
    },
    {
      "age": "78",
      "chf": "false",
      "diabetes": "true",
      "hypertension": "true",
      "sex": "female",
      "stroke_tia": "false",
      "vascular_disease": "false"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/cha2ds2-vasc

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/cha2ds2_vasc",
  "items": [
    {
      "components": [
        {
          "factor": "congestive_heart_failure",
          "points": 0,
          "present": false
        },
        {
          "factor": "hypertension",
          "points": 1,
          "present": true
        },
        {
          "value": 78,
          "factor": "age",
          "points": 2,
          "present": true
        },
        {
          "factor": "diabetes",
          "points": 1,
          "present": true
        },
        {
          "factor": "stroke_tia_thromboembolism",
          "points": 0,
          "present": false
        },
        {
          "factor": "vascular_disease",
          "points": 0,
          "present": false
        },
        {
          "factor": "sex_female",
          "points": 1,
          "present": true
        }
      ],
      "disclaimer": "Not a medical device. Deterministic published-formula or coded-ontology output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "age_years": 78,
      "citation": {
        "authors": "Lip GYH, Nieuwlaat R, Pisters R, Lane DA, Crijns HJ",
        "doi": "10.1378/chest.09-1584",
        "id": "lip-2010",
        "source": "Chest. 2010;137(2):263-272",
        "title": "Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the euro heart survey on atrial fibrillation"
      },
      "formula": "cha2ds2_vasc",
      "formula_expression": "CHA2DS2-VASc = CHF 1 + HTN 1 + Age≥75 2 (or 65-74 1) + diabetes 1 + stroke/TIA 2 + vascular 1 + female 1; max 9",
      "max_score": 9,
      "score": 5,
      "sex": "female"
    },
    {
      "components": [
        {
          "factor": "congestive_heart_failure",
          "points": 0,
          "present": false
        },
        {
          "factor": "hypertension",
          "points": 1,
          "present": true
        },
        {
          "value": 78,
          "factor": "age",
          "points": 2,
          "present": true
        },
        {
          "factor": "diabetes",
          "points": 1,
          "present": true
        },
        {
          "factor": "stroke_tia_thromboembolism",
          "points": 0,
          "present": false
        },
        {
          "factor": "vascular_disease",
          "points": 0,
          "present": false
        },
        {
          "factor": "sex_female",
          "points": 1,
          "present": true
        }
      ],
      "disclaimer": "Not a medical device. Deterministic published-formula or coded-ontology output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "age_years": 78,
      "citation": {
        "authors": "Lip GYH, Nieuwlaat R, Pisters R, Lane DA, Crijns HJ",
        "doi": "10.1378/chest.09-1584",
        "id": "lip-2010",
        "source": "Chest. 2010;137(2):263-272",
        "title": "Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the euro heart survey on atrial fibrillation"
      },
      "formula": "cha2ds2_vasc",
      "formula_expression": "CHA2DS2-VASc = CHF 1 + HTN 1 + Age≥75 2 (or 65-74 1) + diabetes 1 + stroke/TIA 2 + vascular 1 + female 1; max 9",
      "max_score": 9,
      "score": 5,
      "sex": "female"
    }
  ]
}
```

## Response fields

- `formula` (string): cha2ds2_vasc
- `formula_expression` (string): Exact expression used
- `score` (integer): Total points 0-9
- `max_score` (integer): Always 9
- `sex` (string): female or male
- `age_years` (integer): Age used for A2/A scoring
- `components` (array): Per-factor points
- `citation` (object): Chest 2010 citation
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "components": [
    {
      "factor": "congestive_heart_failure",
      "points": 0,
      "present": false
    },
    {
      "factor": "hypertension",
      "points": 1,
      "present": true
    },
    {
      "value": 78,
      "factor": "age",
      "points": 2,
      "present": true
    },
    {
      "factor": "diabetes",
      "points": 1,
      "present": true
    },
    {
      "factor": "stroke_tia_thromboembolism",
      "points": 0,
      "present": false
    },
    {
      "factor": "vascular_disease",
      "points": 0,
      "present": false
    },
    {
      "factor": "sex_female",
      "points": 1,
      "present": true
    }
  ],
  "disclaimer": "Not a medical device. Deterministic published-formula or coded-ontology output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
  "age_years": 78,
  "citation": {
    "authors": "Lip GYH, Nieuwlaat R, Pisters R, Lane DA, Crijns HJ",
    "doi": "10.1378/chest.09-1584",
    "id": "lip-2010",
    "source": "Chest. 2010;137(2):263-272",
    "title": "Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the euro heart survey on atrial fibrillation"
  },
  "formula": "cha2ds2_vasc",
  "formula_expression": "CHA2DS2-VASc = CHF 1 + HTN 1 + Age≥75 2 (or 65-74 1) + diabetes 1 + stroke/TIA 2 + vascular 1 + female 1; max 9",
  "max_score": 9,
  "score": 5,
  "sex": "female"
}
```

## 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_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.
- HTTP 402 `payment_required`: Missing or invalid PAYMENT-SIGNATURE; decode the PAYMENT-REQUIRED header
- HTTP 409 `payment_in_progress`: The same authorization nonce is already being settled; retry shortly
- HTTP 429 `rate_limited`: Too many requests from this client
- HTTP 503 `settlement_uncertain`: Settlement is unconfirmed; retry with the same PAYMENT-SIGNATURE
- HTTP 503 `facilitator_unavailable`: Payment facilitator unavailable
- HTTP 503 `facilitator_misconfigured`: Payment facilitator is not configured
- HTTP 503 `facilitator_unauthorized`: Payment facilitator rejected credentials
- HTTP 503 `ledger_unavailable`: Payment ledger unavailable
- HTTP 503 `payment_unavailable`: Payment processing unavailable

## Related tools

- [HAS-BLED](https://magentlab.com/docs/has-bled) — Compute the HAS-BLED bleeding-risk score from discrete clinical flags.

## Also searched as

- CHA2DS2-VASc
- CHADS2-VASc
- AF stroke score
- Lip 2010 score

## Payment

Required query parameters must be present and valid. 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.

## Guarantees

- Invalid query parameters return HTTP 400 before settlement. You are not charged.
- Settlement finishes before the tool executes. Uncertain settlement fails closed (HTTP 503).
- Execution is timeout-bounded and concurrency-capped.
- Calculator inputs are not persisted. Request logs store path without query.