Atrial fibrillation · LIVE

CHADS-65

Apply the CCS 2014 CHADS-65 algorithm and return oac, asa, or none from age and caller-assigned CHF, hypertension, diabetes, prior stroke/TIA, and vascular disease.

LIVE $0.005 USDC GET /api/calc/chads_65

Markdown: /docs/chads-65.md · Canonical: https://magentlab.com/docs/chads-65

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

What it computes

Apply the CCS 2014 CHADS-65 algorithm and return oac, asa, or none from age and caller-assigned CHF, hypertension, diabetes, prior stroke/TIA, and vascular disease.

When to use

When an agent needs the CCS 2014 CHADS-65 stroke-prevention algorithm for nonvalvular AF/AFL from caller-assigned age and flags, and must not use CHADS2, CHA2DS2-VASc, or HAS-BLED.

When not to use

Not a medical device. Not an anticoagulation order. magent does not examine the patient.
This is the Canadian CCS 2014 algorithm for nonvalvular AF/AFL stroke-prevention discussion. It is not CHADS2, not CHA2DS2-VASc, not HAS-BLED, and not a valve or AF diagnosis.
Age ≥75 is subsumed by age ≥65. There is no separate age≥75 input.
Flags are caller-supplied booleans. magent does not infer CHF, stroke, or vascular disease from text.

Formula

OAC if age ≥ 65 or CHF or hypertension or diabetes or prior stroke/TIA; else ASA if vascular disease (coronary, aortic, or peripheral arterial); else none (CCS 2014 CHADS-65)

Citation

Title: 2014 focused update of the Canadian Cardiovascular Society Guidelines for the management of atrial fibrillation
Authors: Verma A, Cairns JA, Mitchell LB, Macle L, Stiell IG, Gladstone D, McMurtry MS, Connolly S, Cox JL, Dorian P, Ivers N, Leblanc K, Nattel S, Healey JS
Source: Can J Cardiol. 2014;30(10):1114-1130
DOI: 10.1016/j.cjca.2014.08.001

Worked example

Age 70, all flags false

Given: age=70chf=falsediabetes=falsehypertension=falsestroke_tia=falsevascular_disease=false

Age 70 ≥ 65
recommendation is oac

Age 50 with vascular disease

Given: age=50chf=falsediabetes=falsehypertension=falsestroke_tia=falsevascular_disease=true

Age 50 is not ≥ 65; no CHF, hypertension, diabetes, or stroke/TIA
vascular_disease is true; recommendation is asa

Age 50, all flags false

Given: age=50chf=falsediabetes=falsehypertension=falsestroke_tia=falsevascular_disease=false

Age 50 is not ≥ 65; no CHADS2 factors and no vascular disease
recommendation is none

Age 50 with diabetes

Given: age=50chf=falsediabetes=truehypertension=falsestroke_tia=falsevascular_disease=false

Age 50 is not ≥ 65; diabetes is a CHADS2 factor other than age≥75
recommendation is oac

Also searched as

CHADS-65
CCS algorithm
CCS AF
CCS CHADS-65
CHADS65
Canadian AF guidelines
CCS atrial fibrillation
Verma 2014 AF

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/chads_65?age=70&chf=false&hypertension=false&diabetes=false&stroke_tia=false&vascular_disease=false

Full URL: https://api.magentlab.com/api/calc/chads_65?age=70&chf=false&hypertension=false&diabetes=false&stroke_tia=false&vascular_disease=false

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/chads_65?age=70&chf=false&hypertension=false&diabetes=false&stroke_tia=false&vascular_disease=false"

Parameters

Name	Type	Required	Description
`age`	integer	required	Age in years (18-120). ≥65 indicates oral anticoagulant (OAC). Age ≥75 is subsumed by ≥65; there is no separate age≥75 input. 64 does not indicate OAC on age alone.
`chf`	boolean	required	Congestive heart failure as assigned by the caller. true or false. Any true CHADS2 factor other than age≥75 (CHF, hypertension, diabetes, prior stroke/TIA) indicates OAC.
`hypertension`	boolean	required	Hypertension history as assigned by the caller. true or false. Indicates OAC when true.
`diabetes`	boolean	required	Diabetes mellitus as assigned by the caller. true or false. Indicates OAC when true.
`stroke_tia`	boolean	required	Prior stroke or TIA as assigned by the caller. true or false. Indicates OAC when true.
`vascular_disease`	boolean	required	Coronary, aortic, or peripheral arterial disease as assigned by the caller. true or false. Indicates ASA only when OAC is not indicated.

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.

POST /api/calc/chads_65 Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 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 (fixture)

{
  "items": [
    {
      "age": "70",
      "chf": "false",
      "diabetes": "false",
      "hypertension": "false",
      "stroke_tia": "false",
      "vascular_disease": "false"
    },
    {
      "age": "70",
      "chf": "false",
      "diabetes": "false",
      "hypertension": "false",
      "stroke_tia": "false",
      "vascular_disease": "false"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/chads_65",
  "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": "Verma A, Cairns JA, Mitchell LB, Macle L, Stiell IG, Gladstone D, McMurtry MS, Connolly S, Cox JL, Dorian P, Ivers N, Leblanc K, Nattel S, Healey JS",
        "doi": "10.1016/j.cjca.2014.08.001",
        "id": "verma-2014",
        "pmid": "25262857",
        "source": "Can J Cardiol. 2014;30(10):1114-1130",
        "title": "2014 focused update of the Canadian Cardiovascular Society Guidelines for the management of atrial fibrillation"
      },
      "formula": "chads_65",
      "formula_expression": "OAC if age ≥ 65 or CHF or hypertension or diabetes or prior stroke/TIA; else ASA if vascular disease (coronary, aortic, or peripheral arterial); else none (CCS 2014 CHADS-65)",
      "criteria": [
        {
          "value": 70,
          "factor": "age_ge_65",
          "met": true
        },
        {
          "factor": "chf",
          "met": false
        },
        {
          "factor": "hypertension",
          "met": false
        },
        {
          "factor": "diabetes",
          "met": false
        },
        {
          "factor": "stroke_tia",
          "met": false
        },
        {
          "factor": "vascular_disease",
          "met": false
        }
      ],
      "oac_indicated": true,
      "recommendation": "oac"
    },
    {
      "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": "Verma A, Cairns JA, Mitchell LB, Macle L, Stiell IG, Gladstone D, McMurtry MS, Connolly S, Cox JL, Dorian P, Ivers N, Leblanc K, Nattel S, Healey JS",
        "doi": "10.1016/j.cjca.2014.08.001",
        "id": "verma-2014",
        "pmid": "25262857",
        "source": "Can J Cardiol. 2014;30(10):1114-1130",
        "title": "2014 focused update of the Canadian Cardiovascular Society Guidelines for the management of atrial fibrillation"
      },
      "formula": "chads_65",
      "formula_expression": "OAC if age ≥ 65 or CHF or hypertension or diabetes or prior stroke/TIA; else ASA if vascular disease (coronary, aortic, or peripheral arterial); else none (CCS 2014 CHADS-65)",
      "criteria": [
        {
          "value": 70,
          "factor": "age_ge_65",
          "met": true
        },
        {
          "factor": "chf",
          "met": false
        },
        {
          "factor": "hypertension",
          "met": false
        },
        {
          "factor": "diabetes",
          "met": false
        },
        {
          "factor": "stroke_tia",
          "met": false
        },
        {
          "factor": "vascular_disease",
          "met": false
        }
      ],
      "oac_indicated": true,
      "recommendation": "oac"
    }
  ]
}

Response

Field	Type	Description
`formula`	string	chads_65
`formula_expression`	string	CCS 2014 CHADS-65 OAC then ASA then none tree
`recommendation`	string	oac, asa, or none. Not an anticoagulation order.
`oac_indicated`	boolean	true when age ≥ 65 or CHF, hypertension, diabetes, or prior stroke/TIA is present
`criteria`	array	Per-factor rows (age_ge_65, chf, hypertension, diabetes, stroke_tia, vascular_disease) with factor, met, and age value on age_ge_65
`citation`	object	Verma 2014 Can J Cardiol citation
`disclaimer`	string	Not-a-device notice

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "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": "Verma A, Cairns JA, Mitchell LB, Macle L, Stiell IG, Gladstone D, McMurtry MS, Connolly S, Cox JL, Dorian P, Ivers N, Leblanc K, Nattel S, Healey JS",
    "doi": "10.1016/j.cjca.2014.08.001",
    "id": "verma-2014",
    "pmid": "25262857",
    "source": "Can J Cardiol. 2014;30(10):1114-1130",
    "title": "2014 focused update of the Canadian Cardiovascular Society Guidelines for the management of atrial fibrillation"
  },
  "formula": "chads_65",
  "formula_expression": "OAC if age ≥ 65 or CHF or hypertension or diabetes or prior stroke/TIA; else ASA if vascular disease (coronary, aortic, or peripheral arterial); else none (CCS 2014 CHADS-65)",
  "criteria": [
    {
      "value": 70,
      "factor": "age_ge_65",
      "met": true
    },
    {
      "factor": "chf",
      "met": false
    },
    {
      "factor": "hypertension",
      "met": false
    },
    {
      "factor": "diabetes",
      "met": false
    },
    {
      "factor": "stroke_tia",
      "met": false
    },
    {
      "factor": "vascular_disease",
      "met": false
    }
  ],
  "oac_indicated": true,
  "recommendation": "oac"
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

HTTP	Code	When
400	`invalid_age`	age must be an integer from 18 to 120 Returned before settlement; you are not charged.
400	`invalid_flag`	boolean clinical flags must be true or false Returned before settlement; you are not charged.
400	`invalid_items`	POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
400	`invalid_item_count`	items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
400	`invalid_item`	each items entry must be a JSON object Returned before settlement; you are not charged.

Related tools

CHADS2 — Compute the CHADS2 stroke-risk score from discrete clinical flags.
CHA2DS2-VASc — Compute the CHA2DS2-VASc stroke-risk score from discrete clinical 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. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /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.