# AUB-HAS2 cardiovascular risk index

AUB-HAS2

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/aub_has2`
HTML: https://magentlab.com/docs/aub-has2
Markdown: https://magentlab.com/docs/aub-has2.md

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

## What it computes

Sum the six Dakik 2019 AUB-HAS2 1-point elements and return the integer score with low / intermediate / high bands.

## When to use

When an agent needs the published AUB-HAS2 point total for noncardiac surgery and must not invent an operative-clearance decision, an RCRI class, or an ACS treatment.

## When not to use

- Not a medical device. Not an operative clearance, cancellation, or monitoring order.
- Not RCRI and not ACS treatment. AUB-HAS2 is a noncardiac-surgery 30-day death/MI/stroke index (Dakik 2019 derivation).
- magent does not take a cardiac history or assay hemoglobin. history_of_heart_disease, angina_or_dyspnea, vascular_surgery, and emergency_surgery are caller-assigned.
- The paper writes hemoglobin as mg/dl; this tool uses g/dL (or g/L / 10). Provide hemoglobin_g_dl or hemoglobin_g_l, not both. Hemoglobin <12 g/dL scores 1 (12.0 does not).
- Derivation event rates are published cohort percents by integer score (0 / 0.5 / 2.0 / 5.6 / 15.7), not a patient-level prediction.

## Formula

```
AUB-HAS2 = history_of_heart_disease + angina_or_dyspnea + (age ≥75) + (hemoglobin <12 g/dL) + vascular_surgery + emergency_surgery; each 1; max 6; low 0-1, intermediate 2-3, high >3
```

## Citation

[A New Index for Pre-Operative Cardiovascular Evaluation](https://doi.org/10.1016/j.jacc.2019.04.023)
Dakik HA, Chehab O, Eldirani M, Sbeity E, Karam C, Abou Hassan O, Msheik A, Kaspar C, Makki M, Tamim H
J Am Coll Cardiol. 2019;73(24):3067-3078
DOI: [10.1016/j.jacc.2019.04.023](https://doi.org/10.1016/j.jacc.2019.04.023)

## Worked example

### Age 50, hemoglobin 13 g/dL, all flags false

Given: `age=50, angina_or_dyspnea=false, emergency_surgery=false, hemoglobin_g_dl=13, history_of_heart_disease=false, vascular_surgery=false`

1. Age 50 is not ≥75 → 0; hemoglobin 13 g/dL is not <12 → 0; all flags false → 0
2. Score = 0; risk_band low


### Age 80, hemoglobin 11 g/dL, flags false

Given: `age=80, angina_or_dyspnea=false, emergency_surgery=false, hemoglobin_g_dl=11, history_of_heart_disease=false, vascular_surgery=false`

1. Age 80 ≥75 → 1; hemoglobin 11 g/dL <12 → 1; flags false → 0
2. Score = 2; risk_band intermediate


### Age 80, hemoglobin 11 g/dL, heart-disease history and angina or dyspnea

Given: `age=80, angina_or_dyspnea=true, emergency_surgery=false, hemoglobin_g_dl=11, history_of_heart_disease=true, vascular_surgery=false`

1. Age ≥75 → 1; hemoglobin <12 → 1; history_of_heart_disease → 1; angina_or_dyspnea → 1
2. Score = 4; risk_band high


## Also searched as

- AUB-HAS2
- AUB HAS2
- American University of Beirut HAS2
- Dakik cardiovascular risk index
- HAS2 cardiovascular index
- preoperative cardiovascular risk index
- AUB cardiovascular risk index

## Parameters

- `age` (integer, required): Age in years (18-120). Age ≥75 scores 1 (Dakik 2019). 75 scores; 74 does not.
- `hemoglobin_g_dl` (number, optional): Hemoglobin in g/dL (3-22). Provide this or hemoglobin_g_l, not both. Dakik 2019 writes mg/dl; clinical use is g/dL. <12 g/dL scores 1 (11.9 scores; 12.0 does not). magent does not assay hemoglobin.
- `hemoglobin_g_l` (number, optional): Hemoglobin in g/L (30-220). Converted as hemoglobin_g_dl = hemoglobin_g_l / 10. Provide this or hemoglobin_g_dl, not both.
- `history_of_heart_disease` (boolean, required): History of heart disease as assigned by the caller (Dakik 2019). true or false. magent does not take a cardiac history. 1 point if true.
- `angina_or_dyspnea` (boolean, required): Symptoms of angina or dyspnea as assigned by the caller (Dakik 2019). true or false. magent does not take a symptom history. 1 point if true.
- `vascular_surgery` (boolean, required): Vascular surgery as assigned by the caller (Dakik 2019). true or false. 1 point if true.
- `emergency_surgery` (boolean, required): Emergency surgery as assigned by the caller (Dakik 2019). true or false. 1 point if true.

## 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/aub_has2`
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": "50",
      "angina_or_dyspnea": "false",
      "emergency_surgery": "false",
      "hemoglobin_g_dl": "13",
      "history_of_heart_disease": "false",
      "vascular_surgery": "false"
    },
    {
      "age": "50",
      "angina_or_dyspnea": "false",
      "emergency_surgery": "false",
      "hemoglobin_g_dl": "13",
      "history_of_heart_disease": "false",
      "vascular_surgery": "false"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/aub-has2

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/aub_has2",
  "items": [
    {
      "components": [
        {
          "factor": "history_of_heart_disease",
          "points": 0,
          "present": false
        },
        {
          "factor": "angina_or_dyspnea",
          "points": 0,
          "present": false
        },
        {
          "value": 50,
          "factor": "age_ge_75",
          "points": 0,
          "present": false
        },
        {
          "value": 13.0,
          "factor": "hemoglobin_lt_12",
          "points": 0,
          "present": false
        },
        {
          "factor": "vascular_surgery",
          "points": 0,
          "present": false
        },
        {
          "factor": "emergency_surgery",
          "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": "Dakik HA, Chehab O, Eldirani M, Sbeity E, Karam C, Abou Hassan O, Msheik A, Kaspar C, Makki M, Tamim H",
        "doi": "10.1016/j.jacc.2019.04.023",
        "id": "dakik-2019",
        "pmid": "31221255",
        "source": "J Am Coll Cardiol. 2019;73(24):3067-3078",
        "title": "A New Index for Pre-Operative Cardiovascular Evaluation"
      },
      "formula": "aub_has2",
      "formula_expression": "AUB-HAS2 = history_of_heart_disease + angina_or_dyspnea + (age ≥75) + (hemoglobin <12 g/dL) + vascular_surgery + emergency_surgery; each 1; max 6; low 0-1, intermediate 2-3, high >3",
      "max_score": 6,
      "score": 0,
      "age_years": 50,
      "risk_band": "low",
      "emergency_surgery": false,
      "angina_or_dyspnea": false,
      "derivation_event_rate_percent": 0.0,
      "hemoglobin_g_dl": 13.0,
      "history_of_heart_disease": false,
      "vascular_surgery": false
    },
    {
      "components": [
        {
          "factor": "history_of_heart_disease",
          "points": 0,
          "present": false
        },
        {
          "factor": "angina_or_dyspnea",
          "points": 0,
          "present": false
        },
        {
          "value": 50,
          "factor": "age_ge_75",
          "points": 0,
          "present": false
        },
        {
          "value": 13.0,
          "factor": "hemoglobin_lt_12",
          "points": 0,
          "present": false
        },
        {
          "factor": "vascular_surgery",
          "points": 0,
          "present": false
        },
        {
          "factor": "emergency_surgery",
          "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": "Dakik HA, Chehab O, Eldirani M, Sbeity E, Karam C, Abou Hassan O, Msheik A, Kaspar C, Makki M, Tamim H",
        "doi": "10.1016/j.jacc.2019.04.023",
        "id": "dakik-2019",
        "pmid": "31221255",
        "source": "J Am Coll Cardiol. 2019;73(24):3067-3078",
        "title": "A New Index for Pre-Operative Cardiovascular Evaluation"
      },
      "formula": "aub_has2",
      "formula_expression": "AUB-HAS2 = history_of_heart_disease + angina_or_dyspnea + (age ≥75) + (hemoglobin <12 g/dL) + vascular_surgery + emergency_surgery; each 1; max 6; low 0-1, intermediate 2-3, high >3",
      "max_score": 6,
      "score": 0,
      "age_years": 50,
      "risk_band": "low",
      "emergency_surgery": false,
      "angina_or_dyspnea": false,
      "derivation_event_rate_percent": 0.0,
      "hemoglobin_g_dl": 13.0,
      "history_of_heart_disease": false,
      "vascular_surgery": false
    }
  ]
}
```

## Response fields

- `formula` (string): aub_has2
- `formula_expression` (string): Exact expression used
- `score` (integer): AUB-HAS2 points 0-6
- `max_score` (integer): Always 6
- `risk_band` (string): low (0-1), intermediate (2-3), or high (>3 / 4-6)
- `derivation_event_rate_percent` (number): Dakik 2019 derivation 30-day death/MI/stroke percent by integer score: 0, 0.5, 2.0, 5.6, or 15.7 (>3)
- `age_years` (integer): Age used (years)
- `hemoglobin_g_dl` (number): Hemoglobin used in g/dL (g/L inputs converted as g/dL = g/L / 10)
- `history_of_heart_disease` (boolean): Caller-assigned history-of-heart-disease flag used
- `angina_or_dyspnea` (boolean): Caller-assigned angina-or-dyspnea flag used
- `vascular_surgery` (boolean): Caller-assigned vascular-surgery flag used
- `emergency_surgery` (boolean): Caller-assigned emergency-surgery flag used
- `components` (array): Per-element points
- `citation` (object): Dakik 2019 JACC citation
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "components": [
    {
      "factor": "history_of_heart_disease",
      "points": 0,
      "present": false
    },
    {
      "factor": "angina_or_dyspnea",
      "points": 0,
      "present": false
    },
    {
      "value": 50,
      "factor": "age_ge_75",
      "points": 0,
      "present": false
    },
    {
      "value": 13.0,
      "factor": "hemoglobin_lt_12",
      "points": 0,
      "present": false
    },
    {
      "factor": "vascular_surgery",
      "points": 0,
      "present": false
    },
    {
      "factor": "emergency_surgery",
      "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": "Dakik HA, Chehab O, Eldirani M, Sbeity E, Karam C, Abou Hassan O, Msheik A, Kaspar C, Makki M, Tamim H",
    "doi": "10.1016/j.jacc.2019.04.023",
    "id": "dakik-2019",
    "pmid": "31221255",
    "source": "J Am Coll Cardiol. 2019;73(24):3067-3078",
    "title": "A New Index for Pre-Operative Cardiovascular Evaluation"
  },
  "formula": "aub_has2",
  "formula_expression": "AUB-HAS2 = history_of_heart_disease + angina_or_dyspnea + (age ≥75) + (hemoglobin <12 g/dL) + vascular_surgery + emergency_surgery; each 1; max 6; low 0-1, intermediate 2-3, high >3",
  "max_score": 6,
  "score": 0,
  "age_years": 50,
  "risk_band": "low",
  "emergency_surgery": false,
  "angina_or_dyspnea": false,
  "derivation_event_rate_percent": 0.0,
  "hemoglobin_g_dl": 13.0,
  "history_of_heart_disease": false,
  "vascular_surgery": false
}
```

## Errors

- HTTP 400 `invalid_age`: age must be an integer from 18 to 120 Returned before settlement; you are not charged.
- HTTP 400 `invalid_hemoglobin`: hemoglobin_g_l (30-220) or hemoglobin_g_dl (3-22) is required, not both. 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.

Shared HTTP 402 and 503: https://magentlab.com/docs/payments

## Related tools

- [RCRI](https://magentlab.com/docs/rcri) — Sum the six Lee 1999 revised cardiac risk index factors and return class I–IV.

## 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.