# INTERCHEST CAD Score Calculator (Aerts 2017)

> INTERCHEST CAD Score Calculator (Aerts 2017) is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Computes the INTERCHEST score (−1 to 5) for coronary artery disease probability in primary-care chest pain patients using six weighted predictors.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/interchest
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/interchest-cad-score-calculator-aerts-2017-843fd2e0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_f057s_13KlQbjo14ZPCOD

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability interchest-cad-score-calculator-aerts-2017-843fd2e0
```

Example prompt: Calculate the INTERCHEST score for a 58-year-old male with chest pain — the physician suspected something serious, he has a history of CAD, the pain is exertional and feels like pressure, and it is not reproducible on palpation.

## When to prefer this

Use this endpoint when you need to apply the validated Aerts 2017 INTERCHEST clinical decision rule specifically for primary-care chest pain patients. Prefer this over HEART score or EDACS when the clinical context is primary care (not emergency department), as INTERCHEST was validated in that setting. This endpoint is appropriate when the clinician has the six required predictor values available and needs a structured CAD probability estimate without requiring ECG or troponin data.

## Known failure modes

- Missing required query parameters (age, sex, or any boolean flag) returns a 400 error
- Age outside the 18–120 range may be rejected
- Invalid sex enum value (not 'male' or 'female') returns a validation error
- Payment failure or missing x402 payment header returns a 402 error
- Network timeout or service unavailability returns a 5xx error

## How this service works

Aerts 2017 INTERCHEST: six equally weighted predictors for CAD in primary-care chest pain (age ≥55 male or ≥65 female +1; physician suspected serious +1; history of CAD +1; pain on exertion +1; pressure quality +1; pain reproducible on palpation −1). Range −1 to 5. CAD considered absent iff score <2. Published CAD probability 2.1% (95% CI 1.1–3.9) when <2 and 43.0% (35.8–50.4) when ≥2 in the 13.2% prevalence setting. Not HEART, not EDACS. magent does not examine the chest.

## Output

Returns the numeric INTERCHEST score (ranging from −1 to 5), the associated CAD probability category (absent if score <2: ~2.1% CAD probability; present if score ≥2: ~43.0% CAD probability), and the individual predictor contributions, based on the Aerts 2017 validation in a 13.2% CAD prevalence primary-care setting.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "required": [
      "age",
      "sex",
      "physician_suspected_serious",
      "history_of_cad",
      "pain_on_exertion",
      "pressure_quality",
      "pain_reproducible_on_palpation"
     ],
     "properties": {
      "age": {
       "type": "integer",
       "description": "Age in years (18-120). Combined with sex: female ≥65 or male ≥55 scores 1 (Aerts 2017). Age 54 male does not score; 55 male does. Age 64 female does not; 65 female does. magent computes this; do not send a precomputed flag."
      },
      "sex": {
       "enum": [
        "female",
        "male"
       ],
       "type": "string",
       "description": "female or male (required). Combined with age: female ≥65 or male ≥55 scores 1 (Aerts 2017)."
      },
      "history_of_cad": {
       "type": "boolean",
       "description": "History of coronary artery disease (Aerts 2017). true or false as assigned by the caller. magent does not take a cardiac history. +1 if true."
      },
      "pain_on_exertion": {
       "type": "boolean",
       "description": "Pain related to exertion (Aerts 2017). true or false as assigned by the caller. +1 if true."
      },
      "pressure_quality": {
       "type": "boolean",
       "description": "Pain has a pressure quality (Aerts 2017). true or false as assigned by the caller. +1 if true."
      },
      "physician_suspected_serious": {
       "type": "boolean",
       "description": "Physician initially suspected a serious diagnosis (Aerts 2017). true or false as assigned by the caller. magent does not examine the chest. +1 if true."
      },
      "pain_reproducible_on_palpation": {
       "type": "boolean",
       "description": "Pain reproducible on chest-wall palpation (Aerts 2017). true or false as assigned by the caller. magent does not examine the chest. −1 if true."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/interchest-cad-score-calculator-aerts-2017-843fd2e0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.magentlab.com](https://www.zero.xyz/host/api.magentlab.com/llms.txt)