# Grogan 2016 ATTRwt Cardiac Staging Calculator

> Grogan 2016 ATTRwt Cardiac Staging Calculator 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).

Calculates the Grogan 2016 staging score for wild-type transthyretin amyloid cardiomyopathy (ATTRwt) using NT-proBNP and cardiac troponin T values

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/grogan
- 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/grogan-2016-attrwt-cardiac-staging-calculator-f9dffaec
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QbzorZpT6I0yI7bo77SSN

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 grogan-2016-attrwt-cardiac-staging-calculator-f9dffaec
```

Example prompt: Using the Grogan 2016 ATTRwt staging system, what stage is a patient with NT-proBNP of 4200 ng/L and cardiac troponin T of 0.07 ng/mL?

## When to prefer this

Use this endpoint when you need to apply the Grogan 2016 ATTRwt cardiac staging schema specifically — it uses only NT-proBNP and cardiac troponin T (not eGFR, troponin I, BNP, or NYHA class). Prefer this over Mayo AL staging (which is for AL amyloid), Gillmore NAC staging (which requires eGFR), and NYHA functional class. Suitable for automating staging in clinical workflows where biomarker values are already available.

## Known failure modes

- Missing required query parameters (nt_probnp_ng_l or troponin_t_ng_ml) returns a validation error
- Values outside accepted ranges (NT-proBNP: 10–100000 ng/L; troponin T: 0.001–50 ng/mL) may be rejected
- Troponin I values provided instead of troponin T — endpoint only accepts troponin T and will not substitute
- Payment not provided or invalid x402 payment header results in 402 Payment Required

## How this service works

Grogan 2016 ATTRwt staging: 1 point when NT-proBNP >3000 ng/L; 1 point when cardiac TnT >0.05 ng/mL. Stage I = 0, II = 1, III = 2. Equal to a cutoff does not score. Cohort 4-year OS I 57% / II 42% / III 18%; stage III median 20 months (labels, not a prediction). Troponin T only. Not Gillmore NAC (no eGFR). Not Mayo AL. Not NYHA. magent does not assay the biomarkers.

## Output

Returns the Grogan 2016 ATTRwt stage (I, II, or III) based on the computed score (0, 1, or 2 points), with reference cohort 4-year overall survival rates: Stage I ~57%, Stage II ~42%, Stage III ~18% (median 20 months for Stage III). These are historical cohort labels, not individual predictions.

## 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": [
      "nt_probnp_ng_l",
      "troponin_t_ng_ml"
     ],
     "properties": {
      "nt_probnp_ng_l": {
       "type": "number",
       "description": "NT-proBNP in ng/L (10-100000), same numeric value as pg/mL. Grogan 2016 scores 1 point when > 3000; equal to 3000 does not score. magent does not assay NT-proBNP."
      },
      "troponin_t_ng_ml": {
       "type": "number",
       "description": "Cardiac troponin T (cTnT) in ng/mL (0.001-50), same numeric value as 0.05 μg/L. Grogan 2016 scores 1 point when > 0.05; equal to 0.05 does not score. Troponin T only; magent does not invent a troponin I cutoff and does not assay troponin."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/grogan-2016-attrwt-cardiac-staging-calculator-f9dffaec/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)