# H2FPEF Score Calculator (Reddy 2018) > H2FPEF Score Calculator (Reddy 2018) 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 Reddy 2018 H2FPEF points score (0–9) for heart failure with preserved ejection fraction from six discrete clinical inputs ## Facts - Endpoint: GET https://api.magentlab.com/api/calc/h2fpef - 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/h2fpef-score-calculator-reddy-2018-530b45d3 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_qJOujINrq_d9Rz94n9q32 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 h2fpef-score-calculator-reddy-2018-530b45d3 ``` Example prompt: Calculate the H2FPEF score for a 67-year-old patient with a BMI of 33, on three antihypertensive medications, with known paroxysmal atrial fibrillation, an echocardiographic PASP of 38 mmHg, and an E/e′ ratio of 11. ## When to prefer this Use this endpoint when you need a fast, deterministic, published-formula H2FPEF points score (Reddy 2018) for a single patient in an agentic or automated cardiology workflow. Prefer this over manual calculation when integrating into EMR pipelines, clinical decision support agents, or research tools. Do not use if you need the continuous nomogram version of H2FPEF, HFA-PEFF scoring, echocardiographic measurement, BMI computation, a probability output, or a formal diagnosis — this endpoint only implements the discrete 0–9 points score. ## Known failure modes - Missing required query parameters (age, bmi_kg_m2, atrial_fibrillation, antihypertensive_ge_2, pasp_gt_35, e_over_e_prime_gt_9) returns a validation error - Age outside 18–120 or BMI outside 10–80 may be rejected or produce undefined behavior - Boundary values (age=60, BMI=30) score zero per Reddy 2018 strict inequality rules — callers may overlook this - Boolean fields supplied as strings rather than true/false may fail schema validation - Payment not included or insufficient USDC balance returns HTTP 402 ## How this service works Reddy 2018 H2FPEF points score. Six components, max 9: BMI >30 (2), >=2 antihypertensives (1), atrial fibrillation (3), echo PASP >35 mm Hg (1), age >60 (1), E/e' >9 (1). BMI 30 and age 60 do not score. Returns score and max_score only; odds roughly double per point. Not probability classes, not the continuous nomogram, not HFA-PEFF, not a diagnosis or cath substitute. magent does not read echo or compute BMI. ## Output Returns the total H2FPEF integer score (0–9), the maximum possible score (9), and a detailed component breakdown showing which factors are present and their individual point contributions, along with the formula expression, citation (Reddy 2018 Circulation), and a medical disclaimer. ## 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", "bmi_kg_m2", "antihypertensive_ge_2", "atrial_fibrillation", "pasp_gt_35", "e_over_e_prime_gt_9" ], "properties": { "age": { "type": "integer", "description": "Age in years (18-120). Reddy 2018 elderly: scores 1 when >60. Age 60 does not score." }, "bmi_kg_m2": { "type": "number", "description": "Body-mass index in kg/m^2 (10-80). Reddy 2018 heavy/obesity: scores 2 when >30. BMI 30 does not score. Caller-supplied; magent does not compute BMI from height and weight." }, "pasp_gt_35": { "type": "boolean", "description": "Echocardiographic pulmonary artery systolic pressure >35 mm Hg (Reddy 2018 pulmonary hypertension). true or false. Caller-assigned. 1 point if true. magent does not measure PASP." }, "atrial_fibrillation": { "type": "boolean", "description": "Paroxysmal or persistent atrial fibrillation (Reddy 2018). true or false. Caller-assigned. 3 points if true." }, "e_over_e_prime_gt_9": { "type": "boolean", "description": "E/e' ratio >9 (Reddy 2018 filling pressures). true or false. Caller-assigned. 1 point if true. magent does not measure E/e'." }, "antihypertensive_ge_2": { "type": "boolean", "description": "Treatment with two or more antihypertensive drugs (Reddy 2018 hypertensive). true or false. Caller-assigned. 1 point if true." } } } }, "additionalProperties": false }, "output": { "type": "object", "required": [ "type" ], "properties": { "type": { "type": "string" }, "example": { "type": "object" } } } } } ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "path": "/api/calc/h2fpef", "count": 2, "items": [ { "score": 0, "formula": "h2fpef", "citation": { "id": "reddy-2018", "doi": "10.1161/CIRCULATIONAHA.118.034646", "pmid": "29792299", "title": "A Simple, Evidence-Based Approach to Help Guide Diagnosis of Heart Failure With Preserved Ejection Fraction", "source": "Circulation. 2018;138(9):861-870", "authors": "Reddy YNV, Carter RE, Obokata M, Redfield MM, Borlaug BA" }, "age_years": 50, "bmi_kg_m2": 25, "max_score": 9, "components": [ { "value": 25, "factor": "obesity", "points": 0, "present": false }, { "factor": "antihypertensive_ge_2", "points": 0, "present": false }, { "factor": "atrial_fibrillation", "points": 0, "present": false }, { "factor": "pasp_gt_35", "points": 0, "present": false }, { "value": 50, "factor": "age_gt_60", "points": 0, "present": false }, { "factor": "e_over_e_prime_gt_9", "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.", "formula_expression": "H2FPEF = 2*(bmi_kg_m2>30) + antihypertensive_ge_2 + 3*atrial_fibrillation + pasp_gt_35 + (age>60) + e_over_e_prime_gt_9; max 9 (Reddy 2018 points score; not the continuous nomogram, not HFA-PEFF)" }, { "score": 0, "formula": "h2fpef", "citation": { "id": "reddy-2018", "doi": "10.1161/CIRCULATIONAHA.118.034646", "pmid": "29792299", "title": "A Simple, Evidence-Based Approach to Help Guide Diagnosis of Heart Failure With Preserved Ejection Fraction", "source": "Circulation. 2018;138(9):861-870", "authors": "Reddy YNV, Carter RE, Obokata M, Redfield MM, Borlaug BA" }, "age_years": 50, "bmi_kg_m2": 25, "max_score": 9, "components": [ { "value": 25, "factor": "obesity", "points": 0, "present": false }, { "factor": "antihypertensive_ge_2", "points": 0, "present": false }, { "factor": "atrial_fibrillation", "points": 0, "present": false }, { "factor": "pasp_gt_35", "points": 0, "present": false … (truncated) ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/h2fpef-score-calculator-reddy-2018-530b45d3/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)