# Seattle Heart Failure Model (SHFM) Survival Calculator > Seattle Heart Failure Model (SHFM) Survival 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). Computes 1-, 2-, and 3-year survival probabilities for heart failure patients using the Levy 2006 Seattle Heart Failure Model Table 2 multivariate hazard ratios ## Facts - Endpoint: GET https://api.magentlab.com/api/calc/shfm - 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/seattle-heart-failure-model-shfm-survival-calculator-1f2506a2 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_vekvVr5SQJHSoZVU0UpJu 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 seattle-heart-failure-model-shfm-survival-calculator-1f2506a2 ``` Example prompt: Run the Seattle Heart Failure Model for a 68-year-old male with NYHA class 3 heart failure, ejection fraction 25%, ischemic etiology, SBP 110 mmHg, weight 85 kg, furosemide equivalent 80 mg/day, sodium 136 mEq/L, total cholesterol 180 mg/dL, hemoglobin 12.5 g/dL, lymphocytes 18%, uric acid 7.2 mg/dL, no allopurinol, on ACE inhibitor and beta-blocker, no ARB, no K-sparing diuretic, on a statin, no BiV pacemaker, no ICD, no BiV-ICD — and give me his 1-, 2-, and 3-year survival estimates. ## When to prefer this Choose this endpoint when you need a validated, published heart failure prognostic model (Levy 2006 SHFM) that incorporates both clinical variables and medication/device therapies simultaneously. It is preferred over generic mortality calculators when the patient has heart failure and you need 1-, 2-, or 3-year survival estimates that account for NYHA class, EF, labs, and multi-drug therapy. Use it when the caller can supply all required clinical inputs including labs, medication status, and device history. ## Known failure modes - Missing required query parameters returns a validation error - Age outside 14–100 range may be rejected or produce unreliable results - Mutually exclusive device flags (e.g., icd=true and biv_icd=true simultaneously) may cause model inconsistency - Invalid enum values for sex or nyha return a 400 error - Payment not provided or insufficient USDC results in 402 Payment Required - Lab values outside physiologically plausible ranges may produce extrapolated results without warning ## How this service works Levy 2006 Seattle Heart Failure Model 1-, 2-, and 3-year survival from Table 2 multivariate HRs. Score = sum of ln(HR)*x; S(t)=exp(-0.0405*t)**exp(score). Age, sex, NYHA, EF, ischemic etiology, SBP, furosemide-eq diuretic, labs, and already-on ACEI, beta-blocker, ARB, K-sparing diuretic, statin, BiV, ICD, or BiV-ICD. Caller assigns class, etiology, and therapy. magent does not measure labs or blood pressure. Not a diagnosis, prescription, or device order. ## Output Returns the SHFM composite score (sum of ln(HR)*x terms) and S(t)=exp(-0.0405*t)^exp(score) survival probabilities at 1, 2, and 3 years, derived from Levy 2006 Table 2 multivariate hazard ratios. The output reflects the patient's predicted probability of being alive at each time point given their clinical profile and current therapy. ## 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", "nyha", "ef_percent", "ischemic", "sbp_mm_hg", "weight_kg", "loop_diuretic_furosemide_eq_mg_day", "allopurinol", "sodium_meq_l", "total_cholesterol_mg_dl", "hemoglobin_g_dl", "lymphocyte_percent", "uric_acid_mg_dl", "ace_inhibitor", "beta_blocker", "arb", "k_sparing_diuretic", "statin", "biv_pacemaker", "icd", "biv_icd" ], "properties": { "age": { "type": "integer", "description": "Age in years (integer 14-100). Levy 2006 Table 2: per decade, multivariate HR 1.090. magent does not take a date of birth." }, "arb": { "type": "boolean", "description": "Patient already on an angiotensin-receptor blocker as assigned by the caller (true or false). Table 2 already-on HR 0.85. Not a prescription." }, "icd": { "type": "boolean", "description": "Patient already has an ICD (without biventricular pacing) as assigned by the caller (true or false). Table 2 already-on HR 0.73. Mutually exclusive with biv_pacemaker and biv_icd. Not a device order." }, "sex": { "enum": [ "female", "male" ], "type": "string", "description": "Sex used by the forced Table 2 male HR 1.089 (female or male). magent does not assign sex." }, "nyha": { "enum": [ 1, 2, 3, 4 ], "type": "integer", "description": "NYHA class 1-4 as assigned by the caller (integer). Levy 2006 Table 2 multivariate HR 1.600 per class. magent does not examine the patient." }, "statin": { "type": "boolean", "description": "Patient already on a statin as assigned by the caller (true or false). Table 2 already-on / multivariate HR 0.63. Not a prescription." }, "biv_icd": { … (truncated) ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/seattle-heart-failure-model-shfm-survival-calculator-1f2506a2/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)