Extended criteria (experimental). This is the broader ten-condition engine, kept as a secondary area. It shows ICD-10-CM codes and illustrative grouping effects for CDI staff. The primary surface is Before you sign (kidney, measurement only). All extended pages.

Heart failure type (LVEF) and acuity

Rule heart_failure version 2026.11-1 · condition: Heart failure

Published source

Universal Definition and Classification of Heart Failure (HFSA/HFA/JHFS, 2021), as restated in Chandramouli et al., Clin Cardiol 2022 (2021). LVEF classification: HFrEF <=40%, HFmrEF 41-49%, HFpEF >=50%; HFimpEF = baseline <=40%, rise >=10 points, second LVEF >40%. https://eprints.gla.ac.uk/274434/1/274434.pdf · public page checked 2026-11-14

Natriuretic peptide levels supporting HF in hospitalized/decompensated patients: BNP >=100 pg/mL or NT-proBNP >=300 pg/mL (secondary source; primary not open access).

Also: 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure (2021). Section 3.2.1, Table 3 (LVEF categories); Section 11 (acute heart failure). link

Also: 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure (2022). Same LVEF categories (publisher page not loadable during verification). link

Contested or local convention. No guideline gives a numeric definition of "acute" versus "chronic" heart failure. This rule uses a LOCAL CONVENTION: at least two acute indicators (IV loop diuretic, elevated natriuretic peptide, new oxygen requirement) = acute; with a prior history of heart failure = acute on chronic; none with history = chronic; exactly one = clinical judgement.

Inputs

lvef: Latest LVEF within 12 months (%)
lvef_prior_min: Lowest earlier LVEF within 12 months (%)
iv_loop_diuretic: IV loop diuretic given this stay
bnp_max: Highest BNP this stay (pg/mL)
ntprobnp_max: Highest NT-proBNP this stay (pg/mL)
new_o2: Supplemental oxygen started this stay without home oxygen
hf_history: Prior heart failure on the problem list / history

Thresholds

t.ref: 40
t.pres: 50
t.improved_rise: 10
t.bnp: 100
t.ntprobnp: 300

Derived values

Evaluated in order
Name	Expression
np_elevated	`coalesce(bnp_max >= t.bnp, false) or coalesce(ntprobnp_max >= t.ntprobnp, false)`
acute_count	`count(iv_loop_diuretic, np_elevated, new_o2)`
hf_type	`case(lvef <= t.ref, 'systolic', lvef >= t.pres, 'diastolic', 'midrange')`
improved	`coalesce(lvef_prior_min <= t.ref and lvef > t.ref and lvef - lvef_prior_min >= t.improved_rise, false)`
acuity	`case(acute_count >= 2 and hf_history, 'acute on chronic', acute_count >= 2, 'acute', acute_count == 0 and hf_history, 'chronic', null)`

Outcomes

First true outcome wins; an unknown input makes an outcome unknown
Outcome	When	Status	Supports
improved_ef LVEF improved from {lvef_prior_min}% to {lvef}% (HFimpEF); type wording needs the clinician	`improved`	judgement	—
midrange LVEF {lvef}% (HFmrEF, 41-49%); the type wording and its coding convention need the clinician	`hf_type == 'midrange'`	judgement	—
sys_aoc LVEF {lvef}% with {acute_count} acute indicators and prior heart failure	`hf_type == 'systolic' and acuity == 'acute on chronic'`	supported	I50.23 Acute on chronic systolic (HFrEF) heart failure
sys_acute LVEF {lvef}% with {acute_count} acute indicators, no prior heart failure on file	`hf_type == 'systolic' and acuity == 'acute'`	supported	I50.21 Acute systolic (HFrEF) heart failure
sys_chronic LVEF {lvef}%, prior heart failure, no acute indicators	`hf_type == 'systolic' and acuity == 'chronic'`	supported	I50.22 Chronic systolic (HFrEF) heart failure
dia_aoc LVEF {lvef}% with {acute_count} acute indicators and prior heart failure	`hf_type == 'diastolic' and acuity == 'acute on chronic'`	supported	I50.33 Acute on chronic diastolic (HFpEF) heart failure
dia_acute LVEF {lvef}% with {acute_count} acute indicators, no prior heart failure on file	`hf_type == 'diastolic' and acuity == 'acute'`	supported	I50.31 Acute diastolic (HFpEF) heart failure
dia_chronic LVEF {lvef}%, prior heart failure, no acute indicators	`hf_type == 'diastolic' and acuity == 'chronic'`	supported	I50.32 Chronic diastolic (HFpEF) heart failure
one_indicator Only one acute indicator; acuity needs clinical judgement	`acute_count == 1`	judgement	—

ICD-10-CM specificity ladder (FY2026 CC/MCC status as a secondary diagnosis)

I50.9 Heart failure, unspecified · non-CC
I50.20 Systolic heart failure, acuity unspecified · CC (refines I50.9)
I50.30 Diastolic heart failure, acuity unspecified · CC (refines I50.9)
I50.22 Chronic systolic heart failure · CC (refines I50.20)
I50.21 Acute systolic heart failure · MCC (refines I50.20)
I50.23 Acute on chronic systolic heart failure · MCC (refines I50.22, I50.21)
I50.32 Chronic diastolic heart failure · CC (refines I50.30)
I50.31 Acute diastolic heart failure · MCC (refines I50.30)
I50.33 Acute on chronic diastolic heart failure · MCC (refines I50.32, I50.31)

Query topic: cardiac documentation · prompts for an undocumented diagnosis: no

Where clinical judgement is required

Acuity is a local convention (see "contested"); exactly one acute indicator is never concluded.
HFmrEF and HFimpEF type wording is left to the clinician.
The rule does not prompt for heart failure that is not documented at all.

Coding notes

When heart failure is the principal diagnosis, secondary I50.x codes are CC-excluded (Table 6K).