Cardiac Surgery Risk Calculator

The Society for Thoracic Surgery maintains an online Adult Cardiac Surgery Risk Calculator which can be used to estimate the risk of mortality and other complications in cardiac surgery patients. While the only required variables are procedure type, age, and sex, supplying additional information about the patient and procedure increases the accuracy of the score.

Although the calculator is designed for manual input of data fields on the webpage, the underlying API can be used to automate the calculation of the STS scores. This document describes this API in more detail.

API Details

URL: http://riskcalc.sts.org/stswebriskcalc/v1/calculate/stsall
Method: POST
Content type: application/json

Example curl command:

curl -H "Content-Type: application/json" -X POST -d '{"age":70,"gender":"Male","opcab":"Yes, planned","heightcm":100,"weightkg":50}' http://riskcalc.sts.org/stswebriskcalc/v1/calculate/stsall

and the response:

{
  "predmort": 0.00394,
  "predmm": 0.04148,
  "preddeep": 0.00115,
  "pred14d": 0.01323,
  "predstro": 0.00287,
  "predvent": 0.02133,
  "predrenf": 0.00638,
  "predreop": 0.0269,
  "pred6d": 0.7656
}

which corresponds to the likelihoods of:

• Mortality
• Morbidity or Mortality
• DSW Infection
• Long Length of Stay
• Permanent Stroke
• Prolonged Ventilation
• Renal Failure
• Reoperation
• Short Length of Stay

Calculator Inputs

Procedure Type	.json
CAB Only	{ opcab: "Yes, planned" }
AV Replacement	{ opvalve: "Yes", vsav: "Yes, planned", vsavpr: "Replacement" }
MV Replacement Only	{ opvalve: "Yes", vsmv: "Yes, planned", vsmvpr: "Replacement" }
MV Repair	{ opvalve: "Yes", vsmv: "Yes, planned", vsmvpr: "Repair" }
AV Replacement + CAB	{ opcab: "Yes, planned", opvalve: "Yes", vsav: "Yes, planned", vsavpr: "Replacement" }
MV Replacement + CAB	{ opcab: "Yes, planned", opvalve: "Yes", vsmv: "Yes, planned", vsmvpr:"Replacement" }
MV Repair + CAB	{ opcab:"Yes, planned", opvalve:"Yes", vsmv: "Yes, planned", vsmvpr: "Repair" }

Patient Characteristics	.json
Age ∈ [1, 110]	{ age: 50 }
Gender: Male	{ gender: "Male" }
Gender: Female	{ gender: "Female" }
Height (cm) ∈ [20, 251]	{ heightcm: 100 }
Weight (kg) ∈ [10, 250]	{ weightkg: 100 }

Hemo Data-EF	.json
Hemo Data-EF Done: No	{ hdefd: "No" }
Hemo Data-EF Done: Yes	{ hdefd: "Yes" }
Hemo Data-EF Value	{ hdef: 10 }

Heart Failure within 2 weeks	.json
Yes	{ chf: "Yes" }
No	{ chf: "No" }
Unknown	{ chf: "Unknown" }

Race	.json
Race Documented: Yes	{ racedocumented: "Yes" }
Race Documented: No	{ racedocumented: "No" }
Race Documented: Patient declined to disclose	{ racedocumented: "Patient declined to disclose" }
Race - Black / African American: Yes	{ raceblack: "Yes" }
Race - Black / African American: No	{ raceblack: "No" }
Hispanic or Latino or Spanish Ethnicity: Yes	{ ethnicity: "Yes" }
Hispanic or Latino or Spanish Ethnicity: No	{ ethnicity: "No" }
Hispanic or Latino or Spanish Ethnicity: Not Documented	{ ethnicity: "Not Documented" }
Race - Asian: Yes	{ raceasian: "Yes" }
Race - Asian: No	{ raceasian: "No" }

RF	.json
RF-Renal Fail-Dialysis: Yes	{ dialysis: "Yes" }
RF-Renal Fail-Dialysis: No	{ dialysis: "No" }
RF-Renal Fail-Dialysis: Unknown	{ dialysis: "Unknown" }
RF-Last Creat Level ∈ [0.1, 30]	{ creatlst: 20 }

Cardiac Presentation/Symptoms - At Time Of This Admission	.json
Stable Angina	{ cardsymptimeofadm: "Stable Angina" }
Unstable Angina	{ cardsymptimeofadm: "Unstable Angina" }
Angina equivalent	{ cardsymptimeofadm: "Angina equivalent" }
Non-ST Elevation MI (Non-STEMI)	{ cardsymptimeofadm: "Non-ST Elevation MI (Non-STEMI)" }
ST Elevation MI (STEMI)	{ cardsymptimeofadm: "ST Elevation MI (STEMI)" }
Other	{ cardsymptimeofadm: "Other" }
No Symptoms	{ cardsymptimeofadm: "No Symptoms" }

Cardiac Symptoms - At Time Of Surgery	.json
Stable Angina	{ cardsymptimeofsurg: "Stable Angina" }
Unstable Angina	{ cardsymptimeofsurg: "Unstable Angina" }
Angina equivalent	{ cardsymptimeofsurg: "Angina equivalent" }
Non-ST Elevation MI (Non-STEMI)	{ cardsymptimeofsurg: "Non-ST Elevation MI (Non-STEMI)" }
ST Elevation MI (STEMI)	{ cardsymptimeofsurg: "ST Elevation MI (STEMI)" }
Other	{ cardsymptimeofsurg: "Other" }
No Symptoms	{ cardsymptimeofsurg: "No Symptoms" }

MI	.json
Prior MI: Yes	{ prevmi: "Yes" }
Prior MI: No	{ prevmi: "No" }
Prior MI: Unknown	{ prevmi: "Unknown" }
MI-When <=6 hrs	{ miwhen: " <=6 Hrs" }
MI-When >6 but <24 hrs	{ miwhen: " >6 Hrs but <24 Hrs" }
MI-When 1 to 7 days	{ miwhen: "1 to 7 Days" }
MI-When 8 to 21 days	{ miwhen: "8 to 21 Days" }
MI-When >21 days	{ miwhen: " >21 Days" }

Cardiac Arrhythmia	.json
Cardiac Arrhythmia: Yes	{ arrhythmia: "Yes" }
Cardiac Arrhythmia: No	{ arrhythmia: "No" }
Cardiac Arrhythmia: Unknown	{ arrhythmia: "Unknown" }
Cardiac Arrhythmia - Atrial Fibrillation: Paroxysmal	{ arrhythafib: "Paroxysmal" }
Cardiac Arrhythmia - Atrial Fibrillation: Continuous / persistent	{ arrhythafib: "Continuous / persistent" }
Cardiac Arrhythmia - Atrial Fibrillation: None	{ arrhythafib: "None" }

RF	.json
Chronic Lung Disease: Mild	{ chrlungd: "Mild" }
Chronic Lung Disease: Moderate	{ chrlungd: "Moderate" }
Chronic Lung Disease: Severe	{ chrlungd: "Severe" }
Chronic Lung Disease: Lung disease documented, severity unknown	{ chrlungd: "Lung disease documented, severity unknown" }
Chronic Lung Disease: No	{ chrlungd: "No" }
Chronic Lung Disease: Unknown	{ chrlungd: "Unknown" }
Cerebrovascular Dis: Yes	{ cvd: "Yes" }
Cerebrovascular Dis: No	{ cvd: "No" }
Cerebrovascular Dis: Unknown	{ cvd: "Unknown" }
Prior CVA: Yes	{ cva: "Yes" }
Prior CVA: No	{ cva: "No" }
Prior CVA: Unknown	{ cva: "Unknown" }
Peripheral Arterial Disease: Yes	{ pvd: "Yes" }
Peripheral Arterial Disease: No	{ pvd: "No" }
Peripheral Arterial Disease: Unknown	{ pvd: "Unknown" }
Diabetes: Yes	{ diabetes: "Yes" }
Diabetes: No	{ diabetes: "No" }
Diabetes: Unknown	{ diabetes: "Unknown" }
Diabetes-Control: Diet only	{ diabctrl: "Diet only" }
Diabetes-Control: Oral	{ diabctrl: "Oral" }
Diabetes-Control: Insulin	{ diabctrl: "Insulin" }
Diabetes-Control: Other	{ diabctrl: "Other" }
Diabetes-Control: Other subcutaneous medication	{ diabctrl: "Other subcutaneous medication" }
Diabetes-Control: None	{ diabctrl: "None" }
Diabetes-Control: Unknown	{ diabctrl: "Unknown" }
Hypertension: Yes	{ hypertn: "Yes" }
Hypertension: No	{ hypertn: "No" }
Hypertension: Unknown	{ hypertn: "Unknown" }
Immunocompromise: Yes	{ immsupp: "Yes" }
Immunocompromise: No	{ immsupp: "No" }
Immunocompromise: Unknown	{ immsupp: "Unknown" }
Endocarditis: Yes	{ infendo: "Yes" }
Endocarditis: No	{ infendo: "No" }

Coronary	.json
Coronary Anatomy/Disease Known: Yes	{ coranatdisknown: "Yes" }
Coronary Anatomy/Disease Known: No	{ coranatdisknown: "No" }
Num Dis Vessels: One	{ numdisv: "One" }
Num Dis Vessels: Two	{ numdisv: "Two" }
Num Dis Vessels: Three	{ numdisv: "Three" }
Num Dis Vessels: None	{ numdisv: "None" }

Stenonis	.json
Percent Native Artery Stenosis Known: Yes	{ pctstenknown: "Yes" }
Percent Native Artery Stenosis Known: No	{ pctstenknown: "No" }
Percent Stenonis - Left Main ∈ [0, 100]	{ pctstenlmain: 50 }

Status	.json
Elective	{ status: "Elective" }
Urgent	{ status: "Urgent" }
Emergent	{ status: "Emergent" }
Emergent Salvage	{ status: "Emergent Salvage" }

Resuscitation	.json
Yes - Within 1 hour of the start of the procedure	{ resusc: "Yes - Within 1 hour of the start of the procedure" }
No	{ resusc: "No" }
Yes - More than 1 hour but less than 24 hours of the start of the procedure	{ resusc: "Yes - More than 1 hour but less than 24 hours of the start of the procedure" }

Cardiogenic Shock	.json
Yes - At the time of the procedure	{ carshock: "Yes - At the time of the procedure" }
No	{ carshock: "No" }
Yes, not at the time of the procedure but within prior 24 hours	{ carshock: "Yes, not at the time of the procedure but within prior 24 hours" }

Classification-NYHA	.json
Class I	{ classnyh: "Class I" }
Class II	{ classnyh: "Class II" }
Class III	{ classnyh: "Class III" }
Class IV	{ classnyh: "Class IV" }

IABP	.json
IABP: Yes	{ iabp: "Yes" }
IABP: No	{ iabp: "No" }
IABP-When Inserted: Preop	{ iabpwhen: "Preop" }
IABP-When Inserted: Intraop	{ iabpwhen: "Intraop" }
IABP-When Inserted: Postop	{ iabpwhen: "Postop" }

Meds-Inotropes	.json
Yes	{ medinotr: "Yes" }
No	{ medinotr: "No" }

Prev Cardiac Intervent	.json
Prev Cardiac Intervent: Yes	{ prcvint: "Yes" }
Prev Cardiac Intervent: No	{ prcvint: "No" }
Previous PCI: Yes	{ pocpci: "Yes" }
Previous PCI: No	{ pocpci: "No" }
Previous PCI-Interval <= 6 hrs	{ pocpciin: " <= 6 Hours" }
Previous PCI-Interval > 6 hrs	{ pocpciin: " > 6 Hours" }

VD	.json
VD-Mitral: Yes	{ vdmit: "Yes" }
VD-Mitral: No	{ vdmit: "No" }
VD-Stenosis-Mitral: Yes	{ vdstenm: "Yes" }
VD-Stenosis-Mitral: No	{ vdstenm: "No" }
VD-Aortic: Yes	{ vdaort: "Yes" }
VD-Aortic: No	{ vdaort: "No" }
VD-Stenosis-Aortic: Yes	{ vdstena: "Yes" }
VD-Stenosis-Aortic: No	{ vdstena: "No" }
VD-Insuff-Mitral: Trivial/Trace	{ vdinsufm: "Trivial/Trace" }
VD-Insuff-Mitral: Mild	{ vdinsufm: "Mild" }
VD-Insuff-Mitral: Moderate	{ vdinsufm: "Moderate" }
VD-Insuff-Mitral: Severe	{ vdinsufm: "Severe" }
VD-Insuff-Mitral: None	{ vdinsufm: "None" }
VD-Insuff-Mitral: Not documented	{ vdinsufm: "Not documented"}
VD-Insuff-Tricuspid: Trivial/Trace	{ vdinsuft: "Trivial/Trace" }
VD-Insuff-Tricuspid: Mild	{ vdinsuft: "Mild" }
VD-Insuff-Tricuspid: Moderate	{ vdinsuft: "Moderate" }
VD-Insuff-Tricuspid: Severe	{ vdinsuft: "Severe" }
VD-Insuff-Tricuspid: None	{ vdinsuft: "None" }
VD-Insuff-Tricuspid: Not documented	{ vdinsuft: "Not documented" }
VD-Insuff-Aortic: Trivial/Trace	{ vdinsufa: "Trivial/Trace" }
VD-Insuff-Aortic: Mild	{ vdinsufa: "Mild" }
VD-Insuff-Aortic: Moderate	{ vdinsufa: "Moderate" }
VD-Insuff-Aortic: Severe	{ vdinsufa: "Severe" }
VD-Insuff-Aortic: None	{ vdinsufa: "None" }
VD-Insuff-Aortic: Not documented	{ vdinsufa: "Not documented" }

Incidence	.json
First cardiovascular surgery	{ incidenc: "First cardiovascular surgery" }
First re-op cardiovascular surgery	{ incidenc: "First re-op cardiovascular surgery" }
Second re-op cardiovascular surgery	{ incidenc: "Second re-op cardiovascular surgery" }
Third re-op cardiovascular surgery	{ incidenc: "Third re-op cardiovascular surgery" }
Fourth or more re-op cardiovascular surgery	{ incidenc: "Fourth or more re-op cardiovascular surgery" }

Prev CAB	.json
Yes	{ prcab: "Yes" }
No	{ prcab: "No" }

Prev Valve	.json
Yes	{ prvalve: "Yes" }
No	{ prvalve: "No" }