Caristo Diagnostics vs Heartflow (2026)
Both extend a routine coronary CT angiogram beyond anatomy. Heartflow's FFRCT simulates the physiological significance of each lesion; it was first authorized in 2014 and validated against invasive FFR in the prospective HeartFlowNXT study, with the PRECISE randomized trial behind the platform. Caristo's CaRi-Heart measures coronary inflammation and estimates 10 year cardiac mortality risk, including in patients without obstructive disease; it received De Novo authorization in July 2026 and launches in the US from the third quarter. Both publish their limits: Heartflow's indications page and Caristo's Instructions for Use name populations and conditions. If you need to know which lesions limit flow, start with Heartflow. If you need risk in patients whose arteries look clear, start with Caristo.
- Risk in patients whose arteries look clear: ORFAN and CRISP-CT, in The Lancet, link higher inflammation scores to cardiac events, including without obstructive disease.
- A measurement the standard read does not report: CaRi-Heart quantifies coronary inflammation and estimates 10 year cardiac mortality risk.
- Plaque from the same vendor: CaRi-Plaque, cleared in February 2025 (K242240), quantifies plaque and stenosis on the same scan.
- Physiology is the decision: FFRCT estimates the physiological significance of each lesion, validated against invasive FFR in the prospective, multicenter HeartFlowNXT study.
- You want trial evidence on the pathway: the PRECISE randomized trial and the DECIDE registry of about 22,000 patients.
- You want the limits stated: the indications page names populations the analysis was not evaluated in, and trained Case Analysts work each model.
This comparison is published by AI Health Index, an independent research platform that compares healthcare AI vendors objectively. Caristo Diagnostics and Heartflow are each graded against the same capability taxonomy, from each vendor's own public materials and the regulatory record, under the AI Health Index verification standard. No vendor pays for placement, and no vendor has reviewed this page. How this evidence is graded
Plain facts
| Fact | Caristo Diagnostics | Heartflow |
|---|---|---|
| Primary category | Radiology & Imaging AI | Radiology & Imaging AI |
| Founded | Not recorded | 2007 |
| Headquarters | Oxford, England, United Kingdom | Mountain View, California, United States |
| Website | caristo.com | heartflow.com |
Side by Side
Select any grade to read the note behind it.
Product updates
The latest logged changes from each vendor, newest first, each linked to its source.
Caristo Diagnostics
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Regulatory / FDA
The FDA granted De Novo authorization (DEN250042) for CaRi-Heart, which quantifies coronary inflammation from routine coronary CT angiography and estimates a 10 year cardiovascular mortality risk.
Source
Heartflow
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Product / capability
Heartflow PCI Navigator entered commercial use outside of clinical trials, with The Valley Hospital becoming the first U.S. institution to deploy the software.
Source
Each vendor in one paragraph
Written to be quoted whole. Each paragraph opens the AI Health Index profile of the vendor: what the product is, who buys it and what it does.
Caristo Diagnostics, an Oxford spinout, measures coronary inflammation from the same routine coronary CT angiogram used to assess plaque. Inflammation changes the fat around the coronary arteries in a way CT can detect; CaRi-Heart uses AI to quantify it as the FAI-Score and to estimate 10 year cardiac mortality risk (the CaRi-Heart Risk score).
Source: AI Health Index, September 2026
Heartflow created non-invasive coronary physiology from CT. Its Heartflow One platform analyzes a coronary CT angiogram a hospital has already acquired: Roadmap Analysis for stenosis, FFRCT Analysis for the physiological significance of each lesion, simulated from a 3D model of the coronary arteries, Plaque Analysis and plaque staging, and PCI Navigator for planning intervention, now in routine use at The Valley Hospital.
Source: AI Health Index, September 2026
Questions buyers ask
How do Caristo Diagnostics and Heartflow work with the EHR?
CaRi-Plaque receives CT images from the hospital's PACS by secure transmittal (DICOM), and Caristo returns a report to the healthcare professional, with an optional primary care summary report; turnaround is set by contract and can be delayed.
Heartflow describes CT studies sent securely to it without manual export and results returned into both PACS and the electronic record, with a support team that deploys the software and integrates it with PACS, record and other hospital systems. From the AI Health Index, drawn from each vendor's own published materials and the regulatory record, verified September 27, 2026. No vendor pays for placement.
How are Caristo Diagnostics and Heartflow priced and sold?
In Caristo Diagnostics' case, the AMA assigned Category III CPT codes 0992T and 0993T for CaRi-Heart from January 2026; Category III codes track emerging technology and carry no set national payment, so coverage is decided payer by payer. CaRi-Plaque falls under the Category I code for AI plaque analysis.
Heartflow publishes reimbursement resources and a market access value dossier. The dossier records a Category I CPT pathway for AI plaque analysis of coronary CT, CMS payment for plaque analysis as a separate outpatient hospital service, a July 2025 EviCore coverage recommendation for Plaque Analysis, and states frankly that current reimbursement does not adequately pay for FFRCT. From the AI Health Index, drawn from each vendor's own published materials and the regulatory record, verified September 27, 2026. No vendor pays for placement.
How do Caristo Diagnostics and Heartflow handle patient data?
With Caristo Diagnostics, a Data Protection Officer is appointed and named, international transfer safeguards are set out in real detail including adequacy decisions and standard contractual clauses, ISO 27001 certification backs the technical controls, and third party deidentification services are disclosed among the providers relied upon.
Heartflow's trust center names encryption at rest, access monitoring, audit logging, role based access control and backups, names Amazon Web Services as its infrastructure provider, and lists AI training data and bias, AI security and AI monitoring as categories a customer can ask about, with the underlying documents released on request. From the AI Health Index, drawn from each vendor's own published materials and the regulatory record, verified September 27, 2026. No vendor pays for placement.
Which settings and specialties do Caristo Diagnostics and Heartflow cover?
For Caristo Diagnostics, the site also markets preventive screening, drug trial endpoints and intervention planning, which that validation does not cover.
With Heartflow, the intended use covers adults 22 and over with suspected coronary artery disease (the combined analysis) and clinically stable symptomatic patients (FFRCT), and FFRCT's performance was validated in patients who were candidates for invasive angiography, with CT acquired within 60 days of invasive FFR. From the AI Health Index, drawn from each vendor's own published materials and the regulatory record, verified September 27, 2026. No vendor pays for placement.
Related comparisons
Other published head to head assessments involving these vendors or their closest peers. The full set for this category is on the Clinical Decision Support page.
Caristo's evidence comes from the Oxford group that founded it, and its US indication is not yet published. Heartflow's Plaque Analysis and Roadmap are not cleared in Europe, the UK, Australia, Canada or Japan. Neither vendor publishes a price.