Heartflow vs Viz.ai (2026)
Both change what happens after a scan, in different cardiovascular pathways. Heartflow analyzes coronary CT angiography to estimate which lesions limit flow and to quantify plaque, and the decision it informs is whether a patient needs invasive testing. Its FFRCT was validated against invasive FFR in the prospective HeartFlowNXT study, with the PRECISE randomized trial behind the platform. Viz.ai detects and then mobilizes: Viz One alerts and connects the treating team on their phones, and a post hoc analysis of a multicenter randomized trial reported door to groin times 11 minutes shorter in stroke. A cardiology service and a stroke service would each buy one and not the other. If the question is who needs the catheterization lab, start with Heartflow. If it is how fast the stroke team assembles, start with Viz.ai.
- 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 the populations the analysis was not evaluated in, and trained Case Analysts work each model.
- Coordination is the constraint: Viz One pairs detection with automatic alerts and team messaging, so the finding reaches the people who act.
- Its stroke product created the triage and notification category through a 2018 De Novo, and the company reports more than 50 cleared algorithms.
- Security terms published: the Trust Center names SOC 2 Type II, ISO 27001 and ISO 42001, and the subscription privacy policy states a BAA governs patient data.
This comparison is published by AI Health Index, an independent research platform that compares healthcare AI vendors objectively. Heartflow and Viz.ai 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 | Heartflow | Viz.ai |
|---|---|---|
| Primary category | Radiology & Imaging AI | Radiology & Imaging AI |
| Founded | 2007 | 2016 |
| Headquarters | Mountain View, California, United States | San Francisco, California, United States |
| Website | heartflow.com | viz.ai |
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.
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.
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
AI powered care coordination platform, Viz One, that pairs detection algorithms on imaging and ECG with automatic alerts and team messaging on clinicians' phones. It began in stroke: its large vessel occlusion product, ContaCT, received FDA's De Novo authorization in 2018 (DEN170073), which created the regulatory category for imaging triage and notification software.
Source: AI Health Index, September 2026
Questions buyers ask
How do Heartflow and Viz.ai work with the EHR?
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.
With Viz.ai, the platform receives DICOM studies from scanners and PACS, and the De Novo summary describes the notification path to the mobile app with the images attached. The app is the working surface for neurologists, interventionalists and stroke teams across hospital networks. 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 Heartflow and Viz.ai priced and sold?
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.
For Viz.ai, the website sets out how the product is sold: Viz One is an enterprise platform with therapeutic suites (neuro, vascular, cardio, pulmonary, trauma, radiology, oncology) and pilot programs, and the route in is a contact form. 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 Heartflow and Viz.ai handle patient data?
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.
The customer's contract sets how long Viz.ai keeps customer data. Usage data (which studies and alerts a clinician opened, response times) is de-identified to the HIPAA standard at 45 CFR 164.514 before it is used to improve services, build new products or conduct research. 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 Heartflow and Viz.ai cover?
For 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.
With Viz.ai, the oncology, respiratory, neurology and osteoporosis offers are sold as pilot programs. 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.
These sit in different cardiovascular workflows and are compared because both change what happens after the scan. Both name their security certifications and provide the reports on request. Viz.ai sells some modules as pilot programs, and a pilot is not a clearance. Neither publishes pricing.