FFR-CT predicts events three years out, and a normal value is genuinely reassuring

Design

nationwide observational cohort, three-year follow-up

Population

7,836 patients with stable coronary disease having CT angiography with FFR-CT at 27 English sites, 2017-2020

Primary outcome

myocardial infarction, cardiovascular death, all-cause death and revascularisation

Effect

FFR-CT 0.7 or below: adjusted HR 2.94-3.39 for infarction; normal value: 1.5% three-year event rate

Across 27 English sites, 7,836 patients having coronary CT angiography with clinically indicated FFR-CT for stable coronary disease were followed for three years. Median age was 63 and 37.4% were women.

Lower FFR-CT values tracked with worse outcomes in a graded way. After adjustment for risk factors and for stenosis severity on CAD-RADS, a stenosis-specific value of 0.7 or below was associated with myocardial infarction (adjusted HR 2.94 to 3.39), 0.5 or below with cardiovascular death (adjusted HR 2.92) and all-cause death (adjusted HR 1.49), and 0.8 or below with revascularisation. Adding FFR-CT to a model of risk factors and stenosis severity improved discrimination only slightly, from a C index of 0.771 to 0.783. The optimal threshold for future events was 0.67, not the 0.8 used for revascularisation decisions.

The most usable number is the negative one: where stenosis-specific FFR-CT was normal, the three-year rate of infarction or cardiovascular death was 1.5%. Discordance between stenosis-specific and distal-vessel measurements occurred in 36.4% of patients, which matters when a report quotes only one.

• A normal stenosis-specific FFR-CT carried a 1.5% three-year risk of infarction or cardiovascular death.
• Check which measurement your report quotes - stenosis-specific and distal values disagreed in over a third of patients.
• The prognostic threshold of 0.67 is not the same as the 0.8 revascularisation cut-off.
• Values of 0.5 or below identify patients worth discussing at a heart team meeting.
• FFR-CT availability in India is limited to a few centres, so this informs referral rather than routine use.

Why it matters

It puts a figure on what a normal FFR-CT buys you, which is what the patient in front of you is actually asking.

Don't overread it

Observational and industry-platform specific - it does not show that treating on the basis of FFR-CT improves outcomes.

The statistics, in plain English

The added discrimination over risk factors plus stenosis severity was 0.012 on the C index - statistically convincing in 7,836 patients, but small. That is the usual pattern for an imaging marker: it separates groups well on its own while adding modestly to what you already knew. This is also an observational cohort, so the hazard ratios describe who did badly, not what would happen if you acted on the number.

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