Design: Prespecified subgroup analysis of a randomised trial
Population: 6,016 patients with STEMI undergoing radial primary PCI; 4,581 at low bleeding risk
Primary outcome: 30-day all-cause death or BARC 3-5 bleeding
Effect: Low risk 1.4% vs 2.9%, HR 0.49 (0.32-0.75); higher risk 8.1% vs 9.2%, HR 0.88 (0.62-1.26)

BRIGHT-4 randomised 6,016 patients having radial primary PCI for STEMI to bivalirudin with a high-dose infusion for two to four hours after PCI, or heparin alone. The main trial showed lower 30-day death or major (BARC 3 to 5) bleeding with bivalirudin. This prespecified analysis asked whether the benefit was confined to patients at higher bleeding risk.

Three-quarters (76%) had a CRUSADE score under 30, defined as low bleeding risk. In them, the composite occurred in 1.4% with bivalirudin and 2.9% with heparin (HR 0.49, 95% CI 0.32 to 0.75). In higher-risk patients the rates were 8.1% and 9.2% (HR 0.88, 0.62 to 1.26), with a similar absolute difference. The effect on death was consistent across groups.

The finding answers the objection that bivalirudin is worth its cost only in patients likely to bleed. The regimen matters: the benefit came with a sustained high-dose infusion after PCI, which reduces early stent thrombosis.

If you use bivalirudin in primary PCI, continue the high-dose infusion for two to four hours after the procedure, as tested.
Do not reserve bivalirudin only for patients with a high CRUSADE score; the absolute benefit was similar in low-risk patients.
Radial access was used throughout; the result may not transfer to femoral practice.
Weigh cost locally: bivalirudin is considerably more expensive than heparin in India.

Why it matters

It removes the main argument for limiting bivalirudin to patients expected to bleed.

The statistics, in plain English

In low-risk patients the absolute reduction was 1.5 percentage points (95% CI 0.6 to 2.3), so about 67 patients would need bivalirudin to prevent one death or major bleed. In higher-risk patients the confidence interval crosses zero, but the absolute effect was similar and the formal test found no difference between groups on the absolute scale.