Timing of percutaneous coronary intervention in patients with non-ST-elevation myocardial infarction: a SWEDEHEART study.

Aims: Although routine invasive management is recommended in NSTEMI patients, the optimal timing of the procedure is not defined. The aim of this study was to assess outcomes in relation to timing of PCI in NSTEMI patients. Methods and results: This was an observational, prospective, multicentre cohort study from the SWEDEHEART registry including all Swedish PCI centres. We included 40 494 consecutive PCI-treated patients who were admitted to any coronary care unit from 2006 to 2013. The primary outcome was all-cause death, and secondary outcomes were recurrent myocardial infarction (MI), stent thrombosis, and severe in-hospital bleeding. Outcomes were assessed within 1 year from admission in relation to pre-specified cut-offs to define early PCI: within 1, 2, or 3 days. Patients who received delayed PCI, compared with those who did not, were older, and had a higher prevalence of comorbidities (hypertension, hyperlipidaemia, diabetes, and prior stroke) but showed similar angiographic findings. Cox mixed-effects models showed a lower risk of all-cause death with early PCI across all three cut-offs: HR (95% CI) of 0.88 (0.80-0.98), 0.78 (0.71-0.86), and 0.75 (0.68-0.84), for the 1-, 2-, and 3-day cut-offs, respectively. Early PCI was associated with lower risk of recurrent MI for the 2- and 3-day cut-offs, but not for the 1-day cut-off. The reported rates of severe in-hospital bleeding were low, but tended to be higher in patients receiving delayed PCI. Conclusion: In patients undergoing PCI for NSTEMI, early invasive treatment is associated with lower risk of ischaemic outcomes.