Invasive versus conservative strategy in patients aged 80 years or older with non-ST-elevation myocardial infarction or unstable angina pectoris (After Eighty study): an open-label randomised controlled trial

Background: Non-ST-elevation myocardial infarction (NSTEMI) and unstable angina pectoris are frequent causes of hospital admission in the elderly. However, clinical trials targeting this population are scarce, and these patients are less likely to receive treatment according to guidelines. We aimed to investigate whether this population would benefit from an early invasive strategy versus a conservative strategy.

Methods: In this open-label randomised controlled multicentre trial, patients aged 80 years or older with NSTEMI or unstable angina admitted to 16 hospitals in the South-East Health Region of Norway were randomly assigned to an invasive strategy (including early coronary angiography with immediate assessment for percutaneous coronary intervention, coronary artery bypass graft, and optimum medical treatment) or to a conservative strategy (optimum medical treatment alone). A permuted block randomisation was generated by the Centre for Biostatistics and Epidemiology with stratification on the inclusion hospitals in opaque concealed envelopes, and sealed envelopes with consecutive inclusion numbers were made. The primary outcome was a composite of myocardial infarction, need for urgent revascularisation, stroke, and death and was assessed between Dec 10, 2010, and Nov 18, 2014. An intention-to-treat analysis was used. This study is registered with ClinicalTrials.gov, number NCT01255540.

Findings: During a median follow-up of 1·53 years of participants recruited between Dec 10, 2010, and Feb 21, 2014, the primary outcome occurred in 93 (40·6%) of 229 patients assigned to the invasive group and 140 (61·4%) of 228 patients assigned to the conservative group (hazard ratio [HR] 0·53 [95% CI 0·41-0·69], p=0·0001). Five patients dropped out of the invasive group and one from the conservative group. HRs for the four components of the primary composite endpoint were 0·52 (0·35-0·76; p=0·0010) for myocardial infarction, 0·19 (0·07-0·52; p=0·0010) for the need for urgent revascularisation, 0·60 (0·25-1·46; p=0·2650) for stroke, and 0·89 (0·62-1·28; p=0·5340) for death from any cause. The invasive group had four (1·7%) major and 23 (10·0%) minor bleeding complications whereas the conservative group had four (1·8%) major and 16 (7·0%) minor bleeding complications.

Interpretation: In patients aged 80 years or more with NSTEMI or unstable angina, an invasive strategy is superior to a conservative strategy in the reduction of composite events. Efficacy of the invasive strategy was diluted with increasing age (after adjustment for creatinine and effect modification). The two strategies did not differ in terms of bleeding complications.

Funding: Norwegian Health Association (ExtraStiftelsen) and Inger and John Fredriksen Heart Foundation.