Sample size
EVENT, RECRUITMENT
We estimated that a minimum of 30 clusters, each recruiting 100 participants (3000 in total), would give 80% power to detect clinically relevant differences in the primary endpoints with two sided 5% significance tests. For the proportion of guideline directed treatments implemented, this assumed that 95% of recommended treatments would be implemented as standard based on available evidence of drug interventions at that time,For time to first cardiac outcome, a fixed recruitment of 15 clusters of 100 patients per arm would give 80% power to detect a reduction in 12 month event rates from 13% to 10.4% in standard care and GRS arms, respectively. These figures are based on a mean follow-up of 27 months, coefficient of variation of cluster event rates of 0.05, and loss of one cluster per arm representing up to 10% of participants.