A secondary analysis of the MOSCA-FRAIL randomized clinical trial evaluated the outcomes of invasive and conservative treatment strategies in 167 adults aged 70 years or older with frailty and non-ST-segment elevation myocardial infarction (NSTEMI). The trial, conducted between July 2017 and January 2021, extended follow-up to January 2023. The primary outcome was restricted mean survival time (RMST), with secondary outcomes including readmissions and mortality. The invasive strategy involved coronary angiography and revascularization if feasible, while the conservative strategy involved medical treatment with angiography only for recurrent ischemia. The RMST for all-cause mortality was 3.13 years in the invasive group and 3.06 years in the conservative group. The RMST analysis showed inconclusive differences in survival time, with invasive treatment associated with shorter survival in the first year but more prolonged survival after the first year. Kaplan-Meier curves showed no significant differences in mortality, but the curves crossed, indicating a shift from early harm to late benefit in the invasive group. Subgroup analysis revealed that invasive treatment was harmful in patients with higher frailty (CFS >4) but beneficial in those with lower frailty (CFS =4). The results suggest that an initial invasive strategy did not improve outcomes at a median follow-up of 1113 days. However, there was a time-dependent pattern in the distribution of deaths, with early harm followed by late benefit. The phenomenon of depletion of susceptible patients may explain this behavior. The study highlights the complexity of treating frail patients with NSTEMI, emphasizing the need for individualized treatment decisions based on patient characteristics. The findings suggest that a conservative approach may be more appropriate for patients with high frailty, while invasive strategies may benefit those with lower frailty. The results underscore the importance of considering frailty in clinical decision-making for older adults with NSTEMI.A secondary analysis of the MOSCA-FRAIL randomized clinical trial evaluated the outcomes of invasive and conservative treatment strategies in 167 adults aged 70 years or older with frailty and non-ST-segment elevation myocardial infarction (NSTEMI). The trial, conducted between July 2017 and January 2021, extended follow-up to January 2023. The primary outcome was restricted mean survival time (RMST), with secondary outcomes including readmissions and mortality. The invasive strategy involved coronary angiography and revascularization if feasible, while the conservative strategy involved medical treatment with angiography only for recurrent ischemia. The RMST for all-cause mortality was 3.13 years in the invasive group and 3.06 years in the conservative group. The RMST analysis showed inconclusive differences in survival time, with invasive treatment associated with shorter survival in the first year but more prolonged survival after the first year. Kaplan-Meier curves showed no significant differences in mortality, but the curves crossed, indicating a shift from early harm to late benefit in the invasive group. Subgroup analysis revealed that invasive treatment was harmful in patients with higher frailty (CFS >4) but beneficial in those with lower frailty (CFS =4). The results suggest that an initial invasive strategy did not improve outcomes at a median follow-up of 1113 days. However, there was a time-dependent pattern in the distribution of deaths, with early harm followed by late benefit. The phenomenon of depletion of susceptible patients may explain this behavior. The study highlights the complexity of treating frail patients with NSTEMI, emphasizing the need for individualized treatment decisions based on patient characteristics. The findings suggest that a conservative approach may be more appropriate for patients with high frailty, while invasive strategies may benefit those with lower frailty. The results underscore the importance of considering frailty in clinical decision-making for older adults with NSTEMI.