Key Points:
- Evidence for NSTEMI management among older adults is limited, and further limited for frail older adults
- The SENIOR-RITA trial was a multicenter randomized trial of adults older than 75 with NSTEMI, finding that an invasive strategy is safe but not associated with reduced MACEs
- The SENIOR-RITA Frail Analysis was a prospective analysis of frail older adults to investigate the same question among this cohort
- This subgroup analysis similarly found that an invasive approach was safe but not associated with reduced MACEs compared to conservative management
The SENIOR-RITA trial was a multicenter, randomized controlled study that enrolled 1518 patients aged 75 years or older with non–ST-segment elevation myocardial infarction (NSTEMI) to compare an invasive strategy (routine coronary angiography and revascularization plus optimal medical therapy [OMT]) versus a conservative strategy (OMT alone). The trial population was representative of real-world older adults, including a substantial proportion who were frail (32%) and cognitively impaired, with a high burden of comorbidities. Over a median follow-up of 4.1 years, the primary composite outcome of cardiovascular death or nonfatal myocardial infarction occurred in 25.6% of the invasive group and 26.3% of the conservative group (HR 0.94; 95% CI, 0.77-1.14; p = 0.53), indicating no statistically significant difference in the primary endpoint between strategies. Notably, nonfatal myocardial infarction rates were lower in the invasive group (11.7% vs 15.0%; HR 0.75; 95% CI, 0.57–0.99), but this did not translate into a mortality benefit.
The trial demonstrated that an invasive approach in older adults with NSTEMI is safe, with procedural complications occurring in less than 1% of patients but does not confer a significant reduction in cardiovascular death or the composite primary outcome compared to a conservative strategy. These findings suggest that routine invasive management should not be universally applied in this population, and that treatment decisions should be individualized, taking into account frailty, comorbidities, and patient preferences.
The investigators now present a subgroup analysis among frail adults in the study in order to investigate whether conservative strategy with medical therapy alone or invasive strategy plus medical therapy is beneficial among frail older adults with NSTEMI. The investigators prospectively recruited frail adults based on the Fried Frailty Index (incorporating weight loss, exhaustion, slow gait speed, weak grip strength, and low energy), stratifying patients into frail, pre-frail, or robust phenotypes. They screened 8392 adults, recruiting 1518 and ultimately randomizing 1446 into the invasive arm (n=716) or the conservative arm (n=730). Patients were recruited from 52 sites across England. Included patients were at least 75 years old with a type I NSTEMI during index hospitalization (excluded type 2 MI), and exclusion criteria included STEMI or unstable angina (UA), cardiogenic shock, life expectancy < 1 year, previous randomization in SENIOR RITA, inability or contraindication to undergo coronary angiogram.
Primary outcome was time to cardiovascular death or non-fatal MI, same as SENIOR-RITA. The study found frail patients were majority female, older, and more likely to have cognitive impairment and multiple medical comorbidities. However, both arms were well-balanced regarding baseline characteristics including sex, age, and comorbidities.
The analysis found no significant difference in time to major cardiovascular events (HR 1.21; 95% CI, 0.88-1.67, p=0.20). Similarly, there was no difference in non-fatal MI (HR 1.00; 95% CI, 0.61-1.63, p=1.00). Secondary outcomes were also similar between groups, with the exception that those in the invasive arm were more likely to undergo coronary angiogram.
In conclusion, the SENIOR-RITA trial is the largest trial to date in frail older adults with heart attacks. The investigators conclude that in older adults with type I NSTEMI, an invasive strategy is safe. However, an invasive strategy did not significantly reduce combined risk of cardiovascular death or non-fatal MI compared with a conservative strategy in frail older adults. The results of the trial provide a framework for frail older ACS patients and their clinicians to make informed decisions about whether or not to undergo coronary angiogram.
