A trial comparing an invasive and a conservative strategy to treat patients over the age of 75 years with a non-ST-elevation myocardial infarction—SENIOR-RITA—has shown that there was no significant reduction in the combined risk of cardiovascular death or non-fatal myocardial infarction with the invasive strategy.
Presenting the results of the study, the largest of its kind in this population, at the 2024 European Society of Cardiology (ESC) congress, study chair and chief investigator Vijay Kunadian (Translational and Clinical Research Institute, Newcastle University and Freeman Hospital, Newcastle-Upon-Tyne, UK) said that though the invasive strategy did not reduce the primary endpoint, it did appear to be safe overall in older patients.
“Among older adults with type 1 NSTEMI our study showed that an invasive strategy, doing an angiogram and revascularisation procedure,” Kunadian reported. “An invasive strategy did not actually risk the combined risk of cardiovascular death and non-fatal myocardial infarction, as compared to a conservative strategy of medications alone in these patients.
“However, treatment with an invasive strategy did reduce the risk of non-fatal myocardial infarction, and subsequent revascularisation. Our study, in a sense, provides a foundation for older heart attack patients and their clinicians to make informed decisions about whether they need to undergo invasive procedures or not.”
In higher-risk patients after NSTEMI, guidelines recommend an invasive strategy over medications alone. However, older patients with NSTEMI are less likely to receive guideline-recommended care including an invasive strategy, Kunadian detailed, citing a potential fear of the risk of procedural complications among the possible obstacles. Older patients have also been underrepresented in clinical trials of NSTEMI therapies.
In the open-label SENIOR-RITA trial, patients aged ≥75 years presenting with type 1 NSTEMI were randomly allocated (1:1) to one of two treatment groups. In the conservative strategy group, patients received ESC Guideline-recommended secondary prevention therapy, including antiplatelet therapy, statins, angiotensin-converting enzyme inhibitors and beta-blockers.
Patients randomised to the invasive strategy group, in addition to these medications, patients had invasive coronary angiography and, if deemed necessary, coronary revascularisation—percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery.
All patients had formal assessment of frailty, cognition and co-morbidity at baseline and follow-up. The primary endpoint was time to cardiovascular death or non-fatal MI. Secondary endpoints included components of the primary endpoint, all-cause death, subsequent coronary revascularisation and bleeding complications.
In total, 1,518 patients were recruited from around 48 NHS sites across England and Scotland. The mean overall age was 82.4 years and 72% were aged 80 years or older (the oldest being 103 years old). Almost half were female (45%). Overall, 80% of patients were classified as prefrail or frail, more than 60% had cognitive impairment and the majority had a comorbidity index of ≥5, indicating multiple concurrent long-term conditions. Medical therapy was balanced between the two groups.
In the invasive group, 90% had the intended angiography and 50% had revascularisation procedures during hospitalisation, Kunadian reported.
After median follow-up of 4.1 years, there was no difference in the primary endpoint of cardiovascular death or non-fatal MI between the invasive strategy group (25.6%) and the conservative strategy group (26.3%; hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.77–1.14; p=0.53). This pattern was observed for the different prespecified subgroups (including those who were frail, cognitively impaired or had multiple comorbidities).
No differences were observed for cardiovascular death (15.8% with invasive strategy vs. 14.2% with conservative strategy; HR 1.11; 95% CI 0.86–1.44). There was a significant reduction in non-fatal MI, which occurred in 11.7% of patients in the invasive strategy group vs. 15% in the conservative strategy group (HR 0.75; 95% CI 0.57–0.99).
Patients in the invasive strategy group also required fewer subsequent revascularisation procedures than those in the conservative strategy group (3.9% vs. 13.7%; HR 0.26; 95% CI 0.17–0.39). There were no observed differences in the other secondary outcomes, including all-cause death, all MIs combined, stroke, hospitalisation for heart failure or any bleeding complications. The rate of procedural complications was less than 1%.
